Opettajaopiskelijoiden ja oppilaiden kysymysten määrä ja laatu opetusharjoittelussa : –kysymysten yhteys vuorovaikutukseen ja kognitiiviseen tasoon

Tutkimuksen tavoitteena oli selvittää opettajaopiskelijoiden ja oppilaiden esittämien kysymysten määrää ja laatua opetusharjoittelun aikana. Tutkimukset osoittavat, että opettajat käyttävät suuren osan opetusajasta kysymysten esittämiseen, mutta kysymykset ovat kognitiiviselta tasoltaan alhaista, ne ovat yleensä suljettuja ja kysymyksen jälkeinen odotusaika on optimaalisimman oppimisen kannalta liian lyhyt. Lisäksi opettajan muodostama vuorovaikutus luokkahuoneessa on harvoin dialogista. Siksi tämän tutkimuksen tavoitteena oli saada kokonaiskuva opetusharjoittelun aikana tapahtuvasta kysymisestä, analysoida kysymysten yhteyttä sekä luokassa tapahtuvaan kognitioon että vuorovaikutukseen ja tuoda esille pedagoginen malli laadukkaasta kysymyksestä. Tutkimus pohjautuu Vygotskyn sosiokulttuuriseen teoriaan, jonka mukaan oppiminen tapahtuu kielen avulla. Tässä tutkimuksessa kieli tarkoittaa puhuttua kieltä, tarkemmin määriteltynä opettajan ja oppilaiden kysymyksiä. Kysymysten avulla opettaja voi saada selville oppilaan lähikehityksen tason ja pyrkiä viemään oppilaan oppimista kohti korkeampaa tasoa. Kysymys on yksi opettajan eniten käyttämä opetuskeino, jonka laadukkaalla käytöllä on paljon positiivisia vaikutuksia oppilaan oppimiselle ja kehitykselle. Jo tehtyjen tutkimusten mukaan voidaan sanoa, että avoimet kysymykset kehittävät oppilaan ajattelua, kognitiivisesti korkeamman tason kysymykset vaikuttavat positiivisesti oppimiseen ja opettajan antama vähintään kolmen sekunnin vastausaika vaikuttaa positiivisesti oppilaan ajattelun kehittymiseen ja kielellisesti kehittyneempään puheeseen. Tutkimuksen aineisto koostuu kahdeksasta Rauman Normaalikoulun opetusharjoittelun aikana kuvatusta ja äänitetystä opetustunnista. Yhteensä äänitettyä ja videoitua materiaalia oli noin 360 minuuttia. Tutkimukseen osallistui 14 toisen vuoden opettajaopiskelijaa ja 77 oppilasta. Tutkimus toteutettiin analysoimalla litteroitua aineistoa sekä kvalitatiivisilla että kvantitatiivisilla menetelmillä. Tämän tutkimuksen tulosten mukaan opettajaopiskelijat kysyvät valtavan määrän kysymyksiä oppitunnissa. Kysymykset keskittyvät kognitiivisesti alhaiseen tasoon, muistamiseen ja ymmärtämiseen. Opettajaopiskelijat eivät pyrkineet oppilaiden vastausten tai ajatusten laajentamiseen, jonka myötä luokkahuoneessa vallitseva vuorovaikutus oli auktoritatiivista. Dialoginen vuorovaikutus saattoi puuttua kokonaan. Avoimilla kysymyksillä on tilastollisesti merkitsevä yhteys sekä kognitiivisesti korkeampaan ajatteluun että dialogiseen vuorovaikutukseen. Opettajan avoin kysymys johti siis yleensä dialogiseen vuorovaikutukseen ja kognitiivisesti korkeampaan ajatteluun. Suljettu kysymys taas kognitiivisesti alempaan kysymykseen ja auktoritatiiviseen vuorovaikutukseen. Opettajat käyttivät suurimman osan 65,9 % suljettuja kysymyksiä, kun taas avoimia kysymyksiä käytettiin 5,4 %. Jos katsotaan tämän tutkimuksen tuloksia suhteessa luotuun malliin pedagogisesti laadukkaasta kysymyksestä, voidaan sanoa, että opettajaopiskelijoiden kysymysten käyttö ei ollut opetusharjoittelun aikana pedagogisesti laadukasta. Siksi opettajaopiskelijoille tulee järjestää lisää koulutusta kysymysten käytöstä, opettajan ja oppilaan puheen vaikutuksesta ja vuorovaikutuksesta, jotta oppilaiden oppiminen kehittyisi optimaalisemmalla tavalla. Kysymysten laadukkaalla käytöllä voidaan saavuttaa parempaa oppimista, ajattelua ja vuorovaikutusta

