738–2 The Evolution of Therapy for Single Vessel Disease: A Treatment Comparison of Medicine, Angioplasty and Left Internal Mammary Artery Graft for Proximal Left Anterior Descending Disease

Saphenous vein bypass grafting for single vessel disease offers no survival or symptom relief advantage compared to medical therapy. Recent evidence suggests the use of the internal mammary artery or PTCA may be more beneficial than medicine. To examine the outcome of these treatment strategies, a retrospective analysis of prospectively collected data on 23,018 consecutive patients undergoing cardiac catheterization between April 1986 and February 1994 was performed. Of the 6,432 patients with single vessel disease, 1,222 had a proximal left anterior descending (LAD) stenosis>74% and no prior PTCA or CABG. A total of 289 were managed medically, 760 underwent PTCA, and 172 received a left internal mammary artery (LIMA) graft.Baseline demographic data and risk factor profiles were similar except for a higher incidence of diabetes (19 vs 15 vs 11%), history of MI (72 vs 58 vs 48%) CHF (18 vs 7 vs 8%), and total occlusions (44 vs 17 vs 7%) and lower incidence of unstable angina (40 vs 61 vs 64%) in the medical group as compared to PTCA and LIMA graft, respectively.Kaplan-Meier 6-year estimates:EventsMedicinePTCALIMAP-value–unadjusted survival (%)7885910.001–adjusted survival (%)8486900.24–event-free survival (%)5443720.0001ConclusionThere is a trend towards improved long-term survival in proximal LAD disease with a strategy of revascularization, particularly the LIMA graft. Furthermore, event-free survival is significantly improved with the LIMA graft as compared to medical therapy or PTCA

918-7 Limitations of Percutaneous Interventions in the Treatment of Bifurcation Lesions Involving the Left Anterior Descending Coronary Artery

Serious complications may occur when intervention is unsuccessful in bifurcation lesions involving the left anterior descending (LAD) and first major diagonal (D), because of the large amount of involved myocardium. To determine this complication rate, we reviewed 82 consecutive cases, over a 3 year period, in which these lesions were attempted. Sixty-six percent of the subjects were male, and 37% had unstable angina. The mean age was 59 and the mean ejection fraction was 56%. Digital calipers were used to measure vessel minimum lumen (MLD) and reference diameters. For the LAD the final MLD was 1.81mm and for the 0 1.32mm. The final percent mean diameter stenoses for the LAD and D were 41% and 45%, respectively. There were no significant differences in the rates of success or complication between groups treated with angioplasty only (N=68) or directional atherectomy (N=14). The in-hospital event-free success rate was 55%. The in-hospital complication rates were:Recurrent Ischemia16%Ventricular Tachycardia2%Myocardial Infarction14%Stroke2%Bypass Surgery12%Death1%Repeat Procedure4%Composite34%ConclusionLAD bifurcation lesion intervention is associated with a high in-hospital complication rate. Since these lesions are not amenable to stent placement or atherectomy with simultaneous protection of both vessels, these cases should be carefully evaluated before intervention, and bypass surgery should be considered as a treatment option

Assessing and Strengthening African Universities' Capacity for Doctoral Programmes

Imelda Bates and colleagues developed and validated an evidence-based tool for evaluating doctoral programmes in African universities

Evaluation of student engagement with differential media for Flipped Classroom teaching

Flipped learning, where the teaching content is delivered prior to the contact session, is an effective pedagogy. Most commonly, video is used for flipped approaches, although many other media are also effective, such as written, audio or electronic resources. The ideal medium used for information delivery is likely to vary, depending on the needs and learning approaches of each individual learner. Is there, therefore, a medium which is ideal for most students, or would flipped learning best be delivered using a suite of multimedia sources for the core information? This project aims to investigate the preferences shown by undergraduate students for different media in a series of flipped pedagogic settings. The project also aims to investigate whether there are any correlations between media preferences and student personality types and study approaches. Initial findings suggest that students engage readily with flipped learning pedagogies, although it is rare for students to engage with teaching materials well in advance of the class session. Early findings suggests that students show a preference for video as a medium of delivery for taught content

