New Records for \u3ci\u3eEuhrychiopsis Lecontei\u3c/i\u3e (Coleoptera: Curculionidae) and Their Densities in Wisconsin Lakes

The native aquatic weevil, Euhrychiopsis lecontei is currently being researched as a potential biological control for the exotic aquatic macrophyte Eurasian watermilfoil (Myriophyllum spicatum), yet little is known about its specific distribution in North America. In this study, E. lecontei was collected in 25 of 27 lakes surveyed for the weevil in Wisconsin, greatly increasing the known distribution of the species in this state. E. lecontei densities evaluated in 14 Wisconsin lakes ranged from \u3c0.01 to 1.91 weevils per apical stem of milfoil. These new records indicate that E. lecontei is widespread throughout Wisconsin and is associated with natural declines of M. spicatum in some lakes. Additional sampling for E. lecontei and research on its ecology and life history are needed to understand the role of this organism in aquatic ecosystems

Temporal and spatial changes in milfoil distribution and biomass associated with weevils in Fish Lake, WI

During the course of an eight year monitoring effort, the Wisconsin Department of Natural Resources documented a significant decline in milfoil biomass and distribution in Fish Lake, Wisconsin. Average milfoil biomass declined by 40- 50% from 374-524 g dw m -2 during 1991-93 to 265 g dw m -2 during both 1994 and 1995. Milfoil recovered fully in 1996- 98 to 446- 564 g dw m -2 . The size of the milfoil bed, as discerned from aerial photographs, shrank from a maximum coverage of 40 ha in 1991 to less than 20 ha during 1995. During the “crash” of 1994-95, milfoil plants exhibited typical signs of weevil-induced damage, including darkened, brittle, hollowed-out growing tips, and the arching and collapse of stems associated with loss of buoyancy. Monitoring of weevils and stem damage during 1995-98 showed highest densities and heaviest damage occurred near shore and subsequently fanned out into deeper water from core infestation sites each spring. The extent of milfoil stem damage was positively correlated with weevil densities (monthly sampling). However, weevil densities and stem damage were lower during 1995 (when milfoil biomass was in decline) than during 1996-98 (when milfoil biomass was fully recovered)

Euhrychiopsis lecontei distribution, abundance, and experimental augmentations for Eurasian watermilfoil control in Wisconsin lakes

The specialist aquatic herbivore Euhrychiopsis lecontei (Dietz) is currently being researched as a potential biological control agent for Eurasian watermilfoil (Myriophyllum spicatum L.). Our research in Wisconsin focused on 1) determining milfoil weevil distribution across lakes, 2) assessing limnological characteristics associated with their abundance, and 3) evaluating milfoil weevil augmentation as a practical management tool for controlling Eurasian watermilfoil

A simple test for the existence of two accretion modes in Active Galactic Nuclei

By analogy to the different accretion states observed in black-hole X-ray binaries (BHXBs), it appears plausible that accretion disks in active galactic nuclei (AGN) undergo a state transition between a radiatively efficient and inefficient accretion flow. If the radiative efficiency changes at some critical accretion rate, there will be a change in the distribution of black hole masses and bolometric luminosities at the corresponding transition luminosity. To test this prediction, I consider the joint distribution of AGN black hole masses and bolometric luminosities for a sample taken from the literature. The small number of objects with low Eddington-scaled accretion rates mdot < 0.01 and black hole masses Mbh < 10^9 Msun constitutes tentative evidence for the existence of such a transition in AGN. Selection effects, in particular those associated with flux-limited samples, systematically exclude objects in particular regions of the black hole mass-luminosity plane. Therefore, they require particular attention in the analysis of distributions of black hole mass, bolometric luminosity, and derived quantities like the accretion rate. I suggest further observational tests of the BHXB-AGN unification scheme which are based on the jet domination of the energy output of BHXBs in the hard state, and on the possible equivalence of BHXB in the very high (or "steep power-law") state showing ejections and efficiently accreting quasars and radio galaxies with powerful radio jets.Comment: Accepted by ApJ; 14 pages, 4 figures, uses emulateap

Observation Of Light Diffusion And Correlation Transport In Nematic Liquid Crystals

Light diffusion and temporal correlation transport are studied in an orientationally ordered multiply scattering medium. In particular, we experimentally demonstrate the anisotropic diffusion of light through a turbid nematic liquid crystal, and we measure the temporal correlations of these diffused speckle fields for the first time. The measurements are shown to provide useful information about this material, specifically the average rotational viscosity of the director. Computer simulations corroborate both the experimental observations and a more rigorous analytic theoretical formulation of this problem

The Jet of 3C 17 and the Use of Jet Curvature as a Diagnostic of the X-ray Emission Process

