Workshop on evaluating personal search

The first ECIR workshop on Evaluating Personal Search was held on 18th April 2011 in Dublin, Ireland. The workshop consisted of 6 oral paper presentations and several discussion sessions. This report presents an overview of the scope and contents of the workshop and outlines the major outcomes

Effects of chronic widespread pain on the health status and quality of life of women after breast cancer surgery

BACKGROUND: Most research and treatment of post-breast cancer chronic pain has focused on local or regional pain problems in the operated area. The purpose of this pilot study was to compare and contrast the pain characteristics, symptom impact, health status, and quality of life of post-breast cancer surgery women with regional chronic pain versus those with widespread chronic pain. METHODS: A cross-sectional, descriptive design compared two groups of women with chronic pain that began after surgery: regional pain (n = 11) and widespread pain (n = 12). Demographics, characteristics of the surgery, as well as standardized questionnaires that measured pain (Brief Pain Inventory (BPI), Short Form McGill Pain Questionnaire (MPQ-SF)), disease impact (Fibromyalgia Impact Questionnaire (FIQ), Functional Assessment of Cancer Therapy-Breast (FACT-B)), health status (Medical Outcomes Short Form (SF-36)) and quality of life (Quality of Life Scale (QOLS)) were gathered. RESULTS: There were no significant differences between the groups on any demographic or type of surgery variable. A majority of both groups described their pain as aching, tender, and sharp on the MPQ-SF. On the BPI, intensity of pain and pain interference were significantly higher in the widespread pain group. Differences between the two groups reached statistical significance on the FIQ total score as well as the FACT-B physical well-being, emotional well-being and breast concerns subscales. The SF-36 physical function, physical role, and body pain subscales were significantly lower in the widespread pain group. QOLS scores were lower in the widespread pain group, but did not reach statistical significance. CONCLUSION: This preliminary work suggests that the women in this study who experienced widespread pain after breast cancer surgery had significantly more severity of pain, pain impact and lower physical health status than those with regional pain

On the minimum number of neighbours for good routing performance in MANETs

In a mobile ad hoc network, where nodes are deployed without any wired infrastructure and communicate via multihop wireless links, the network topology is based on the nodes’ locations and transmission ranges. The nodes communicate through wireless links, with each node acting as a relay when necessary to allow multihop communications. The network topology can have a major impact on network performance. We consider the impact of number and placement of neighbours on mobile network performance. Specifically, we consider how neighbour node placement affects the network overhead and routing delay. We develop an analytical model, verified by simulations, which shows widely varying performance depending on source node speed and, to a lesser extent, number of neighbour nodes

Stokes Parameters as a Minkowskian Four-vector

It is noted that the Jones-matrix formalism for polarization optics is a six-parameter two-by-two representation of the Lorentz group. It is shown that the four independent Stokes parameters form a Minkowskian four-vector, just like the energy-momentum four-vector in special relativity. The optical filters are represented by four-by-four Lorentz-transformation matrices. This four-by-four formalism can deal with partial coherence described by the Stokes parameters. A four-by-four matrix formulation is given for decoherence effects on the Stokes parameters, and a possible experiment is proposed. It is shown also that this Lorentz-group formalism leads to optical filters with a symmetry property corresponding to that of two-dimensional Euclidean transformations.Comment: RevTeX, 22 pages, no figures, submitted to Phys. Rev.

Jones-matrix Formalism as a Representation of the Lorentz Group

It is shown that the two-by-two Jones-matrix formalism for polarization optics is a six-parameter two-by-two representation of the Lorentz group. The attenuation and phase-shift filters are represented respectively by the three-parameter rotation subgroup and the three-parameter Lorentz group for two spatial and one time dimensions. It is noted that the Lorentz group has another three-parameter subgroup which is like the two-dimensional Euclidean group. Possible optical filters having this Euclidean symmetry are discussed in detail. It is shown also that the Jones-matrix formalism can be extended to some of the non-orthogonal polarization coordinate systems within the framework of the Lorentz-group representation.Comment: RevTeX, 27 pages, no figures, to be published in J. Opt. Soc. Am.