Creating seating plans: A practical application

© 2016 Operational Research Society Ltd. All rights reserved. 0160-5682/16. This paper examines the interesting problem of designing seating plans for large events such as weddings and gala dinners where, among other things, the aim is to construct solutions where guests are sat on the same tables as friends and family, but, perhaps more importantly, are kept away from those they dislike. This problem is seen to be N P-complete from a number of different perspectives. We describe the problem model and heuristic algorithm that is used on the commercial website www.weddingseatplanner.com. We present results on the performance of this algorithm, demonstrating the factors that can influence run time and solution quality, and also present a comparison with an equivalent IP model used in conjunction with a commercial solver

Low reproductive performance and high sow mortality in a pig breeding herd: a case study

Sow performance is a key component of the productivity of commercial pig farms. Reproductive failure in the sow is common in pig production. For every 100 sows served, 89 should farrow. In absence of specific diseases such as porcine parvovirus, pseudo-rabies, swine fever, leptospirosis and brucellosis, management failures are the most important causes of loss. A syndrome associated with reproductive inefficiency, and post-service vaginal discharge and high sow mortality in a commercial pig farm is described. Pregnancy failures exceeded 20% and sow mortality exceeded 12% for two consecutive years. The abnormal post-service vaginal discharge rate was 1.7% during the period of investigation

Smeared versus localised sources in flux compactifications

We investigate whether vacuum solutions in flux compactifications that are obtained with smeared sources (orientifolds or D-branes) still survive when the sources are localised. This seems to rely on whether the solutions are BPS or not. First we consider two sets of BPS solutions that both relate to the GKP solution through T-dualities: (p+1)-dimensional solutions from spacetime-filling Op-planes with a conformally Ricci-flat internal space, and p-dimensional solutions with Op-planes that wrap a 1-cycle inside an everywhere negatively curved twisted torus. The relation between the solution with smeared orientifolds and the localised version is worked out in detail. We then demonstrate that a class of non-BPS AdS_4 solutions that exist for IASD fluxes and with smeared D3-branes (or analogously for ISD fluxes with anti-D3-branes) does not survive the localisation of the (anti) D3-branes. This casts doubts on the stringy consistency of non-BPS solutions that are obtained in the limit of smeared sources.Comment: 23 pages; v2: minor corrections, added references, version published in JHE

Assessing the Interocular Symmetry of Foveal Outer Nuclear Layer Thickness in Achromatopsia

Purpose: We examine the interocular symmetry of foveal outer nuclear layer (ONL) thickness measurements in subjects with achromatopsia (ACHM). Methods: Images from 76 subjects with CNGA3- or CNGB3-associated ACHM and 42 control subjects were included in the study. Line or volume scans through the fovea of each eye were acquired using optical coherence tomography (OCT). Image quality was assessed for each image included in the analysis using a previously-described maximum tissue contrast index (mTCI) metric. Three foveal ONL thickness measurements were made by a single observer and interocular symmetry was assessed using the average of the three measurements for each eye. Results: Mean (± standard deviation) foveal ONL thickness for subjects with ACHM was 79.7 ± 18.3 μm (right eye) and 79.2 ± 18.7 μm (left eye) compared to 112.9 ± 15.2 (right eye) and 112.1 ± 13.9 μm (left eye) for controls. Foveal ONL thickness did not differ between eyes for ACHM (P = 0.636) or control subjects (P = 0.434). No significant relationship between mTCI and observer repeatability was observed for either control (P = 0.140) or ACHM (P = 0.351) images. Conclusions: While foveal ONL thickness is reduced in ACHM compared to controls, the high interocular symmetry indicates that contralateral ONL measurements could be used as a negative control in early-phase monocular treatment trials. Translational Relevance: Foveal ONL thickness can be measured using OCT images over a wide range of image quality. The interocular symmetry of foveal ONL thickness in ACHM and control populations supports the use of the non-study eye as a control for clinical trial purposes

