Collars and partitions of hyperbolic cone-surfaces

For compact Riemann surfaces, the collar theorem and Bers' partition theorem are major tools for working with simple closed geodesics. The main goal of this paper is to prove similar theorems for hyperbolic cone-surfaces. Hyperbolic two-dimensional orbifolds are a particular case of such surfaces. We consider all cone angles to be strictly less than $\pi$ to be able to consider partitions.Comment: 11 pages, 9 figures; v2: minor changes, to appear in Geometriae Dedicat

Epithermal Neutron Beam Interference with Cardiac Pacemakers

Peer reviewe

Void Growth in BCC Metals Simulated with Molecular Dynamics using the Finnis-Sinclair Potential

The process of fracture in ductile metals involves the nucleation, growth, and linking of voids. This process takes place both at the low rates involved in typical engineering applications and at the high rates associated with dynamic fracture processes such as spallation. Here we study the growth of a void in a single crystal at high rates using molecular dynamics (MD) based on Finnis-Sinclair interatomic potentials for the body-centred cubic (bcc) metals V, Nb, Mo, Ta, and W. The use of the Finnis-Sinclair potential enables the study of plasticity associated with void growth at the atomic level at room temperature and strain rates from 10^9/s down to 10^6/s and systems as large as 128 million atoms. The atomistic systems are observed to undergo a transition from twinning at the higher end of this range to dislocation flow at the lower end. We analyze the simulations for the specific mechanisms of plasticity associated with void growth as dislocation loops are punched out to accommodate the growing void. We also analyse the process of nucleation and growth of voids in simulations of nanocrystalline Ta expanding at different strain rates. We comment on differences in the plasticity associated with void growth in the bcc metals compared to earlier studies in face-centred cubic (fcc) metals.Comment: 24 pages, 12 figure

PAEP (progestagen-associated endometrial protein)

Review on PAEP (progestagen-associated endometrial protein), with data on DNA, on the protein encoded, and where the gene is implicated

Varhaiskasvatuksen vaikutus lapsen kiintymyssuhteisiin

Tiivistelmä. Tämän kandidaatintutkielman tavoitteena on selvittää, millaisia vaikutuksia päiväkotiympäristössä tapahtuvalla ryhmätoiminnalla on lapsen jo luotuihin kiintymyssuhteisiin ja voiko lapsi muodostaa kiintymyssuhteita myös varhaiskasvatuksen henkilöstöön, eli lyhyemmin varhaiskasvattajiin. Lisäksi tavoitteena on antaa tietoa siitä, mitä ovat kiintymyssuhteet, miten ne muodostuvat ja millaisia vaikutuksia niillä on lapsen elämään. Tutkielma on toteutettu kvalitatiivisena tutkimuksena ja tutkimusmenetelmänä on käytetty kirjallisuuskatsausta. Lähteinä on käytetty sekä suomenkielistä että englanninkielistä painettua kirjallisuutta ja tutkimusartikkeleita. Olen perehtynyt myös varhaiskasvatuslakiin ja varhaiskasvatussuunnitelman perusteisiin ja käyttänyt niitä lähteinä. Kiintymyssuhdeteoriaan pohjautuvat kiintymyssuhteet ovat merkittävä osa lapsen sosiaalista kehitystä ja niiden vaikutukset ulottuvat myös muiden taitojen kehitykseen ja pitkälle lapsen myöhempään elämään. Kiintymyssuhteen näkyvä osa on kiintymyskäyttäytyminen, jota on kuvattu toiseen ihmiseen kohdistuvana läheisyyden etsimisenä ja ylläpitämisenä. Kiintymyskäyttäytymistä ilmenee esimerkiksi erotilanteissa, joissa sen muoto määrittelee kiintymyssuhteen laadun. Kiintymyssuhteet voidaan jaoitella turvallisiin kiintymyssuhteisiin ja turvattomiin kiintymyssuhteisiin, jotka taas voidaan jakaa edelleen erilaisiin tarkempiin kategorioihin. Varhaiskasvatuksen pariin siirtyvä lapsi on usein muodostanut jo ensisijaisia kiintymyssuhteita vanhempiinsa. Varhaiskasvatus muuttaa lapsen päivärytmiä ja aiheuttaa tilanteen, jossa lapsi ei voi olla koko päivää ensisijaisen kiintymyskohteensa kanssa. Tästä johtuen on aiheellista pohtia, millaisia varhaiskasvatuksen vaikutukset kiintymyssuhteisiin oikein ovat. Lisäksi on tärkeää selvittää, voiko lapsi luoda kiintymyssuhteita myös päiväkodissa varhaiskasvattajiin, ja voidaanko näillä kiintymyssuhteilla tukea lapsen kasvua ja kehitystä. Tutkielma osoittaa, että lapsen kiintymyssuhteet ovat merkittävä osa hänen varhaisimpia vuosiaan ja niillä on vaikutusta myös hänen myöhempään elämäänsä. Lapsi muodostaa kiintymyssuhteita sekä perheenjäseniinsä että mahdollisesti myös varhaiskasvattajiin. Lisäksi vastauksena tutkimuskysymykseen tutkielma osoittaa, että varhaiskasvatuksella ei ole tilastollisesti merkittäviä vaikutuksia lapsen kiintymyssuhteisiin, mutta yksilöllisiä vaikutuksia on havaitt

