[useAMS,usedcolumn]mn2e supertabular,epsf,rotate empty ¡ ∼ > ∼ −0.6ex −.2ex<∼ -0.6ex −.2ex>∼ MNRAS, A&A, ApJ, AJ, ARA&A, PASP, Nat, -6mm document [A submillimetre difference between radio galaxies and radio quasars] A submillimetre difference between radio galaxies and radio quasars: evidence for quasar-heated dust and synchronized submillimetre and radio source activity [Willott et al.]Chris J. Willott 1 , Steve Rawlings 1 , Elese N. Archibald 2 & James S. Dunlop 3 abstract We present submillimetre photometry of 11 3CR and 6CE radio quasars of similar 151-MHz radio luminosity and redshifts to the radio galaxies studied at 1.3 < z < 2 by Archibald et al. (2001). We detect all bar one quasar at 850 m, and five quasars are confirmed as dusty hyperluminous objects by detections at shorter wavelengths. Our observations reveal a clear difference between the submillimetre luminosity distributions of the radio quasars and a matched sample of radio galaxies: the quasars are ∼ 5-times brighter than the radio galaxies and ≥ 2-times brighter accounting for possible synchrotron contamination. This difference is in quantitative agreement with a receding-torus unified scheme for radio sources in which the torus opening angle depends on quasar optical luminosity, provided that there is a close relationship between the optical and submillimetre luminosities. The implication is that quasar-heated dust dominates the submillimetre emission for powerful radio quasars at z ∼ 1.5. We find a significant anti-correlation between submillimetre/far-infrared luminosity L FIR and radio source age in the sense that hyperluminous quasars tend to be associated with young (< 10 7 yr) sources. This suggests that the processes controlling L FIR are synchronized with the jet-triggering event and that L FIR declines on a ∼ 10 7 yr timescale. There is evidence for a small amount of obscuration in the hyperluminous quasars from reddening and associated or broad absorption lines. We speculate that shortly after jet triggering, dust is more widely distributed than at later times and is heated by the quasar nucleus and/or a short-lived synchronized starburst. Any such starburst would form only a few per cent of the total stellar mass in agreement with the evidence for dominant old stellar populations in z ∼ 1.5 radio galaxies. In contrast, high-redshift (z > 3) radio galaxies with similar submillimetre luminosities could have longer star-formation timescales due to the greater availability of gas and could be forming the bulk of their stellar populations.

Culicoides variipennis sonorensis Wirth & Jones and C. nubeculosus (Meigen) were orally infected with African horse sickness virus (AHSV) type 9 and subsequently incubated at 10, 15, 20 and 25°C (R.H. 80%±10%). A time course of infection rates and virus titres was recorded by assaying flies individually or in pools, and survival rates of flies were also estimated. Survival rates at 10, 15 and 20°C were very similar and 80-90% of flies remained alive after 14 days; at 25°C after the same period survival was reduced to 40%. None of the C. nubeculosus became persistently infected with AHSV, but the virus took longer to clear as the incubation temperature dropped. At temperatures of 10, 15, 20 and 25°C virus was undetectable on days 12, 8, 5, and 4 days post infection (dpi), respectively. In C. v. sonorensis both the infection rate and rate of virogenesis were related to temperature. At 25°C a maximum mean titre of 10 43 TCID 50 /fly was reached by 9 dpi and the infection rate remained between 60 and 80%. At 20°C virogenesis was slower and a maximum mean titre of 10 43 TCID 50 /fly was reached only after 23 days; the infection rate was also reduced to 50-70%. At 15°C there was an overall decline in virus titre with time, although between 12 and 15 dpi some pools of flies contained 10 30 -10 40 TCID 50 /fly, demonstrating that virogenesis can occur. The infection rate at this temperature decreased dramatically to 0-15% after 9 dpi. At 10°C there was no detectable virogenesis and all pools tested at 13 dpi were negative. The apparent infection rate dropped to 0-5% between 13 and 55 days post infection. However, when surviving flies were then returned to 25 °C for 3 days the infection rate increased to 15.5%. It therefore appears that at low temperatures the virus does not replicate but infectious virus may persist at a level below that detectable by the usual assay systems. The implications of these findings for the epidemiology of AHS are discussed.

No abstract

The identity of vectors of disease are often required speedily in epidemiological studies but with a precision which excludes as many other species as possible. Identification keys usually require the examination of many different parts of the suspected vector to pinpoint the species. This consumes considerable time and resources, so epidemiologists tend to ignore them. A simplified approach to identification is proposed, using the characteristics of a single part of the body (the wings) of biting midges of the genus Culicoides. The level of differentiation was epidemiologically valuable. The monoclave could not differentiate all the species from each other but more than one third (20/58) of identifications were for single species, and a further 12/58 identifications gave only two possibilities, making 55.2% of identifications to an accuracy of at most one of two species. The diagnosis of vector species was reached in a maximum of six decision points. The only notable exception to valuable differentiation was the four species in the Culicoides obsoletus group which had almost identical female wing patterns. The ready availability of simple keys, which can be used by anyone without formal training in taxonomy, for all the species of a group in a region should encourage greater standardisation of identifications in all studies, including those not primarily aimed at systematics. These monoclaves can also serve as the primary tools to build computerised image-recognition systems for genera, families and orders of insects. Keywords: Culicoides, biting midges, vectors, epidemiology, identification, wing patterns, Iberian peninsula, monoclave. RESUMENClave de patrones alares de ceratopogónidos del género Culicoides Latreille (Diptera: Ceratopogonidae) en la Península Ibérica, para estudios epidemiológicos Con frequencia en los estudios epidemiológicos hace falta conocer con rapidez, pero también con precisión, la identidad de los vectores. Por lo general los procedimientos de identificación y las claves exigen el examen de un elevado número de partes diferentes del vector sospechoso. Este enfoque consume mucho tiempo y recursos por lo que tiende a ser evitado por los epidemiólogos. Se propone un sistema simplificado para la identificación, el cual utiliza las caracteristicas de sólo una parte del cuerpo (las alas) de los ceratopogónidos del género Culicoides. El nivel de diferenciación es bueno (55.2 % de las 58 especies presentes) y abarca casi todas las especies implicadas en la transmisión de virus y otros agentes patógenos de animales en la Península Ibérica. El diagnóstico de una especie precisa un máximo de seis criterios. La única excepción importante la constituyen las cuatro especies del grupo Culicoides obsoletus, las hembras de las cuales muestran un diseño alar casi idén-tico. La utilización de claves sencillas debería proporcionar una mejor estandarización de la identificación en todos los estudios, incluso los realizados por no sistemáticos. Estas claves pueden servir como el instrumento más impo...

Collections of biting midges were made over 24 months from sixty sites spread across Iberia. Information on the distribution of the vector of African horse sickness virus, Culicoides imicola, from these 3119 samples showed that this species was annually present across south-western Spain as far as 3 degrees 53'W and throughout most of Portugal, up to 41 degrees 5'N. C. imicola was found in all areas where African horse sickness epizootics had occurred in 1987-90 and also in areas outside the epizootic zones. Seasonal patterns of capture success of C. imicola, from seventeen frequently sampled sites where the vector was present, usually showed a late summer-early autumn peak. At the sites furthest south there was a discrete peak, mostly in September or October, before and after which the numbers captured increased or decreased steadily. At higher latitudes peak abundances occurred as early as May or as late as November, population build up was less uniform and numbers often declined rapidly after the peak was reached. Both the distribution and seasonal abundance patterns closely matched transmission patterns of African horse sickness virus, which rose during late summer and caused most cases during the autumn months.