Virtual patient design : exploring what works and why : a grounded theory study

Objectives: Virtual patients (VPs) are online representations of clinical cases used in medical education. Widely adopted, they are well placed to teach clinical reasoning skills. International technology standards mean VPs can be created, shared and repurposed between institutions. A systematic review has highlighted the lack of evidence to support which of the numerous VP designs may be effective, and why. We set out to research the influence of VP design on medical undergraduates. Methods: This is a grounded theory study into the influence of VP design on undergraduate medical students. Following a review of the literature and publicly available VP cases, we identified important design properties. We integrated them into two substantial VPs produced for this research. Using purposeful iterative sampling, 46 medical undergraduates were recruited to participate in six focus groups. Participants completed both VPs, an evaluation and a 1-hour focus group discussion. These were digitally recorded, transcribed and analysed using grounded theory, supported by computer-assisted analysis. Following open, axial and selective coding, we produced a theoretical model describing how students learn from VPs. Results: We identified a central core phenomenon designated ‘learning from the VP’. This had four categories: VP Construction; External Preconditions; Student–VP Interaction, and Consequences. From these, we constructed a three-layer model describing the interactions of students with VPs. The inner layer consists of the student's cognitive and behavioural preconditions prior to sitting a case. The middle layer considers the VP as an ‘encoded object’, an e-learning artefact and as a ‘constructed activity’, with associated pedagogic and organisational elements. The outer layer describes cognitive and behavioural change. Conclusions: This is the first grounded theory study to explore VP design. This original research has produced a model which enhances understanding of how and why the delivery and design of VPs influence learning. The model may be of practical use to authors, institutions and researchers

Young mothers in care, contributing to the contemporary debate

Teenage pregnancy has become a broad issue in contemporary society and has become a focus for concern for young women in or exiting the care system. The article draws on interviews with twenty-four young mothers in, or on the fringes of the care system. It highlights the thoughts and feelings of these young women, specifically looking at the relationships that they have with their mothers, the father of their baby and their social workers. The mothers' sources of support and their perceptions of these are discussed. Implications for practice for working with this discrete group of young mothers are explored

Fitting measured evapotranspiration data to the FAO56 dual crop coefficient method

The FAO-56 publication of the UN Food and Agriculture Organization contains guidelines on constructing and applying a ‘dual crop coefficient’ method to characterize the behavior of evapotranspiration (ET) on a day to day basis. The dual crop coefficient (Kc) method substantially improves the ability to fit simulated with measured data, as compared to the ‘single’ Kc method, by partitioning evaporation from soil (Es) from transpiration from vegetation. This permits the separate estimation of Es when there are known wetting events from precipitation and irrigation and assists in explaining behavior of measured data. The application of the dual Kc method is relatively straight forward, especially when applied using the straight-line segment method for the basal Kc curve, Kcb. Illustrations are given on fitting the dual Kc method and Kcb curve to daily ET data for irrigated and rainfed corn crops near Mead, Nebraska measured by eddy covariance and sensitivity to various soil and root zone parameters. Assessment of transferring Kcb curve parameters to other fields and years indicates that soil and root zone parameters are relatively transferrable with little modification, whereas lengths of the four crop growth stages do vary from year to year due to differences in cultivar type and possibly differences in weather

Identifying Behavioral Phenotypes and Heterogeneity in Heart Valve Surface Endothelium

Heart valvular endothelial cells (VECs) are distinct from vascular endothelial cells (ECs), but have an uncertain context within the spectrum of known endothelial phenotypes, including lymphatic ECs (LECs). Profiling the phenotypes of the heart valve surface VECs would facilitate identification of a proper seeding population for tissue-engineered valves, as well as elucidate mechanisms of valvular disease. Porcine VECs and porcine aortic ECs (AECs) were isolated from pig hearts and characterized to assess known EC and LEC markers. A transwell migration assay determined their propensity to migrate toward vascular endothelial growth factor, an angiogenic stimulus, over 24 h. Compared to AECs, Flt-1 was expressed on almost double the percentage of VECs, measured as 74 versus 38%. The expression of angiogenic EC markers CXCR4 and DLL4 was >90% on AECs, whereas VECs showed only 35% CXCR4+ and 47% DLL4+. AECs demonstrated greater migration (71.5 ± 11.0 cells per image field) than the VECs with 30.0 ± 15.3 cells per image field (p = 0.032). In total, 30% of VECs were positive for LYVE1+/Prox1+, while these markers were absent in AECs. In conclusion, the population of cells on the surface of heart valves is heterogeneous, consisting largely of nonangiogenic VECs and a subset of LECs. Previous studies have indicated the presence of LECs within the interior of the valves; however, this is the first study to demonstrate their presence on the surface. Identification of this unique endothelial mixture is a step forward in the development of engineered valve replacements as a uniform EC seeding population may not be the best option to maximize transplant success

Faking it for the higher-ups: Status and surface acting in workplace meetings

Recent evidence suggests that surface acting occurs in workplace meetings. Even in light of these findings, it remains unknown why employees would choose to surface act in meetings with their colleagues and supervisors, and how this form of emotion regulation affects employees in the short-term. A sample of working adults were asked to report their levels of surface acting during multiple workplace meetings. Results indicate that employees engage in surface acting during meetings, and that their surface acting is positively related to the presence of higher-status attendees in these meetings. Additionally, surface acting during meetings is negatively related to perceptions of both meeting psychological safety and meeting effectiveness. We also highlight the important role of one’s job level as a moderating condition when examining the relationship between surface acting and perceived meeting effectiveness. Our results suggest that individuals who are higher-up in an organization’s hierarchy may perceive meetings as less effective when they surface act when compared to individuals who are in lower levels of the organization