Predictors of response to pharmacological treatments in treatment-resistant schizophrenia - A systematic review and meta-analysis

Background: As the burden of treatment-resistant schizophrenia (TRS) on patients and society is high it is important to identify predictors of response to medications in TRS. The aim was to analyse whether baseline patient and study characteristics predict treatment response in TRS in drug trials. Methods: A comprehensive search strategy completed in PubMed, Cochrane and Web of Science helped identify relevant studies. The studies had to meet the following criteria: English language clinical trial of pharmacological treatment of TRS, clear definition of TRS and response, percentage of response reported, at least one baseline characteristic presented, and total sample size of at least 15. Meta-regression techniques served to explore whether baseline characteristics predict response to medication in TRS. Results: 77 articles were included in the systematic review. The overall sample included 7546 patients, of which 41% achieved response. Higher positive symptom score at baseline predicted higher response percentage. None of the other baseline patient or study characteristics achieved statistical significance at predicting response. When analysed in groups divided by antipsychotic drugs, studies of clozapine and other atypical antipsychotics produced the highest response rate. Conclusions: This meta-analytic review identified surprisingly few baseline characteristics that predicted treatment response. However, higher positive symptoms and the use of atypical antipsychotics - particularly clozapine -was associated with the greatest likelihood of response. The difficulty involved in the prediction of medication response in TRS necessitates careful monitoring and personalised medication management. There is a need for more investigations of the predictors of treatment response in TRS.Peer reviewe

Mobile learning in teacher training

Abstract This paper describes a mobile learning project, where mobile devices are used for educational activities. The main focus of this paper is teacher training. Experiences on the use of mobile technology and how it was used in teacher training, especially how trainees and supervising teachers felt about it, are presented. The pilot study was carried out at the Department of Home Economics and Craft Science in University of Helsinki. The idea of the pilot was that the supervising teacher and trainee students could discus and share their ideas about teaching methods through the mobile device and use of a short message service (SMS) and digital pictures as a part of the supervising process. The use of digital pictures which were delivered via the mobile device proved to be surprisingly successful. The goal of these innovative pilot projects is to create flexible teaching solutions, which will enable access to information using different devices, and support learning in a variety of situations

