Groups of Galaxies in the Two Micron All-Sky Redshift Survey

We present the results of applying a percolation algorithm to the initial release of the Two Micron All-Sky Survey Extended Source Catalog, using subsequently measured redshifts for almost all of the galaxies with K < 11.25 mag. This group catalog is based on the first near-IR all-sky flux-limited survey that is complete to |b| = 5 deg. We explore the dependence of the clustering on the length and velocity scales involved. The paper describes a group catalog, complete to a limiting redshift of 10,000 km/s, created by maximizing the number of groups containing 3 or more members. A second catalog is also presented, created by requiring a minimum density contrast of 80 to identify groups. We identify known nearby clusters in the catalogs and contrast the groups identified in the two catalogs. We examine and compare the properties of the determined groups and verify that the results are consistent with the UZC-SSRS2 and northern CfA redshift survey group catalogs. The all-sky nature of the catalog will allow the development of a flow-field model based on the density field inferred from the estimated cluster masses.Comment: Accepted for publication in ApJ (29 pages including 13 figures). A version with high-resolution figures is available at http://www.cfa.harvard.edu/~acrook/preprints

The Dipole Anisotropy of the 2mass Redshift Survey

We estimate the flux weighted acceleration on the Local Group (LG) from the near-infrared Two Micron All Sky Redshift Survey (2MRS). The near-infrared flux weighted dipoles are very robust because they closely approximate a mass weighted dipole, bypassing the effects of redshift distortions and require no preferred reference frame. We use this method with the redshift information to determine the change in dipole with distance. The LG dipole seemingly converges by 60 Mpc/h. Assuming convergence, the comparison of the 2MRS flux dipole and the CMB dipole provides a value for the combination of the mass density and luminosity bias parameters Omega_m^0.6/b_L= 0.40+/-0.09.Comment: 4 pages, 2 figures, Contribution to Rencontres de Moriond: Contents and Structures of the Universe, March 18-25, 2006, La Thuil

Evidence for universal structure in galactic halos

The late infall of dark matter onto a galaxy produces structure (such as caustics) in the distribution of dark matter in the halo. We argue that such structure is likely to occur generically on length scales proportional to $l \sim t_0 v_{rot}$, where $t_0$ is the age of the universe and $v_{rot}$ is the rotation velocity of the galaxy. A set of 32 extended galactic rotation curves is analyzed. For each curve, the radial coordinate is rescaled according to $r\to \tilde r \equiv r (v_0 / v_{rot})$, where we choose $v_0 = 220 km/s$. A linear fit to each rescaled rotation curve is subtracted, and the residuals are binned and averaged. The sample shows significant features near $\tilde r = 40 kpc$ and $\tilde r = 20 kpc$. This is consistent with the predictions of the self-similar caustic ring model of galactic halos.Comment: 4 pages, LaTeX, 1 epsf figur

Analysis of Rotation Curves in the framework of R^n gravity

We present an analysis of a devised sample of Rotation Curves (RCs), aimed at checking the consequences of a modified f(R) gravity on galactic scales. Originally motivated by the the dark energy mystery, this theory may serve as a possibility of explaining the observed non-Keplerian profiles of galactic RCs in terms of a break-down of the Einstein General Relativity. We show that in general the power-law f(R) version could fit well the observations with reasonable values for the mass model parameters, encouraging further investigation on R^n gravity from both observational and theoretical points of view.Comment: Accepted for publication on Mon.Not.Roy.Astron.So

Systematic review of the safety and efficacy of foam sclerotherapy for venous disease of the lower limbs

Background: Foam sclerotherapy is a potential treatment for lower limb venous disease. Methods: A systematic review, with no restriction on study design, to assess the safety and efficacy of foam sclerotherapy. Results: 69 studies were included. For serious adverse events including pulmonary embolism and deep vein thrombosis, the median event rates were less than 1%. Median rate for visual disturbance was 1.4%. Median rates for some other adverse events were more common, including headache (4.2%), thrombophlebitis (4.7%), matting/skin staining/pigmentation (17.8%) and pain at the site of injection (25.6%). Median rate for complete occlusion of treated veins was 87.0% and for recurrence or development of new veins was 8.1%. Evidence from meta-analysis for complete occlusion suggests that foam sclerotherapy is associated with a lower rate compared with surgery (RR 0.86, 95% CI 0.67 to 1.10) and a higher rate compared with liquid sclerotherapy (RR 1.39, 95% CI 0.91 to 2.11). However, there was substantial heterogeneity across the studies in the meta-analysis. Conclusion: Serious adverse events were rare. There is insufficient evidence to reliably compare the effectiveness of foam sclerotherapy with other minimally invasive therapies or surgery. Evidence from high quality randomised controlled trials is required.This manuscript is based on a systematic review commissioned and funded by the National Institute for Health and Clinical Excellence (NICE) through its Interventional Procedures Programme. The Health Services Research Unit is supported by a core grant from the Chief Scientist Office of the Scottish Executive Health Department

