On vote-taking and complete decoding of certain error-correcting codes

It is shown how complete decoding of maximum distance separable codes can be accomplished by a vote-taking algorithm or an equivalent distance correlation method. It is also indicated where this method of decoding might find application

Pennsylvania v. Conroy: Expanded Administrative Expense Priority for State-Funded CERCLA Cleanups Note

In Pennsylvania v. Conroy, the United States Court of Appeals for the Third Circuit affirmed the decision of the United States District Court for the Western District of Pennsylvania. The court held that cleanup expenses incurred by a state environmental agency to remove the threat posed by hazardous wastes should be treated as administrative expenses under the Bankruptcy Code. Thus, the Third Circuit afforded state response costs high priority when the assets of the bankruptcy estate were distributed. In addition, this case expanded prior decisions by holding that administrative and legal costs incurred by a state agency, usually around 10% of the total costs, should also be awarded to the agency. This expansion is the most important contribution of Conroy. This paper will suggest amending the Bankruptcy Code to include an express administrative expense priority for hazardous waste remediation. Such an amendment is necessary, since neither the courts nor Congress has resolved the issue. Since 1986, however, the trend in the federal circuit courts has been toward affording state cleanup costs a high priority

Detection of large scale intrinsic ellipticity-density correlation from the Sloan Digital Sky Survey and implications for weak lensing surveys

The power spectrum of weak lensing shear caused by large-scale structure is an emerging tool for precision cosmology, in particular for measuring the effects of dark energy on the growth of structure at low redshift. One potential source of systematic error is intrinsic alignments of ellipticities of neighbouring galaxies (II correlation) that could mimic the correlations due to lensing. A related possibility pointed out by Hirata and Seljak (2004) is correlation between the intrinsic ellipticities of galaxies and the density field responsible for gravitational lensing shear (GI correlation). We present constraints on both the II and GI correlations using 265 908 spectroscopic galaxies from the SDSS, and using galaxies as tracers of the mass in the case of the GI analysis. The availability of redshifts in the SDSS allows us to select galaxies at small radial separations, which both reduces noise in the intrinsic alignment measurement and suppresses galaxy- galaxy lensing (which otherwise swamps the GI correlation). While we find no detection of the II correlation, our results are nonetheless statistically consistent with recent detections found using the SuperCOSMOS survey. In contrast, we have a clear detection of GI correlation in galaxies brighter than L* that persists to the largest scales probed (60 Mpc/h) and with a sign predicted by theoretical models. This correlation could cause the existing lensing surveys at z~1 to underestimate the linear amplitude of fluctuations by as much as 20% depending on the source sample used, while for surveys at z~0.5 the underestimation may reach 30%. (Abridged.)Comment: 16 pages, matches version published in MNRAS (only minor changes in presentation from original version

Precision Cosmology from the Lyman-alpha Forest: Power Spectrum and Bispectrum

We investigate the promise of the Ly-alpha forest for high precision cosmology in the era of the Sloan Digital Sky Survey using low order N-point statistics. We show that with the existing data one can determine the amplitude, slope and curvature of the slope of the matter power spectrum with a few percent precision. Higher order statistics such as the bispectrum provide independent information that can confirm and improve upon the statistical precision from the power spectrum alone. The achievable precision is comparable to that from the cosmic microwave background with upcoming satellites, and complements it by measuring the power spectrum amplitude and shape at smaller scales. Since the data cover the redshift range 2<z<4, one can also extract the evolution of the growth factor and Hubble parameter over this range, and provide useful constraints on the presence of dark energy at z>2.Comment: 14 pages, 17 figures, accepted to MNRAS; minor changes made (section 2) and references adde

Anaerobes and short-chain fatty acids in crevicular fluid from adults with chronic periodontitis

Pathogeny of adult chronic periodontitis is still unclear. Bacteriological and chemical analysis of crevicular fluid have shown, in active sites of the disease, a simultaneous presence of anaerobes and their major by-product: short-chain fatty acids. The last can decrease «in vitro» the neutrophil intracellular pH, whenever these cells are incubated in an acid medium. Clinical investigations are scarce which hold out data useful to attempt verifying this possible physiopathological mechanism. This work shows the presence of anaerobes in the active periodontal pockets, together with the presence of short-chain fatty acids likely to reach a concentration level comparable to that used for inhibiting neutrophils «in vitro».Forthcoming studies should investigate about a possible intracellular pH drop in the neutrophils and other cells of the inflamed periodontium.La pathogénie des parodontites chroniques de l’adulte n’est pas encore bien comprise. Des analyses bactériologiques et chimiques du liquide créviculaire ont permis de mettre en évidence, dans des sites actifs de la maladie, des germes anaérobies et leurs principaux produits cataboliques: les acides gras à courte chaîne.Ceux-ci peuvent réduire «in vitro» le pH intracellulaire des neutrophiles en suspension dans un tampón acide. Peu d’études présentent des données cliniques permettant de vérifier «in vivo» cet éventuel mécanisme physiopathologique. Ce travail montre la présence simultanée, dans des poches parodontales, de germes anaérobies et d’acides gras à courte chaîne à des concentrations similaires à celles utilisées pour inhiber «in vitro» des neutrophiles. D’autres travaux devront étudier la chute éventuelle du pH intracellulaire des cellules du parodonte en état d’inflammation chronique