The impact of vertical off-centering on image noise and breast dose in chest CT with organ-based tube current modulation : A phantom study

Publisher Copyright: © 2022 Associazione Italiana di Fisica Medica e SanitariaPurpose: To determine the effects of patient vertical off-centering when using organ-based tube current modulation (OBTCM) in chest computed tomography (CT) with focus on breast dose. Materials and methods: An anthropomorphic adult female phantom with two different breast attachment sizes was scanned on GE Revolution EVO and Siemens Definition Edge CT systems using clinical chest CT protocols and anterior-to-posterior scouts. Scans with and without OBTCM were performed at different table heights (GE: centered, ±6 cm, and ± 3 cm; Siemens: centered, −6 cm, and ± 3 cm). The dose effects were studied with metal-oxidesemiconductor field-effect transistor dosimeters with complementary Monte Carlo simulations to determine full dose maps. Changes in image noise were studied using standard deviations of subtraction images from repeated acquisitions without dosimeters. Results: Patient off-centering affected both the behavior of the normal tube current modulation as well as the extent of the OBTCM. Generally, both OBTCM techniques provided a substantial decrease in the breast doses (up to 30% local decrease). Lateral breast regions may, however, in some cases receive higher doses when OBTCM is enabled. This effect becomes more prominent when the patient is centered too low in the CT gantry. Changes in noise roughly followed the expected inverse of the change in dose. Conclusions: Patient off-centering was shown to affect the outcome of OBTCM in chest CT examination, and on some occasions, resulting in higher exposure. The use of modern dose optimization tools such as OBTCM emphasizes the importance of proper centering when preparing patients to CT scans.Peer reviewe

The effect of vertical centering and scout direction on automatic tube voltage selection in chest CT : a preliminary phantom study on two different CT equipments

Purpose: To determine the effect of patient's vertical off-centering and scout direction on the function of automatic tube voltage selection (ATVS) and tube current modulation (TCM) in chest computed tomography (CT). Methods: Chest phantom was scanned with Siemens and GE CT systems using three clinical chest CT protocols exploiting ATVS and a fixed 120 kVp chest protocol. The scans were performed at five vertical positions of the phantom (- 6 to + 6 cm from the scanner isocenter). The effects of scout direction (posterior-to-anterior, anterior-to-posterior, and lateral) and vertical off-centering on the function of ATVS and TCM were studied by examining changes in selected voltage, radiation dose (volume CT dose index, CTDIvol), and image noise and contrast. Results: Both scout direction and vertical off-centering affected ATVS. The effect differed between the vendors for the studied geometry, demonstrating differences in technical approaches. The greatest observed increase in CTDI vot due to off-centering was 91%. Anterior-to-posterior scout produced highest doses at the uppermost table position, whereas posterior-to-anterior scout produced highest doses at the lowermost table position. Dose varied least using lateral scouts. Vertical off-centering impacted image noise and contrast due to the combined effect of ATVS, TCM, structural noise, and bowtie fillers. Conclusions: Patient vertical off-centering and scout direction affected substantially the CTDI vot and image quality in chest CT examinations. Vertical off-centering caused variation also in the selected tube voltage. The function of ATVS and TCM methods differ significantly between the CT vendors, resulting in differences in CTDIvol and image noise characteristics.Peer reviewe