Ferromagnetic resonance in ϵ\epsilon-Co magnetic composites

We investigate the electromagnetic properties of assemblies of nanoscale $\epsilon$-cobalt crystals with size range between 5 nm to 35 nm, embedded in a polystyrene (PS) matrix, at microwave (1-12 GHz) frequencies. We investigate the samples by transmission electron microscopy (TEM) imaging, demonstrating that the particles aggregate and form chains and clusters. By using a broadband coaxial-line method, we extract the magnetic permeability in the frequency range from 1 to 12 GHz, and we study the shift of the ferromagnetic resonance with respect to an externally applied magnetic field. We find that the zero-magnetic field ferromagnetic resonant peak shifts towards higher frequencies at finite magnetic fields, and the magnitude of complex permeability is reduced. At fields larger than 2.5 kOe the resonant frequency changes linearly with the applied magnetic field, demonstrating the transition to a state in which the nanoparticles become dynamically decoupled. In this regime, the particles inside clusters can be treated as non-interacting, and the peak position can be predicted from Kittel's ferromagnetic resonance theory for non-interacting uniaxial spherical particles combined with the Landau-Lifshitz-Gilbert (LLG) equation. In contrast, at low magnetic fields this magnetic order breaks down and the resonant frequency in zero magnetic field reaches a saturation value reflecting the interparticle interactions as resulting from aggregation. Our results show that the electromagnetic properties of these composite materials can be tuned by external magnetic fields and by changes in the aggregation structure.Comment: 14 pages, 13 figure

Coexistence of Single and Double-Quantum Vortex Lines

We discuss the configurations in which singly and doubly quantized vortex lines may coexist in a rotating superfluid. General principles of energy minimization lead to the conclusion that in equilibrium the two vortex species segregate within a cylindrical vortex cluster in two coaxial domains where the singly quantized lines are in the outer annular region. This is confirmed with simulation calculations on discrete vortex lines. Experimentally the coexistence can be studied in rotating superfluid $^3$He-A. With cw NMR techniques we find the radial distribution of the two vortex species to depend on how the cluster is prepared: (i) By cooling through $T_c$ in rotation, coexistence in the minimum energy configuration is confirmed. (ii) A glassy agglomerate is formed if one starts with an equilibrium cluster of single-quantum vortex lines and adds to it sequentially double-quantum lines, by increasing the rotation velocity in the superfluid state. This proves that the energy barriers, which separate different cluster configurations, are too high for metastabilities to anneal.Comment: 12 pages, 11 figures; Changed content, 15 pages, 14 figure

Susceptibility and Percolation in 2D Random Field Ising Magnets

The ground state structure of the two-dimensional random field Ising magnet is studied using exact numerical calculations. First we show that the ferromagnetism, which exists for small system sizes, vanishes with a large excitation at a random field strength dependent length scale. This {\it break-up length scale} $L_b$ scales exponentially with the squared random field, $\exp(A/\Delta^2)$. By adding an external field $H$ we then study the susceptibility in the ground state. If $L>L_b$, domains melt continuously and the magnetization has a smooth behavior, independent of system size, and the susceptibility decays as $L^{-2}$. We define a random field strength dependent critical external field value $\pm H_c(\Delta)$, for the up and down spins to form a percolation type of spanning cluster. The percolation transition is in the standard short-range correlated percolation universality class. The mass of the spanning cluster increases with decreasing $\Delta$ and the critical external field approaches zero for vanishing random field strength, implying the critical field scaling (for Gaussian disorder) $H_c \sim (\Delta -\Delta_c)^\delta$, where $\Delta_c = 1.65 \pm 0.05$ and $\delta=2.05\pm 0.10$. Below $\Delta_c$ the systems should percolate even when H=0. This implies that even for H=0 above $L_b$ the domains can be fractal at low random fields, such that the largest domain spans the system at low random field strength values and its mass has the fractal dimension of standard percolation $D_f = 91/48$. The structure of the spanning clusters is studied by defining {\it red clusters}, in analogy to the ``red sites'' of ordinary site-percolation. The size of red clusters defines an extra length scale, independent of $L$.Comment: 17 pages, 28 figures, accepted for publication in Phys. Rev.