Massive Open Online Courses (MOOCs) have received much attention in higher education; however, evidence about MOOCs at the K-12 level is scarce. To shed light on the phenomenon, we use the i-MOOC ...that aims at fostering upper secondary level students’ information literacy. The i-MOOC is a blended MOOC developed and refined in a design research process; it meets established criteria for high-quality MOOCs. In 2020, 1032 upper secondary level students in German-speaking Switzerland took the i-MOOC; the sample comprises N = 167 students who voluntarily filled in a questionnaire. The students are mainly from high schools and vocational schools. Learning effects are captured with a performance test. Information literacy gains are significant and medium in size: d = 0.75. The technology acceptance of students is evaluated using the extended unified theory of acceptance and use of technology (UTAUT2). Student technology acceptance of K-12 MOOCs is primarily driven by hedonic motivation, i.e., perceived fun and entertainment. However, this type of motivation negatively predicts learning gains. Implications for teachers and educational decision makers are discussed.
•A systematic literature review on empirical evidence for K-12 MOOCs.•A conceptual framework for the quantitative evaluation of K-12 MOOCs.•Empirical evidence for a K-12 MOOC at upper secondary level in Switzerland.•Based on our evidence, the validity of student evaluation of K-12 MOOCs is doubtful.•Based on our evidence, hedonic motivation is a negative predictor for learning gain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Digitale Ökosysteme bieten in Form von offenen Lernsystemen einen neuen Gestaltungsrahmen, um die Chancen der fortgeschrittenen Digitalisierung in einer Netzwerkökonomie zu nutzen. Bildungsprozesse ...in einem Ökosystem ermöglichen eine individualisierte Studiengestaltung, personalisiertes Lernen auf der Basis intelligenter Systeme sowie eine stärkere Verknüpfung von Forschung und Lehre. Offene Lernökosysteme können in diesem Zusammenhang als Bindeglied zu Open Education im digitalen Bildungsraum aufgefasst werden. Das Fallbeispiel ‚Digital Israel‘ zeigt ein derartiges Ökosystem auf der Ebene des Bildungssystems.
ESCRT-III proteins assemble into ubiquitous membrane-remodeling polymers during many cellular processes. Here we describe the structure of helical membrane tubes that are scaffolded by bundled ...ESCRT-III filaments. Cryo-ET reveals how the shape of the helical membrane tube arises from the assembly of two distinct bundles of helical filaments that have the same helical path but bind the membrane with different interfaces. Higher-resolution cryo-EM of filaments bound to helical bicelles confirms that ESCRT-III filaments can interact with the membrane through a previously undescribed interface. Mathematical modeling demonstrates that the interface described above is key to the mechanical stability of helical membrane tubes and helps infer the rigidity of the described protein filaments. Altogether, our results suggest that the interactions between ESCRT-III filaments and the membrane could proceed through multiple interfaces, to provide assembly on membranes with various shapes, or adapt the orientation of the filaments towards the membrane during membrane remodeling.
Approximately 50% of patients with uveal melanoma (UM) will develop metastatic disease, usually involving the liver. The outcome of metastatic UM (mUM) is generally poor and no standard therapy has ...been established. Additionally, clinicians lack a validated prognostic tool to evaluate these patients. The aim of this work was to develop a reliable prognostic nomogram for clinicians.
Two cohorts of mUM patients, from Veneto Oncology Institute (IOV) (N=152) and Mayo Clinic (MC) (N=102), were analyzed to develop and externally validate, a prognostic nomogram.
The median survival of mUM was 17.2 months in the IOV cohort and 19.7 in the MC cohort. Percentage of liver involvement (HR 1.6), elevated levels of serum LDH (HR 1.6), and a WHO performance status=1 (HR 1.5) or 2-3 (HR 4.6) were associated with worse prognosis. Longer disease-free interval from diagnosis of UM to that of mUM conferred a survival advantage (HR 0.9). The nomogram had a concordance probability of 0.75 (SE .006) in the development dataset (IOV), and 0.80 (SE .009) in the external validation (MC). Nomogram predictions were well calibrated.
The nomogram, which includes percentage of liver involvement, LDH levels, WHO performance status and disease free-interval accurately predicts the prognosis of mUM and could be useful for decision-making and risk stratification for clinical trials.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Current molecular biology laboratories rely heavily on the purification and manipulation of nucleic acids. Yet, commonly used centrifuge- and column-based protocols require specialised equipment, ...often use toxic reagents, and are not economically scalable or practical to use in a high-throughput manner. Although it has been known for some time that magnetic beads can provide an elegant answer to these issues, the development of open-source protocols based on beads has been limited. In this article, we provide step-by-step instructions for an easy synthesis of functionalised magnetic beads, and detailed protocols for their use in the high-throughput purification of plasmids, genomic DNA, RNA and total nucleic acid (TNA) from a range of bacterial, animal, plant, environmental and synthetic sources. We also provide a bead-based protocol for bisulfite conversion and size selection of DNA and RNA fragments. Comparison to other methods highlights the capability, versatility, and extreme cost-effectiveness of using magnetic beads. These open-source protocols and the associated webpage (https://bomb.bio) can serve as a platform for further protocol customisation and community engagement.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose
There is no present consensus on the most reliable anatomical landmarks or axes for tibial rotational alignment in total knee arthroplasty (TKA). The goal was therefore to review the ...literature and compare accuracy and repeatability of different axes for tibial baseplate rotation in TKA.
Methods
Medline and Embase were searched for articles that reported accuracy in terms of error or discrepancy from the trans-epicondylar axes (TEA), and/or repeatability in terms of intraclass correlation coefficient, of one or more axes used for tibial baseplate rotation in TKA. Twenty-one articles met criteria, and their data were extracted and tabulated.
