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

Pre-surgical Caregiver Burden and Anxiety Are Associated with Post-Surgery Cortisol over the Day in Caregivers of Coronary Artery Bypass Graft Surgery Patients.

BACKGROUND: The relationship between pre-surgical distress and diurnal cortisol following surgery has not been investigated prospectively in caregivers of coronary artery bypass graft (CABG) patients before. We aimed to examine the relationship between pre-surgical anxiety and caregiver burden and diurnal cortisol measured 2 months after the surgery in the caregivers of CABG patients. METHOD: We used a sample of 103 caregivers of elective CABG patients that were assessed 28.86 days before and 60.94 days after patients' surgery. Anxiety and caregiver burden were assessed using the anxiety subscale of the Hospital Anxiety and Depression Scale and the Oberst Burden Scale respectively. Saliva samples were collected to measure cortisol area under the curve with respect to ground (AUCg) and diurnal cortisol slope. Anxiety and caregiver burden were entered into linear regression models simultaneously. RESULTS: While high levels of pre-surgical anxiety were positively associated with increased follow-up levels of AUCg (β = 0.30, p = 0.001), greater pre-surgery perceived burden score was associated with steeper cortisol slope (β = 0.27, p = 0.017) after controlling for a wide range of covariates. CONCLUSION: These outcomes support the utility of psychological interventions aimed to increase the awareness of caregiving tasks and demands in informal caregivers

Evaluation of selected chemical processes for production of low-cost silicon phase 2. silicon material task, low-cost silicon solar array project

Progress from October 1, 1977, through December 31, 1977, is reported in the design of the 50 MT/year experimental facility for the preparation of high purity silicon by the zinc vapor reduction of silicon tetrachloride in a fluidized bed of seed particles to form a free flowing granular product

Coulomb-Driven Cluster-Glass Behavior in Mn-Intercalated Ti1+yS2

We have investigated the low-temperature spin-glasslike phase in the intercalated transition-metal dichalcogenide Mn0.09Ti1.1S2. A departure from Curie–Weiss behavior in the paramagnetic regime indicated the formation of small ferromagnetically correlated clusters. The Vogel–Fulcher law provided an excellent description of relaxation times in the vicinity of the transition, showing that the glasslike phase occurs due to interaction between the clusters. Cole–Cole plots for data close to the transition were linear, which is consistent with a simple exponential distribution of cluster sizes. A Monte Carlo simulation of the dichalcogenide system, including excess self-intercalated Ti ions, gave an exponential cluster-size distribution for a relatively narrow range of concentration values of Mn and Ti ions, values that were consistent with those of the Mn0.09Ti1.1S2 sample. Strong commonality in the relaxation behavior with certain ferroelectric relaxor systems suggests underlying similarity in the microscopic structure of the clusters in both systems, which may be chainlike or quasi-one-dimensional

Polysorbate 80 Inhibition of Pseudomonas aeruginosa Biofilm Formation and Its Cleavage by the Secreted Lipase LipA

Surface-associated bacterial communities known as biofilms are an important source of nosocomial infections. Microorganisms such as Pseudomonas aeruginosa can colonize the abiotic surfaces of medical implants, leading to chronic infections that are difficult to eradicate. Our study demonstrates that polysorbate 80 (PS80), a surfactant commonly added to food and medicines, is able to inhibit biofilm formation by P. aeruginosa on a variety of surfaces, including contact lenses

Population Stratification of a Common APOBEC Gene Deletion Polymorphism

The APOBEC3 gene family plays a role in innate cellular immunity inhibiting retroviral infection, hepatitis B virus propagation, and the retrotransposition of endogenous elements. We present a detailed sequence and population genetic analysis of a 29.5-kb common human deletion polymorphism that removes the APOBEC3B gene. We developed a PCR-based genotyping assay, characterized 1,277 human diversity samples, and found that the frequency of the deletion allele varies significantly among major continental groups (global F (ST) = 0.2843). The deletion is rare in Africans and Europeans (frequency of 0.9% and 6%), more common in East Asians and Amerindians (36.9% and 57.7%), and almost fixed in Oceanic populations (92.9%). Despite a worldwide frequency of 22.5%, analysis of data from the International HapMap Project reveals that no single existing tag single nucleotide polymorphism may serve as a surrogate for the deletion variant, emphasizing that without careful analysis its phenotypic impact may be overlooked in association studies. Application of haplotype-based tests for selection revealed potential pitfalls in the direct application of existing methods to the analysis of genomic structural variation. These data emphasize the importance of directly genotyping structural variation in association studies and of accurately resolving variant breakpoints before proceeding with more detailed population-genetic analysis

A Variant in a MicroRNA complementary site in the 3' UTR of the KIT oncogene increases risk of acral melanoma.

MicroRNAs (miRNAs) are small ∼22nt single stranded RNAs that negatively regulate protein expression by binding to partially complementary sequences in the 3' untranslated region (3' UTRs) of target gene messenger RNAs (mRNA). Recently, mutations have been identified in both miRNAs and target genes that disrupt regulatory relationships, contribute to oncogenesis and serve as biomarkers for cancer risk. KIT, an established oncogene with a multifaceted role in melanogenesis and melanoma pathogenesis, has recently been shown to be upregulated in some melanomas, and is also a target of the miRNA miR-221. Here, we describe a genetic variant in the 3' UTR of the KIT oncogene that correlates with a greater than fourfold increased risk of acral melanoma. This KIT variant results in a mismatch in the seed region of a miR-221 complementary site and reporter data suggests that this mismatch can result in increased expression of the KIT oncogene. Consistent with the hypothesis that this is a functional variant, KIT mRNA and protein levels are both increased in the majority of samples harboring the KIT variant. This work identifies a novel genetic marker for increased heritable risk of melanoma

Measurement of the half-life of the T=12\frac{1}{2} mirror decay of 19^{19}Ne and its implication on physics beyond the standard model

The $\frac{1}{2}^+ \rightarrow \frac{1}{2}^+$ superallowed mixed mirror decay of $^{19}$Ne to $^{19}$F is excellently suited for high precision studies of the weak interaction. However, there is some disagreement on the value of the half-life. In a new measurement we have determined this quantity to be $T_{1/2}$ = $17.2832 \pm 0.0051_{(stat)}$ $\pm 0.0066_{(sys)}$ s, which differs from the previous world average by 3 standard deviations. The impact of this measurement on limits for physics beyond the standard model such as the presence of tensor currents is discussed.Comment: 5 pages, 3 figures, 1 tabl