868 research outputs found
Limitations of Counseling and Testing in CDC\u27s HIV Prevention Efforts
To the Editor: We were delighted to see that our colleagues at the Centers for Disease Control and Prevention (CDC) had read our article (Darrow et al., 1998a) and responded (Wolitski and Doll, 1999). Their criticisms of our cross-sectional study of 51 HIV-infected men who have sex with men (MSM) and live in South Beach are welcomed and appreciated. In this brief reply, we continue the dialogue by addressing their concerns and recommending an appropriate course of action
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Savannah River National Laboratory Involvement in the European ENSEMBLE Program
Many atmospheric transport and dispersion models now exist to provide consequence assessment during emergency response to near-field releases. One way of estimating the uncertainty for a given forecast is to statistically analyze an ensemble of results from several models. ENSEMBLE is a European Union program that utilizes an internet-based system to ingest transport results from numerous modeling agencies. This paper addresses the involvement of the Savannah River National Laboratory (SRNL) in ENSEMBLE, and the resulting improvements in SRNL modeling capabilities. SRNL, the only United States agency involved in the ENSEMBLE program, uses a prognostic atmospheric numerical model (the Regional Atmospheric Modeling System, RAMS) to provide three-dimensional and time-varying meteorology as input to a stochastic Lagrangian particle mode . The model design used by SRNL is discussed, including recent upgrades to the system using parallel processing which allows for finer grid resolution in the generation of the meteorology
Exclosures: An Experimental Technique for Protection of Northern Bobwhite Nests
Nest predation has been implicated as a factor affecting northern bobwhite (Colinus virginianus) recruitment rates. Public stakeholders are increasingly questioning use of lethal methods to manage predation. We evaluated a nonlethal method consisting of single nest treatments using an exclosure to protect nests from potential predators. The exclosure treatment also included use of Amdrot (hydramethylnon) and Snake-a-wayt repellents to deter red-imported fire ants (Solenopsis invicta) and snakes, respectively. We compared nest success of treated (n 1⁄4 8) to untreated nests (n 1⁄4 18). Treated nests were 88% successful which was a 2-fold increase over unprotected nests. We did not observe any difference in hen behavior between treatment and controls. This technique may be useful to study nest success of wild quail and is not intended to be a management technique to influence overall population growth
Impact of HIV Counseling and Testing on HIV-Infected Men who have Sex with Men: The South Beach Health Survey
The impact of HIV counseling and testing on sexual risk-taking and related behaviors reported by HIV-infected men who have sex with men (MSM) was examined in a cross-sectional study conducted among a representative sample of residents living in a resort area. Participants provided specimens of oral mucosal transudate for HIV-antibody testing, were interviewed in their homes, and completed a self-administered questionnaire. Specimens were tested by modified ELISA and, if repeatedly positive, confirmed by Western blot. Of 205 men enrolled, 51 (24.9%) tested positive for antibody to HIV. All 51 had been counseled and tested for antibody to HIV-1 (median = 4 tests); 37 (74%) of 50 reported that their most recent test was positive. Twenty (39.2%) said they had engaged in unprotected insertive anal intercourse in the past year; 15 (29.4%) engaged in unprotected insertive anal intercourse with partners who may have been susceptible to HIV infection. Men who reported that their last HIV-antibody test was positive were three times more likely to have engaged in unprotected insertive anal intercourse in the past year (45.9%) as those who did not know they were infected with HIV (15.4%). Counseling and testing is ineffective as a measure for promoting behavior change among HIV-positive MSM in South Beach. More effective social and behavioral interventions must be developed, implemented, and evaluated
FiberGLAST: a scintillating fiber approach to the GLAST mission
FiberGLAST is a scintillating fiber gamma-ray detector designed for the GLAST mission. The system described below provides superior effective area and field of view for modest cost and risk. An overview of the FiberGLAST instrument is presented, as well as a more detailed description of the principle elements of the primary detector volume. The triggering and readout electronics are described, and Monte Carlo Simulations of the instrument performance are presented
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Inferred summer precipitation for southern Ontario back to AD 610, as reconstructed from ring widths of Thuja occidentalis
We present a network of seven ring-width chronologies of eastern white-cedar (Thuja occidentalis L.) from the Niagara Escarpment in southern Ontario, Canada. Using principal component regression, a 350-year June-July precipitation reconstruction (SOR) is developed for the region. Prior to the 20th century, the SOR series shows reasonable coherence, particularly at the decadal scale, with an independent tree-ring-based reconstruction of the Palmer drought severity index (PDSI) for roughly the same region. A weakening of the tree-growth – climate relationship in recent decades results in a regression model explaining 21% of the variance in the original climate series when the recent data are used for calibration. We therefore compromise with a model, calibrated for the period 1900–1960, which explains 33% of the variance. The model, while not terribly strong, does pass verification tests, indicating some degree of predictive skill. The longest chronology in our network, the 2787-year Flowerpot Island (FLOW) chronology, also exhibits common variability with the PDSI reconstruction, particularly on decadal and longer time scales and was used to infer hydroclimatic conditions back to AD 610. The combined information of the SOR, PDSI, and FLOW series suggests that dry conditions existed for the periods 1700–1725, 1750–1800, and 1840–1900, and wet conditions for the periods 1675–1700, 1730–1750, and 1810–1840. Over longer time scales, the FLOW chronology shows that summer precipitation was particularly variable during the 7th, 9th, 13th, and 16th centuries
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OPTIMIZING RADIOLOGICAL MONITOR SITING OVER THE CONTINENTAL U.S.
