Representation of Sound Objects within Early-Stage Auditory Areas: A Repetition Effect Study Using 7T fMRI.

Environmental sounds are highly complex stimuli whose recognition depends on the interaction of top-down and bottom-up processes in the brain. Their semantic representations were shown to yield repetition suppression effects, i. e. a decrease in activity during exposure to a sound that is perceived as belonging to the same source as a preceding sound. Making use of the high spatial resolution of 7T fMRI we have investigated the representations of sound objects within early-stage auditory areas on the supratemporal plane. The primary auditory cortex was identified by means of tonotopic mapping and the non-primary areas by comparison with previous histological studies. Repeated presentations of different exemplars of the same sound source, as compared to the presentation of different sound sources, yielded significant repetition suppression effects within a subset of early-stage areas. This effect was found within the right hemisphere in primary areas A1 and R as well as two non-primary areas on the antero-medial part of the planum temporale, and within the left hemisphere in A1 and a non-primary area on the medial part of Heschl's gyrus. Thus, several, but not all early-stage auditory areas encode the meaning of environmental sounds.

Modified atmosphere packaging extending the storage life of 'douradão' peach

'Douradão' peach is a perishable product and when cold stored is subject to chilling injury. The objective of the experiment was to evaluate the effect of modified atmosphere packaging (MAP) and cold storage on quality and storage life of these peaches. Fruits were packed in polypropylene (PP) trays and placed inside low density polyethylene (LDPE) bags (30, 50, 60, 75 μm thickness) with active modified atmosphere (10 kPa CO2 + 1.5kPa O2, balance N2). The control was made with peaches held in nonwrapped PP trays. Fruits were kept at 1 ± 1 °C and 90 ± 5% relative humidity (RH) for 28 days and CO2 and O2 within packages was monitored every two days. After 14, 21 and 28 days, samples were withdrawn from MAP and kept in air at 25 ± 1 °C and 90 ± 5% RH for ripening. On the day of removal from the cold storage and after 4 days, peaches were evaluated for weight loss, decay incidence, flesh firmness, woolliness incidence, soluble solids content (SSC), titratable acidity (TA) and juice content. The results showed that MAP had influence on reducing weight loss and prevented postharvest decay. MAP of 1-2 kPa O2 and 3-6 kPa CO2 at 1 °C (from 50 and 60 μm LDPE films) were effective for keeping good quality of 'Douradão' peaches during 28 days of storage, the ripe fruits showed reduced incidence of woolliness, adequate juiciness and flesh firmness. Packages of 30 and 75 μm LDPE films were ineffective for reducing woolliness during cold storage. MAP fruits showed lower SSC and no relevant effect on TA. Control fruits did not present marketable conditions after 14 days of cold storage.

Effects of modified atmosphere packaging on ripening of 'Douradão' peach related to pectolytic enzymes activities and chilling injury symptoms

The present study evaluated the effects of modified atmosphere packaging on inhibition of the development of chilling injury symptoms in 'Douradão' peach after cold storage and the possible involvement of cell wall enzymes. Fruits were harvested at the middle stadium of ripening, packed in polypropylene trays and placed inside low density polyethylene (LDPE) bags (30, 50, 60 and 75 µm of thickness) with active modified atmosphere (10 kPa CO2 + 1.5 kPa O2, balance N2). The following treatments were tested: Control: peaches held in nonwrapped trays; MA30: LDPE film - 30 µm; MA50: LDPE film - 50 µm; MA60: LDPE film - 60 µm and MA75: LDPE film - 75 µm. Fruits were kept at 1±1ºC and 90±5% relative humidity (RH) for 28 days. After 14, 21 and 28 days, samples were withdrawn from MAP and kept in air at 25±1ºC and 90±5% RH for ripening. On the day of removal and after 4 days, peaches were evaluated for woolliness incidence, pectolytic enzymes activities. The respiratory rate and ethylene synthesis were monitored during 6 days of ripening. The results showed that MA50 and MA60 treatments had positive effect on the inhibition of the development of woolly texture and reduced pectin methylesterase activity on the ripe fruits, keeping good quality of 'Douradão' peach during 28 days of cold storage. The treatments Control, MA30 and MA75 showed higher woolliness incidence and did not present marketable conditions after 14 days of cold storage.

