18,831 research outputs found

    Modelling the spinning dust emission from LDN 1780

    Full text link
    We study the anomalous microwave emission (AME) in the Lynds Dark Nebula (LDN) 1780 on two angular scales. Using available ancillary data at an angular resolution of 1 degree, we construct an SED between 0.408 GHz to 2997 GHz. We show that there is a significant amount of AME at these angular scales and the excess is compatible with a physical spinning dust model. We find that LDN 1780 is one of the clearest examples of AME on 1 degree scales. We detected AME with a significance > 20σ\sigma. We also find at these angular scales that the location of the peak of the emission at frequencies between 23-70 GHz differs from the one on the 90-3000 GHz map. In order to investigate the origin of the AME in this cloud, we use data obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) that provides 2 arcmin resolution at 30 GHz. We study the connection between the radio and IR emissions using morphological correlations. The best correlation is found to be with MIPS 70ÎŒ\mum, which traces warm dust (T∌\sim50K). Finally, we study the difference in radio emissivity between two locations within the cloud. We measured a factor ≈6\approx 6 of difference in 30 GHz emissivity. We show that this variation can be explained, using the spinning dust model, by a variation on the dust grain size distribution across the cloud, particularly changing the carbon fraction and hence the amount of PAHs.Comment: 14 pages, 11 figures, submitted to MNRA

    Inductive Reasoning Games as Influenza Vaccination Models: Mean Field Analysis

    Full text link
    We define and analyze an inductive reasoning game of voluntary yearly vaccination in order to establish whether or not a population of individuals acting in their own self-interest would be able to prevent influenza epidemics. We find that epidemics are rarely prevented. We also find that severe epidemics may occur without the introduction of pandemic strains. We further address the situation where market incentives are introduced to help ameliorating epidemics. Surprisingly, we find that vaccinating families exacerbates epidemics. However, a public health program requesting prepayment of vaccinations may significantly ameliorate influenza epidemics.Comment: 20 pages, 7 figure

    New diatom taxa from the world’s first marine Bioblitz held in New Zealand: Skeletomastus a new genus, Skeletomastus coelatus nov. comb. and Pleurosigma inscriptura a new species

    Get PDF
    Diatoms were investigated as part of the world’s first marine Bioblitz held on the south coast of Wellington, New Zealand, in October 2007. Two unusual diatoms were associated with the red alga Herposiphonia ceratoclada. They were examined by light and scanning electron microscopy. The first, previously described as »Cocconeis coelata« Arnott ex Greville, is a thick-ribbed biraphid diatom that appears to have an undular raphe and marginal septum like some Mastogloia species, but it does not have partecta in the valvocopula. Instead it has short marginal ribs that support a pseudoseptum. Its solid lyre and multiseriate striae with cibrate pores could be modifications of similar structures in Aneumastus aksaraiensis Spaulding et al. It typifies the new genus Skeletomastus which appears to be close to both Mastogloia and Aneumastus, hence the name. The second is a proposed new Pleurosigma species, P. inscriptura with naviculoid symmetry and a markedly sigmoid raphe system with deflected ends. It appears bright blue in darkfield illumination which helped us locate it in other samples from theWellington region.We compare it with some other Pleurosigma species and consider their diffraction properties

    Thermal conductive connection and method of making same Patent

    Get PDF
    Thermal conductive, electrically insulated cleavable adhesive connection between electronic module and heat sin

    Nd:YAG development for spaceborne laser ranging system

    Get PDF
    The results of the development of a unique modelocked laser device to be utilized in future NASA space-based, ultraprecision laser ranger systems are summarized. The engineering breadboard constructed proved the feasibility of the pump-pulsed, actively modelocked, PTM Q-switched Nd:YAG laser concept for the generation of subnanosecond pulses suitable for ultra-precision ranging. The laser breadboard also included a double-pass Nd:YAG amplifier and provision for a Type II KD*P frequency doubler. The specific technical accomplishment was the generation of single 150 psec, 20-mJ pulses at 10 pps at a wavelength of 1.064 micrometers with 25 dB suppression of pre-and post-pulses

    The use of conjugase preparations in the microbiological assay of folic acid

    Get PDF
    This article does not have an abstract

    Measuring public perceptions of sex offenders: reimagining the Community Attitudes Toward Sex Offenders (CATSO) scale

    Get PDF
    The Community Attitudes Toward Sex Offenders (CATSO) scale is an 18-item self-report questionnaire designed to measure respondents’ attitudes toward sex offenders. Its original factor structure has been questioned by a number of previous studies, and so this paper sought to reimagine the scale as an outcome measure, as opposed to a scale of attitudes. A face validity analysis produced a provisional three-factor structure underlying the CATSO: ‘punitiveness,’ ‘stereotype endorsement,’ and ‘risk perception.’ A sample of 400 British members of the public completed a modified version of the CATSO, the Attitudes Toward Sex Offenders scale, the General Punitiveness Scale, and the Rational-Experiential Inventory. A three-factor structure of a 22-item modified CATSO was supported using half of the sample, with factors being labeled ‘sentencing and management,’ ‘stereotype endorsement,’ and ‘risk perception.’ Confirmatory factor analysis on data from the other half of the sample endorsed the three-factor structure; however, two items were removed in order to improve ratings of model fit. This new 20-item ‘Perceptions of Sex Offenders scale’ has practical utility beyond the measurement of attitudes, and suggestions for its future use are provided
    • 

    corecore