Mechanisms of postcardiac surgery atrial fibrillation: more pieces in a difficult puzzle

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Applications of finite element computer modelling and thermal infrared remote sensing to the study of geothermal anomalies

Buried heat sources can be investigated by examining thermal infrared images and comparing these with the results of theoretical models which predict the thermal anomaly a given heat source may generate. Key factors influencing surface temperature include the geometry and temperature of the heat source, the surface meteorological environment, and the thermal conductivity and anisotropy of the rock. In general, a geothermal heat flux of greater than 2% of solar insolation is required to produce a detectable thermal anomaly in a thermal infrared image. A heat source of, for example, 2-300K greater than the average surface temperature must be a t depth shallower than 50m for the detection of the anomaly in a thermal infrared image, for typical terrestrial conditions. Atmospheric factors are of critical importance. While the mean atmospheric temperature has little significance, the convection is a dominant factor, and can act to swamp the thermal signature entirely. Given a steady state heat source that produces a detectable thermal anomaly, it is possible to loosely constrain the physical properties of the heat source and surrounding rock, using the surface thermal anomaly as a basis. The success of this technique is highly dependent on the degree to which the physical properties of the host rock are known. Important parameters include the surface thermal properties and thermal conductivity of the rock. Modelling of transient thermal situations was carried out, to assess the effect of time dependant thermal fluxes. One-dimensional finite element models can be readily and accurately applied to the investigation of diurnal heat flow, as with thermal inertia models. Diurnal thermal models of environments on Earth, the Moon and Mars were carried out using finite elements and found to be consistent with published measurements. The heat flow from an injection of hot lava into a near surface lava tube was considered. While this approach was useful for study, and long term monitoring in inhospitable areas, it was found to have little hazard warning utility, as the time taken for the thermal energy to propagate to the surface in dry rock (several months) in very long. The resolution of the thermal infrared imaging system is an important factor. Presently available satellite based systems such as Landsat (resolution of 120m) are inadequate for detailed study of geothermal anomalies. Airborne systems, such as TIMS (variable resolution of 3-6m) are much more useful for discriminating small buried heat sources. Planned improvements in the resolution of satellite based systems will broaden the potential for application of the techniques developed in this thesis. It is important to note, however, that adequate spatial resolution is a necessary but not sufficient condition for successful application of these techniques

Uptake and usage of Virtual Learning Environments in the Irish tertiary sector: findings from a multi-institutional student usage survey

In early 2008 Six Irish tertiary institutions conducted an online survey of their students usage of Virtual Learning Environments in their respective institutions. The survey used a common set of questions. Five of these institutions have, on condition of anonymity, pooled their results for comparison and study and this paper presents the findings of this research. The five institutions represent a diversity of organisational histories and VLE systems. It is often assumed that technology issues are a key driver of VLE uptake and usage, however, the data indicates that these technical issues have relatively little effect on the ground. Organisational factors, such as the maturity of the implementation, are shown to have a more substantial effect on uptake, usage and utility of the systems. The paper also discusses issues around the conduct of the survey, confidentiality and data sharing, and the potential for ongoing surveys to build into a longitudinal data set

Sleep-related memory consolidation in the psychosis spectrum phenotype

Sleep and memory processing impairments range from mild to severe in the psychosis spectrum. Relationships between memory processing and sleep characteristics have been described for schizophrenia, including unaffected first-degree relatives, but they are less clear across other high-risk groups within the psychosis spectrum. In this study, we investigated high-risk individuals with accumulated risk-factors for psychosis and subthreshold symptoms. Out of 1898 screened individuals, 44 age- and sex-matched participants were sub-grouped into those with substantial environmental risk factors for psychosis and subthreshold psychotic symptoms (high-risk group) and those without these phenotypes (low-risk controls). Four groups (high/low risk, morning/evening training) were trained and tested in the laboratory for sustained attention, motor skill memory (finger-tapping task) and declarative memory (word-pair learning task) immediately after training, again after a night of EEG-recorded sleep at home or a period of daytime wakefulness, and again after 24 h from training. No differences in sustained attention or in memory consolidation of declarative and motor skill memory were found between groups for any time period tested. However, a group difference was found for rapid-eye movement (REM) sleep in relation to motor skill memory: the longer the total sleep time, particularly longer REM sleep, the greater the performance gain, which occurred only in high-risk individuals. In conclusion, our results suggest a gain in motor skill performance with sufficient sleep opportunity for longer REM sleep in high-risk individuals with subthreshold psychotic symptoms. Declarative memory did not benefit from sleep consolidation above or beyond that of the control group

Clinical utility of the Mood and Anxiety Symptom Questionnaire (MASQ) in a sample of young help-seekers

<p>Abstract</p> <p>Background</p> <p>The overlap between Depression and Anxiety has led some researchers to conclude that they are manifestations of a broad, non-specific neurotic disorder. However, others believe that they can be distinguished despite sharing symptoms of general distress. The Tripartite Model of Affect proposes an anxiety-specific, a depression-specific and a shared symptoms factor. Watson and Clark developed the Mood and Anxiety Symptom Questionnaire (MASQ) to specifically measure these Tripartite constructs. Early research showed that the MASQ distinguished between dimensions of Depression and Anxiety in non-clinical samples. However, two recent studies have cautioned that the MASQ may show limited validity in clinical populations. The present study investigated the clinical utility of the MASQ in a clinical sample of adolescents and young adults.</p> <p>Methods</p> <p>A total of 204 Young people consecutively referred to a specialist public mental health service in Melbourne, Australia were approached and 150 consented to participate. From this, 136 participants completed both a diagnostic interview and the MASQ.</p> <p>Results</p> <p>The majority of the sample rated for an Axis-I disorder, with Mood and Anxiety disorders most prevalent. The disorder-specific scales of the MASQ significantly discriminated Anxiety (61.0%) and Mood Disorders (72.8%), however, the predictive accuracy for presence of Anxiety Disorders was very low (29.8%). From ROC analyses, a proposed cut-off of 76 was proposed for the depression scale to indicate 'caseness' for Mood Disorders. The resulting sensitivity/specificity was superior to that of the CES-D.</p> <p>Conclusion</p> <p>It was concluded that the depression-specific scale of the MASQ showed good clinical utility, but that the anxiety-specific scale showed poor discriminant validity.</p

