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Discussions around assessment integrity often focus on the exam conditions and the motivations and values of those who cheated in comparison with those who did not. We argue that discourse needs to move away from a binary representation of cheating. Instead, we propose that the conversation may be more productive and more impactful by focusing on those who do not cheat, but who are tempted to do so. We conceptualise this group as being at risk of future cheating behaviour and potentially more receptive of targeted strategies to support their integrity decisions. In this paper we report on a large-scale survey of university students (n = 7,511) who had just completed one or more end of semester online exams. In doing so we explore students' reported temptation to cheat. Analysis surrounding this "at risk" group reveals students who were Tempted (n = 1379) had significant differences from those who Cheated (n = 216) as well as those who were Not tempted (n = 5916). We focus on four research questions exploring whether there are specific online exam conditions, security settings, student attitudes or perceptions which are more strongly associated with the temptation to cheat. The paper offers insights to help institutions to minimise factors that might lead to breaches of assessment integrity, by focusing on the temptation to cheat during assessment.

Online examinations are a common experience in higher education. Their security is a key concern for education communities, and has resulted in a variety of cheating countermeasures. There is broad consensus in the literature that there is no one measure, including proctoring, which eradicates cheating behaviours. As a result, this study is exploratory, seeking to add to our understanding of the range of factors that may interact with frequency of cheating behaviour in online examinations. This large-scale study (N = 7839) is based in one Australian university which pivoted to online examinations during the 2021 COVID-19 lockdowns. Students who reported cheating (n = 216) revealed a wide range of factors that may have influenced their behaviours. A key observation is that cheating, although less frequent than reported elsewhere, occurred regardless of the security measure, assessment design, examination condition, and across the spectrum of student demographic variables. However, there were statistically significant differences in relation to frequency of cheating according to certain demographics, examination conditions, motivations, attitudes and perceptions. Although some forms of proctoring did demonstrate reduced frequencies in self-reported cheating, they are demonstrably incomplete solutions due to the complexity of other variables.

Due to recent conceptual shifts towards learner-centred feedback, there is a potential gap between research and practice. Indeed, few models or studies have sought to identify or evaluate which semantic messages, or feedback components, teachers should include in learner-centred feedback comments. Instead, teacher practices are likely to be primarily shaped by 'old paradigm' conceptualisations of feedback. In response, the current study develops a taxonomy of learner-centred feedback components based on a rapid systematic review of the literature. The face, content and construct validity of the taxonomy are then established through an empirical study with teachers and students at two Australian universities. The outcome of this study is a conceptual model featuring eight learner-centred feedback components. This model will help teachers design effective feedback processes and support learners to make sense of and use feedback information to improve their future work and learning strategies.

Current conceptualisations of feedback contend that it should be a learner-centred process. In practice, however, text-based feedback comments from teachers are a convenient and common source of feedback information, despite appearing to be contra-indicative of learner-centred models. This raises the question of how teachers can tackle the design of text-based learner-centred feedback, but at present there is limited empirical evidence available to answer this question. In response, we conducted a rapid review and qualitative synthesis of 95 peer-reviewed scholarly publications on feedback, and appraised the results through the lens of four diverse conceptualisations of learner-centred feedback. This process led to the development of a framework of 12 learner-centred design attributes for text-based feedback, which were organised around three layers of design: contexts, characteristics and components. Each of these design attributes are discussed and practical recommendations are synthesised from the literature. Areas in need of additional empirical research are also highlighted.

Research indicates that effective learner-centred feedback requires learner agency, impact and sensemaking. While scholars are focusing on supporting agency and impact, limited research has addressed sensemaking. This is problematic, because if learners fail to understand feedback, impact is likely to be reduced. In response, this study examines (non) alignment between teacher intent and student sensemaking of authentic feedback comments. The sample included four teachers and eighteen students from two Australian universities. Data were collected via stimulated recall interviews and a feedback coding task. The results suggest that sensemaking of strength-based comments, critiques and actionable information was aided when the comments were clear and specific. On the other hand, sensemaking was limited when comments were designed to mitigate against negative affect, overloaded with multiple intentions, or overly brief. This study informs theory around learner-centred feedback design which, in turn, improves the likelihood that teacher comments will be interpreted accurately by learners. [ABSTRACT FROM AUTHOR]

Byline: Nicholas Boustead, Kris Ryan, Gregory J. Sheard The growth of short-wave elliptical instabilities in a Lamb-Oseen vortex pair subject to non-uniform strain fields at close vortex spacing is considered using direct numerical simulation at a Reynolds number Re = 20000. A linear stability analysis demonstrates that with reduced vortex spacing the growth rate of all axial wave-numbers is enhanced relative to that of the fastest-growing mode. A coupling of vortices is observed at close vortex spacing, which may lead to improved non-linear instability growth, and the development of fluid cross-over regions. These fluid cross-over regions are shown to be products of a linear growth regime.

