Is a picture worth a thousand words?

Background: It has previously been suggested that the use of illustrations in MCQs may have variable effects on individual items. This study examines the effect of illustrated questions, as opposed to pure text, to discern if any overall bias between the two formats is detectable. Summary of work: We reviewed 6 Histology MCQ papers from our Medical Junior Cycle. Classical test theory analysis was performed on all MCQs, which were then divided into two groups, those with associated images and those without. Summary of results: We analysed 195 single best answer MCQs; 100 with associated illustrations, 95 without. The number of students per examination ranged from 277 to 347, with a total of 60,850 student-question interactions. There was no difference in question difficulty between the two groups (0.800 vs. 0.770; p = 0.862, Mann-Whitney-U). The discriminating power of the questions, as measured by point biserial correlation, was also identical (0.315 vs. 0.300; p = 0.939; Independent t-test). Conclusions: We found no overall bias or effect on either item difficulty or discrimination resulting from the addition of illustrations. We suggest that illustrated questions, as with textual vignettes, may test a range of cognitive levels depending on how they are employed

Bone microstructure, turnover and peri-articular osteopathies.

Sheep are a practical model for postmenopausal pathologies and have been used for investigation of a number of conditions to date, including the bone diseases osteoporosis and osteoarthritis (Newton, 2004; Parker et al, 2003; Thorndike et al, 1998). With regard to many of the structural parameters, the ovine stifle joint may be considered to be a 1:3 scale model of the human knee joint (Osterhoff et al, 2010). 23 sheep were examined in this study; 10 of the sheep underwent ovariectomy (OVX), while the remainder (n=13) were kept as controls (CON). Five fluorochrome dyes were administered intravenously at 12 week intervals via the jugular vein to both groups, to label sites of bone turnover. These animals were then sacrificed at 12 months postoperatively. My data showed significant alterations within the subchondral trabecular architecture at one-year post-ovariectomy, with reduced bone volume fraction, thinning of individual trabeculae and an increase in trabecular separation; these findings are consistent with those elsewhere in the ovine skeleton (Cornish et al., 2006; Jiang et al, 2005; Mitton et al., 1998; Mittra et al., 2005; Nafei et al., 2000; Newton et al., 2004; Schorlemmer et al., 2003). In addition, I confirmed that bone turnover was significantly higher in both trabecular bone and the subchondral bone plate at one-year postovariectomy. Remodelling of trabecular bone was due to both classically described hemi-osteonal and intra-trabecular osteonal remodelling, while osteons within the subchondral plate have relatively late mineralisation of lamellae. The presence of osteopenia and elevated subchondral bone turnover within the medial tibial plateau provides a possible mechanism for subchondral microfractures in the aetiology of spontaneous osteonecrosis of the knee (SPONK). Further utilisation of the ovariectomised ewe would be useful for further study in this field. I was unable to detect any measurable difference in osteoarthritis between the two study groups. While previous studies have suggested a link between trabecular thinning and osteoarthritis, I was unable to confirm this. Osteoarthritis was associated with a thinning of the subchondral plate, specifically the subchondral cortical bone. I found no correlation between bone turnover rates of either the subchondral trabecular bone or bone plate with osteoarthritis. I conclude that while ovariectomy may not increase the risk of osteoarthritis per se, it will cause osteopenia; if osteoarthritis then occurs, the synergy between these two disease processes will mean that the osteoarthritis in the ovariectomised group will be more severe

The Anatomical Society core embryology syllabus for undergraduate medicine

A modified Delphi methodology was used to develop a consensus regarding a series of learning outcome statements to act as the foundation of an undergraduate medical core embryology syllabus. A Delphi panel was formed by recruiting stakeholders with experience in leading undergraduate teaching of medical students. The panel (n = 18), including anatomists, embryologists and practising clinicians, were nominated by members of Council and/or the Education Committee of the Anatomical Society. Following development of an a priori set of learning outcome statements (n = 62) by the authors, panel members were asked in the first of a two‐stage process to ‘accept’, ‘reject’ or ‘modify’ each learning outcome, to propose additional outcomes if desired. In the second stage, the panel was asked to either accept or reject 16 statements which had either been modified, or had failed to reach consensus, during the first Delphi round. Overall, 61 of 62 learning outcome statements, each linked to examples of clinical conditions to provide context, achieved an 80% level of agreement following the modified Delphi process and were therefore deemed accepted for inclusion within the syllabus. The proposed syllabus allows for flexibility within individual curricula, while still prioritising and focusing on the core level of knowledge of embryological processes by presenting the essential elements to all newly qualified doctors, regardless of their subsequent chosen specialty

