Optical quality assurance of GEM foils

An analysis software was developed for the high aspect ratio optical scanning system in the Detec- tor Laboratory of the University of Helsinki and the Helsinki Institute of Physics. The system is used e.g. in the quality assurance of the GEM-TPC detectors being developed for the beam diagnostics system of the SuperFRS at future FAIR facility. The software was tested by analyzing five CERN standard GEM foils scanned with the optical scanning system. The measurement uncertainty of the diameter of the GEM holes and the pitch of the hole pattern was found to be 0.5 {\mu}m and 0.3 {\mu}m, respectively. The software design and the performance are discussed. The correlation between the GEM hole size distribution and the corresponding gain variation was studied by comparing them against a detailed gain mapping of a foil and a set of six lower precision control measurements. It can be seen that a qualitative estimation of the behavior of the local variation in gain across the GEM foil can be made based on the measured sizes of the outer and inner holes.Comment: 12 pages, 29 figure

Search for highly-ionizing particles in pp collisions at the LHC's Run-1 using the prototype MoEDAL detector

A search for highly electrically charged objects (HECOs) and magnetic monopoles is presented using 2.2 fb(-1) of p - p collision data taken at a centre of mass energy (E-CM) of 8 TeV by the MoEDAL detector during LHC's Run-1. The data were collected using MoEDAL's prototype Nuclear Track Detectord array and the Trapping Detector array. The results are interpreted in terms of Drell-Yan pair production of stable HECO and monopole pairs with three spin hypotheses (0, 1/2 and 1). The search provides constraints on the direct production of magnetic monopoles carrying one to four Dirac magnetic charges and with mass limits ranging from 590 GeV/c(2) to 1 TeV/c(2). Additionally, mass limits are placed on HECOs with charge in the range 10e to 180e, where e is the charge of an electron, for masses between 30 GeV/c(2) and 1 TeV/c(2).Peer reviewe

Early root growth and architecture of fast- and slow-growing Norway spruce (Picea abies) families differ-potential for functional adaptation

The relationship between the growth rate of aboveground parts of trees and fine root development is largely unknown. We investigated the early root development of fast-and slow-growing Norway spruce (Picea abies (L.) H. Karst.) families at a developmental stage when the difference in size is not yet observed. Seedling root architecture data, describing root branching, were collected with the WinRHIZO (TM) image analysis system, and mixed models were used to determine possible differences between the two growth phenotypes. A new approach was used to investigate the spatial extent of root properties along the whole sample root from the base of 1-year-old seedlings to the most distal part of a root. The root architecture of seedlings representing fastgrowing phenotypes showed similar to 30% higher numbers of root branches and tips, which resulted in larger root extensions and potentially a better ability to acquire nutrients. Seedlings of fast-growing phenotypes oriented and allocated root tips and bio-mass further away from the base of the seedling than those growing slowly, a possible advantage in nutrient-limited and heterogeneous boreal forest soils. We conclude that a higher long-term growth rate of the aboveground parts in Norway spruce may relate to greater allocation of resources to explorative roots that confers a competitive edge during early growth phases in forest ecosystems.Peer reviewe

