35 research outputs found

    Evaluation of Interventions in Blended Learning Using a Communication Skills Serious Game

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    Serious games often employ a scripted dialogue for player interaction with a virtual character. In our serious game Communicate, a domain expert develops a structured, scripted scenario as a sequence of potential interactions in an authoring tool. A player is often a student learning communication skills and a virtual character represents a person that a student talks to. In the original version of Communicate, a player `converses' with a virtual character by clicking on one of the multiple statement options. Since 2018, we perform blended learning sessions for final year computer science students using Communicate. Our goal is to improve these sessions and in this paper, we apply the action research method over three semesters to iteratively improve these blended learning sessions. In the first semester, our baseline, we conduct sessions where students play a scenario in multiple choice format. In the second semester, we enhance Communicate by enabling a student to enter open text input in an improved scenario. In the third semester, we enhance a session by incorporating peer teaching. Students fill in an evaluation survey after a session and we compare the evaluation of students from the three semesters. Results show that student ratings are significantly higher in sessions incorporating peer teaching compared to the baseline

    Rescue from Stx2-Producing E. coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice

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    Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection

    Rescue from Stx2-Producing E. coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice

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    Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 Ă— 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 Ă— 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection

    An application of the Rasch model to reading comprehension measurement

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    An effective reading comprehension measurement demands robust psychometric tools that allow teachers and researchers to evaluate the educational practices and track changes in students’ performance. In this study, we illustrate how Rasch model can be used to attend such demands and improve reading comprehension measurement. We discuss the construction of two reading comprehension tests: TRC-n, with narrative texts, and TRC-e, with expository texts. Three vertically scaled forms were generated for each test (TRC-n-2, TRC-n-3, TRC-n-4; TRC-e-2, TRC-e-3 and TRC-e-4), each meant to assess Portuguese students in second, third and fourth grade of elementary school. The tests were constructed according to a nonequivalent groups with anchor test design and data were analyzed using the Rasch model. The results provided evidence for good psychometric qualities for each test form, including unidimensionality and local independence and adequate reliability. A critical view of this study and future researches are discussed.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), PortugalThis research was supported by Grant FCOMP-01-0124-FEDER-010733 from Fundação para a Ciência e Tecnologia (FCT) and the European Regional Development Fund (FEDER) through the European program COMPETE (Operational Program for Competitiveness Factors) under the National Strategic Reference Framework (QREN).info:eu-repo/semantics/publishedVersio

    Adipose tissue is the first colonization site of <i>Leptospira interrogans</i> in subcutaneously infected hamsters

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    <div><p>Leptospirosis is one of the most widespread zoonoses in the world, and its most severe form in humans, “Weil’s disease,” may lead to jaundice, hemorrhage, renal failure, pulmonary hemorrhage syndrome, and sometimes,fatal multiple organ failure. Although the mechanisms underlying jaundice in leptospirosis have been gradually unraveled, the pathophysiology and distribution of leptospires during the early stage of infection are not well understood. Therefore, we investigated the hamster leptospirosis model, which is the accepted animal model of human Weil’s disease, by using an <i>in vivo</i> imaging system to observe the whole bodies of animals infected with <i>Leptospira interrogans</i> and to identify the colonization and growth sites of the leptospires during the early phase of infection. Hamsters, infected subcutaneously with 10<sup>4</sup> bioluminescent leptospires, were analyzed by <i>in vivo</i> imaging, organ culture, and microscopy. The results showed that the luminescence from the leptospires spread through each hamster’s body sequentially. The luminescence was first detected at the injection site only, and finally spread to the central abdomen, in the liver area. Additionally, the luminescence observed in the adipose tissue was the earliest detectable compared with the other organs, indicating that the leptospires colonized the adipose tissue at the early stage of leptospirosis. Adipose tissue cultures of the leptospires became positive earlier than the blood cultures. Microscopic analysis revealed that the leptospires colonized the inner walls of the blood vessels in the adipose tissue. In conclusion, this is the first study to report that adipose tissue is an important colonization site for leptospires, as demonstrated by microscopy and culture analyses of adipose tissue in the hamster model of Weil’s disease.</p></div

    Bioluminescence dissemination of <i>Leptospira</i> in hamsters.

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    <p>(A) The survival rate of Golden Syrian hamsters (n = 8) infected subcutaneously with 10<sup>4</sup> <i>L</i>. <i>interrogans</i> strain M1307 into the right inguinal region, and representative ventral view photographic images tracking the hamster infections on different days post-infection. Images depict photographs overlaid with color representations of luminescence intensity, measured in photons/second/cm<sup>2</sup>/sr as indicated on the scales, where red is the most intense (3×10<sup>5</sup>) and purple is the least intense (3×10<sup>4</sup>). (B,C) Average luminescence intensities in each ROI of injection site (B) and abdominal center (C) at different days post-infection. Data are expressed as the means ± SEM of total flux in photons/second in each ROI in eight infected hamsters (●) and two uninfected controls (◦). <i>p</i> values (*<i>p</i><0.05), between groups.</p

    Bioluminescence changes in hamster organs.

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    <p>Representative bioluminescence images (ventral view) from M1307-infected hamsters at each phase. Images represent subcutaneous tissues after skin incision and organs after laparotomy, as well as <i>ex vivo</i> organs (blood plus liver and kidney cross sections). The scale is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172973#pone.0172973.g001" target="_blank">Fig 1</a>.</p
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