Imagining the impossible before breakfast: the relation between creativity, dissociation, and sleep

Dissociative symptoms have been related to higher rapid eye movement sleep density, a sleep phase during which hyperassociativity may occur. This may enhance artistic creativity during the day. To test this hypothesis, we conducted a creative photo contest to explore the relation between dissociation, sleep, and creativity. During the contest, participants (N = 72) took one photo per day for five consecutive days, based on specific daily themes (consisting of single words) and the instruction to take as creative a photo as possible each day. Furthermore, they completed daily measures of state dissociation and a short sleep diary The photos and their captions were ranked by two professional photographers and two clinical psychologists based on creativity, originality, bizarreness, and quality. We expected that dissociative people would rank higher in the contest compared with low-dissociative participants, and that the most original photos would be taken on days when the participants scored highest on acute dissociation. We found that acute dissociation predicted a higher ranking on creativity. Poorer sleep quality and fewer hours of sleep predicted more bizarreness in the photos and captions. None of the trait measures could predict creativity. In sum, acute dissociation related to enhanced creativity. These findings contribute to our understanding of dissociative symptomatology

A factor analytic investigation of the Tripartite model of affect in a clinical sample of young Australians

<p>Abstract</p> <p>Background</p> <p>The Mood and Anxiety Symptom Questionnaire (MASQ) was designed to specifically measure the Tripartite model of affect and is proposed to offer a delineation between the core components of anxiety and depression. Factor analytic data from adult clinical samples has shown mixed results; however no studies employing confirmatory factor analysis (CFA) have supported the predicted structure of distinct Depression, Anxiety and General Distress factors. The Tripartite model has not been validated in a clinical sample of older adolescents and young adults. The aim of the present study was to examine the validity of the Tripartite model using scale-level data from the MASQ and correlational and confirmatory factor analysis techniques.</p> <p>Methods</p> <p>137 young people (M = 17.78, SD = 2.63) referred to a specialist mental health service for adolescents and young adults completed the MASQ and diagnostic interview.</p> <p>Results</p> <p>All MASQ scales were highly inter-correlated, with the lowest correlation between the depression- and anxiety-specific scales (r = .59). This pattern of correlations was observed for all participants rating for an Axis-I disorder but not for participants without a current disorder (r = .18). Confirmatory factor analyses were conducted to evaluate the model fit of a number of solutions. The predicted Tripartite structure was not supported. A 2-factor model demonstrated superior model fit and parsimony compared to 1- or 3-factor models. These broad factors represented Depression and Anxiety and were highly correlated (r = .88).</p> <p>Conclusion</p> <p>The present data lend support to the notion that the Tripartite model does not adequately explain the relationship between anxiety and depression in all clinical populations. Indeed, in the present study this model was found to be inappropriate for a help-seeking community sample of older adolescents and young adults.</p

Defining a new standard for IVUS optimized drug eluting stent implantation: The PRAVIO study

ObjectivesPreliminary Investigation to the Angiographic Versus IVUS Optimization Trial is a single center prospective observational intravascular ultrasound (IVUS) guided stent implantation study assessing new criteria for optimal drug eluting stent (DES) deployment.BackgroundIVUS assessment of DES often reveals underexpansion and malapposition. Optimal stent deployment is currently poorly defined and previous criteria may not be suitable in long and complex lesions.MethodsOptimization was defined as achieving &gt;/or 70% of the cross-sectional area (CSA) of the postdilation balloon. This criterion was applied in 113 complex lesions. The size of this balloon was calculated according to vessel media-to-media diameters at various sites inside the stented segment. The IVUS guided treated lesions were matched according to diabetes, vessel type, reference vessel diameter, minimum lumen diameter (MLD), and lesion length with a group of angiographic treated lesions to compare final MLD achieved.ResultsMean minimum stent CSA according to the postdilation balloon utilized was 4.62 mm(2), 6.26 mm(2), 7.87 mm(2), and 9.87 mm(2) for 2.5 mm, 3.0 mm, 3.5 mm, and 4 mm balloons, respectively. Final MLD (mm) was significantly larger in the IVUS compared to the angiographic-guided group (3.09 +/- 0.50 vs. 2.67 +/- 0.54; P &lt; 0.0001). There were no procedural complications related to IVUS use.ConclusionsWe propose new IVUS criteria based on vessel remodeling that results in an increment in the final MLD, compared to angiographic guidance, which is much larger than any previously published study. This criterion seems to be safely achievable. A proposed randomized study (angiographic vs. IVUS optimization trial) has been launched to test these concepts

The Grizzly, October 7, 1983

Career Workshops Held • What\u27s in a Name • Fago Opens Lecture Series • Lantern Makes National Anthology • Campus Memo • Letters to the Editor • Red and Gold Days Inaugurated • Sorority Pledging Underway • Half-Price Student Rushes for Genty! • Keep it Clean • Renaissance Play at Ursinus Commemoration • ATO Incident at Penn • Politics Sells Papers • Yearbook Sale Begins Monday • Ursinus Soccer Romps Over Hopkins • Volleyball Scores Second Victory • Grizzlies Fall to Swarthmorehttps://digitalcommons.ursinus.edu/grizzlynews/1103/thumbnail.jp