Alakoulun opettajien keinot käsitellä oppilaiden välisiä vertaissuhdehaasteita

Tiivistelmä. Tässä tutkimuksessa tarkastellaan opettajien keinoja käsitellä oppilaiden välisiä vertaissuhdehaasteita. Tutkimuksen tavoitteena on selvittää, mitä keinoja opettajat käyttävät puuttuessaan oppilaiden keskinäisiin haasteisiin. Tutkimus tarkastelee myös opettajien kokemuksia keinojen riittävyyteen vaikuttavista tekijöistä. Tutkimuksessa selvitetään, mitkä tekijät vahvistavat ja mitkä puolestaan heikentävät opettajien kokemusta keinojen riittävyydestä. Tämä tutkimus tarkastelee vertaissuhdehaasteita kriittisen kiusaamistutkimuksen näkökulmasta. Kriittinen kiusaamistutkimus kritisoi vallalla olevaa perinteistä kiusaamistutkimusta, joka tarkastelee kiusaamista yksilökeskeisestä näkökulmasta. Kriittisessä kiusaamistutkimuksessa huomioidaan sosiaalisten, yhteiskunnallisten ja institutionaalisten tekijöiden vaikutus kiusaamisilmiön syntymisen taustalla. Tutkimus toteutettiin laadullisena tutkimuksena, jonka aineistoa varten haastatellaan neljää alakoulussa työskentelevää opettajaa. Haastattelut toteutetaan teemahaastatteluina. Aineiston analyysi toteutetaan aineistolähtöisenä sisällönanalyysina. Tutkimuksen tulosten mukaan alakoulun opettajat käsittelevät oppilaiden välisiä vertaissuhdehaasteita monilla tavoilla. Vertaissuhdehaasteita ennaltaehkäistään muun muassa tunne- ja vuorovaikutustaitoja tukemalla sekä yhteisiä sääntöjä ja sopimuksia laatimalla. Ennaltaehkäisevistä toimista huolimatta vertaissuhdehaasteita ilmenee, ja tällöin opettajat käsittelevät tilanteita muun muassa keskustelun, ratkaisukeskeisen lähestymistavan ja erilaisten toimintamallien avulla. Opettajien keinojen riittävyyttä käsitellä vertaissuhdehaasteita vahvistavat muun muassa kokemus, sujuva yhteistyö huoltajien kanssa, kollegoiden tuki ja oma asenne. Keinojen riittävyyttä puolestaan heikentävät heikko oppilaan tuntemus, ajan puute sekä sujumaton yhteistyö huoltajien kanssa. Myös koulun ulkopuolella syntyneet haasteet oppilaiden välillä haastavat opettajia kulkeutuessaan kouluun, sillä opettajien keinot puuttua koulun ulkopuolisiin tapahtumiin ovat rajalliset

Asthma, allergies and respiratory symptoms in different activity groups of swimmers exercising in swimming halls

Background Respiratory symptoms are common in competitive swimmers. However, among these and in swimmers at other activity levels the swimming distance, the total spent time in swimming halls and their medical background varies. Our objectives were, first, to assess their medical histories and the associations with respiratory symptoms among swimmers in different activity groups and then second, to study the pulmonary function findings and related medications in competitive swimmers who exercise in swimming hall environments the most. Methods First, 1118 participants consisting of 133 competitive-, 734 fitness- and 251 occasional swimmers answered questionnaires concerning their medical background, their respiratory symptoms in connection to swimming distance and their amount of time spent in swimming halls. Secondly, in 130 competitive swimmers, pulmonary function was tested by spirometry and a specific questionnaire was used to assess respiratory symptoms, medical histories and prescribed medication. Results Respiratory symptoms were reported by 18% of the studied swimmers. Competitive swimmers had significantly more symptoms than fitness- and occasional swimmers. Naturally competitive swimmers swum more than 2000 m and stayed by the pool more than 90 min, longer than the other activity groups of swimmers. Spirometry testing showed airway obstruction in 15 swimmers, which was 12% of the 130 competitive swimmers. 21 of them, had physician-diagnosed asthma and 16 of these individuals had prescribed medication for it. Conclusions Competitive swimmers had the highest swimming hall exposure and reported significantly more respiratory symptoms. A high prevalence of airway obstruction findings in competitive swimmers with asthma and allergies suggests a need for future recommendations for regular testing and special medical care for competitive swimmers.Peer reviewe

Sosiaalisten taitojen edistäminen liikunnan avulla perusasteen alakoulun kontekstissa

