Half-Integer Filling Factor States in Quantum Dots

Emergence of half-integer filling factor states, such as nu=5/2 and 7/2, is found in quantum dots by using numerical many-electron methods. These states have interesting similarities and differences with their counterstates found in the two-dimensional electron gas. The nu=1/2 states in quantum dots are shown to have high overlaps with the composite fermion states. The lower overlap of the Pfaffian state indicates that electrons might not be paired in quantum dot geometry. The predicted nu=5/2 state has high spin polarization which may have impact on the spin transport through quantum dot devices.Comment: 4 pages, accepted to Phys. Rev. Let

Adiponectin and Leptin and Their Associations with Cardiovascular Risk Factors and Markers of Subclinical Atherosclerosis in Young Adults

Background: Effective prevention of atherosclerosis requires identification of individuals at high risk already in childhood. Adipose tissue produces various proteins that participate in the regulation of metabolism and have been suggested to influence the cardiovascular system directly and via inflammation. Aims: The aims of this study were to examine serum levels of adipose tissue-derived proteins adiponectin and leptin in Finnish children, adolescents and adults and to study their associations with metabolic syndrome, carotid intima-media thickness and flow-mediated dilatation of the brachial artery. Moreover, the aim was to study if adiponectin levels in childhood and adolescence predict carotid atherosclerosis in adulthood. Participants and methods: The present thesis is part of the Cardiovascular Risk in Young Finns Study. In 1980, 3,596 children and adolescents aged 3-18 years participated in the study. Serum adiponectin concentrations were measured from samples taken in 1980, 2001 and 2007 and leptin concentrations from samples taken in 1980 and 2001. Ultrasonic evaluation of carotid artery intima-media thickness and brachial artery flow-mediated dilatation were performed in 2001 and 2007. Results: Serum adiponectin levels decreased from childhood to adulthood in both males and females whereas serum leptin levels increased in females and decreased slightly in males. In adulthood, decreased serum adiponectin levels were associated with incident metabolic syndrome, increased carotid artery intima-media thickness and attenuated flow-mediated dilatation of the brachial artery. Serum adiponectin levels in childhood were inversely associated with carotid atherosclerosis in adulthood. There were no independent associations between leptin levels and surrogate markers of atherosclerosis. Conclusions: Serum adiponectin, but not leptin, levels may be a useful biomarker in cardiovascular risk assessment.Adiponektiini ja leptiini nuorilla suomalaisilla aikuisilla ja niiden yhteys sydän- ja verisuonitautien riskitekijöihin sekä varhaisiin verisuonimuutoksiin. Lasten Sepelvaltimotaudin Riskitekijät (LASERI) -tutkimus Tausta: Valtimonkovettumataudin ehkäisemiseksi olisi tärkeää tunnistaa jo lapsuudessa henkilöt, joille tulisi tarjota ennaltaehkäisevää ohjausta. Rasvakudoksen tuottamilla valkuaisaineilla on suuri merkitys monissa elimistön toiminnoissa ja niillä on esitetty olevan suoria ja välillisiä vaikutuksia myös verenkiertoelimistöön. Tavoite: Tämän tutkimuksen tavoitteena oli kuvata rasvakudoksen tuottamien adiponektiinin ja leptiinin seerumipitoisuudet suomalaisilla lapsilla, nuorilla ja aikuisilla sekä tutkia niiden yhteyksiä metaboliseen oireyhtymään, ultraäänellä mitattuun kaulavaltimon seinämäpaksuuteen ja olkavaltimon sisäkalvon toimintaan. Lisäksi tavoitteena oli selvittää, ennustaako lapsuus- ja nuoruusiässä mitattu seerumin adiponektiinipitoisuus aikuisiällä kaulavaltimon seinämän paksuuntumista. Menetelmät: Tämä väitöskirjatutkimus on osa Lasten Sepelvaltimotaudin Riskitekijät -tutkimusta, johon osallistui 3596 lasta (iältään 3-18 vuotta) vuonna 1980. Seerumin adiponektiinipitoisuuksia on määritetty vuosien 1980, 2001 ja 2007 näytteistä ja leptiinipitoisuuksia vuosien 1980 ja 2001 näytteistä. Kaulavaltimon ja olkavaltimon ultraäänitutkimukset tehtiin tutkittaville vuosina 2001 ja 2007. Tulokset: Seerumin adiponektiinipitoisuudet pienenivät lapsuudesta aikuisuuteen tytöillä ja pojilla. Leptiinin pitoisuus seerumissa suurentui tytöillä lapsuusiästä aikuisikään, kun taas pojilla pitoisuus hieman pieneni. Aikuisilla seerumin pieni adiponektiinipitoisuus oli yhteydessä metabolisen oireyhtymän ilmaantuvuuteen, suurempaan kaulavaltimon sisäseinämän paksuuteen ja pienentyneeseen olkavaltimon laajentumiskykyyn. Pieni adiponektiinipitoisuus lapsuus- ja nuoruusiässä ennusti suurentunutta riskiä kaulavaltimon seinämän paksuuntumiselle aikuisena. Seerumin leptiinipitoisuudella ei ollut itsenäistä yhteyttä valtimomuutoksiin. Johtopäätökset: Seerumin adiponektiinipitoisuuden määrittäminen saattaa auttaa valtimonkovettumataudin riskin arvioinnissa.Siirretty Doriast