This study presents the benefits of changing the delivery of a second-year engineering course from the traditional lecture-based format to the flipped approach that is becoming increasingly embraced by universities. The new format involved replacing theoretical lectures with online recordings and devoting the class time to working through problems (workshops). These workshops were complemented by pre- and post-class activities. The success of this change is measured by comparing the outcomes of the flipped and traditional offerings of the same course. This comparison reveals the following benefits from flipping the course: higher marks; improved engagement; and widespread student satisfaction with the flipped format based on student feedback. These outcomes are compared with those reported in the literature for similar teaching approaches. This paper differs from most previous studies by considering all of these outcomes together for one course. The detailed explanation of how the course was flipped provides a model that can be applied to successfully flip other courses. This paper concludes by provocatively raising several key issues that are surprisingly absent or glossed over in the literature. Further studies of these issues are proposed to make a firm case for flipped learning. [ABSTRACT FROM AUTHOR]

Platelets can become activated in response to changes in flow-induced shear; however, the underlying molecular mechanisms are not clearly understood. Here we present new techniques for experimentally measuring the flow-induced shear rate experienced by platelets prior to adhering to a thrombus. We examined the dynamics of blood flow around experimentally grown thrombus geometries using a novel combination of experimental (ex vivo) and numerical (in silico) methodologies. Using a microcapillary system, platelet aggregate formation was analysed at elevated shear rates in the presence of coagulation inhibitors, where thrombus formation is predominantly platelet-dependent. These approaches permit the resolution and quantification of thrombus parameters at the scale of individual platelets (2 μm) in order to quantify real time thrombus development. Using our new techniques we can correlate the shear rate experienced by platelets with the extent of platelet adhesion and aggregation. The techniques presented offer the unique capacity to determine the flow properties for a temporally evolving thrombus field in real time. [ABSTRACT FROM AUTHOR]

A Batchelor vortex represents the asymptotic solution of a trailing vortex in an aircraft wake. In this study, an unequal-strength, counter-rotating Batchelor vortex pair is employed as a model of the wake emanating from one side of an aircraft wing; this model is a direct extension of several prior investigations that have considered unequal-strength Lamb–Oseen vortices as representations of the aircraft wake problem. Both solution of the linearized Navier–Stokes equations and direct numerical simulations are employed to study the linear and nonlinear development of a vortex pair with a circulation ratio of $\Lambda = \ensuremath{-} 0. 5$. In contrast to prior investigations considering a Lamb–Oseen vortex pair, we note strong growth of the Kelvin mode $[\ensuremath{-} 2, 0] $ coupled with an almost equal growth rate of the Crow instability. Three stages of nonlinear instability development are defined. In the initial stage, the Kelvin mode amplitude becomes sufficiently large that oscillations within the core of the weaker vortex are easily observable and significantly affect the profile of the weaker vortex. In the secondary stage, filaments of secondary vorticity emanate from the weaker vortex and are convected around the stronger vortex. In the tertiary stage, a transition in the dominant instability wavelength is observed from the short-wavelength Kelvin mode to the longer-wavelength Crow instability. Much of the instability growth is observed on the weaker vortex of the pair, although small perturbations in the stronger vortex are observed in the tertiary nonlinear growth phase. [ABSTRACT FROM PUBLISHER]

A numerical investigation was conducted into the different flow states, and bifurcations leading to changes of state, found in open cylinders of medium to moderate depth driven by a constant rotation of the vessel base. A combination of linear stability analysis, for cylinders of numerous height-to-radius aspect ratios (H/R), and nonlinear stability analysis and three-dimensional simulations for a cylinder of aspect ratio 1.5, has been employed. Attention is focused on the breaking of SO(2) symmetry. A comprehensive map of transition Reynolds numbers as a function of aspect ratio is presented by combining a detailed stability analysis with the limited existing data from the literature. For all aspect ratios considered, the primary instabilities are identified as symmetry-breaking Hopf bifurcations, occurring at Reynolds numbers well below those of the previously reported axisymmetric Hopf transitions. It is revealed that instability modes with azimuthal wavenumbers m = 1, 3 and 4 are the most unstable in the range 1.0 < H/R < 4, and that numerous double Hopf bifurcation points exist. Critical Reynolds numbers generally increase with cylinder aspect ratio, though a decrease in stability occurs between aspect ratios 1.5 and 2.0, where a local minimum in critical Reynolds number occurs. For H/R = 1.5, a detailed characterisation of instability modes is given. It is hypothesized that the primary instability leading to transition from steady axisymmetric flow to unsteady three-dimensional flow is related to deformation of shear layers that are present in the flow, in particular at the interfacial region between the vortex breakdown bubble and the primary recirculation. [ABSTRACT FROM PUBLISHER]

