Update Measurement of the b Baryon Lifetime

The lifetime of the b baryons has been measured by the ALEPH detector using two independent data samples. From a maximum likelihood fit to the impact parameter distribution of leptons in $\Lambda\ell^-$ combinations, the b baryon lifetime is measured. The lifetime of the $\Lambda_{b}^{0}$ baryon is measured from a maximum likelihood fit to the proper time distribution of $\Lambda_{c}^+\ell^-$ candidates

Updated Measurement of the b baryon lifetime

sing about 4 million hadronic Z decays recorded with the Aleph detector, the lifetime of the b baryons has been measured using two independent data samples. From a maximum likelihood fit to the impact parameter distribution of leptons in 1085 Lambda-lepton combinations containing a b baryon sample of 719 decays the measured b baryon lifetime is \tau = 1.18 \pm 0.08(stat) \pm 0.07 (syst) ps The lifetime of the Lambda_b baryon from a maximum likelihood fit to the proper time distribution of 193 Lambda_c-lepton candidates is \tau_{\Lambda_b} = 1.21^{+0.13}_{-0.12}{stat}) \pm 0.04 {syst} ps. The combined result of the two measurements yields an averaged value \tau_{\Lambda_b} = 1.19 \pm{0.0

Vascular surgery and the Internet: A poor source of patient-oriented information

AbstractObjective: Increasing numbers of patients use the Internet to obtain medical information. The Internet is easily accessible, but available information is under no guidelines or regulations. We sought to evaluate the type, quality, and focus of vascular disease information presented on the Internet and the role in patient education with simple search techniques. Methods: The arbitrarily chosen search phrases “abdominal aortic aneurysm (AAA),” “carotid surgery (CEA),” “claudication surgery,” and “leg gangrene surgery” were entered into five common Internet search engines. No attempt was made to refine searches. As indicated by the search engines, the 50 most commonly encountered web sites for both AAA and CEA were reviewed. The first 25 claudication sites and the first 25 gangrene sites were combined for a total of 50 leg ischemia (LIS) sites. An information score (IS) was developed as a weighted score ranging from 0 (poor) to 100 (outstanding) and was designed to assess how well the web page educated the patient about the disease, the treatment options, and the medical and surgical complications. Each vascular surgery web site was classified according to the author, the referenced information source, and the therapeutic recommendations. This was followed by an evaluation of each web site with the IS independently scored by two observers. Results: Of the 150 web sites, 146 were accessible. Ninety-six sites (65.8%) had no useful patient-oriented information (IS < 10). The mean IS and the ranges were: AAA, 14.9 (0 to 72.0); CEA, 17.5 (0 to 77.0); and LIS, 12.2 (0 to 44.5; P = .9). The mean IS of the 59 sites with scores of more than 10 were: AAA, 39.8 (n = 17); CEA, 44.8 (n = 19); and LIS, 24.8 (n = 23; P < .01, as compared with LIS scores). Differences in IS between observers were not significant (P = .9). Misleading or unconventional care recommendations were recognized in one AAA site (1 of 47, 2.1%), two CEA sites (2 of 49, 4.1%), and 13 LIS sites (13 of 50, 26.0%). The Joint Vascular Societies web page was identified only as a tertiary link. Conclusion: Patient-oriented vascular surgery information, for common vascular diseases, is difficult to find on the Internet. The overall quality is poor, and information is difficult to obtain in part because of the large number of irrelevant sites. Of the sites that were relevant to patient education (33%), one third presented information that was classified by the authors as misleading or unconventional. This was most apparent in the leg ischemia sites. The Internet is a poor overall source of patient-oriented vascular surgery information and education. Focused and refined searches and improvements in search engines and educational web sites may yield improved information. Public and medical community awareness needs to be improved regarding the severe limitations of the Internet as an information resource. (J Vasc Surg 1999;30:84-91.

The LCG PI project: using interfaces for physics data analysis

In the context of the LHC computing grid (LCG) project, the applications area develops and maintains that part of the physics applications software and associated infrastructure that is shared among the LHC experiments. The "physicist interface" (PI) project of the LCG application area encompasses the interfaces and tools by which physicists will directly use the software, providing implementations based on agreed standards like the analysis systems subsystem (AIDA) interfaces for data analysis. In collaboration with users from the experiments, work has started with implementing the AIDA interfaces for (binned and unbinned) histogramming, fitting and minimization as well as manipulation of tuples. These implementations have been developed by re-using existing packages either directly or by using a (thin) layer of wrappers. In addition, bindings of these interfaces to the Python interpreted language have been done using the dictionary subsystem of the LCG applications area/SEAL project. The actual status and the future planning of the project will be presented

Engineering a costume for performance using illuminated LED-yarns

A goal in the field of wearable technology is to blend electronics with textile fibers to create garments that drape and conform as normal, with additional functionality provided by the embedded electronics. This can be achieved with electronic yarns (E-yarns), in which electronics are integrated within the fibers of a yarn. A challenge is incorporating non-stretch E-yarns with stretch fabric that is desirable for some applications. To address this challenge, E-yarns containing LEDs were embroidered onto the stretch fabric of a unitard used as part of a carnival costume. A zig-zag pattern of attachment of E-yarns was developed. Tensile testing showed this pattern was successful in preventing breakages within the E-yarns. Use in performance demonstrated that a dancer was unimpeded by the presence of the E-yarns within the unitard, but also a weakness in the junctions between E-yarns was observed, requiring further design work and reinforcement. The level of visibility of the chosen red LEDs within black E-yarns was low. The project demonstrated the feasibility of using E-yarns with stretch fabrics. This will be particularly useful in applications where E-yarns containing sensors are required in close contact with skin to provide meaningful on-body readings, without impeding the wearer

Pippi - painless parsing, post-processing and plotting of posterior and likelihood samples

Interpreting samples from likelihood or posterior probability density functions is rarely as straightforward as it seems it should be. Producing publication-quality graphics of these distributions is often similarly painful. In this short note I describe pippi, a simple, publicly-available package for parsing and post-processing such samples, as well as generating high-quality PDF graphics of the results. Pippi is easily and extensively configurable and customisable, both in its options for parsing and post-processing samples, and in the visual aspects of the figures it produces. I illustrate some of these using an existing supersymmetric global fit, performed in the context of a gamma-ray search for dark matter. Pippi can be downloaded and followed at http://github.com/patscott/pippi .Comment: 4 pages, 1 figure. v3: Updated for pippi 2.0. New features include hdf5 support, out-of-core processing, inline post-processing with arbitrary Python code in the input file, and observable-specific data cuts. Pippi can be downloaded from http://github.com/patscott/pipp