The US Environmental Protection Agency (EPA) is installing a network of sensors in the US to monitor background radiation and elevated radiation levels expected from a possible nuclear incident. The network (RadNet) of 180 fixed sensors is intended to provide a basic estimate of the radiation level throughout the US and enhanced accuracy near population centers. This report discusses one of the objective methods for locating these monitors based on criteria outlined by the EPA. The analysis employs a representative climatology of incident scenarios that includes 50 release locations, four seasons and four times of the day. This climatology was calculated from 5,600 simulations generated with NOAA-ARL's HYSPLIT Lagrangian trajectory model. The method treats the release plumes as targets and monitors are located to maximize the number of plumes detected with the network. Weighting schemes based on detection only, dose-weighted detection and population-dose weighted detection were evaluated. The result shows that most of the monitors are located around the population centers, as expected. However, there are monitors quite uniformly distributed around the less populated areas. The monitors at the populated areas will provide early warning to protect the general public, and the monitors spread across the country will provide valuable data for modelers to estimate the extent and the transport of the radioactive contamination
Induction heating coupler
An induction heating device includes a handle having a hollow interior and two opposite ends, a wrist connected to one end of the handle, a U-shaped pole piece having two spaced apart ends, a tank circuit including an induction coil wrapped around the pole piece and a capacitor connected to the induction coil, a head connected to the wrist and including a housing for receiving the U-shaped pole piece, the two spaced apart ends of the pole piece extending outwardely beyond the housing, and a power source connected to the tank circuit. When the tank circuit is energized and a susceptor is placed in juxtaposition to the ends of the U-shaped pole piece, the susceptor is heated by induction heating due to magnetic flux passing between the two ends of the pole piece
New Class of Precision Antimicrobials Redefines Role of Clostridium difficile S-layer in Virulence and Viability
There is a medical need for antibacterial agents that do not damage the resident gut microbiota or promote the spread of antibiotic resistance. We recently described a prototypic precision bactericidal agent, Av-CD291.2, which selectively kills specific Clostridium difficile strains and prevents them from colonizing mice. We have since selected two Av-CD291.2–resistant mutants that have a surface (S)-layer–null phenotype due to distinct point mutations in the slpA gene. Using newly identified bacteriophage receptor binding proteins for targeting, we constructed a panel of Avidocin-CDs that kills diverse C. difficile isolates in an S-layer sequence-dependent manner. In addition to bacteriophage receptor recognition, characterization of the mutants also uncovered important roles for S-layer protein A (SlpA) in sporulation, resistance to innate immunity effectors, and toxin production. Surprisingly, S-layer–null mutants were found to persist in the hamster gut despite a complete attenuation of virulence. These findings suggest antimicrobials targeting virulence factors dispensable for fitness in the host force pathogens to trade virulence for viability and would have clear clinical advantages should resistance emerge. Given their exquisite specificity for the pathogen, Avidocin-CDs have substantial therapeutic potential for the treatment and prevention of C. difficile infections
Ariel - Volume 6 Number 4 (Alternate Version)
Editors
Mark Dembert
J.D. Kanofsky
Frank Chervenak
John Lammie
Curt Cummings
Entertainment
Robert Breckenridge
Joe Conti
Gary Kaskey
Photographer
Larry Glazerman
Overseas Editor
Mike Sinason
Humorist
Jim McCann
Staff
Kenn Jaffe
Bob Sklaroff
Halley Faust
Jim Burke
Jay Amsterdam
Morton A. Klein
Nancy Redfer
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