Cryptic diversity in a fig wasp community-morphologically differentiated species are sympatric but cryptic species are parapatric

A key debate in ecology centres on the relative importance of niche and neutral processes in determining patterns of community assembly with particular focus on whether ecologically similar species with similar functional traits are able to coexist. Meanwhile, molecular studies are increasingly revealing morphologically indistinguishable cryptic species with presumably similar ecological roles. Determining the geographic distribution of such cryptic species provides opportunities to contrast predictions of niche versus neutral models. Discovery of sympatric cryptic species increases alpha diversity and supports neutral models, while documentation of allopatric/parapatric cryptic species increases beta diversity and supports niche models. We tested these predictions using morphological and molecular data, coupled with environmental niche modelling analyses, of a fig wasp community along its 2700 km latitudinal range. Molecular methods increased previous species diversity estimates from eight to eleven species, revealing morphologically cryptic species in each of the four wasp genera studied. Congeneric species pairs that were differentiated by a key morphological functional trait (ovipositor length) coexisted sympatrically over large areas. In contrast, morphologically similar species, with similar ovipositor lengths, typically showed parapatric ranges with very little overlap. Despite parapatric ranges, environmental niche models of cryptic congeneric pairs indicate large regions of potential sympatry, suggesting that competitive process are important in determining the distributions of ecologically similar species. Niche processes appear to structure this insect community and cryptic diversity may typically contribute mostly to beta rather than alpha diversity

Ultra-stable optical clock with two cold-atom ensembles

Atomic clocks based on optical transitions are the most stable, and therefore precise, timekeepers available. These clocks operate by alternating intervals of atomic interrogation with dead time required for quantum state preparation and readout. This non-continuous interrogation of the atom system results in the Dick effect, an aliasing of frequency noise of the laser interrogating the atomic transition. Despite recent advances in optical clock stability achieved by improving laser coherence, the Dick effect has continually limited optical clock performance. Here we implement a robust solution to overcome this limitation: a zero-dead-time optical clock based on the interleaved interrogation of two cold-atom ensembles. This clock exhibits vanishingly small Dick noise, thereby achieving an unprecedented fractional frequency instability of $6 \times 10^{-17} / \sqrt{\tau}$ for an averaging time $\tau$ in seconds. We also consider alternate dual-atom-ensemble schemes to extend laser coherence and reduce the standard quantum limit of clock stability, achieving a spectroscopy line quality factor $Q> 4 \times 10^{15}$

Social Justice and Technocracy: Tracing the Narratives of Inclusive Education in the United States

Over the past two decades, the percentage of American students with disabilities educated in general classrooms with their nondisabled peers has risen by approximately fifty percent. This gradual but steady policy shift has been driven by two distinct narratives of organisational change. The social justice narrative espouses principles of equality and caring across human differences. The narrative of technocracy creates top-down, administrative pressure through hierarchical systems based on quantitative performance data. This article examines these two primary policy narratives of inclusive education in the United States, exploring the conceptual features of each and initiating an analysis of their application in the public schools

Developing 1D nanostructure arrays for future nanophotonics

There is intense and growing interest in one-dimensional (1-D) nanostructures from the perspective of their synthesis and unique properties, especially with respect to their excellent optical response and an ability to form heterostructures. This review discusses alternative approaches to preparation and organization of such structures, and their potential properties. In particular, molecular-scale printing is highlighted as a method for creating organized pre-cursor structure for locating nanowires, as well as vapor–liquid–solid (VLS) templated growth using nano-channel alumina (NCA), and deposition of 1-D structures with glancing angle deposition (GLAD). As regards novel optical properties, we discuss as an example, finite size photonic crystal cavity structures formed from such nanostructure arrays possessing highQand small mode volume, and being ideal for developing future nanolasers