Influence of Tutor Behaviours on the Process of Problem-Based Learning

__Abstract__ The theme of this thesis revolves around the behaviours of the tutor in problem-based learning (PBL) and its effects on the learning in this approach. Although a substantial amount of research on PBL has been conducted over the years, it is still relatively unclear how learning takes place during the PBL process. In addition, factors that influence the learning process such as the quality of problems, the tutor and the use of scaffolds are areas that require greater investigation (Schmidt, Rotgans and Yew, 2011). With these considerations in mind, the research conducted in this thesis aims to deepen the understanding of what occurs during the actual learning process of PBL and in particular, the impact PBL tutors have on student learning

Effects of tutor-related behaviours on the process of problem-based learning

Tutors in a Problem-Based Learning (PBL) curriculum are thought to play active roles in guiding students to develop frameworks for use in the construction of knowledge. This implies that both subject-matter expertise and the ability of tutors to facilitate the learning process must be important in helping students learn. This study examines the behavioural effects of tutors in terms of subject-matter expertise, social congruence and cognitive congruence on students’ learning process and on their final achievement. The extent of students’ learning at each PBL phase was estimated by tracking the number of relevant concepts recalled at the end of each learning phase, while student achievement was based on students’ ability to describe and elaborate upon the relationship between relevant concepts learned. By using Analysis of Covariance, social congruence of the tutor was found to have a significant influence on learning in each PBL phase while all of the tutor-related behaviours had a significant impact on student achievement. The results suggest that the ability of tutors to communicate informally with students and hence create a less threatening learning environment that promotes a free flow exchange of ideas, has a greater impact on learning at each of the PBL phases as compared to tutors’ subject-matter expertise and their ability to explain concepts in a way that is easily understood by students. The data presented indicates that these tutor-related behaviours are determinants of learning in a PBL curriculum, with social congruence having a greater influence on learning in the different PBL phases

Patterns of Oncogene Coexpression at Single-Cell Resolution Influence Survival in Lymphoma

Cancers often overexpress multiple clinically relevant oncogenes, but it is not known if combinations of oncogenes in cellular subpopulations within a cancer influence clinical outcomes. Using quantitative multispectral imaging of the prognostically relevant oncogenes MYC, BCL2, and BCL6 in diffuse large B-cell lymphoma (DLBCL), we show that the percentage of cells with a unique combination MYC+BCL2+BCL6- (M+2+6-) consistently predicts survival across four independent cohorts (n = 449), an effect not observed with other combinations including M+2+6+. We show that the M+2+6- percentage can be mathematically derived from quantitative measurements of the individual oncogenes and correlates with survival in IHC (n = 316) and gene expression (n = 2,521) datasets. Comparative bulk/single-cell transcriptomic analyses of DLBCL samples and MYC/BCL2/BCL6-transformed primary B cells identify molecular features, including cyclin D2 and PI3K/AKT as candidate regulators of M+2+6- unfavorable biology. Similar analyses evaluating oncogenic combinations at single-cell resolution in other cancers may facilitate an understanding of cancer evolution and therapy resistance

Is learning in problem-based learning cumulative?

Problem-based learning (PBL) is generally organized in three phases, involving collaborative and self-directed learning processes. The hypothesis tested here is whether learning in the different phases of PBL is cumulative, with learning in each phase depending on that of the previous phase. The scientific concepts recalled by 218 students at the end of each PBL phase were used to estimate the extent of students’ learning. The data were then analyzed using structural equation modeling. Results show that our hypothesized model fits the data well. Alternative hypotheses according to which achievement is predicted either by collaborative learning alone or by self-directed learning alone did not fit the data. We conclude that the learning in each PBL phase is cumulative, and strongly influenced by the earlier phase, thus providing support for the PBL cycle of problem analysis, self-directed learning, and a subsequent reporting phase. We also demonstrate an efficient method to capture and quantify students’ learning during the PBL process

Enhanced Catalysis of the Electrochemical Oxygen Evolution Reaction by Iron(III) Ions Adsorbed on Amorphous Cobalt Oxide