Results
The selected articles evaluated 15 different axes, 13 for reliability, 12 for repeatability. The lowest errors or discrepancies from the projected TEA were reported for the original ‘Akagi line’ (posterior cruciate ligament posteriorly to medial border of tibial tuberosity), its variant using the sulcus of the tibial spines as anterior landmark, as well as the anterior tibial border and the curve-on-curve technique. The best inter-observer repeatabilities were reported for ‘Akagi line’ variants that use the geometric centre of the tibial plateau posteriorly and the medial border of the tibial tuberosity, or the medial sixth of the patellar tendon anteriorly. Considering accuracy and repeatability simultaneously, only two axes were found to satisfy both criteria consistently: the original ‘Akagi line’ and the anterior tibial border.
Conclusions
Because of the small number of studies found, the collected evidence remains insufficient to recommend reference axes for intra-operative rotational alignment of the tibial baseplate in TKA. A combination of two or more anatomical landmarks or projected axes could be used to ensure adequate tibial baseplate rotation, while considering individual patient morphology and implant design to optimize knee kinematics and prevent prosthetic overhang.
Level of evidence
Level IV, systematic review of level III and IV studies.
Abstract
OBJECTIVES
Resection of thymic tumours including the removal of both the tumour and the thymus gland (thymothymectomy; TT) is the procedure of choice and is recommended in most relevant ...articles in the literature. Nevertheless, in recent years, some authors have suggested that resection of the tumour (simple thymomectomy; ST) may suffice from an oncological standpoint in patients with early-stage thymoma who do not have myasthenia gravis (MG) (non-MG). The goal of our study was to compare the short- and long-term outcomes of ST versus TT in non-MG early-stage thymomas using the European Society of Thoracic Surgeons thymic database.
METHODS
A total of 498 non-MG patients with pathological stage I thymoma were included in the study. TT was performed in 466 (93.6%) of 498 patients who had surgery with curative intent; ST was done in 32 (6.4%). The completeness of resection, the rate of complications, the 30-day mortality, the overall recurrence and the freedom from recurrence were compared. We performed crude and propensity score-adjusted comparisons by surgical approach (ST vs TT).
RESULTS
TT showed the same rate of postoperative complications, 30-day mortality and postoperative length of stay as ST. The 5-year overall survival rate was 89% in the TT group and 55% in the ST group. The 5-year freedom from recurrence was 96% in the TT group and 79% in the ST group.
CONCLUSION
Patients with early-stage thymoma without MG who have a TT show significantly better freedom from recurrence than those who have an ST, without an increase in postoperative morbidity rate.
In Guided Tissue Regeneration (GTR), barrier membranes are used to allow selective cell populations to multiply and to promote periodontal regeneration. A frequent complication is membrane exposure ...to the oral cavity followed by bacterial colonization. The purpose of this in-vitro-study was to elucidate, if rinsing with a chlorhexidine digluconate solution (CHX) prevents bacterial adhesion, and whether it interferes with attachment of periodontal ligament (PDL) fibroblasts and epithelial cells to membrane surfaces.
Firstly, two bioresorbable membranes (polylactide-based and collagen-based) were dipped into 0.06% CHX and 0.12% CHX, before biofilms (2-species representing periodontal health, 6-species representing a periodontitis) were formed for 2 h and 8 h. Subsequently, colony forming units (cfu) were counted. Secondly, the membranes were treated with CHX and inoculated in bacteria suspension two-time per day for 3 d before cfu were determined. In additional series, the influence of CHX and bacterial lysates on attachment of epithelial cells and PDL fibroblasts was determined. Parameter-free tests were applied for statistical analysis.
Cfu in "healthy" biofilms did not differ between the two membranes, more cfu were counted in "periodontitis" biofilm on collagen than on polylactide membranes. One-time dipping of membranes into CHX solutions did not markedly influence the cfu counts of both biofilms on polylactide membrane; those on collagen-based membrane were significantly reduced with being 0.12% CHX more active than 0.06% CHX. More-fold CHX dipping of membranes reduced concentration-dependent the cfu counts of both biofilms on both membranes. In general, the number of attached gingival epithelial cells and PDL fibroblasts was higher on collagen than on polylactide membrane. Lysates of the periodontopathogenic bacteria inhibited attachment of PDL fibroblasts to membranes. CHX decreased in a concentration-dependend manner the number of attached gingival epithelial cells and PDL fibroblasts.
The present in-vitro results appear to indicate that membranes in GTR should only be used when bacteria being associated with periodontal disease have been eliminated. An exposure of the membrane should be avoided. Rinsing with CHX may prevent or at least retard bacterial colonization on membrane exposed to the oral activity. However, a certain negative effect on wound healing cannot be excluded.
The current paper presents the development and validation
of a unit-level Organizational Citizenship Behavior (OCB) scale based on the
Referent-Shift Consensus Model (RSCM). In Study 1, with 124 ...individuals measured
twice, both an Exploratory Factor Analysis (EFA) and a Confirmatory Factor
Analysis (CFA) established and confirmed a five-factor solution (helping
behavior, sportsmanship, loyalty, civic virtue, and conscientiousness).
Test-retest reliabilities at a 2-month interval were high (between .59
and .79 for the subscales, .83 for the total scale). In Study 2, unit-level OCB
was analyzed in a sample of 129 work teams. Both Interrater Reliability (IRR)
measures and Interrater Agreement (IRA) values provided support for RSCM
requirements. Finally, unit-level OCB was associated with group task
interdependence and was more predictable (by job satisfaction and integrity of
the supervisor) than individual-level OCB in previous research.
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CEKLJ, FFLJ, NUK, ODKLJ, PEFLJ, UPUK
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