Enterprise Transformation Research Summit

LAI 2009 Enterprise Transformation Research Summit overvie

The example of CaPSURE: lessons learned from a national disease registry

IntroductionAlthough randomized controlled trials (RCTs) remain the gold standard for determining evidence-based clinical practices, large disease registries that enroll large numbers of patients have become paramount as a relatively cost-effective additional tool.MethodsWe highlight the advantages of disease registries focusing on the example of prostate cancer and the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE™) registry.ResultsCaPSURE collects approximately 1,000 clinical and patient-reported variables, in over 13,000 men that are enrolled. Thus far, CaPSURE has yielded over 130 peer-reviewed publications, with several others in press, in key areas of risk migration, practice patterns, outcome prediction, and quality of life outcomes.ConclusionsDisease registries, like CaPSURE complement RCTs and CaPSURE, have provided a means to better understand many aspects of prostate cancer epidemiology, practice patterns, oncologic and HRQOL outcomes, and costs of care across populations. Specialized observational disease registries such as CaPSURE provide insight and have broad implications for disease management and policy

A Comparison of Women’s Travel to Mammography Services and Average Week Day Trip Length

Long travel distances/times to a mammography service may act as a barrier that hinders women from seeking screening mammography on a recommended schedule. Average weekday trip length data from the New South Wales Travel Survey was compared with the average distance women travelled to a mammography service, the difference was tested using the Wilcoxon Signed Rank Test. The distance travelled to mammography services was statistically greater than the average week day trip length from the New South Wales Travel Survey (4.3 km, 95% CI 3.3 to 5.9 kms, p,0.001). This study has identified that within New South Wales there is a significant difference between average week day trip length travel and client travel to mammography services. Therefore, highlighting that women are undertaking a greater than normal travel burden to access mammography services. The comparison of normal weekday travel and travel to mammography services has enabled the burden of travel to mammography services to be identified. Reducing the burden of travel to mammography services is pivotal to increasing the utilization of mammography services and reducing the inequalities in health comes

Economic geology: Volatile destruction

International audienceDirect evidence for the role of volatiles in magmatic ore formation has been elusive. Magma degassing at Merapi volcano in Indonesia is found to be directly linked to the selective leaching of metals from sulphide melts that ultimately form ore deposits

Is Our Universe Natural?

It goes without saying that we are stuck with the universe we have. Nevertheless, we would like to go beyond simply describing our observed universe, and try to understand why it is that way rather than some other way. Physicists and cosmologists have been exploring increasingly ambitious ideas that attempt to explain why certain features of our universe aren't as surprising as they might first appear.Comment: Invited review for Nature, 11 page

Phase structure of black branes in grand canonical ensemble

This is a companion paper of our previous work [1] where we studied the thermodynamics and phase structure of asymptotically flat black $p$-branes in a cavity in arbitrary dimensions $D$ in a canonical ensemble. In this work we study the thermodynamics and phase structure of the same in a grand canonical ensemble. Since the boundary data in two cases are different (for the grand canonical ensemble boundary potential is fixed instead of the charge as in canonical ensemble) the stability analysis and the phase structure in the two cases are quite different. In particular, we find that there exists an analog of one-variable analysis as in canonical ensemble, which gives the same stability condition as the rather complicated known (but generalized from black holes to the present case) two-variable analysis. When certain condition for the fixed potential is satisfied, the phase structure of charged black $p$-branes is in some sense similar to that of the zero charge black $p$-branes in canonical ensemble up to a certain temperature. The new feature in the present case is that above this temperature, unlike the zero-charge case, the stable brane phase no longer exists and `hot flat space' is the stable phase here. In the grand canonical ensemble there is an analog of Hawking-Page transition, even for the charged black $p$-brane, as opposed to the canonical ensemble. Our study applies to non-dilatonic as well as dilatonic black $p$-branes in $D$ space-time dimensions.Comment: 32 pages, 2 figures, various points refined, discussion expanded, references updated, typos corrected, published in JHEP 1105:091,201