A New Expansion for Nucleon-Nucleon Interactions

We introduce a new and well defined power counting for the effective field theory describing nucleon-nucleon interactions. Because of the large NN scattering lengths it differs from other applications of chiral perturbation theory and is facilitated by introducing an unusual subtraction scheme and renormalization group analysis. Calculation to subleading order in the expansion can be done analytically, and we present the results for both the 1S0 and 3S1-3D1 channels.Comment: 10 pages, 3 figures, latex. Corrected typo, small change to tex

Fabrication and Composition Control of NiTi Shape Memory Thin Films for Microactuators

Microactuators fabricated with NiTi thin films take advantage of this material’s large energy density (~5-10 joules/cm3) and high strain recovery (~8%). Microelectromechanical Systems (MEMS) devices designed with these actuators can serve as biosensors, micro-fluidic pumps or optical switches. However, the fundamental mechanical properties stemming from the crystalline structure of these shape memory NiTi films have not been fully characterized with MEMS scale test structures. Understanding the relationship of crystalline structure, film stoichiometry, and phase transformation temperatures is crucial when designing a MEMS actuator. In addition, force displacement curves for both the martensite and austenite phases of NiTi are necessary to know how an actuator will perform. Atomically equal NiTi thin films were deposited on silicon wafers by co-sputtering a NiTi and a Ti target at 250W and 75W respectively. These power settings yielded a deposition rate of 12 angstroms per second. Pre-sputtering the NiTi and Ti targets effectively reduced the base pressure and cleaned the target surfaces, which made oxygen undetectable in the films. A 100 nm chromium layer provided excellent adhesion to Si, but poor adhesion to SiO2. The films will eventually be used in a cantilever test structure in conjunction with a surface profilometer to measure their mechanical and actuation properties

An Effective Field Theory Calculation of the Parity Violating Asymmetry in n+p -> d+gamma

Weak interactions are expected to induce a parity violating pion-nucleon coupling, h_{\pi NN}^{(1)}. This coupling should be measurable in a proposed experiment to study the parity violating asymmetry A_\gamma in the process \vec n + p \to d+\gamma. We compute the leading dependence of A_\gamma on the coupling h_{\pi NN}^{(1)} using recently developed effective field theory techniques and find an asymmetry of A_\gamma = +0.17 h_{\pi NN}^{(1)} at leading order. This asymmetry has the opposite sign to that given by Desplanques, Donoghue and Holstein.Comment: 7 pages, 2 figures from 3 eps files, late

Characterising the tumour morphological response to therapeutic intervention:an ex vivo model

In cancer, morphological assessment of histological tissue samples is a fundamental part of both diagnosis and prognosis. Image analysis offers opportunities to support that assessment through quantitative metrics of morphology. Generally, morphometric analysis is carried out on two dimensional tissue section data and so only represents a small fraction of any tumour. We present a novel application of three-dimensional (3D) morphometrics for 3D imaging data obtained from tumours grown in a culture model. Minkowski functionals, a set of measures that characterise geometry and topology in n-dimensional space, are used to quantify tumour topology in the absence of and in response to therapeutic intervention. These measures are used to stratify the morphological response of tumours to therapeutic intervention. Breast tumours are characterised by estrogen receptor (ER) status, human epidermal growth factor receptor (HER)2 status and tumour grade. Previously, we have shown that ER status is associated with tumour volume in response to tamoxifen treatment ex vivo. Here, HER2 status is found to predict the changes in morphology other than volume as a result of tamoxifen treatment ex vivo. Finally, we show the extent to which Minkowski functionals might be used to predict tumour grade.Minkowski functionals are generalisable to any 3D data set, including in vivo and cellular systems. This quantitative topological analysis can provide a valuable link among biomarkers, drug intervention and tumour morphology that is complementary to existing, non-morphological measures of tumour response to intervention and could ultimately inform patient treatment

Identifying prognostic structural features in tissue sections of colon cancer patients using point pattern analysis

Diagnosis and prognosis of cancer is informed by the architecture inherent in cancer patient tissue sections. This architecture is typically identified by pathologists, yet advances in computational image analysis facilitate quantitative assessment of this structure. In this article we develop a spatial point process approach in order to describe patterns in cell distribution within tissue samples taken from colorectal cancer (CRC) patients. In particular, our approach is centered on the Palm intensity function. This leads to taking an approximate-likelihood technique in fitting point processes models. We consider two Neyman-Scott point processes and a void process, fitting these point process models to the CRC patient data. We find that the parameter estimates of these models may be used to quantify the spatial arrangement of cells. Importantly, we observe characteristic differences in the spatial arrangement of cells between patients who died from CRC and those alive at follow-up

Decision analytic model for evaluation of suspected coronary disease with stress testing and coronary CT angiography.