Tiivistelmä. Tutkielman lähtökohtana on selvittää, kuinka koululiikunnan avulla voidaan edistää lasten sosiaalisten taitojen kehittymistä. Tässä tutkielmassa avataan koululiikuntaan ja sosiaalisiin taitoihin liittyviä käsitteitä laajasti sekä käsitellään erilaisia keinoja tukea lasten sosiaalisia taitoja. Työn yhtenä tavoitteena onkin löytää keinoja liikuntatunneille lasten sosiaalisten taitojen tukemiseksi. Tutkimuskysymyksemme kuuluu näin: Kuinka koululiikunnan avulla voidaan tukea sosiaalisten taitojen kehittymistä? Tässä kandidaatintutkielmassa keskitytään alakouluikäisten eli 7–12-vuotiaiden oppilaiden sosiaalisten taitojen tukemiseen. Tämä kandidaatintutkielma toteutetaan kuvailevana kirjallisuuskatsauksena. Tutkielmassa tutustutaan laajasti aihetta koskevaan kirjallisuuteen ja tutkimustietoon. Tutkielma osoittaa koululiikunnan olevan merkittävä väline lasten sosiaalisten taitojen tukemiseen. Kandidaatintutkielma tuo ilmi, ettei koululiikunta automaattisesti tue näiden taitojen kehittymistä, mutta koululiikunta oppiaineena tarjoaa oivalliset puitteet sosiaalisten taitojen kehittämiseen. Näitä puitteita hyödyntämällä voidaan systemaattisesti tukea oppilaiden sosiaalisten taitojen kehittymistä. Tutkielmassa käytettyjen lähteiden pohjalta voidaan tulla siihen tulokseen, että opettajan asenne ja motivaatio vaikuttavat siihen, kuinka oppilaat omaksuvat nämä taidot. Opettaja toimii tuntien aikana sosiaalisten taitojen käytön mallina oppilaille, ja näin ollen taidot peilautuvat myös oppilaiden toimintaan. Tutkielmasta käy ilmi, että yhteistoiminnallisella ja oppilaslähtöisellä opetuksella on merkittävä rooli sosiaalisten taitojen tukemisessa. Erityisesti yhteiseen tavoitteeseen tähtäävät pelit ja leikit auttavat oppilaiden sosiaalisten taitojen kehitystä. Myös vaihtuvat pari- ja ryhmäjaot tukevat sosiaalisten taitojen omaksumista. Lisäksi voidaan todeta, että sosiaalisista taidoista keskusteleminen ja niiden tarkoituksellinen harjoittelu tukevat sosiaalisten taitojen oppimista. Liikuntatuntien suunnittelun tueksi on saatavilla erilaisia valmiita sosiaalisten taitojen tukemiseen tarkoitettuja opetusohjelmia ja -materiaaleja, joita opettaja voi opetuksessaan hyödyntää. Koululiikunta tarjoaa väylän luontevaan yhdessäoloon sekä vuorovaikutussuhteiden luomiseen ja niiden syventämiseen

Employing infrared microscopy (IRM) in combination with a pre-trained neural network to visualise and analyse the defect distribution in Cadmium Telluride crystals

While Cadmium Telluride (CdTe) excels in terms of photon radiation absorption properties and outperforms silicon (Si) in this respect, the crystal growth, characterization and processing into a radiation detector is much more complicated. Additionally, large concentrations of extended crystallographic defects, such as grain boundaries, twins, and tellurium (Te) inclusions, vary from crystal to crystal and can reduce the spectroscopic performance of the processed detector. A quality assessment of the material prior to the complex fabrication process is therefore crucial. To locate the Te-defects, we scan the crystals with infrared microscopy (IRM) in different layers, obtaining a 3D view of the defect distribution. This provides us with important information on the defect density and locations of Te inclusions, and thus a handle to assess the quality of the material. For the classification of defects in the large amount of IRM image data, a convolutional neural network is employed. From the post-processed and analysed IRM data, 3D defect maps of the CdTe crystals are created, which make different patterns of defect agglomerations inside the crystals visible. In total, more than 100 crystals were scanned with the current IRM setup. In this paper, we compare two crystal batches, each consisting of 12 samples. We find significant differences in the defect distributions of the crystals.Peer reviewe

Modeling the impact of defects on the charge collection efficiency of a Cadmium Telluride detector

