Information Outlook, March 1999

Volume 3, Issue 3https://scholarworks.sjsu.edu/sla_io_1999/1002/thumbnail.jp

Variable Point Sources in Sloan Digital Sky Survey Stripe 82. I. Project Description and Initial Catalog (0 h < R.A. < 4 h)

We report the first results of a study of variable point sources identified using multi-color time-series photometry from Sloan Digital Sky Survey (SDSS) Stripe 82 over a span of nearly 10 years (1998-2007). We construct a light-curve catalog of 221,842 point sources in the R.A. 0-4 h half of Stripe 82, limited to r = 22.0, that have at least 10 detections in the ugriz bands and color errors of < 0.2 mag. These objects are then classified by color and by cross-matching them to existing SDSS catalogs of interesting objects. We use inhomogeneous ensemble differential photometry techniques to greatly improve our sensitivity to variability. Robust variable identification methods are used to extract 6520 variable candidates in this dataset, resulting in an overall variable fraction of ~2.9% at the level of 0.05 mag variability. A search for periodic variables results in the identification of 30 eclipsing/ellipsoidal binary candidates, 55 RR Lyrae, and 16 Delta Scuti variables. We also identify 2704 variable quasars matched to the SDSS Quasar catalog (Schneider et al. 2007), as well as an additional 2403 quasar candidates identified by their non-stellar colors and variability properties. Finally, a sample of 11,328 point sources that appear to be nonvariable at the limits of our sensitivity is also discussed. (Abridged.)Comment: 67 pages, 27 figures. Accepted for publication in ApJS. Catalog available at http://shrike.pha.jhu.edu/stripe82-variable

Out of cite, out of mind: the current state of practice, policy, and technology for the citation of data

PREFACE The growth in the capacity of the research community to collect and distribute data presents huge opportunities. It is already transforming old methods of scientific research and permitting the creation of new ones. However, the exploitation of these opportunities depends upon more than computing power, storage, and network connectivity. Among the promises of our growing universe of online digital data are the ability to integrate data into new forms of scholarly publishing to allow peer-examination and review of conclusions or analysis of experimental and observational data and the ability for subsequent researchers to make new analyses of the same data, including their combination with other data sets and uses that may have been unanticipated by the original producer or collector. The use of published digital data, like the use of digitally published literature, depends upon the ability to identify, authenticate, locate, access, and interpret them. Data citations provide necessary support for these functions, as well as other functions such as attribution of credit and establishment of provenance. References to data, however, present challenges not encountered in references to literature. For example, how can one specify a particular subset of data in the absence of familiar conventions such as page numbers or chapters? The traditions and good practices for maintaining the scholarly record by proper references to a work are well established and understood in regard to journal articles and other literature, but attributing credit by bibliographic references to data are not yet so broadly implemented

Cell-based HTS identifies a chemical chaperone for preventing ER protein aggregation and proteotoxicity

The endoplasmic reticulum (ER) is responsible for folding secretory and membrane proteins, but disturbed ER proteostasis may lead to protein aggregation and subsequent cellular and clinical pathologies. Chemical chaperones have recently emerged as a potential therapeutic approach for ER stress-related diseases. Here, we identified 2-phenylimidazo[2,1-b]benzothiazole derivatives (IBTs) as chemical chaperones in a cell-based high-throughput screen. Biochemical and chemical biology approaches revealed that IBT21 directly binds to unfolded or misfolded proteins and inhibits protein aggregation. Finally, IBT21 prevented cell death caused by chemically induced ER stress and by a proteotoxin, an aggression-prone prion protein. Taken together, our data show the promise of IBTs as potent chemical chaperones that can ameliorate diseases resulting from protein aggregation under ER stress

The Psychopharmacology of Novel Synthetic Cannabinoids

Over recent years, the rapid proliferation of novel psychoactive substances has presented significant challenges to health professionals, regulators, and forensic scientists alike. Synthetic cannabinoids comprise an increasingly prevalent and diverse class of compounds that are used by many people around the world for recreational purposes. These compounds tend to produce psychoactive effects similar to, but stronger than, those of the prototypical cannabis-derived receptor agonist ∆9-tetrahydrocannabinol. The majority of modern synthetic cannabinoids have never been systematically assessed for their effects in humans, meaning that their psychopharmacological and toxicological effects remain largely uncharacterised. Unfortunately, but perhaps not surprisingly, these compounds are implicated in scores of toxic and fatal episodes worldwide. This thesis presents a series of studies aimed at building new knowledge regarding the behavioural and physiological effects of specific synthetic cannabinoids, their potency and metabolism, their long-term effects on cognitive function and brain neurochemistry, and analytical techniques that may be useful in the development of agonist substitution therapies to assist with synthetic cannabinoid withdrawal. The results obtained in this thesis and the wider literature are combined to identify in vivo structure-activity and structure-metabolism relationships for a wide variety of synthetic cannabinoids. These relationships may prove useful for the prediction of the psychopharmacological properties and metabolic pathways of future novel synthetic cannabinoids, reducing the burden involved in testing large numbers of novel compounds individually. Based on rodent assays, long-lasting cognitive impairments and subtle biochemical modulations are predicted in chronic synthetic cannabinoid users. Finally, analytical techniques for evaluating and monitoring agonist replacement therapy for synthetic cannabinoid withdrawal are established