RATIONALE AND OBJECTIVES: The aim of this study was to apply a decision analytic model for the evaluation of coronary artery disease (CAD) to define the optimal utilization of coronary computed tomographic angiography (cCTA) and stress testing. MATERIALS AND METHODS: The model tested in this study assumes that CAD is evaluated with a stress test and/or cCTA and that a patient with positive evaluation results undergoes cardiac catheterization. On the basis of values of sensitivity, specificity, and radiation dose from the published literature and test costs from the Medicare fee schedule, a decision tree model was constructed as a function of disease prevalence. RESULTS: The false-negative rate is lowest when cCTA is used as an isolated test. The false-positive rate is minimized when cCTA is used in combination with stress echocardiography. Effective radiation is minimized by use of stress electrocardiography or stress echocardiography alone or prior to cCTA. When the pretest probability of CAD is low, a strategy that uses stress echocardiography followed by cCTA minimizes the false-positive rate and effective radiation exposure, with relatively low imaging costs and with a false-negative rate only slightly higher than a strategy including stress myocardial scintigraphy. As the pretest probability of CAD increases above 20%, the false-negative rate of stress echocardiography followed by cCTA increases by \u3e5% relative to cCTA alone. CONCLUSION: Effective radiation dose and imaging costs for the workup of CAD may be minimized by an appropriate combination of stress testing and cCTA. A strategy that uses stress echocardiography followed by cCTA is most appropriate for the evaluation of low-risk patients with CAD with a pretest probability \u3c 20%, while cCTA alone may be more appropriate in intermediate-risk patients

Singing Actors and Dancing Singers

This article looks at two recent and widely recognized productions of Henry Purcell's Dido and Aeneas (by choreographer Sasha Waltz, Berlin 2005, and theatre director Sebastian Nübling, Basel 2006) and discusses three main aspects: 1. Genre: coming from a Tanztheater (Waltz) and a Sprechtheater (Nübling) background, each director renegotiates conventions of the operatic genre and consciously evades expectations in pursuit of a new and challenging experience for both the performers and their audience. 2. Physicality: both productions place the performers' bodies at the forefront of the mise-en-scne they remap the singing, dancing, acting body by questioning conventions and expectations commonly found in the production and reception process. 3. Adaptation: both productions take unconventional liberties by adapting in a domain where notions of Werktreue (fidelity to the original work or score) still reign. Adopting ideas from Nicholas Cook and Mikhail Bakhtin, I will argue that the conceptual, musical and theatrical implications of both productions indicate a renegotiation of the social and performative relevance of operatic performance

Modeling payback from research into the efficacy of left-ventricular assist devices as destination therapy

Objectives: Ongoing developments in design have improved the outlook for left-ventricular assist device (LVAD) implantation as a therapy in end-stage heart failure. Nevertheless, early cost-effectiveness assessments, based on first-generation devices, have not been encouraging. Against this background, we set out (i) to examine the survival benefit that LVADs would need to generate before they could be deemed cost-effective; (ii) to provide insight into the likelihood that this benefit will be achieved; and (iii) from the perspective of a healthcare provider, to assess the value of discovering the actual size of this benefit by means of a Bayesian value of information analysis. Methods: Cost-effectiveness assessments are made from the perspective of the healthcare provider, using current UK norms for the value of a quality-adjusted life-year (QALY). The treatment model is grounded in published analyses of the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) trial of first-generation LVADs, translated into a UK cost setting. The prospects for patient survival with second-generation devices is assessed using Bayesian prior distributions, elicited from a group of leading clinicians in the field. Results: Using established thresholds, cost-effectiveness probabilities under these priors are found to be low (.2 percent) for devices costing as much as £60,000. Sensitivity of the conclusions to both device cost and QALY valuation is examined. Conclusions: In the event that the price of the device in use would reduce to £40,000, the value of the survival information can readily justify investment in further trials