Localized Tachyons and the g_cl conjecture

We consider C/Z_N and C^2/Z_N orbifolds of heterotic string theories and Z_N orbifolds of AdS_3. We study theories with N=2 worldsheet superconformal invariance and construct RG flows. Following Harvey, Kutasov, Martinec and Moore, we compute g_cl and show that it decreases monotonically along RG flows- as conjectured by them. For the heterotic string theories, the gauge degrees of freedom do not contribute to the computation of g_cl.Comment: Corrections and clarifications made, 19 page

Exploring segregation and sharing in a divided city: A PGIS approach

This article presents a novel exploratory investigation into the location and characteristics of spaces that are segregated and shared between Protestant and Catholic communities in Belfast, Northern Ireland (UK). Focusing on a particularly segregated part of the city, this study uses state-of-the-art participatory geographic information systems (PGIS) and visualization techniques to create qualitative, bottom-up maps of segregation and sharing within the city, as experienced by the people who live there. In doing so, it identifies important and previously unreported patterns in segregation and sharing between sectarian communities, challenging normative approaches to PGIS, illustrating how alternative methods might provide deeper insights into complex social geographies such as those of segregation. Finally, the findings of this work are formulated into a set of hypotheses that can contribute to a future research agenda into segregation and sharing, both in Belfast and in other divided cities

The One-loop QCD Corrections for γ∗toQQˉqqˉ\gamma^* to Q\bar Q q\bar q

We calculate the one-loop QCD corrections for the decay of an off-shell vector boson with vector couplings into two pairs of quarks of equal or unequal flavours keeping all orders in the number of colours. These matrix elements are relevant for the calculation of the next-to-leading order ${\cal O}(\alpha_s^3)$ corrections to four jet production in electron-positron annihilation, the production of a gauge boson accompanied by two jets in hadron-hadron collisions and three jet production in deep inelastic scattering. We use standard techniques for computing the interference of one-loop and tree level Feynman diagrams, but organise the results in terms of combinations of scalar loop integrals that are finite in the limit of vanishing Gram determinants and are therefore numerically stable.Comment: 8 pages, 1 Postscript figure, LaTeX,sign changed in eq 5 and

Standard and Null Weak Values

Weak value (WV) is a quantum mechanical measurement protocol, proposed by Aharonov, Albert, and Vaidman. It consists of a weak measurement, which is weighed in, conditional on the outcome of a later, strong measurement. Here we define another two-step measurement protocol, null weak value (NVW), and point out its advantages as compared to WV. We present two alternative derivations of NWVs and compare them to the corresponding derivations of WVs.Comment: 11 pages, 2 figures. To appear in Quantum Theory: A Two-Time Success Story: Yakir Aharonov Festschrif

Cost-effectiveness of insulin pumps compared with multiple daily injections, both provided with structured education, for adults with type 1 diabetes:a health economic analysis of the Relative Effectiveness of Pumps over Structured Education (REPOSE) randomised controlled trial

Objectives To assess the long-term cost-effectiveness of insulin pumps and Dose Adjustment for Normal Eating (pumps+DAFNE) compared with multiple daily insulin injections and DAFNE (MDI+DAFNE) for adults with type 1 diabetes mellitus (T1DM) in the UK. Methods We undertook a cost–utility analysis using the Sheffield Type 1 Diabetes Policy Model and data from the Relative Effectiveness of Pumps over Structured Education (REPOSE) trial to estimate the lifetime incidence of diabetic complications, intervention-based resource use and associated effects on costs and quality-adjusted life years (QALYs). All economic analyses took a National Health Service and personal social services perspective and discounted costs and QALYs at 3.5% per annum. A probabilistic sensitivity analysis was performed on the base case. Further uncertainties in the cost of pumps and the evidence used to inform the model were explored using scenario analyses. Setting Eight diabetes centres in England and Scotland. Participants Adults with T1DM who were eligible to receive a structured education course and did not have a strong clinical indication or a preference for a pump. Intervention Pumps+DAFNE. Comparator MDI+DAFNE. Main outcome measures Incremental costs, incremental QALYs gained and incremental cost-effectiveness ratios (ICERs). Results Compared with MDI+DAFNE, pumps+DAFNE was associated with an incremental discounted lifetime cost of +£18 853 (95% CI £6175 to £31 645) and a gain in discounted lifetime QALYs of +0.13 (95% CI -0.70 to +0.96). The base case mean ICER was £142 195 per QALY gained. The probability of pump+DAFNE being cost-effective using a cost-effectiveness threshold of £20 000 per QALY gained was 14.0%. All scenario and subgroup analyses examined indicated that the ICER was unlikely to fall below £30 000 per QALY gained. Conclusions Our analysis of the REPOSE data suggests that routine use of pumps in adults without an immediate clinical need for a pump, as identified by National Institute for Health and Care Excellence, would not be cost-effective. Trial registration number ISRCTN61215213