Reconstructed Density and Velocity Fields from the 2MASS Redshift Survey

We present the reconstructed real-space density and the predicted velocity fields from the Two Mass Redshift Survey (2MRS). The 2MRS is the densest all-sky redshift survey to date and includes about 23,200 galaxies with extinction corrected magnitudes brighter than K = 11.25. Our method is based on the expansion of these fields in Fourier-Bessel functions. Within this framework, the linear redshift distortions only affect the density field in the radial direction and can easily be deconvolved using a distortion matrix. Moreover, in this coordinate system, the velocity field is related to the density field by a simple linear transformation. The shot noise errors in the reconstructions are suppressed by means of a Wiener filter which yields a minimum variance estimate of the density and velocity fields. Using the reconstructed real-space density fields, we identify all major superclusters and voids. At 50 Mpc/h, our reconstructed velocity field indicates a back-side infall to the Great Attractor region of vi = (491 +/- 200)(beta/0.5) km/sec in the Local Group frame and v = (64 +/- 205)(beta/0.5) km/sec in the cosmic microwave background (CMB) frame and beta is the redshift distortion parameter. The direction of the reconstructed dipole agrees well with the dipole derived by Erdogdu et al. (2006). The misalignment between the reconstructed 2MRS and the CMB dipoles drops to 13 degrees at around 5000 km/sec but then increases at larger distances. A version of this paper with high resolution figures can be obtained from http://www.nottingham.ac.uk/~ppzzpeComment: 21 pages. 22 figures, accepted for publication in MNRAS. The figures are coarsely resolved, a version of this paper with high resolution figures can be obtained from http://www.nottingham.ac.uk/~ppzzp

Sentinel lymph node mapping in gynecologic malignancies

Lymph node status is the most important prognostic factor for women with vulvar, cervical and endometrial carcinoma and complete lymph node dissection has historically been an integral part of the surgical treatment of these diseases. Lymphadenectomy can be morbid for patients, who may experience wound breakdown, lymphocyst formation or chronic lymphedema, among other problems. Sentinel lymph node mapping is a newer technology that allows selective removal of the first node draining a tumor thereby allowing a potentially less aggressive procedure to be performed. Sentinel node mapping is well accepted for the management of breast carcinoma and cutaneous melanoma, and has resulted in reduced morbidity without adversely affecting survival. Sentinel node mapping is currently being investigated for treatment of gynecologic cancers. Recent studies show promise for incorporating the sentinel node mapping technique for treatment of several gynecologic malignancies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135208/1/ijgo69.pd

Mass-to-light ratio gradients in early-type galaxy haloes

Since the near future should see a rapidly expanding set of probes of the halo masses of individual early-type galaxies, we introduce a convenient parameter for characterising the halo masses from both observational and theoretical results: \dML, the logarithmic radial gradient of the mass-to-light ratio. Using halo density profiles from LCDM simulations, we derive predictions for this gradient for various galaxy luminosities and star formation efficiencies $\epsilon_{SF}$. As a pilot study, we assemble the available \dML\ data from kinematics in early-type galaxies - representing the first unbiassed study of halo masses in a wide range of early-type galaxy luminosities - and find a correlation between luminosity and \dML, such that the brightest galaxies appear the most dark-matter dominated. We find that the gradients in most of the brightest galaxies may fit in well with the LCDM predictions, but that there is also a population of fainter galaxies whose gradients are so low as to imply an unreasonably high star formation efficiency $\epsilon_{SF} > 1$. This difficulty is eased if dark haloes are not assumed to have the standard LCDM profiles, but lower central concentrations.Comment: 17 pages, 13 figures. Accepted for publication on MNRA

MOND and the dark baryons

We consider for the first time the implications on the modified gravity MOND model of galaxies, of the presence of dark baryons, under the form of cold molecular gas in galaxy discs. We show that MOND models of rotation curves are still valid and universal, but the critical acceleration a0 separating the Newtonian and MONDian regimes has a lower value. We quantify this modification, as a function of the scale factor c between the total gas of the galaxy and the measured atomic gas. The main analysis concerns 43 resolved rotation curves and allows us to find the best pair (a0 = 0.96 10e-10 m.s-2, c = 3), which is also compatible to the one obtained from a second method by minimizing the scatter in the baryonic Tully-Fisher relation.Comment: 11 pages, 8 figures, accepted in A&