Branching ratios for deexcitation processes of daughter nuclei following invisible dinucleon decays in 16O

Various theories beyond the standard model of particle physics predict the existence of baryon number violating processes resulting in nucleon decay. When occurring within an atomic nucleus, such a decay will be followed by secondary decays of the daughter nucleus unless its ground state is directly populated. In this paper, we estimate branching ratios for processes associated with dinucleon decays of the 16O nucleus. To this end, we use a simple shell model for the ground state of 16O. For decays from the 1s1/2 configuration, which result in highly excited states in the daughter nucleus, we employ a statistical model with the Hauser-Feshbach theory. Our analysis indicates that the branching ratio for gamma-ray emission in the energy range between 5 and 9 MeV, which is relevant to low-threshold water Cherenkov experiments such as SNO+, is 4.53%, 35.7%, and 20.2% for the nn, pp, and pn decays in 16O, respectively. In particular, emission of 6.09 MeV and 7.01 MeV gamma-rays from 14C, and 6.45 MeV and 7.03 MeV gamma-rays from 14N, have branching ratios as large as 10.9%, 20.1%, 7.73% and 8.90%, respectively

An adjustable focusing system for a 2 MeV H- ion beam line based on permanent magnet quadrupoles

A compact adjustable focusing system for a 2 MeV H- RFQ Linac is designed, constructed and tested based on four permanent magnet quadrupoles (PMQ). A PMQ model is realised using finite element simulations, providing an integrated field gradient of 2.35 T with a maximal field gradient of 57 T/m. A prototype is constructed and the magnetic field is measured, demonstrating good agreement with the simulation. Particle track simulations provide initial values for the quadrupole positions. Accordingly, four PMQs are constructed and assembled on the beam line, their positions are then tuned to obtain a minimal beam spot size of (1.2 x 2.2) mm^2 on target. This paper describes an adjustable PMQ beam line for an external ion beam. The novel compact design based on commercially available NdFeB magnets allows high flexibility for ion beam applications.Comment: published in JINST (4th Feb 2013

Drama education as a method of climate change education from the perspective of early childhood education specialists

Ilmastonmuutos on aikamme keskeinen ilmiö ja haaste, jota olisi syytä käsitellä kaikilla elämän alueilla. Ilmastonmuutosta koskevaa opetusta ja kasvatusta eli ilmastokasvatusta toteutetaan kuitenkin vain hyvin rajallisesti. Ilmastokasvatuksesta on tehty viime vuosina enenevissä määrin tutkimusta, mutta varhaiskasvatuksen ilmastokasvatusta on tutkittu vasta erittäin niukasti. Aiempien tutkimusten mukaan ilmastonmuutosta koskeva uutisointi voi herättää lapsissa monenlaisia tunteita ja ajatuksia. Tutkimusten perusteella on esitetty, että esimerkiksi taidelähtöisten opetusmenetelmien avulla voidaan käsitellä ilmastonmuutoksen herättämiä tunteita ja ajatuksia sekä vahvistaa toiveikkuutta ja uskoa omiin vaikutusmahdollisuuksiin. Taidekasvatuksen muodoista draamakasvatusta ilmastokasvatuksen menetelmänä ei ole juurikaan tutkittu. Tämän tutkimuksen tavoitteena oli lisätä tietoa siitä, mitä ilmastokasvatus voisi olla varhaiskasvatuksessa. Tutkimuksessa selvitetään varhaiskasvatusalan asiantuntijoiden määrityksiä ilmastokasvatukselle sekä heidän näkemyksiään siitä, mitä mahdollisuuksia draamakasvatuksen menetelmät tarjoavat ilmastokasvatuksen toteuttamiselle. Suunnittelin ja toteutin ilmastodraamatyöpajoja varhaiskasvatusalan asiantuntijoille ja hankin tutkimusaineistoni työpajojen yhteydessä. Tutkimuksen osallistujat tuottivat lyhyitä kirjoitelmia, minkä lisäksi kaksi työpajaa videoitiin. Analysoin kirjoitelma-aineistoa sekä videoaineistoa laadullisesti teorialähtöisen sisällönanalyysin keinoin. Käytin analyysin pohjana ensisijaisesti ilmastokasvatuksen kokonaisvaltaista polkupyörämallia (Tolppanen ym. 2017). Tutkimukseen osallistuneet varhaiskasvatusalan asiantuntijat määrittivät ilmastokasvatuksen sisällöiksi tiedon ja ymmärryksen lisäämisen, toimintaan kannustamisen, arvojen ja maailmankuvan kehittämisen sekä tunteiden käsittelyn. Asiantuntijoiden epävarmuus sekä huolet hankalien tunteiden herättämisestä lapsissa näyttäytyivät esteinä ilmastokasvatuksen toteuttamiselle varhaiskasvatuksessa. Tutkittavien näkökulmasta draamakasvatuksen menetelmillä näytti olevan mahdollisuuksia useiden ilmastokasvatuksen osa-alueiden toteuttamiseen. Tietojen lisäämiseen, ajattelun taitojen kehittymiseen, maailmankuvan rakentumiseen, voimaantumiseen ja tunteiden käsittelemiseen liittyvät draamakasvatuksen mahdollisuudet nousivat esiin. Draamakasvatuksen menetelmät tarjoavat konkreettisia keinoja varhaiskasvatuksen ilmastokasvatuksen toteuttamiseen ja kehittämiseen.Climate change is a fundamental phenomenon and challenge of our time and it should be dealt with in all areas of life. However, climate change education is being implemented very limitedly. During recent years there has been increasing amount of research on climate change education, but climate change education in early childhood education has been studied very sparingly. According to previous research, news about climate change can arouse many kinds of emotions and thoughts in children. Based on research, it has been proposed that through art-driven teaching methods it is possible to deal with emotions and thoughts aroused by climate change and strengthen hopefulness and belief in one’s own influence. Of the forms of art education, drama education as a method of climate change education has hardly been studied. The aim of this study was to add knowledge of what climate change education could be in early childhood education. The study investigates early childhood education specialists’ definitions of climate change education and their views on what possibilities drama education methods can offer for implementation of climate change education. I designed and implemented climate drama workshops for early childhood education specialists and collected the research data in the context of the workshops. Participants of the study produced short writings and in addition two of the workshops were videotaped. I analyzed the writing data and the video data qualitatively using the method of theory-based content analysis. Aa a basis for the analysis I used primarily the holistic bicycle model on climate change education (Tolppanen ym. 2017). The early childhood education specialists who participated in the study defined adding knowledge and understanding, encouraging to action, developing values and conceptions of the world and dealing with emotions as contents of climate change education. Specialists’ uncertainty and worries about arousing difficult emotions in children appeared as barriers for implementing climate change education in early childhood education. From the perspective of the study subjects, drama education methods seemed to have possibilities for implementing several parts of climate change education. Drama educations possibilities related to adding knowledge, developing thinking skills, building conceptions of the world, empowering and dealing with emotions were brought up. Methods of drama education offer practical ways for implementing and developing climate change education in early childhood education