We report on the X-ray emission from the radio jet of 3C 17 from Chandra observations and compare the X-ray emission with radio maps from the VLA archive and with the optical-IR archival images from the Hubble Space Telescope. X-ray detections of two knots in the 3C 17 jet are found and both of these features have optical counterparts. We derive the spectral energy distribution for the knots in the jet and give source parameters required for the various X-ray emission models, finding that both IC/CMB and synchrotron are viable to explain the high energy emission. A curious optical feature (with no radio or X-ray counterparts) possibly associated with the 3C 17 jet is described. We also discuss the use of curved jets for the problem of identifying inverse Compton X-ray emission via scattering on CMB photons.Comment: 6 pages, 6 figure (3 in color), 4 tables, ApJ accepte

A Survey of z ~ 6 Quasars in the Sloan Digital Sky Survey Deep Stripe. II. Discovery of Six Quasars at z AB>21

We present the discovery of six new quasars at z ~ 6 selected from the Sloan Digital Sky Survey (SDSS) southern survey, a deep imaging survey obtained by repeatedly scanning a stripe along the celestial equator. The six quasars are about 2 mag fainter than the luminous z ~ 6 quasars found in the SDSS main survey and 1 mag fainter than the quasars reported in Paper I. Four of them comprise a complete flux-limited sample at 21 < z_(AB) < 21.8 over an effective area of 195 deg^2. The other two quasars are fainter than z_(AB) = 22 and are not part of the complete sample. The quasar luminosity function at z ~ 6 is well described as a single power law Φ(L_(1450))α L^β_(1450) over the luminosity range –28 < M_(1450) < –25. The best-fitting slope β varies from –2.6 to –3.1, depending on the quasar samples used, with a statistical error of 0.3-0.4. About 40% of the quasars discovered in the SDSS southern survey have very narrow Lyα emission lines, which may indicate small black hole masses and high Eddington luminosity ratios, and therefore short black hole growth timescales for these faint quasars at early epochs

A new quality of life consultation template for patients with venous leg ulceration

OBJECTIVE: Chronic venous leg ulcers (CVLUs) are common and recurrent, however, care for patients predominantly has a focus which overlooks the impact of the condition on quality of life. The aim of this study was to develop a simple, evidence-based consultation template, with patients and practitioners, which focuses consultations on quality of life themes. METHOD: A nominal group was undertaken to develop a new consultation template for patients with CVLUs based on the findings of earlier qualitative study phases. RESULTS: A user-friendly two-sided A4 template was designed to focus nurse-patient consultations on the quality of life challenges posed by CVLUs. CONCLUSION: CVLUs impact negatively on the quality of life of the patient but this receives inadequate attention during current consultations. This new template will help to ensure that key concerns are effectively raised, explored and addressed during each consultation. DECLARATION OF INTEREST: The NHS West Midlands Strategic Health Authority funded this study. The authors have no conflicts of interest to declare.NHS West Midlands Health Authorit

Constraints on the Compact Object Mass in the Eclipsing HMXB XMMU J013236.7+303228 in M33

We present optical spectroscopic measurements of the eclipsing High Mass X-ray Binary XMMU J013236.7+303228 in M33. Based on spectra taken at multiple epochs of the 1.73d binary orbital period we determine physical as well as orbital parameters for the donor star. We find the donor to be a B1.5IV sub-giant with effective temperature T=22,000-23,000 K. From the luminosity, temperature and known distance to M33 we derive a radius of R = 8.9 \pm 0.5 R_sun. From the radial--velocity measurements, we determine a velocity semi-amplitude of K_opt = 63 \pm 12 km/sec. Using the physical properties of the B-star determined from the optical spectrum, we estimate the star's mass to be M_opt = 11 \pm 1 M_sun. Based on the X-ray spectrum, the compact companion is likely a neutron star, although no pulsations have yet been detected. Using the spectroscopically derived B-star mass we find the neutron star companion mass to be M_X = 2.0 \pm 0.4 M_sun, consistent with the neutron star mass in the HMXB Vela X-1, but heavier than the canonical value of 1.4 M_sun found for many millisecond pulsars. We attempt to use as an additional constraint that the B star radius inferred from temperature, flux, and distance, should equate the Roche radius, since the system accretes by Roche lobe overflow. This leads to substantially larger masses, but from trying to apply the technique to known systems, we find that the masses are consistently overestimated. Attempting to account for that in our uncertainties, we derive M_X = 2.2^{+0.8}_{-0.6} M_sun and M_opt =13 \pm 4 M_sun. We conclude that precise constraints require detailed modeling of the shape of the Roche surface.Comment: 11 pages emulateapj, 9 figures, ApJ accepte

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