New sub-millimeter limits on dust in the 55 Cancri planetary system

We present new, high-sensitivity sub-millimeter observations towards 55 Cancri, a nearby G8 star with one, or possibly two, known planetary companion(s). Our 850 $\mu$m map, obtained with the SCUBA instrument on the James Clerk Maxwell Telescope, shows three peaks of emission at the 2.5 mJy level in the vicinity of the star's position. However, the observed peaks are 25\arcsec--40\arcsec away from the star and a deep $R$-band optical image reveals faint point sources that coincide with two of the sub-millimeter peaks. Thus, we do not find evidence for dust emission spatially associated with 55 Cancri. The excess 60 $\mu$m emission detected with ISO may originate from one or more of the 850 $\mu$m peaks that we attribute to background sources. Our new results, together with the HST/NICMOS coronographic images in the near-infrared, place stringent limits on the amount of dust in this planetary system, and argue against the existence of a detectable circumstellar dust disk around 55 Cnc.Comment: 11 pages, 2 PostScript figures, to appear in The Astrophysical Journal Letter

Far-infrared and sub-millimetre imaging of HD 76582's circumstellar disc

Debris discs, the tenuous rocky and icy remnants of planet formation, are believed to be evidence for planetary systems around other stars. The JCMT/SCUBA-2 debris disc legacy survey ‘SCUBA-2 Observations of Nearby Stars’ (SONS) observed 100 nearby stars, amongst them HD 76582, for evidence of such material. Here, we present imaging observations by JCMT/SCUBA-2 and Herschel/PACS at sub-millimetre and far-infrared wavelengths, respectively. We simultaneously model the ensemble of photometric and imaging data, spanning optical to sub-millimetre wavelengths, in a self-consistent manner. At far-infrared wavelengths, we find extended emission from the circumstellar disc providing a strong constraint on the dust spatial location in the outer system, although the angular resolution is too poor to constrain the interior of the system. In the sub-millimetre, photometry at 450 and 850 µm reveals a steep fall-off that we interpret as a disc dominated by moderately sized dust grains (amin = 36 µm), perhaps indicative of a non-steady-state collisional cascade within the disc. A disc architecture of three distinct annuli, comprising an unresolved component at 20 au and outer components at 80 and 270 au, along with a very steep particle size distribution (γ = 5), is proposed to match the observations

Dust in the 55 Cancri planetary system

The presence of debris disks around $\sim$ 1-Gyr-old main sequence stars suggests that an appreciable amount of dust may persist even in mature planetary systems. Here we report the detection of dust emission from 55 Cancri, a star with one, or possibly two, planetary companions detected through radial velocity measurements. Our observations at 850$\mu$m and 450$\mu$m imply a dust mass of 0.0008-0.005 Earth masses, somewhat higher than that in the the Kuiper Belt of our solar system. The estimated temperature of the dust grains and a simple model fit both indicate a central disk hole of at least 10 AU in radius. Thus, the region where the planets are detected is likely to be significantly depleted of dust. Our results suggest that far-infrared and sub-millimeter observations are powerful tools for probing the outer regions of extrasolar planetary systems.Comment: 8 pages and 2 figures, to appear in the Astrophysical Journa

Subchondral osteopenia and accelerated bone remodelling post-ovariectomy - a possible mechanism for subchondral microfractures in the aetiology of spontaneous osteonecrosis of the knee?