Characterizing geometric distortions of 3D sequences in clinical head MRI

Objective Phantoms are often used to estimate the geometric accuracy in magnetic resonance imaging (MRI). However, the distortions may differ between anatomical and phantom images. This study aimed to investigate the applicability of a phantom-based and a test-subject-based method in evaluating geometric distortion present in clinical head-imaging sequences. Materials and methods We imaged a 3D-printed phantom and test subjects with two MRI scanners using two clinical head-imaging 3D sequences with varying patient-table positions and receiver bandwidths. The geometric distortions were evaluated through nonrigid registrations: the displaced acquisitions were compared against the ideal isocenter positioning, and the varied bandwidth volumes against the volume with the highest bandwidth. The phantom acquisitions were also registered to a computed tomography scan. Results Geometric distortion magnitudes increased with larger table displacements and were in good agreement between the phantom and test-subject acquisitions. The effect of increased distortions with decreasing receiver bandwidth was more prominent for test-subject acquisitions. Conclusion Presented results emphasize the sensitivity of the geometric accuracy to positioning and imaging parameters. Phantom limitations may become an issue with some sequence types, encouraging the use of anatomical images for evaluating the geometric accuracy.Peer reviewe

Ejection fraction in myocardial perfusion imaging assessed with a dynamic phantom : comparison between IQ-SPECT and LEHR

BACKGROUND: Developments in single photon emission tomography instrumentation and reconstruction methods present a potential for decreasing acquisition times. One of such recent options for myocardial perfusion imaging (MPI) is IQ-SPECT. This study was motivated by the inconsistency in the reported ejection fraction (EF) and left ventricular (LV) volume results between IQ-SPECT and more conventional low-energy high-resolution (LEHR) collimation protocols. IQ-SPECT and LEHR quantitative results were compared while the equivalent number of iterations (EI) was varied. The end-diastolic (EDV) and end-systolic volumes (ESV) and the derived EF values were investigated. A dynamic heart phantom was used to produce repeatable ESVs, EDVs and EFs. Phantom performance was verified by comparing the set EF values to those measured from a gated multi-slice X-ray computed tomography (CT) scan (EF(True)). The phantom with an EF setting of 45, 55, 65 and 70% was imaged with both IQ-SPECT and LEHR protocols. The data were reconstructed with different EI, and two commonly used clinical myocardium delineation software were used to evaluate the LV volumes. RESULTS: The CT verification showed that the phantom EF settings were repeatable and accurate with the EF(True) being within 1% point from the manufacture’s nominal value. Depending on EI both MPI protocols can be made to produce correct EF estimates, but IQ-SPECT protocol produced on average 41 and 42% smaller EDV and ESV when compared to the phantom’s volumes, while LEHR protocol underestimated volumes by 24 and 21%, respectively. The volume results were largely similar between the delineation methods used. CONCLUSIONS: The reconstruction parameters can greatly affect the volume estimates obtained from perfusion studies. IQ-SPECT produces systematically smaller LV volumes than the conventional LEHR MPI protocol. The volume estimates are also software dependent.Peer reviewe

Space and Time in Hybrid Teaching and Learning Environments: Two Cases and Design Principles

The opportunities and challenges of teaching and learning in the same and different space and time have been discussed in the field of distance education for several decades. Within COVID-19, a new type of experimenting and research interest in so-called hybrid learning has emerged. In this article, we present the results from exploring “hybridity” from the perspective of classical categorizations of different forms of learning in terms of time and space. We explored the phenomenon through two cases with the same high-level strategic objective, serving hybrid interaction. In case A, we evaluated university library spaces renovated to serve hybrid teaching and learning. In case B, the focus was on the implementation of a university course redesigned during the pandemic from blended learning to include more hybrid interaction. Multifaceted data was collected, including video recordings (case A), recorded videoconference sessions, and written student feedback (case B). Qualitative data analyses relied on ethnography and contextual inquiry. Based on the analyses of the case studies, we propose five design principles for designing hybrid teaching and learning that aim to overcome the limitations of the same space and time: (1) Ensuring access to required tools, infrastructure, and support; (2) Design primarily for same time, different place learning; (3) Design primarily for same time, same place learning; (4) Less is more; and (5) “Le bon Dieu est dans le détail.” These design principles provide guidance to the design process of hybrid teaching and learning to increase the chances of reaching a successful solution.Peer reviewe

