Zoning of mucosal phenotype, dysplasia, and telomerase activity measured by telomerase repeat assay protocol in Barrett's esophagus

Glandular dysplasia in Barrett's esophagus may regress spontaneously but can also progress to cancer. The human telomerase RNA template and the human telomerase reverse transcriptase enzyme which do not, of themselves, correlate strongly with telomerase activity, are too often overexpressed in Barrett's dysplasia to predict individual cancer risk. This study relates telomerase activity, mucosal phenotype, and dysplasia in Barrett's esophagus. Biopsies (n = 256) from squamous esophagus, columnar-lined esophagus every 2 cm, esophago-gastric junction, gastric body, and antrum from 32 patients with long-segment Barrett's esophagus were evaluated by telomerase repeat assay protocol (TRAP). Three biopsies for histology (n = 794) were simultaneously taken at each anatomical level. These and all prior and subsequent biopsies (n = 1917) were reviewed for mucosal phenotypes and dysplasia severity. Intestinal-type Barrett's mucosa was present at all levels in Barrett's esophagus. At least one Barrett's biopsy was TRAP(+) in 22 of 32 patients. TRAP positivity of intestinal-type Barrett's mucosa increased distally, possibly as a consequence of mucosal exposure to acid or bile reflux. Native gastric mucosa was rarely TRAP(+) (1/31 corpus, 2/32 antrum), whereas native squamous mucosa usually was TRAP(+) (31/32). Dysplasia almost always involved intestinal-type Barrett's mucosa (85/87; P</p

A parameter-free total Lagrangian smooth particle hydrodynamics algorithm applied to problems with free surfaces

This paper presents a new Smooth Particle Hydrodynamics computational framework for the solution of inviscid free surface flow problems. The formulation is based on the Total Lagrangian description of a system of first-order conservation laws written in terms of the linear momentum and the Jacobian of the deformation. One of the aims of this paper is to explore the use of Total Lagrangian description in the case of large deformations but without topological changes. In this case, the evaluation of spatial integrals is carried out with respect to the initial undeformed configuration, yielding an extremely efficient formulation where the need for continuous particle neighbouring search is completely circumvented. To guarantee stability from the SPH discretisation point of view, consistently derived Riemann-based numerical dissipation is suitably introduced where global numerical entropy production is demonstrated via a novel technique in terms of the time rate of the Hamiltonian of the system. Since the kernel derivatives presented in this work are fixed in the reference configuration, the non-physical clumping mechanism is completely removed. To fulfil conservation of the global angular momentum, a posteriori (least-squares) projection procedure is introduced. Finally, a wide spectrum of dedicated prototype problems is thoroughly examined. Through these tests, the SPH methodology overcomes by construction a number of persistent numerical drawbacks (e.g. hour-glassing, pressure instability, global conservation and/or completeness issues) commonly found in SPH literature, without resorting to the use of any ad-hoc user-defined artificial stabilisation parameters. Crucially, the overall SPH algorithm yields equal second order of convergence for both velocities and pressure

SMART Research: Toward Interdisciplinary River Science in Europe

Interdisciplinary science is rapidly advancing to address complex human-environment interactions. River science aims to provide the methods and knowledge required to sustainably manage some of the planet’s most important and vulnerable ecosystems; and there is a clear need for river managers and scientists to be trained within an interdisciplinary approach. However, despite the science community’s recognition of the importance of interdisciplinary training, there are few studies examining interdisciplinary graduate programs, especially in science and engineering. Here we assess and reflect on the contribution of a 9-year European doctoral program in river science: ‘Science for MAnagement of Rivers and their Tidal Systems’ Erasmus Mundus Joint Doctorate (SMART EMJD). The program trained a new generation of 36 early career scientists under the supervision of 34 international experts from different disciplinary and interdisciplinary research fields focusing on river systems, aiming to transcend the boundaries between disciplines and between science and management. We analyzed the three core facets of the SMART program, namely: (1) interdisciplinarity, (2) internationalism, and (3) management-oriented science. We reviewed the contents of doctoral theses and publications and synthesized the outcomes of two questionnaire surveys conducted with doctoral candidates and supervisors. A high percentage of the scientific outputs (80%) were interdisciplinary. There was evidence of active collaboration between different teams of doctoral candidates and supervisors, in terms of joint publications (5 papers out of the 69 analyzed) but this was understandably quite limited given the other demands of the program. We found evidence to contradict the perception that interdisciplinarity is a barrier to career success as employment rates were high (97%) and achieved very soon after the defense, both in academia (50%) and the private/public sector (50%) with a strong international dimension. Despite management-oriented research being a limited (9%) portion of the ensemble of theses, employment in management was higher (22%). The SMART program also increased the network of international collaborations for doctoral candidates and supervisors. Reflections on doctoral training programs like SMART contribute to debates around research training and the career opportunities of interdisciplinary scientists