Laajakaistaverkon topologian visualisointi

Viimeisten vuosien aikana laajakaistaoperaattoreiden laajakaistaverkot ovat nopeiden ja kiinteähintaisten laajakaistaliittymien johdosta kasvaneet suuriksi kokonaisuuksiksi. Kokonaisuuksia hallitaan erilaisilla verkonhallintatyökaluilla. Verkonhallintatyökalut sisältävät suuren määrän eri tasoista tietoa laitteista ja laitteiden välisistä suhteista. Kokonaisuuksien hahmottaminen ilman tiedoista rakennettua kuvaa on vaikeaa ja hidasta. Laajakaistaverkon topologian visualisoinnissa muodostetaan kuva laitteista ja niiden välisistä suhteista. Visualisoitua kuvaa voidaan käyttää osana verkonhallintatyökalua, jolloin käyttäjälle muodostuu nopeasti näkymä verkon laitteista ja rakenteesta eli topologiasta. Visualisoinnissa kuvan piirto-ongelma täytyy muuttaa graafin piirto-ongelmaksi. Graafin piirto-ongelmassa verkon rakennetta käsitellään graafina, joka mahdollistaa kuvan muodostamisen automaattisia piirtomenetelmiä hyväksikäyttäen. Halutunlainen ulkoasu kuvalle muodostetaan automaattisilla piirtomenetelmillä, joilla laitteiden ja laitteiden välisten suhteiden esitystapoja voidaan muuttaa. Esitystavoilla voidaan muuttaa esimerkiksi laitteiden muotoa, väriä ja kokoa. Esitystapojen lisäksi piirtomenetelmien tärkein tehtävä on laskea laitteiden sijaintien koordinaattien arvot, jotka loppujen lopuksi määräävät koko kuvan rakenteen. Koordinaattien arvot lasketaan piirtoalgoritmeilla, joista voimiin perustuvat algoritmit sopivat parhaiten laajakaistaverkkojen laitteiden sijaintien laskemiseen. Tämän diplomityön käytännön työssä toteutettiin laajakaistaverkon topologian visualisointityökalu.

Spectral Analysis of Buffers in Communication Systems

Muokatun matriisi-geometrian tekniikan kehitys yleimmäksi jonoksi on esitelty tässä työssä. Jonotus systeemi koostuu useista jonoista joilla on rajatut kapasiteetit. Tässä työssä on myös tutkittu PH-tyypin jakautumista kun ne jaetaan. Rakenne joka vastaa lopullista Markovin ketjua jossa on itsenäisiä matriiseja joilla on QBD rakenne. Myös eräitä rajallisia olotiloja on käsitelty tässä työssä. Sen esitteleminen matriisi-geometrisessä muodossa, muokkaamalla matriisi-geometristä ratkaisua on tämän opinnäytetyön tulos.

The structure of human tRNALys3 anticodon bound to HIV genome is stabilized by modified nucleosides and adjacent mismatch base pairs

Replication of human immunodeficiency virus (HIV) requires base pairing of the reverse transcriptase primer, human tRNA(Lys3), to the viral RNA. Although the major complementary base pairing occurs between the HIV primer binding sequence (PBS) and the tRNA's 3'-terminus, an important discriminatory, secondary contact occurs between the viral A-rich Loop I, 5'-adjacent to the PBS, and the modified, U-rich anticodon domain of tRNA(Lys3). The importance of individual and combined anticodon modifications to the tRNA/HIV-1 Loop I RNA's interaction was determined. The thermal stabilities of variously modified tRNA anticodon region sequences bound to the Loop I of viral sub(sero)types G and B were analyzed and the structure of one duplex containing two modified nucleosides was determined using NMR spectroscopy and restrained molecular dynamics. The modifications 2-thiouridine, s(2)U(34), and pseudouridine, Psi(39), appreciably stabilized the interaction of the anticodon region with the viral subtype G and B RNAs. The structure of the duplex results in two coaxially stacked A-form RNA stems separated by two mismatched base pairs, U(162)*Psi(39) and G(163)*A(38), that maintained a reasonable A-form helix diameter. The tRNA's s(2)U(34) stabilized the interaction between the A-rich HIV Loop I sequence and the U-rich anticodon, whereas the tRNA's Psi(39) stabilized the adjacent mismatched pairs.