Comparison of Stomatal Conductance Approaches in JSBACH

Non peer reviewe

Old Content and Modern Tools : Searching Named Entities in a Finnish OCRed Historical Newspaper Collection 1771–1910

Named Entity Recognition (NER), search, classification and tagging of names and name-like informational elements in texts, has become a standard information extraction procedure for textual data. NER has been applied to many types of texts and different types of entities: newspapers, fiction, historical records, persons, locations, chemical compounds, protein families, animals etc. In general, the performance of a NER system is genre- and domain-dependent and also used entity categories vary [Nadeau and Sekine 2007]. The most general set of named entities is usually some version of a tripartite categorization of locations, persons, and organizations. In this paper we report trials and evaluation of NER with data from a digitized Finnish historical newspaper collection (Digi). Experiments, results, and discussion of this research serve development of the web collection of historical Finnish newspapers. Digi collection contains 1,960,921 pages of newspaper material from 1771–1910 in both Finnish and Swedish. We use only material of Finnish documents in our evaluation. The OCRed newspaper collection has lots of OCR errors; its estimated word level correctness is about 70–75 % [Kettunen and Pääkkönen 2016]. Our principal NE tagger is a rule-based tagger of Finnish, FiNER, provided by the FIN-CLARIN consortium. We also show results of limited category semantic tagging with tools of the Semantic Computing Research Group (SeCo) of the Aalto University. Three other tools are also evaluated briefly. This paper reports the first large scale results of NER in a historical Finnish OCRed newspaper collection. Results of this research supplement NER results of other languages with similar noisy data. As the results are also achieved with a small and morphologically rich language, they illuminate the relatively well-researched area of Named Entity Recognition from a new perspective.Peer reviewe

Comparison of reconstruction and acquisition choices for quantitative T2* maps and synthetic contrasts

Aim and scope: A Gradient Echo Plural Contrast Imaging technique (GEPCI) is a post-processing method, which can be used to obtain quantitative T2* values and generate multiple synthetic contrasts from a single acquisition. However, scan duration and image reconstruction from k-space data present challenges in a clinical workflow. This study aimed at optimizing image reconstruction and acquisition duration to facilitate a post-processing method for synthetic image contrast creation in clinical settings. Materials and methods: This study consists of tests using the American College of Radiology (ACR) image quality phantom, two healthy volunteers, four mild traumatic brain injury patients and four small vessel disease patients. The measurements were carried out on a 3.0 T scanner with multiple echo times. Reconstruction from k-space data and DICOM data with two different coil-channel combination modes were investigated. Partial Fourier techniques were tested to optimize the scanning time. Conclusions: Sum of squares coil-channel combination produced artifacts in phase images, but images created with adaptive combination were artifact-free. The voxel-wise median signed difference of T2* between the vendor's adaptive channel combination and k-space reconstruction modes was 2.9 +/- 0.7 ms for white matter and 4.5 +/- 0.6 ms for gray matter. Relative white matter/gray matter contrast of all synthetic images and contrast-to-noise ratio of synthetic T1-weighted images were almost equal between reconstruction modes. Our results indicate that synthetic contrasts can be generated from the vendor's DICOM data with the adaptive combination mode without affecting the quantitative T2* values or white matter/gray matter contrast.Peer reviewe

3D Convolutional Neural Network Applied to CT Angiography in the Detection of an Acute Ischemic Stroke

Peer reviewe