Constraints on Cosmic Strings due to Black Holes Formed from Collapsed Cosmic String Loops

The cosmological features of primordial black holes formed from collapsed cosmic string loops are studied. Observational restrictions on a population of primordial black holes are used to restrict $f$, the fraction of cosmic string loops which collapse to form black holes, and $\mu$, the cosmic string mass-per-unit-length. Using a realistic model of cosmic strings, we find the strongest restriction on the parameters $f$ and $\mu$ is due to the energy density in $100 MeV$ photons radiated by the black holes. We also find that inert black hole remnants cannot serve as the dark matter. If earlier, crude estimates of $f$ are reliable, our results severely restrict $\mu$, and therefore limit the viability of the cosmic string large-scale structure scenario.Comment: (Plain Tex, uses tables.tex -- wrapped lines corrected), 11 pages, FERMILAB-Pub-93/137-

Comparing the Role of Mechanical Forces in Vascular and Valvular Calcification Progression

Calcification is a prevalent disease in most fully developed countries and is predominantly observed in heart valves and nearby vasculature. Calcification of either tissue leads to deterioration and, ultimately, failure causing poor quality of life and decreased overall life expectancy in patients. In valves, calcification presents as Calcific Aortic Valve Disease (CAVD), in which the aortic valve becomes stenotic when calcific nodules form within the leaflets. The initiation and progression of these calcific nodules is strongly influenced by the varied mechanical forces on the valve. In turn, the addition of calcific nodules creates localized disturbances in the tissue biomechanics, which affects extracellular matrix (ECM) production and cellular activation. In vasculature, atherosclerosis is the most common occurrence of calcification. Atherosclerosis exhibits as calcific plaque formation that forms in juxtaposition to areas of low blood shear stresses. Research in these two manifestations of calcification remain separated, although many similarities persist. Both diseases show that the endothelial layer and its regulation of nitric oxide is crucial to calcification progression. Further, there are similarities between vascular smooth muscle cells and valvular interstitial cells in terms of their roles in ECM overproduction. This review summarizes valvular and vascular tissue in terms of their basic anatomy, their cellular and ECM components and mechanical forces. Calcification is then examined in both tissues in terms of disease prediction, progression, and treatment. Highlighting the similarities and differences between these areas will help target further research toward disease treatment

Deep Learning for Neuroimaging: a Validation Study

Deep learning methods have recently made notable advances in the tasks of classification and representation learning. These tasks are important for brain imaging and neuroscience discovery, making the methods attractive for porting to a neuroimager’s toolbox. Success of these methods is, in part, explained by the flexibility of deep learning models. However, this flexibility makes the process of porting to new areas a difficult parameter optimization problem. In this work we demonstrate our results (and feasible parameter ranges) in application of deep learning methods to structural and functional brain imaging data. These methods include deep belief networks and their building block the restricted Boltzmann machine. We also describe a novel constraint-based approach to visualizing high dimensional data. We use it to analyze the effect of parameter choices on data transformations. Our results show that deep learning methods are able to learn physiologically important representations and detect latent relations in neuroimaging data

Peripheral Innate Immune Activation Correlates With Disease Severity in GRN Haploinsufficiency.

Objective: To investigate associations between peripheral innate immune activation and frontotemporal lobar degeneration (FTLD) in progranulin gene (GRN) haploinsufficiency. Methods: In this cross-sectional study, ELISA was used to measure six markers of innate immunity (sCD163, CCL18, LBP, sCD14, IL-18, and CRP) in plasma from 30 GRN mutation carriers (17 asymptomatic, 13 symptomatic) and 29 controls. Voxel based morphometry was used to model associations between marker levels and brain atrophy in mutation carriers relative to controls. Linear regression was used to model relationships between plasma marker levels with mean frontal white matter integrity [fractional anisotropy (FA)] and the FTLD modified Clinical Dementia Rating Scale sum of boxes score (FTLD-CDR SB). Results: Plasma sCD163 was higher in symptomatic GRN carriers [mean 321 ng/ml (SD 125)] compared to controls [mean 248 ng/ml (SD 58); p < 0.05]. Plasma CCL18 was higher in symptomatic GRN carriers [mean 56.9 pg/ml (SD 19)] compared to controls [mean 40.5 pg/ml (SD 14); p < 0.05]. Elevation of plasma LBP was associated with white matter atrophy in the right frontal pole and left inferior frontal gyrus (p FWE corrected <0.05) in all mutation carriers relative to controls. Plasma LBP levels inversely correlated with bilateral frontal white matter FA (R2 = 0.59, p = 0.009) in mutation carriers. Elevation in plasma was positively correlated with CDR-FTLD SB (b = 2.27 CDR units/μg LBP/ml plasma, R2 = 0.76, p = 0.003) in symptomatic carriers. Conclusion: FTLD-GRN is associated with elevations in peripheral biomarkers of macrophage-mediated innate immunity, including sCD163 and CCL18. Clinical disease severity and white matter integrity are correlated with blood LBP, suggesting a role for peripheral immune activation in FTLD-GRN