The first confirmed superoutburst of the SU UMa type dwarf nova SDSS J083931.35+282824.0

We report unfiltered CCD photometry of the first confirmed superoutburst of the recently discovered dwarf nova, SDSS J083931.35+282824.0 in April 2010. From a quiescence magnitude of ~19.8 it rose to 14.0, an outburst amplitude of at least 5.8 magnitudes. Only the plateau phase of the outburst was observed during which superhumps with peak-to-peak amplitude of up to 0.28 magnitudes were present, confirming this to be an SU UMa type dwarf nova. The mean superhump period was Psh = 0.07836(2) during the first 3 days and this subsequently decreased to 0.07800(3) d. Analysis of the data revealed tentative evidence for an orbital period Porb = 0.07531(25) d. The fractional superhump period excess was epsilon = 0.039(6), which is consistent with other dwarf novae of similar orbital period.Comment: 12 pages, 3 figures. Accepted for publication in the Journal of the British Astronomical Associatio

The Homogeneity of Identifaction Decisions by Different Groups on LD Adolescents

This research was published by the KU Center for Research on Learning, formerly known as the University of Kansas Institute for Research in Learning Disabilities.Three related studies were designed to address some key issues confronting the learning disability field concerning the identification of learning disabled adolescents. The first study (Research Report No. 9) addressed the question of which group(s) of professionals or parents make the most homogeneous identification decisions on learning disabilities' criteria. In the second study, (Research Report No. 10) the temporal and interscorer reliability as well as the construct and content validity of the Modified Component Disability Instrument was investigated. The reliability and validity of the Modified Component Disability Checklist and Secondary Test battery were investigated in the third study (Research Report No. 11)

Identification Decisions: Who is the Most Consistent?

This research was published by the KU Center for Research on Learning, formerly known as the University of Kansas Institute for Research in Learning Disabilities.This study was designed to: (a) examine the type of judgments on LD characteristics rendered by multidisciplinary team members and (b) explore which of the groups typically represented on a staffing team was most homogeneous in making decisions on LD students. The consistency of judgment among groups were comparable when making judgments on LD and non-LD characteristics. Thus, the findings were supportive of the multidisciplinary approach to identification and evaluation of LD children and youth

Bilirubin Nanoparticles Reduce Diet-Induced Hepatic Steatosis, Improve Fat Utilization, and Increase Plasma β-Hydroxybutyrate

The inverse relationship of plasma bilirubin levels with liver fat accumulation has prompted the possibility of bilirubin as a therapeutic for non-alcoholic fatty liver disease. Here, we used diet-induced obese mice with non-alcoholic fatty liver disease treated with pegylated bilirubin (bilirubin nanoparticles) or vehicle control to determine the impact on hepatic lipid accumulation. The bilirubin nanoparticles significantly reduced hepatic fat, triglyceride accumulation, de novo lipogenesis, and serum levels of liver dysfunction marker aspartate transaminase and ApoB100 containing very-low-density lipoprotein. The bilirubin nanoparticles improved liver function and activated the hepatic β-oxidation pathway by increasing PPARα and acyl-coenzyme A oxidase 1. The bilirubin nanoparticles also significantly elevated plasma levels of the ketone β-hydroxybutyrate and lowered liver fat accumulation. This study demonstrates that bilirubin nanoparticles induce hepatic fat utilization, raise plasma ketones, and reduce hepatic steatosis, opening new therapeutic avenues for NAFLD

Impulsive phase transport

The transport of nonthermal electrons is explored. The thick-target electron beam model, in which electrons are presumed to be accelerated in the corona and typically thermalized primarily in the chromosphere and photosphere, is supported by observations throughout the electromagnetic spectrum. At the highest energies, the anisotropy of gamma-ray emission above 10 MeV clearly indicates that these photons are emitted by anisotropically-directed particles. The timing of this high-energy gamma-radiation with respect to lower-energy hard X-radiation implies that the energetic particles have short life-times. For collisional energy loss, this means that they are stopped in the chromosphere or below. Stereoscopic (two-spacecraft) observations at hard X-ray energies (up to 350 keV) imply that these lower-energy (but certainly nonthermal) electrons are also stopped deep in the chromosphere. Hard X-ray images show that, in spatially resolved flares whose radiation consists of impulsive bursts, the impulsive phase starts with X-radiation that comes mostly from the foot-points of coronal loops whose coronal component is outlined by microwaves