The oxygen evolution reaction (OER) is the bottleneck in the efficient production of hydrogen gas fuel via the electrochemical splitting of water. In this work, we present and elucidate the workings of an OER catalytic system which consists of cobalt oxide (CoO_<i>x</i>) with adsorbed Fe³⁺ ions. The CoO_<i>x</i> was electrodeposited onto glassy-carbon-disk electrodes, while Fe³⁺ was added to the 1 M KOH electrolyte. Linear sweep voltammetry and chronopotentiometry were used to assess the system’s OER activity. The addition of Fe³⁺ significantly lowered the average overpotential (η) required by the cobalt oxide catalyst to produce 10 mA/cm² O₂ current from 378 to 309 mV. The Tafel slope of the CoO_<i>x</i> + Fe³⁺ catalyst also decreased from 59.5 (pure CoO_<i>x</i>) to 27.6 mV/dec, and its stability lasted ∼20 h for 10 mA/cm² O₂ evolution. Cyclic voltammetry showed that oxidation of the deposited CoO_<i>x</i>, from Co²⁺ to Co³⁺ occurred at a more positive potential when Fe³⁺ was added to the electrolyte. This could be attributed to interactions between the Co and Fe atoms. Comprehensive X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy were conducted. The in situ XANES spectra of Co sites in the CoO_<i>x</i>, CoO_<i>x</i> + Fe³⁺, and control Fe₄₈Co₅₂O_<i>x</i> catalysts were similar during the OER, which indicates that the improved OER performance of the CoO_<i>x</i> + Fe³⁺ catalyst could not be directly correlated to changes in the Co sites. The XANES spectra of Fe indicated that Fe³⁺ adsorbed on CoO_<i>x</i> did not further oxidize under OER conditions. However, Fe’s coordination number was notably reduced from 6 in pure FeO_<i>x</i> to 3.7 when it was adsorbed on CoO_<i>x</i>. No change in the Fe–O bond lengths/strengths was found. The nature and mechanistic role of Fe adsorbed on CoO_<i>x</i> are discussed. We propose that Fe sites with oxygen vacancies are responsible for the improved OER activity of CoO_<i>x</i> + Fe³⁺ catalyst

A Factor XIa Inhibitor Engineered from Banded Krait Venom Toxin: Efficacy and Safety in Rodent Models of Arterial and Venous Thrombosis

Activated factor XI (FXIa) is an important antithrombotic drug target. Clinical and pre-clinical data have demonstrated that its inhibition attenuates thrombosis with minimal risk of excessive bleeding. We isolated Fasxiator from the venom of banded krait Bungarus fasciatus and subsequently engineered FasxiatorN17R,L19E, with improved affinity (Ki = 0.9 nM) and selectivity towards FXIa. Here, we assess the in vivo efficacy and bleeding risk of rFasxiatorN17R, L19E in pre-clinical animal models. Rats injected intravenously (i.v.) with bolus rFasxiatorN17R, L19E showed the specific in vivo attenuation of the intrinsic coagulation pathway, lasting for at least 60 min. We performed the in vivo dose-ranging experiments for rFasxiatorN17R, L19E as follows: FeCl3-induced carotid artery occlusion in rats (arterial thrombosis); inferior vena cava ligation in mice (venous thrombosis); tail bleeding time in both rats and mice (bleeding risk). Head-to-head comparisons were made using therapeutic dosages of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) for arterial and venous thrombosis, respectively. In the arterial thrombosis model, 2 mg/kg i.v. rFasxiatorN17R,L19E achieved a similar antithrombotic efficacy to that of UFH, with &gt;3-fold lower bleeding time. In the venous thrombosis model, the 10 mg/kg subcutaneous (s.c.) injection of rFasxiatorN17R,L19E achieved similar efficacy and bleeding levels to those of LMWH enoxaparin. Overall, rFasxiatorN17R,L19E represents a promising molecule for the development of FXIa-targeting anticoagulants

Efficacy and safety of front-line treatment regimens for Waldenstrom macroglobulinaemia: a systematic review and meta-analysis

Abstract Rituximab-based chemo-immunotherapy is currently the standard first-line treatment for Waldenstrom macroglobulinaemia (WM), while ibrutinib has emerged as an alternative. In the absence of randomised trials (RCTs) comparing these regimens, the optimal first-line treatment for WM remains uncertain. In this systematic review and meta-analysis, we sought to assess the efficacy and safety of first-line treatment regimens for WM. We searched key databases from January 2007 to March 2023, including phase II and III trials, including treatment-naïve WM patients treated with rituximab-based regimens or ibrutinib. Response rates, progression-free survival (PFS), overall survival (OS), and toxicities were evaluated. Four phase III and seven phase II trials were included among 736 unique records. Pooled response rates from all comparative and non-comparative trials were 46%, 33% and 26% for bendamustine rituximab (BR), bortezomib-dexamethasone, cyclophosphamide, rituximab (BDRC) and ibrutinib rituximab (IR), respectively. Two-year pooled PFS was 89%, 81% and 82% with BR, BDRC and IR, respectively. Neuropathy was more frequent with bortezomib, while haematologic and cardiac toxicities were more common with chemo-immunotherapy and ibrutinib-based regimens respectively. Our findings suggest that BR yields higher response rates than bortezomib or ibrutinib-based combinations. RCTs comparing BR against emerging therapies, including novel Bruton Tyrosine Kinase Inhibitors, are warranted

The Contribution of MYC and PLK1 Expression to Proliferative Capacity in Diffuse Large B-Cell Lymphoma

10.1080/10428194.2019.1633629Leukemia & Lymphoma60133214-322

Determinants of response to daratumumab in Epstein-Barr virus-positive natural killer and T-cell lymphoma

10.1136/jitc-2020-002123JOURNAL FOR IMMUNOTHERAPY OF CANCER9