Abstract: The bubble-type vortex breakdown inside a cylinder with flow driven by rotation of the base, has applications in mixing. We investigate this phenomena and its effect on the environment inside an open cylinder, with potential application as a tissue-engineering bioreactor, with tissue-scaffolds of two different geometries immersed in the fluid. Addition of scaffolds induces a blockage effect, hindering the flow in the central vortex core returning to the rotating base. This promotes early onset of vortex breakdown and alters the final shape of vortex breakdown bubbles. Placement of the scaffolds centrally on the cylinder axis yields almost identical levels and distributions of shear stress between the upper and lower surfaces of scaffolds. A change from a disk shaped to an ellipsoidal scaffold, of the same size, reduces the intensity of the maximum shear stresses at the scaffold surface by up to 50%. There is a range of Reynolds numbers where increasing Reynolds number, and hence possibly increasing mixing efficiency, leads to a decrease in the maximum levels of fluid forces at the scaffold surfaces. This is an important conclusion for scaffold based tissue engineering where improved mixing is sought, but often sacrificed in favor of minimizing fluid forces. [Copyright &y& Elsevier]

Abstract: The creation of vortex pairs occurs in a range of industries, including mixing, transport, and plastic moulding. In particular, vortex pairs are observed in the wake of aircraft, and are the cause of a significant hazard in the aviation industry. Instabilities, which grow on vortex pairs, have the potential to lead to enhanced dissipation, thus limiting this safety concern, in addition to enhancing mixing in chemical engineering industries. To date research has mostly considered instabilities growing on a vortex pair where each vortex has the same magnitude of circulation. However, in practice it is unusual to have an equal-strength vortex pair. This investigation is the first to consider the instability modes that may develop on a Lamb–Oseen vortex pair of arbitrary circulation ratio. We find a significant change in the growth rates of all instability modes reported previously for an equal-strength vortex pair. All simulations employ an accurate spectral-element method to discretise the domain coupled with a three-step time splitting scheme. A wide range of instability wavelengths is considered to ensure that all instability modes are captured. By identifying and enhancing the leading instability modes, we are able to enhance the dissipation of the vortex pair. [Copyright &y& Elsevier]

The wakes behind square cylinders with variation in incidence angle are computed over a range of Reynolds numbers to elucidate the three-dimensional stability and dynamics up to a Reynolds number of Re =300, based on the projected height of the inclined square cylinder. Three-dimensional instability modes are predicted and computed using a linear stability analysis technique and three-dimensional simulations, respectively. Depending on the incidence angle, the flow is found to transition to three-dimensional flow through either a mode A instability, or a subharmonic mode C instability. The mode A instability is predicted as the firstoccurring instability at incidence angles smaller than 12° and greater than 26?, with the mode C instability predicted between these incidence angles. At a zero-degree angle of incidence, the wake instabilities closely match modes A, B and a quasiperiodic mode predicted in earlier studies behind square and circular cylinders. With increasing angle of incidence, the three-dimensional wake transition Reynolds number first increases from Re =164 as the mode A instability weakens, before decreasing again beyond an incidence angle of 12° as the wake becomes increasingly unstable to the mode C instability, and then again to the mode A instability as the incidence angle approaches 45°. A spanwise autocorrelation analysis from computations over a cylinder span 20 times the square cross-section side length reveals that beyond the onset of three-dimensional instabilities, the vortex street breaks down with patterns consistent with spatio-temporal chaos. This effect was more pronounced at higher incidence angles. [ABSTRACT FROM AUTHOR]

Thrombus formation in hemostasis or thrombotic disease is initiated by the rapid adhesion, activation, and aggregation of circulating platelets in flowing blood. At arterial or pathological shear rates, for example due to vascular stenosis or circulatory support devices, platelets may be exposed to highly pulsatile blood flow, while even under constant flow platelets are exposed to pulsation due to thrombus growth or changes in vessel geometry. The aim of this study is to investigate platelet thrombus formation dynamics within flow conditions consisting of either constant or variable shear. Human platelets in anticoagulated whole blood were exposed ex vivo to collagen type I-coated microchannels subjected to constant shear in straight channels or variable shear gradients using different stenosis geometries (50%, 70%, and 90% by area). Base wall shears between 1800 and 6600 s−1, and peak wall shears of 3700 to 29,000 s−1 within stenoses were investigated, representing arterial-pathological shear conditions. Computational flow-field simulations and stenosis platelet thrombi total volume, average volume, and surface coverage were analysed. Interestingly, shear gradients dramatically changed platelet thrombi formation compared to constant base shear alone. Such shear gradients extended the range of shear at which thrombi were formed, that is, platelets became hyperthrombotic within shear gradients. Furthermore, individual healthy donors displayed quantifiable differences in extent/formation of thrombi within shear gradients, with implications for future development and testing of antiplatelet agents. In conclusion, here, we demonstrate a specific contribution of blood flow shear gradients to thrombus formation, and provide a novel platform for platelet functional testing under shear conditions. [ABSTRACT FROM AUTHOR]