Exploratory Chandra Observations of the Three Highest Redshift Quasars Known

We report on exploratory Chandra observations of the three highest redshift quasars known (z = 5.82, 5.99, and 6.28), all found in the Sloan Digital Sky Survey. These data, combined with a previous XMM-Newton observation of a z = 5.74 quasar, form a complete set of color-selected, z > 5.7 quasars. X-ray emission is detected from all of the quasars at levels that indicate that the X-ray to optical flux ratios of z ~ 6 optically selected quasars are similar to those of lower redshift quasars. The observations demonstrate that it will be feasible to obtain quality X-ray spectra of z ~ 6 quasars with current and future X-ray missions.Comment: 15 pages, ApJL, in press; small revisions to address referee Comment

Reliability and Validity of the Bayesian Identification Procedure for Learning Disabled Adolescents

This research was published by the KU Center for Research on Learning, formerly known as the University of Kansas Institute for Research in Learning Disabilities.Three related studies were designed to address some key issues confronting the learning disability field concerning the identification of learning disabled adolescents. The first study (Research Report No. 9) addressed the question of which group(s) of professionals or parents make the most homogeneous identification decisions on learning disabilities criteria. In the second study, (Research Report No. 10) the temporal and interscorer reliability as well as the construct and content validity of the Modified Component Disability Instrument was investigated. The reliability and validity of the Modified Component Disability Checklist and Secondary Test battery were investigated in the third study (Research Report No. 11)

A Multi-Trait Multi-Method Analysis of the Bayesian Screening Instrument and Test Battery for LD Adolescents

This research was published by the KU Center for Research on Learning, formerly known as the University of Kansas Institute for Research in Learning Disabilities.Three related studies were designed to address some key issues confronting the learning disability field concerning the identification of learning disabled adolescents . The first study (Research Report No. 9) addressed the question of which group(s) of professionals or parents make the most homogeneous identification decisions on learning disabilities' criteria. ·In the second study, (Research Report No. 10) the temporal and interscorer reliability as well as the construct and content validity of the Modified Component Disability Instrument was investigated. The reliability and validity of the Modified Component Disability Checklist and Secondary Test battery were investigated in the third study (Research Report No. 11)

Dust Reddening in SDSS Quasars

We explore the form of extragalactic reddening toward quasars using a sample of 9566 quasars with redshifts 0<z<2.2, and accurate optical colors from the Sloan Digital Sky Survey (SDSS). We confirm that dust reddening is the primary explanation for the red ``tail'' of the color distribution of SDSS quasars. Our fitting to 5-band photometry normalized by the modal quasar color as a function of redshift shows that this ``tail'' is well described by SMC-like reddening but not by LMC-like, Galactic, or Gaskell et al. (2004) reddening. Extension to longer wavelengths using a subset of 1886 SDSS-2MASS matches confirms these results at high significance. We carry out Monte-Carlo simulations that match the observed distribution of quasar spectral energy distributions using a Lorentzian dust reddening distribution; 2% of quasars selected by the main SDSS targeting algorithm (i.e., which are not extincted out of the sample) have E_{B-V} > 0.1; less than 1% have E_{B-V} > 0.2, where the extinction is relative to quasars with modal colors. Reddening is uncorrelated with the presence of intervening narrow-line absorption systems, but reddened quasars are much more likely to show narrow absorption at the redshift of the quasar than are unreddened quasars. Thus the reddening towards quasars is dominated by SMC-like dust at the quasar redshift.Comment: 29 pages including 8 figures. AJ, September 2004 issu