Ring-type singular solutions of the biharmonic nonlinear Schrodinger equation

We present new singular solutions of the biharmonic nonlinear Schrodinger equation in dimension d and nonlinearity exponent 2\sigma+1. These solutions collapse with the quasi self-similar ring profile, with ring width L(t) that vanishes at singularity, and radius proportional to L^\alpha, where \alpha=(4-\sigma)/(\sigma(d-1)). The blowup rate of these solutions is 1/(3+\alpha) for 4/d\le\sigma<4, and slightly faster than 1/4 for \sigma=4. These solutions are analogous to the ring-type solutions of the nonlinear Schrodinger equation.Comment: 21 pages, 13 figures, research articl

The Masses and Shapes of Dark Matter Halos from Galaxy-Galaxy Lensing in the CFHTLS

We present the first galaxy-galaxy weak lensing results using early data from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). These results are based on ~22 sq. deg. of i' data. From this data, we estimate the average velocity dispersion for an L* galaxy at a redshift of 0.3 to be 137 +- 11 km/s, with a virial mass, M_{200}, of 1.1 +- 0.2 \times 10^{12} h^{-1} Msun and a rest frame R-band mass-to-light ratio of 173 +- 34 h Msun/Lsun. We also investigate various possible sources of systematic error in detail. Additionally, we separate our lens sample into two sub-samples, divided by apparent magnitude, thus average redshift. From this early data we do not detect significant evolution in galaxy dark matter halo mass-to-light ratios from a redshift of 0.45 to 0.27. Finally, we test for non-spherical galaxy dark matter halos. Our results favor a dark matter halo with an ellipticity of ~0.3 at the 2-sigma level when averaged over all galaxies. If the sample of foreground lens galaxies is selected to favor ellipticals, the mean halo ellipticity and significance of this result increase.Comment: 12 pages, 11 figures, accepted to ApJ, uses emulateap

Detection of intrinsic cluster alignments to 100 Mpc/h in the SDSS

We measure the large-scale intrinsic alignments of galaxy clusters in the Sloan Digital Sky Survey (SDSS) using subsets of two cluster catalogues: 6625 clusters with 0.1<z<0.3 from the maxBCG cluster catalogue (Koester et al. 2007, 7500 sq. deg.), and 8081 clusters with 0.08<z<0.44 from the Adaptive Matched Filter catalogue (Dong et al. 2008, 6500 sq. deg.). We search for two types of cluster alignments using pairs of clusters: the alignment between the projected major axes of the clusters (`correlation' alignment), and the alignment between one cluster major axis and the line connecting it to the other cluster in the pair (`pointing' alignment). In each case, we use the cluster member galaxy distribution as a tracer of the cluster shape. All measurements are carried out with each catalogue separately, to check for dependence on cluster selection procedure. We find a strong detection of the pointing alignment on scales up to 100 Mpc/h, at the 6 or 10-sigma level depending on the cluster selection algorithm used. The correlation alignment is only marginally detected up to ~20 Mpc/h, at the 2 or 2.5-sigma level. These results support our current theoretical understanding of galaxy cluster intrinsic alignments in the LCDM paradigm, although further work will be needed to understand the impact of cluster selection effects and observational measurement errors on the amplitude of the detection.Comment: 6 pages, 2 figures, submitted to MNRAS; minor revisions to address referee comments primarily in section 5, no changes to result

Sensor Fusion of Structure-from-Motion, Bathymetric 3D, and Beacon-Based Navigation Modalities

This paper describes an approach for the fusion of 30 data underwater obtained from multiple sensing modalities. In particular, we examine the combination of imagebased Structure-From-Motion (SFM) data with bathymetric data obtained using pencil-beam underwater sonar, in order to recover the shape of the seabed terrain. We also combine image-based egomotion estimation with acousticbased and inertial navigation data on board the underwater vehicle. We examine multiple types of fusion. When fusion is pe?$ormed at the data level, each modality is used to extract 30 information independently. The 30 representations are then aligned and compared. In this case, we use the bathymetric data as ground truth to measure the accuracy and drijl of the SFM approach. Similarly we use the navigation data as ground truth against which we measure the accuracy of the image-based ego-motion estimation. To our knowledge, this is the frst quantitative evaluation of image-based SFM and egomotion accuracy in a large-scale outdoor environment. Fusion at the signal level uses the raw signals from multiple sensors to produce a single coherent 30 representation which takes optimal advantage of the sensors' complementary strengths. In this papel; we examine how lowresolution bathymetric data can be used to seed the higherresolution SFM algorithm, improving convergence rates, and reducing drift error. Similarly, acoustic-based and inertial navigation data improves the convergence and driji properties of egomotion estimation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86044/1/hsingh-35.pd