Potential application of mesh-free SPH method in turbulent river flows

A comprehensive review has been completed on the simulation of turbulent flow over rough beds using mesh-free particle models. Based on the outcomes of this review, an improved Smoothed Particle Hydrodynamics (SPH) method has been developed for open channel flows over a rough bed, in which a mixing length model is used for modeling the 2D turbulence and a drag force equation is proposed for treating the boundary shear. The proposed model was applied to simulate a depth-limited open channel flow over a rough bed surface. The results of the velocity profile and shear stress distribution show a good agreement with the experimental data and existing analytical solutions. This work reveals that in order to correctly model turbulent open channel flow over a rough bed, the treatment of both flow turbulence and bed roughness effect is equally important

"Obesity" and "Clinical Obesity" Men's understandings of obesity and its relation to the risk of diabetes: A qualitative study

<p>Abstract</p> <p>Background</p> <p>The 2007 Wanless report highlights the ever increasing problem of obesity and the consequent health problems. Obesity is a significant cause of diabetes. An increasing evidence base suggests that in terms of reducing diabetes and CVD risk, it is better to be "fit and fat" than unfit and of normal weight. There has been very little previous research into the understandings that men in the general population hold about the issues of weight, exercise and health; we therefore undertook this study in order to inform the process of health promotion and diabetes prevention in this group.</p> <p>Methods</p> <p>A qualitative study in North East England General Practice using a purposive sample of men aged 25 and 45 years (selection process designed to include 'normal', 'overweight' and 'obese' men). One to one audio-recorded semi structured interviews focused on: overweight and obesity, diet, physical activity and diabetes. Transcripts were initially analysed using framework analysis. Emerging themes interlinked.</p> <p>Results</p> <p>The men in this study (n = 17) understand the word obesity differently from the clinical definition; "obesity" was used as a description of those with fat in a central distribution, and understandings of the term commonly take into account fitness as well as weight. Men in their late 30s and early 40s described becoming more aware of health issues. Knowledge of what constitutes a 'healthy lifestyle' was generally good, but men described difficulty acting upon this knowledge for various reasons e.g. increasing responsibilities at home and at work. Knowledge of diabetes and the link between obesity and diabetes was poor.</p> <p>Conclusion</p> <p>Men in this study had a complex understanding of the interlinked importance of weight and fitness in relation to health. Obesity is understood as a description of people with centrally distributed fat, in association with low fitness levels. There is a need to increase understanding of the causes and consequences of diabetes. Discussion of increased health awareness by men round the age of 40 may indicate a window of opportunity to intervene at this time.</p

Sexual Size Dimorphism and Body Condition in the Australasian Gannet

Funding: The research was financially supported by the Holsworth Wildlife Research Endowment. Acknowledgments We thank the Victorian Marine Science Consortium, Sea All Dolphin Swim, Parks Victoria, and the Point Danger Management Committee for logistical support. We are grateful for the assistance of the many field volunteers involved in the study.Peer reviewedPublisher PD

Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees

email Suzanne orcd idCopyright: © 2015 Williams et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Loss of flight promotes beetle diversification

The evolution of flight is a key innovation that may enable the extreme diversification of insects. Nonetheless, many species-rich, winged insect groups contain flightless lineages. The loss of flight may promote allopatric differentiation due to limited dispersal power and may result in a high speciation rate in the flightless lineage. Here we show that loss of flight accelerates allopatric speciation using carrion beetles (Coleoptera: Silphidae). We demonstrate that flightless species retain higher genetic differentiation among populations and comprise a higher number of genetically distinct lineages than flight-capable species, and that the speciation rate with the flightless state is twice that with the flight-capable state. Moreover, a meta-analysis of 51 beetle species from 15 families reveals higher genetic differentiation among populations in flightless compared with flight-capable species. In beetles, which represent almost one-fourth of all described species, repeated evolution of flightlessness may have contributed to their steady diversification since the Mesozoic era