Cadmium telluride is a favorable material for X-ray detection as it has an outstanding characteristic for room temperature operation. It is a high-Z material with excellent photon radiation absorption properties. However, CdTe single crystals may include a large number of extended crystallographic defects, such as grain boundaries, twins, and tellurium (Te) inclusions, which can have an impact on detector performance. A Technology Computer Aided Design (TCAD) local defect model has been developed to investigate the effects of local defects on charge collection efficiency (CCE). We studied a 1 mm thick Schottky-type CdTe radiation detector with transient current technique by using a red laser at room temperature. By raster scanning the detector surface we were able to study signal shaping within the bulk, and to locate surface defects by observing their impact on the CCE. In this paper we present our TCAD model with localized defect, and compare the simulation results to TCT measurements. In the model an inclusion with a diameter of 10 mu m was assumed. The center of the defect was positioned at 6 mu m distance from the surface. We show that the defect has a notable effect on current transients, which in turn affect the CCE of the CdTe detector. The simulated charge collection at the position of the defect decreases by 80 % in comparison to the defect-free case. The simulations show that the defects give a characteristic shape to TCT signal. This can further be used to detect defects in CdTe detectors and to estimate the overall defect density in the material.Peer reviewe

Using mutual information to investigate non-linear correlation between AE index, ULF Pc5 wave activity and electron precipitation

In this study, we use mutual information from information theory to investigate non-linear correlation between geomagnetic activity indicated by auroral electrojet (AE) index with both the global ultra low frequency (ULF) Pc5 wave power and medium energy (>= 30 keV) electron precipitation at the central outer radiation belt. To investigate the energy and magnetic local time (MLT) dependence of the non-linearity, we calculate the mutual information and Pearson correlation coefficient separately for three different energy ranges (30-100 keV, 100-300 keV and >= 300 keV) and four different MLT sectors (0-6, 6-12, 12-18, 18-24). We compare results from 2 years 2004 and 2007 representing geomagnetically more active and less active years, respectively. The correlation analysis between the AE index and electron precipitation shows a clear MLT and energy dependence in both active and quiet conditions. In the two lowest energy ranges of the medium energy electrons (30-100 keV and 100-300 keV) both non-linear correlation and Pearson correlation indicate strong dependence with the AE index in the dawn sector. The linear dependence indicated by the Pearson correlation coefficient decreases from dawn to dusk while the change in the non-linear correlation is smaller indicating an increase in the non-linearity from dawn to dusk. The non-linearity between the AE index and electron precipitation is larger at all MLT sectors except MLTs 6-12 during geomagnetically more active year when larger amount of the activity is driven by interplanetary coronal mass ejections (ICMEs) compared to lower activity year with high speed stream (HSS) and stream interaction region (SIR) driven activity. These results indicate that the processes leading to electron precipitation become more non-linear in the dusk and during geomagnetically more active times when the activity is driven by ICMEs. The non-linearity between the AE index and global ULF Pc5 activity is relatively low and seems not to be affected by the difference in the geomagnetic activity during the 2 years studied.Peer reviewe

Cytokine-Coding Oncolytic Adenovirus TILT-123 Is Safe, Selective, and Effective as a Single Agent and in Combination with Immune Checkpoint Inhibitor Anti-PD-1

Oncolytic viruses provide a biologically multi-faceted treatment option for patients who cannot be cured with currently available treatment options. We constructed an oncolytic adenovirus, TILT-123, to support T-cell therapies and immune checkpoint inhibitors in solid tumors. Adenoviruses are immunogenic by nature, are easy to produce in large quantities, and can carry relatively large transgenes. They are the most commonly used gene therapy vectors and are well tolerated in patients. TILT-123 expresses two potent cytokines, tumor necrosis factor alpha and interleukin-2, to stimulate especially the T-cell compartment in the tumor microenvironment. Before entering clinical studies, the safety and biodistribution of TILT-123 was studied in Syrian hamsters and in mice. The results show that TILT-123 is safe in animals as monotherapy and in combination with an immune checkpoint inhibitor anti-PD-1. The virus treatment induces acute changes in circulating immune cell compartments, but the levels return to normal by the middle of the treatment period. The virus is rapidly cleared from healthy tissues, and it does not cause damage to vital organs. The results support the initiation of a phase 1 dose-escalation trial, where melanoma patients receiving a tumor-infiltrating lymphocyte therapy are treated with TILT-123 (NCT04217473).Peer reviewe