On how high performers keep cool brains in situations of cognitive overload

What happens in the brain when we reach or exceed our capacity limits? Are there individual differences for performance at capacity limits? We used functional magnetic resonance imaging (fMRI) to investigate the impact of increases in processing demand on selected cortical areas when participants performed a parametrically varied and challenging dual task. Low-performing participants respond with large and load-dependent activation increases in many cortical areas when exposed to excessive task requirements, accompanied by decreasing performance. It seems that these participants recruit additional attentional and strategy-related resources with increasing difficulty, which are either not relevant or even detrimental to performance. In contrast, the brains of the high-performing participants "keep cool” in terms of activation changes, despite continuous correct performance, reflecting different and more efficient processing. These findings shed light on the differential implications of performance on activation patterns and underline the importance of the interindividual-differences approach in neuroimaging researc

Retardation of myelination due to dietary vitamin B12 deficiency: cranial MRI findings

Vitamin B12 deficiency is known to be associated with signs of demyelination, usually in the spinal cord. Lack of vitamin B12 in the maternal diet during pregnancy has been shown to cause severe retardation of myelination in the nervous system. We report the case of a 14 1/2-month-old child of strictly vegetarian parents who presented with severe psychomotor retardation. This severely hypotonic child had anemia due to insufficient maternal intake of vitamin B12 with associated megaloblastic anemia. MRI of the brain revealed severe brain atrophy with signs of retarded myelination, the frontal and temporal lobes being most severely affected. It was concluded that this myelination retardation was due to insufficient intake of vitamin B12 and vitamin B12 therapy was instituted. The patient responded well with improvement of clinical and imaging abnormalities. We stress the importance of MRI in the diagnosis and follow-up of patients with suspected diseases of myelinatio

Multiresolution fuzzy clustering of functional MRI data

Recent developments in the analysis of functional MRI data reveal a shift from hypothesis-driven statistical tests to unsupervised strategies. One of the most promising approaches is the fuzzy clustering algorithm (FCA), whose potential to detect activation patterns has already been demonstrated. But the FCA suffers from three drawbacks: first the computational complexity, second the higher sensitivity to noise and third the dependence on the random initialization. With the multiresolution approach presented here, these weak points are significantly improved, as is demonstrated in our tests with simulated and real functional MRI dat

Unwarping of Unidirectionally Distorted EPI Images

Echo-planar imaging (EPI) is a fast nuclear magnetic resonance imaging (MRI) method. Unfortunately, local magnetic field inhomogeneities induced mainly by the subject's presence cause significant geometrical distortion, predominantly along the phase-encoding direction, which must be undone to allow for meaningful further processing. So far, this aspect has been too often neglected. In this paper, we suggest a new approach using an algorithm specifically developed for the automatic registration of distorted EPI images with corresponding anatomically correct MRI images. We model the deformation field with splines, which gives us a great deal of flexibility, while comprising the affine transform as a special case. The registration criterion is least squares. Interestingly, the complexity of its evaluation does not depend on the resolution of the control grid. The spline model gives us good accuracy thanks to its high approximation order. The short support of splines leads to a fast algorithm. A multiresolution approach yields robustness and additional speed-up. The algorithm was tested on real as well as synthetic data, and the results were compared with a manual method. A wavelet-based Sobolev-type random deformation generator was developed for testing purposes. A blind test indicates that the proposed automatic method is faster, more reliable, and more precise than the manual one

A laserball calibration device for the SNO+ scintillator phase

Located 2 km underground in SNOLAB, Sudbury, Canada, SNO+ is a large scale liquid scintillator experiment that primarily aims to search for neutrinoless double beta decay. Whilst SNO+ has light and radioactive calibration sources external to the inner volume, an internally deployed optical source is necessary for the full characterization of the detector model. A laser diffuser ball developed for SNO has previously demonstrated to be an effective optical calibration device for both SNO and SNO+ water phase. Since the introduction of liquid scintillator for SNO+, the material compatibility, cleanliness, and radiopurity requirements of any materials in contact with the internal medium have increased. Improving on the original SNO laserball design, a new laserball calibration device has been developed for the SNO+ scintillator phase with the goal of measuring the optical properties of the detector and performing routine PMT gain and timing calibrations. Simulations have been written to model the diffusion properties to optimise optical and temporal performance for calibration. Prototype laserballs have been built and characterised, demonstrating sub-ns timing resolution and a quasi-isotropic light distributionComment: 21 pages, 16 figure