Proportionality and Party Success in Europe

This thesis consists of four articles and an introductory section. The main research questions in all the articles are about proportionality and party success in Europe, at European, national or district levels. Proportionality in this thesis denotes the proximity of seat shares parties receive compared to their respective vote shares, after the electoral system’s allocation process. This proportionality can be measured through numerous indices that illustrate either the overall proportionality of an electoral system or a particular election. The correspondence of a single party’s seat shares to its vote shares can also be measured. The overall proportionality is essential in three of the articles (1, 2 and 4), where the system’s performance is studied by means of plots. In article 3, minority party success is measured by advantage-ratios that reveal single party’s winnings or losses in the votes to seat allocation process. The first article asks how proportional are the European parliamentary (EP) electoral systems, how do they compare with results gained from earlier studies and how do the EP electoral systems treat different sized parties. The reasons for different outcomes are looked for in explanations given by traditional electoral studies i.e. electoral system variables. The countries studied (EU15) apply electoral systems that vary in many important aspects, even though a certain amount of uniformity has been aspired to for decades. Since the electoral systems of the EP elections closely resemble the national elections, the same kinds of profiles emerge as in the national elections. The electoral systems indeed treat the parties differentially and six different profile types can be found. The counting method seems to somewhat determine the profile group, but the strongest variables determining the shape of a countries’ profile appears to be the average district magnitude and number of seats allocated to each country. The second article also focuses on overall proportionality performance of an electoral system, but here the focus is on the impact of electoral system changes. I have developed a new method of visualizing some previously used indices and some new indices for this purpose. The aim is to draw a comparable picture of these electoral systems’ changes and their effects. The cases, which illustrate this method, are four elections systems, where a change has occurred in one of the system variables, while the rest remained unchanged. The studied cases include the French, Greek and British European parliamentary systems and the Swedish national parliamentary system. The changed variables are electoral type (plurality changed to PR in the UK), magnitude (France splitting the nationwide district into eight smaller districts), legal threshold (Greece introducing a three percent threshold) and counting method (d’Hondt was changed to modified Sainte-Laguë in Sweden). The radar plots from elections after and before the changes are drawn for all country cases. When quantifying the change, the change in the plots area that is created has also been calculated. Using these radar plots we can observe that the change in electoral system type, magnitude, and also to some extent legal threshold had an effect on overall proportionality and accessibility for small parties, while the change between the two highest averages counting method had none. The third article studies the success minority parties have had in nine electoral systems in European heterogeneous countries. This article aims to add more motivation as to why we should care how different sized parties are treated by the electoral systems. Since many of the parties that aspire to represent minorities in European countries are small, the possibilities for small parties are highlighted. The theory of consociational (or power-sharing) democracy suggests that, in heterogeneous societies, a proportional electoral system will provide the fairest treatment of minority parties. The OSCE Lund Recommendations propose a number of electoral system features, which would improve minority representation. In this article some party variables, namely the unity of the minority parties and the geographical concentration of the minorities were included among possible explanations. The conclusions are that the central points affecting minority success were indeed these non-electoral system variables rather than the electoral system itself. Moreover, the size of the party was a major factor governing success in all the systems investigated; large parties benefited in all the studied electoral systems. In the fourth article the proportionality profiles are again applied, but this time to district level results in Finnish parliamentary elections. The level of proportionality distortion is also studied by way of indices. The average magnitudes during the studied periodrange from 7.5 to 26.2 in the Finnish electoral districts and this opens up unequal opportunities for parties in different districts and affects the shape of the profiles. The intra-country case allows the focus to be placed on the effect of district magnitude, since all other electoral systems are kept constant in an intra-country study. The time span in the study is from 1962 to 2007, i.e. the time that the districts have largely been the same geographically. The plots and indices tell the same story, district magnitude and electoral alliances matter. The district magnitude is connected to the overall proportionality of the electoral districts according to both indices, and the profiles are, as expected, also closer to perfect proportionality in large districts. Alliances have helped some small parties to gain a much higher seat share than their respective vote share and these successes affect some of the profiles. The profiles also show a consistent pattern of benefits for the small parties who ally with the larger parties.