New Structure In The Shapley Supercluster

We present new radial velocities for 189 galaxies in a 91 sq. deg region of the Shapley supercluster measured with the FLAIR-II spectrograph on the UK Schmidt Telescope. The data reveal two sheets of galaxies linking the major concentrations of the supercluster. The supercluster is not flattened in Declination as was suggested previously and it may be at least 30 percent larger than previously thought with a correspondingly larger contribution to the motion of the Local Group.Comment: LaTex: 2 pages, 1 figure, includes conf_iap.sty style file. To appear in proceedings of The 14th IAP Colloquium: Wide Field Surveys in Cosmology, held in Paris, 1998 May 26--30, eds. S.Colombi, Y.Mellie

Scaling relations of the colour-detected cluster RzCS 052 at z=1.016 and of some other high redshift clusters

We report on the discovery of the z=1.016 cluster RzCS 052 using a modified red sequence method, followup spectroscopy and X-ray imaging. This cluster has a velocity dispersion of 710+-150 km/s, a virial mass of 4.0e14 Msol (based on 21 spectroscopically confirmed members) and an X-ray luminosity of (0.68+- 0.47)e44 ergs/s in the [1-4] keV band. This optically selected cluster appears to be of richness class 3 and to follow the known L_X-sigma_v relation for high redshift X-ray selected clusters. Using these data, we find that the halo occupation number for this cluster is only marginally consistent with what expected assuming a self-similar evolution of cluster scaling relations, suggesting perhaps a break of them at z~1. We also rule out a strong galaxy merging activity between z=1 and today. Finally, we present a Bayesian approach to measuring cluster velocity dispersions and X-ray luminosities in the presence of a background: we critically reanalyze recent claims for X-ray underluminous clusters using these techniques and find that the clusters can be accommodated within the existing L_X -sigma_v relation.Comment: MNRAS, in pres

Nicotine on Children's Hands: Limited Protection of Smoking Bans and Initial Clinical Findings.

BackgroundThirdhand smoke (THS) pollutants, such as nicotine, accumulate on the hands of children who live in homes with smokers and are exposed to secondhand smoke. Our objective was to examine whether levels of hand nicotine in exposed children are associated with demographics, environmental factors, and clinical findings.MethodsParticipants were caregivers who smoke and children (mean age (SD) = 2.6 (3.7) years) who were part of an ongoing 2-group, randomized controlled trial of an emergency department-based tobacco cessation intervention (N = 104). The primary outcome measure was nicotine on the child's hand. Caregivers reported demographics and smoking patterns; children's medical records were abstracted for chief complaint, medical history, and diagnoses.ResultsAll children had detectable hand nicotine (geometric mean [GeoM] = 86.2 ng/wipe; range = 3.5-2, 190.4 ng/wipe). Children in the age group of 2 to 4 years old (GeoM = 185.6 ng/wipe) had higher levels than the children in the age groups of 0 to 1 (GeoM = 68.9 ng/wipe, P < .001), 5 to 9 (GeoM = 77.9 ng/wipe, P = .04), and 10 to 15 years old (GeoM = 74.2 ng/wipe, P = .048). Children whose caregivers smoked 6 to 14 (GeoM = 97.2 ng/wipe, P = .047) and 15 to 40 cigarettes/day (GeoM = 124.0 ng/wipe, P = .01) had higher levels than children whose caregivers smoked 1 to 5 cigarettes/day (GeoM = 59.7 ng/wipe). Children with 6 to 14 cigarettes/day (GeoM = 163.11 ng/wipe, P = .007) and 15 to 40 cigarettes/day (GeoM = 186.1, P = .003) smoked inside the home by all smokers had significantly higher levels than homes with 0 cigarettes (GeoM = 81.3 ng/wipe). Similar differences in hand nicotine levels were found for smoking frequency of all household members in any location. Children with complaints of cough/congestion (GeoM = 97.7 ng/wipe) had higher levels than those without cough/congestion (GeoM = 59.0 ng/wipe, P = .01).ConclusionsThe high hand nicotine levels in children whose caregivers do not necessarily smoke indoor demonstrate that indoor smoking bans do not safeguard against THS exposure and the associations with increased home smoking activity indicate that hand wipes may be a noninvasive way to characterize children's exposure. The findings of associated cough and congestion with higher THS levels need to be examined further

Computing coset leaders and leader codewords of binary codes

In this paper we use the Gr\"obner representation of a binary linear code $\mathcal C$ to give efficient algorithms for computing the whole set of coset leaders, denoted by $\mathrm{CL}(\mathcal C)$ and the set of leader codewords, denoted by $\mathrm L(\mathcal C)$. The first algorithm could be adapted to provide not only the Newton and the covering radius of $\mathcal C$ but also to determine the coset leader weight distribution. Moreover, providing the set of leader codewords we have a test-set for decoding by a gradient-like decoding algorithm. Another contribution of this article is the relation stablished between zero neighbours and leader codewords