Osteopenia and subchondral microfractures are implicated in the aetiology of spontaneous osteonecrosis of the knee. The ovine tibia shows significant alterations of the trabecular architecture within the subchondral bone of the medial tibial plateau post-ovariectomy, including reduced trabecular bone volume fraction. We hypothesise that accelerated subchondral bone resorption may also play a role in increasing microfracture risk at this site. 23 sheep were examined in this study; 10 of the sheep underwent ovariectomy (OVX), while the remainder (n=13) were kept as controls (CON). Five fluorochrome dyes were administered intravenously at 12 week intervals via the jugular vein to both groups, to label sites of bone turnover. These animals were then sacrificed at 12 months post-operatively. Bone turnover was significantly increased in the OVX group in both trabecular bone (2.024 vs. 1.047, p = 0.05) and within the subchondral bone plate (4.68 vs. 0.69 # / mm2; p \u3c 0.001). In addition to the classically-described turnover visible along trabecular surfaces, we also found visual evidence of intra-trabecular osteonal remodelling. In conclusion, this study shows significant alterations in bone turnover in both trabecular bone and within the subchondral bone plate at one-year post-ovariectomy. Remodelling of trabecular bone was due to both classically described hemi-osteonal and intra-trabecular osteonal remodelling. The presence of both localised osteopenia and accelerated bone remodelling within the medial tibial plateau provide a possible mechanism for subchondral microfractures in the aetiology of spontaneous osteonecrosis of the knee. Further utilisation of the ovariectomised ewe may be useful for further study in this field

New constraints on the millimetre emission of six debris discs

The presence of dusty debris around main-sequence stars denotes the existence of planetary systems. Such debris discs are often identified by the presence of excess continuum emission at infrared and (sub-)millimetre wavelengths, with measurements at longer wavelengths tracing larger and cooler dust grains. The exponent of the slope of the disc emission at submillimetre wavelengths, ‘q’, defines the size distribution of dust grains in the disc. This size distribution is a function of the rigid strength of the dust producing parent planetesimals. As a part of the survey ‘PLAnetesimals around TYpical Pre-main seqUence Stars’, we observed six debris discs at 9 mm using the Australian Telescope Compact Array. We obtain marginal (∼3σ) detections of three targets: HD 105, HD 61005 and HD 131835. Upper limits for the three remaining discs, HD 20807, HD 109573 and HD 109085 provide further constraint of the (sub-)millimetre slope of their spectral energy distributions. The values of q (or their limits) derived from our observations are all smaller than the oft-assumed steady-state collisional cascade model (q = 3.5), but lie well within the theoretically expected range for debris discs q ∼ 3–4. The measured q values for our targets are all <3.3, consistent with both collisional modelling results and theoretical predictions for parent planetesimal bodies being ‘rubble piles’ held together loosely by their self-gravity

Delivering word retrieval therapies for people with aphasia in a virtual communication environment

Background: Delivering therapy remotely, via digital technology, can enhance provision for people with aphasia. EVA Park is a multi-user virtual island that can be used for such delivery. The first EVA Park study showed that daily language stimulation delivered via the platform improved functional communication and was positively received by users (Marshall et al, 2016; Amaya et al, 2018). This paper reports two single case studies, evaluating its capacity to deliver targeted language interventions. The first employed therapy for noun retrieval, using cued picture naming and modified Sematic Feature Analysis. The second employed modified Verb Network Strengthening Treatment (VNeST). Aims: This study aimed to determine if treatment delivery was feasible in EVA Park, as assessed by participant compliance, treatment fidelity and participants’ views. It explored the impact of the therapies on treated and untreated word production, connected speech and functional communication. Methods & Procedures: Two participants with aphasia each received 20 sessions of individual therapy in EVA Park, delivered over 5 weeks. Feasibility was assessed by measuring compliance with the therapy regime, recording and checking the fidelity of 20% of treatment sessions, and using post therapy interviews to explore participant views. Treatment outcomes were evaluated via repeated measures single case designs, in which assessments were administered twice before therapy, immediately post therapy and five weeks later. Outcome measures included Object Picture Naming (study 1), Sentence Elicitation Pictures (study 2), Naming 84 items from the Object and Action Naming Battery (study 2), Narrative Production (Study 2), the Northwestern Assessment of Verb and Sentences: Argument Structure Production Test (Study 2) and Communication Activities of Daily Living – 2 (Study 1 & 2). Outcomes & Results: Feasibility results were excellent. Both participants were fully compliant with the therapy regime. There was at least 90% fidelity with the treatment protocols and participant views were positive. Outcomes varied across the studies. The noun therapy significantly improved the naming of treated words, with good maintenance. Lexical gains were less evident on the Sentence Elicitation Pictures used in the VNeST study. Neither study demonstrated generalisation to untreated words, connected speech or functional communication. Conclusions: Two treatment approaches, designed for face to face delivery, could be delivered remotely in EVA Park. Outcomes for the noun treatment were comparable to previous evaluations. Comparisons with previous research were more challenging for VNeST, owing to differences in methodology. Further evaluations of other treatment approaches are warranted