115 research outputs found

    Variability of Active Galactic Nuclei from the Optical to X-ray Regions

    Full text link
    Some progress in understanding AGN variability is reviewed. Reprocessing of X-ray radiation to produce significant amounts of longer-wavelength continua seems to be ruled out. In some objects where there has been correlated X-ray and optical variability, the amplitude of the optical variability has exceeded the amplitude of X-ray variability. We suggest that accelerated particles striking material could be linking X-ray and optical variability (as in activity in the solar chromosphere). Beaming effects could be significant in all types of AGN. The diversity in optical/X-ray relationships at different times in the same object, and between different objects, might be explained by changes in geometry and directions of motion relative to our line of sight. Linear shot-noise models of the variability are ruled out; instead there must be large-scale organization of variability. Variability occurs on light-crossing timescales rather than viscous timescales and this probably rules out the standard Shakura-Sunyaev accretion disk. Radio-loud and radio-quiet AGNs have similar continuum shapes and similar variability properties. This suggests similar continuum origins and variability mechanisms. Despite their extreme X-ray variability, narrow-line Seyfert 1s (NLS1s) do not show extreme optical variability.Comment: Invited talk given at Euro Asian Astronomical Society meeting in Moscow, June 2002. 20 pages, 4 figures. References update

    Perspectives of family members participating in cultural assessment of psychiatric disorders: Findings from the DSM-5 International Field Trial

    Get PDF
    Despite the important roles families play in the lives of many individuals with mental illness across cultures, there is a dearth of data worldwide on how family members perceive the process of cultural assessment as well as to how to best include them. This study addresses this gap in our knowledge through analysis of data collected across six countries as part of a DSM-5 Field Trial of the Cultural Formulation Interview (CFI). At clinician discretion, individuals who accompanied patients to the clinic visit (i.e. patient companions) at the time the CFI was conducted were invited to participate in the cultural assessment and answer questions about their experience. The specific aims of this paper are (1) to describe patterns of participation of patient companions in the CFI across the six countries, and (2) to examine the comparative feasibility, acceptability, and clinical utility of the CFI from companion perspectives through analysis of both quantitative and qualitative data. Among the 321 patient interviews, only 86 (at four of 12 sites) included companions, all of whom were family members or other relatives. The utility, feasibility and acceptability of the CFI were rated favourably by relatives, supported by qualitative analyses of debriefing interviews. Cross-site differences in frequency of accompaniment merit further study

    Reduced-Risk Management of Rhagoletis cerasi Flies (Host Race Prunus) in Combination with a Preliminary Phenological Model

    Get PDF
    Seasonal flight activity of Rhagoletis cerasi (L.) (Diptera: Tephritidae) adults was monitored using yellow sticky traps at sweet cherry orchards under different management regimes in Bursa, northwestern Turkey, during 1997–1998. In the reduced-risk backyard orchards, soil ploughing in the fall or spring to destroy the pupae was combined with a single application of an insecticide, while conventionally managed orchards received six to seven insecticide applications for controlling adults. Traps in commercial orchards caught significantly fewer adults than those in reduced-risk backyard orchards. Levels of cherry fruit fly fruit damage were very low (0.1%) in commercial orchards, whereas infestation rates averaged 2.2% in reduced-risk orchards. A preliminary phenology model was developed for optimal timing of insecticide applications based on air temperature summations since 1 February. In the reduced-risk backyard orchards, the first flies were captured between 25 May and 2 June, corresponding to an average degree-day (DD) accumulation of 582.50 ± 10.50 DD at an altitude of 150 m. However, first adult emergence at 1170 m was recorded between 6 and 14 June, averaging 667.50 ± 14.50 DD. Adult emergence exhibited bimodal peaks in a single flight at low altitude but there was a single peak at high altitude sites. Total adult flight period averaged 459 ± 29.50 and 649 ± 25.50 DD at low and high altitude sites, respectively. Our prediction model suggests that the optimum spray-window for a single insecticide application occurs between 577.70 and 639.40 DD at 150 m and between 780.90 and 848.60 DD at 1170 m

    Recent Locomotive Practice in France

    No full text

    Evolution, challenges, and perspective in the implementation of projects with renewable energy sources: Colombia case

    Get PDF
    This work quantifies the evolution in the implementation and development of renewable energies in Colombia, as well as evidence the current challenges and development prospects. The high demand for electricity in Colombia is increasing due to the great increase in population, industry and commerce, which generates greater energy consumption and as a consequence economic, social and environmental problems. The objective of this study was to analyze the behavior of the energy projects submitted to the Mining Energy Planning Group (UPME) during the last 15 years until July 2022, as well as to study the research areas with the highest performance. technology and the corresponding radiation intensity. In addition, it shows an historic information about the projects presented both not in force as of the date of closing of this investigation, classified according to their source, according to their range of power and according to its stage of implementation, finally, we made a synthesis of the new regulations governing the motivation and implementation of projects with renewable energy sources, being as this work a very good source of reference for further studies of the implementation of renewable energy sources in Colombia
    • …
    corecore