Survey of Mosquitoes in High and Low Incidence Areas for West Nile Virus in Shelby County, Tennessee with Assessment of Parity Rates, Host Selection, and Seasonal Abundance

West Nile Virus (WNV) was reported as present in ShelbyCountyin 2001 with 44 blue jays testing positive for WNV. The first reported human WNV case had an onset date of 27 July 2002. There were 40 human cases in 2002, six of which were fatal. The 2002 human cases were clustered within the I-240 beltway, the older residential area of greater ShelbyCounty. Adult mosquito collections were made from the first week in June through the first week in November for 2003 and 2004. A representative site was selected from both the high and low human WNV incidence area of ShelbyCounty, and mosquito populations surveyed using CDC light-traps, omni-directional Fay traps, gravid traps, and by aspiration of natural and artificial resting stations. Collection data for 2004 reported here are only through 6 October. There were significantly higher numbers of Aedes vexans, Anopheles quadrimaculatus, and Ochlerotatus triseriatus collected in the low human WNV incidence area and higher numbers collected of Culex pipiens collected in the high incidence area in a site by species comparison (P= 0.0025). Total number of mosquitoes collected did not differ between sites (P= 0.36). 2003 Memphis Botanic Gardens (MBG) gravid trap data were compared with collection data from 26 Shelby County Vector Control (SCVC) gravid trap sites. There were differences between 2003 surveillance sites overall (P\u3c 0.0001) with MBG sites having lower numbers of Cx. pipiens than any SCVC site. However, the two sites were not statistically different. Rainfall was found to play a significant role in weekly collection totals (P= 0.0089), as was average weekly temperature (P \u3c 0.0001). This varied for individual years indicating that climatalogical effects cannot be assessed based on one year’s data. Blood-fed mosquitoes were collected from Shelby County, Tennessee in 2003 and 2004 using backpack and handheld battery-powered aspirators in addition to gravid traps. Only three of the collected species, Aedes vexans, Culex pipiens, and Ochlerotatus triseriatus, have been processed to identify blood-meal host. Combined trapping methods produced 399 engorged female mosquitoes. Of the 53 female mosquitoes tested, 33 Cx. pipiens, 18 Ae. vexans, and two Oc. triseriatus, hosts for 32 of those were positively identified using a polymerase chain reaction method, which utilized avian and mammalian specific oligoneucleotide pimers designed from conserved portions of the large mitochondrial ribosomal subunit gene (16S). The results for Cx. pipiens analyzed thus far varied by collection season with winter collections (N=9) being 100% avian (2 of 2 identified) and summer collections (N=24) being 94% mammalian (15 of 16 identified). Adult female mosquitoes previously identified to species were dissected and parity determined. Approximately 40 individuals per mont

Outflows in Infrared-Luminous Starbursts at z < 0.5. I. Sample, NaI D Spectra, and Profile Fitting

We have conducted a spectroscopic survey of 78 starbursting infrared-luminous galaxies at redshifts up to z = 0.5. We use moderate-resolution spectroscopy of the NaI D interstellar absorption feature to directly probe the neutral phase of outflowing gas in these galaxies. Over half of our sample are ultraluminous infrared galaxies that are classified as starbursts; the rest have infrared luminosities in the range log(L_IR/L_sun) = 10.2 - 12.0. The sample selection, observations, and data reduction are described here. The absorption-line spectra of each galaxy are presented. We also discuss the theory behind absorption-line fitting in the case of a partially-covered, blended absorption doublet observed at moderate-to-high resolution, a topic neglected in the literature. A detailed analysis of these data is presented in a companion paper.Comment: 59 pages, 18 figures in AASTeX preprint style; to appear in September issue of ApJ

Role of ATP hydrolysis in the DNA translocase activity of the bovine papillomavirus (BPV-1) E1 helicase

The E1 protein of bovine papillomavirus type-1 is the viral replication initiator protein and replicative helicase. Here we show that the C-terminal ∼300 amino acids of E1, that share homology with members of helicase superfamily 3 (SF3), can act as an autonomous helicase. E1 is monomeric in the absence of ATP but assembles into hexamers in the presence of ATP, single-stranded DNA (ssDNA) or both. A 16 base sequence is the minimum for efficient hexamerization, although the complex protects ∼30 bases from nuclease digestion, supporting the notion that the DNA is bound within the protein complex. In the absence of ATP, or in the presence of ADP or the non–hydrolysable ATP analogue AMP–PNP, the interaction with short ssDNA oligonucleotides is exceptionally tight (T(1/2) > 6 h). However, in the presence of ATP, the interaction with DNA is destabilized (T(1/2) ∼60 s). These results suggest that during the ATP hydrolysis cycle an internal DNA-binding site oscillates from a high to a low-affinity state, while protein–protein interactions switch from low to high affinity. This reciprocal change in protein–protein and protein–DNA affinities could be part of a mechanism for tethering the protein to its substrate while unidirectional movement along DNA proceeds

Exact encounter times for many random walkers on regular and complex networks

The exact mean time between encounters of a given particle in a system consisting of many particles undergoing random walks in discrete time is calculated, on both regular and complex networks. Analytical results are obtained both for independent walkers, where any number of walkers can occupy the same site, and for walkers with an exclusion interaction, when no site can contain more than one walker. These analytical results are then compared with numerical simulations, showing very good agreement.Comment: 11 pages, 4 figures. Submitted for publicatio

Stellar and Gaseous Nuclear Disks Observed in Nearby (U)LIRGs

We present near-infrared integral field spectroscopy of the central kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies undergoing major mergers. These observations were taken with OSIRIS assisted by the Keck I and II Adaptive Optics systems, providing spatial resolutions of a few tens of parsecs. The resulting kinematic maps reveal gas disks in at least 16 out of 19 nuclei and stellar disks in 11 out of 11 nuclei observed in these galaxy merger systems. In our late-stages mergers, these disks are young (stellar ages $<30$ Myr) and likely formed as gas disks which became unstable to star formation during the merger. On average, these disks have effective radii of a few hundred parsecs, masses between $10^{8}$ and $10^{10} M_{Sun}$, and $v/\sigma$ between 1 and 5. These disks are similar to those created in high-resolution hydrodynamical simulations of gas-rich galaxy mergers, and favor short coalescence times for binary black holes. The few galaxies in our sample in earlier stages of mergers have disks which are larger ($r_{eff}\sim200-1800$ pc) and likely are remnants of the galactic disks that have not yet been completely disrupted by the merger.Comment: accepted for publication in Ap

Promotion of retroviral entry in the absence of envelope protein by chlorpromazine

AbstractRetrovirus packaging cell lines that express the Moloney murine leukemia virus gag, pol, and env genes and a retroviral vector genome can produce virus particles that are capable of transducing cells. Normally if the packaging cell line does not produce a functional viral fusion glycoprotein, such as the retroviral envelope protein or a foreign viral glycoprotein, then the viruses will be incapable of transducing cells. We have found that incubating envelope protein-deficient virus particles bound to cells with chlorpromazine leads to transduction. Chlorpromazine (CPZ) is a membrane-active reagent that is commonly used to induce the hemifusion to fusion transition when membrane fusion is mediated by partially defective viral glycoproteins. The concentration and pH dependence of the promotion of transduction by CPZ is consistent with a role for CPZ micelle formation in viral entry. These data indicate that caution is warranted when experiments concerning membrane fusion completion promoted by CPZ are analyzed