52 research outputs found
Detection of orbital and superhump periods in Nova V2574 Ophiuchi (2004)
We present the results of 37 nights of CCD unfiltered photometry of nova
V2574 Oph (2004) from 2004 and 2005. We find two periods of 0.14164 d (~3.40 h)
and 0.14773 d (~3.55 h) in the 2005 data. The 2004 data show variability on a
similar timescale, but no coherent periodicity was found. We suggest that the
longer periodicity is the orbital period of the underlying binary system and
that the shorter period represents a negative superhump. The 3.40 h period is
about 4% shorter than the orbital period and obeys the relation between
superhump period deficit and binary period. The detection of superhumps in the
light curve is evidence of the presence of a precessing accretion disk in this
binary system shortly after the nova outburst. From the maximum magnitude -
rate of decline relation, we estimate the decay rate t_2 = 17+/-4 d and a
maximum absolute visual magnitude of M_Vmax = -7.7+/-1.7 mag.Comment: 6 pages, 6 figures, 2 .sty files, AJ accepted, minor change to one of
reference
Circadian Rhythms in Visual Responsiveness in the Behaviorally Arrhythmic Drosophila Clock Mutant ClkJrk
An organism's biological day is characterized by a pattern of anticipatory physiological and behavioral changes that are governed by circadian clocks to align with the 24-h cycling environment. Here, we used flash electroretinograms (ERGs) and steady-state visually evoked potentials (SSVEPs) to examine how visual responsiveness in wild-type Drosophila melanogaster and the circadian clock mutant ClkJrk varies over circadian time. We show that the ERG parameters of wild-type flies vary over the circadian day, with a higher luminance response during the subjective night. The SSVEP response that assesses contrast sensitivity also showed a time-of-day dependence, including 2 prominent peaks within a 24-h period and a maximal response at the end of the subjective day, indicating a tradeoff between luminance and contrast sensitivity. Moreover, the behaviorally arrhythmic ClkJrk mutants maintained a circadian profile in both luminance and contrast sensitivity, but unlike the wild-types, which show bimodal profiles in their visual response, ClkJrk flies show a weakening of the bimodal character, with visual responsiveness tending to peak once a day. We conclude that the ClkJrk mutation mainly affects 1 of 2 functionally coupled oscillators and that the visual system is partially separated from the locomotor circadian circuits that drive bouts of morning and evening activity. As light exposure is a major mechanism for entrainment, our work suggests that a detailed temporal analysis of electrophysiological responses is warranted to better identify the time window at which circadian rhythms are most receptive to light-induced phase shifting
Features and Outcomes of 899 Patients With Drug-Induced Liver Injury: The DILIN Prospective Study
The drug-induced liver injury network (DILIN) is conducting a prospective study of patients with DILI in the United States. We present characteristics and subgroup analyses from the first 1257 patients enrolled in the study
Currency Conversion the Linked Data Way
Abstract. In many business applications that could be built on the basis of Linked Open Data, the conversion of monetary amounts from one currency to another is a much-needed functionality. For example, hotel prices in a comparison shopping application may have to deal with prices given in differing currencies. While currency conversion APIs exist on the Web, their integration into operations over RDF data is still burdensome and requires proprietary code. In this paper, we propose to integrate currency conversion functionality from open Web APIs into the Linked Open Data (LOD) cloud in a conceptually clean, scalable way that (1) adheres to the LOD design guidelines, (2) removes the need for proprietary code, (3) can be accessed from client-side JavaScript, and (4) works with any standard SPARQL processor that is able to retrieve a RDF representation by dereferencing a resource URI. We argue that our solution serves as a good generic pattern for integrating Web APIs into the LOD cloud, beyond the practical relevance of the concrete implementation
Movie Going in St. Petersburg in the 1970s
This is the audio file, transcript, and analysis of the interview with Viktoria Sorkina conducted by Maggie Burke and transcribed and analyzed by Mary Burke, Alex McGrath and Jennifer Stolz. The interview was conducted in July 2010 in St. Petersburg, Russia
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