Dimensions of Diastemata and Associated Periodontal Food Pockets in Donkey Cheek Teeth

Equine cheek teeth (CT) diastemata often cause deep periodontal food pocketing and are therefore regarded as a painful dental disorder of equidae. However, there appears to be no information available on the size or shape of these diastemata. This post mortem study examined 16 donkey skulls (mean age = 32-years) containing 45 CT diastemata to define the anatomical shape and dimensions of these diastemata, and of the associated periodontal food pockets that occur with this disorder. Diastemata were found to more commonly involve mandibular (56.0 %) compared with maxillary CT (44.0 %), and 71.0 % of these diastemata had adjacent intercurrent dental disorders that may have predisposed donkeys to the diastemata. The median widths of all diastemata were 2.0-mm at the occlusal surface and 3.1-mm at the gingival margin, with no differences in widths between the lateral or medial aspects of diastemata. Diastemata were defined as open (60.0 %) or valve (40.0 %) based on their gross appearance. This classification was confirmed to be accurate by measurements that showed valve diastemata to have an occlusal to gingival width ratio of 0.4, in contrast to open diastemata where this ratio was 1.07. Food was impacted in 89.0 % of diastemata, but all diastemata had adjacent periodontal disease. Periodontal food pocketing was present adjacent to 76.0 % of diastemata, more commonly on the lateral aspect (73.0 % prevalence; mean pocket depth = 4.1-mm) than the medial aspect (47.0 % prevalence; mean pocket depth = 2.4-mm). The depth of periodontal pockets of diastemata was not associated with the height of the erupted crowns of adjacent CT. </jats:p

Towards a Stringy Resolution of the Cosmological Singularity

We study cosmological solutions to the low-energy effective action of heterotic string theory including possible leading order $\alpha'$ corrections and a potential for the dilaton. We consider the possibility that including such stringy corrections can resolve the initial cosmological singularity. Since the exact form of these corrections is not known the higher-derivative terms are constructed so that they vanish when the metric is de Sitter spacetime. The constructed terms are compatible with known restrictions from scattering amplitude and string worldsheet beta-function calculations. Analytic and numerical techniques are used to construct a singularity-free cosmological solution. At late times and low-curvatures the metric is asymptotically Minkowski and the dilaton is frozen. In the high-curvature regime the universe enters a de Sitter phase.Comment: 6 pages, 2 Figures; minor revisions; references added; REVTeX 4; version to appear in Phys. Rev.

LMDA\u27s 20th Aniversary 1985-2005: Celebrating the First Twenty Years

Contents include: Introduction: Only the Beginning..., A Brief History of LMDA, LMDA Canada - A History, Being There: Chance Memories of a Kitchen Dog, Interviews with the Past Presidents of LMDA, The LMDA Lifetime Achievement Award: Portraits of the Lessing Award, The Elliott Hayes Award: A Thumbprint History, LMDA\u27s Residency Programs, LMDA: A Living Chronology, Afterward: Looking Forward to Looking Ahead