An Action Design Research

This master’s thesis focuses on studying how modularity can be applied in designing robotic process automation (RPA) solutions and what effects it has to the RPA implementations. Past research has found several benefits of increasing modularity in designing, coordinating, and managing complex systems and many kinds of design problems have been solved with it. This thesis examines how the principles of modularity resonate with RPA. The study follows the Action Design Research method to examine a case in real-life context and to enable the participation of practitioners and end users in the case organization. It describes in detail how a modular RPA solution was created for automating an entity consisting of several different tasks in the case organization. The solution can be viewed as an artifact that can be utilized to calibrate an organization’s RPA journey by adding efficiency in RPA projects. This is achieved by enhancing the scalability and reusability of the RPA components. The results of this study suggest that RPA solutions can be viewed as complex systems into which modularity principles can be adapted, generating a variety of benefits from the viewpoints of automation development and administration. The main benefits include decreased implementation time and cost, enhanced error management, increased control of automation, increased capability to respond to versatile automation demand, and enhanced automation complexity management

Vortices in quantum droplets: Analogies between boson and fermion systems

The main theme of this review is the many-body physics of vortices in quantum droplets of bosons or fermions, in the limit of small particle numbers. Systems of interest include cold atoms in traps as well as electrons confined in quantum dots. When set to rotate, these in principle very different quantum systems show remarkable analogies. The topics reviewed include the structure of the finite rotating many-body state, universality of vortex formation and localization of vortices in both bosonic and fermionic systems, and the emergence of particle-vortex composites in the quantum Hall regime. An overview of the computational many-body techniques sets focus on the configuration interaction and density-functional methods. Studies of quantum droplets with one or several particle components, where vortices as well as coreless vortices may occur, are reviewed, and theoretical as well as experimental challenges are discussed.Comment: Review article, 53 pages, 53 figure

Clinical Learning Environment and Supervision. Development and Validation of the CLES Evaluation Scale

The purpose of the study is: (1) to describe how nursing students' experienced their clinical learning environment and the supervision given by staff nurses working in hospital settings; and (2) to develop and test an evaluation scale of Clinical Learning Environment and Supervision (CLES). The study has been carried out in different phases. The pilot study (n=163) explored the association between the characteristics of a ward and its evaluation as a learning environment by students. The second version of research instrument (which was developed by the results of this pilot study) were tested by an expert panel (n=9 nurse teachers) and test-retest group formed by student nurses (n=38). After this evaluative phase, the CLES was formed as the basic research instrument for this study and it was tested with the Finnish main sample (n=416). In this phase, a concurrent validity instrument (Dunn & Burnett 1995) was used to confirm the validation process of CLES. The international comparative study was made by comparing the Finnish main sample with a British sample (n=142). The international comparative study was necessary for two reasons. In the instrument developing process, there is a need to test the new instrument in some other nursing culture. Other reason for comparative international study is the reflecting the impact of open employment markets in the European Union (EU) on the need to evaluate and to integrate EU health care educational systems. The results showed that the individualised supervision system is the most used supervision model and the supervisory relationship with personal mentor is the most meaningful single element of supervision evaluated by nursing students. The ward atmosphere and the management style of ward manager are the most important environmental factors of the clinical ward. The study integrates two theoretical elements - learning environment and supervision - in developing a preliminary theoretical model. The comparative international study showed that, Finnish students were more satisfied and evaluated their clinical placements and supervision with higher scores than students in the United Kingdom (UK). The difference between groups was statistical highly significant (p= 0.000). In the UK, clinical placements were longer but students met their nurse teachers less frequently than students in Finland. Arrangements for supervision were similar. This research process has produced the evaluation scale (CLES), which can be used in research and quality assessments of clinical learning environment and supervision in Finland and in the UK. CLES consists of 27 items and it is sub-divided into five sub-dimensions. Cronbach's alpha coefficient varied from high 0.94 to marginal 0.73. CLES is a compact evaluation scale and user-friendliness makes it suitable for continuing evaluation.Siirretty Doriast

Wigner molecules in polygonal quantum dots: A density functional study

We investigate the properties of many-electron systems in two-dimensional polygonal (triangle, square, pentagon, hexagon) potential wells by using the density functional theory. The development of the ground state electronic structure as a function of the dot size is of particular interest. First we show that in the case of two electrons, the Wigner molecule formation agrees with the previous exact diagonalization studies. Then we present in detail how the spin symmetry breaks in polygonal geometries as the spin density functional theory is applied. In several cases with more than two electrons, we find a transition to the crystallized state, yielding coincidence with the number of density maxima and the electron number. We show that this transition density, which agrees reasonably well with previous estimations, is rather insensitive to both the shape of the dot and the electron number.Comment: 8 pages, 11 figure