108 research outputs found
Further Characterization of the Three-Choice Morphine, Cyclazocine and Saline Discrimination Paradigm: Opioids with Agonist and Antagonist Properties1
Sensitization and tolerance to the discriminative stimulus effects of mu-opioid agonists
The discriminative stimulus effects of several μ-opioid agonists were examined under conditions of opioid sensitization or tolerance, i.e., before and after 1-week SC infusions of naloxone or μ-opioid agonists. Rats were trained to discriminate 3.0 mg/kg morphine from saline using a two-lever, discrete trial, shock-avoidance/escape procedure. The rats generalized completely to morphine, fentanyl, meperidine, buprenorphine, and etorphine, and partially to pentazocine. A 7-day infusion of naloxone (0.3 mg/kg per h) potentiated the discriminative stimulus effects of all of these drugs. The magnitude of the increased potency varied indirectly with the efficacy of the μ-opioid agonists; potency ratios (pre-infusion ED 50 /post-infusion ED 50 ) ranged from 1.58 (etorphine) to 3.58 (pentazocine). Stimulus generalization to morphine, fentanyl, and meperidine also was examined following infusions of equieffective doses of each of these three drugs. Differences among drugs were generally small, and failed to reach statistical significance. Nonetheless, the induction of μ-opioid tolerance did seem to vary with the efficacy of the three μ-opioid agonists. Thus, meperidine (6.25 mg/kg per h), which has the lowest efficacy of the drugs infused, produced the greatest shift to the right of the stimulus-generalization curves of these three drugs; the post-meperidine PR ranged between 0.40 and 0.61. Fentanyl (0.1 mg/kg per h), a drug with a higher efficacy at μ-opioid receptors, did not produce tolerance to the discriminative stimulus effects of morphine, fentanyl, or meperidine; potency ratios ranged from 0.50 to 0.75. Potency ratios for buprenorphine, etorphine, fentanyl, meperidine, and morphine after 7-day morphine infusions (0.75 mg/kg per h) ranged from 0.38 (buprenorphine) to 0.80 (etorphine). Morphine induced significant tolerance only to the discriminative stimulus effects of fentanyl. Our results suggest that different cellular mechanisms underlie the development of tolerance and sensitization to the discriminative stimulus effects of μ-opioid agonists.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46342/1/213_2005_Article_BF02244991.pd
The u'g'r'i'z' Standard Star Network
We present the 158 standard stars that define the u'g'r'i'z' photometric
system. These stars form the basis for the photometric calibration of the Sloan
Digital Sky Survey (SDSS). The defining instrument system and filters, the
observing process, the reduction techniques, and the software used to create
the stellar network are all described. We briefly discuss the history of the
star selection process, the derivation of a set of transformation equations for
the UBVRcIc system, and plans for future work.Comment: References to URLs in paper have been updated to reflect moved
website. Accepted by AJ. 50 pages, including 20 pages of text, 9 tables, and
15 figures. Plain ASCII text versions of Tables 8 and 9 can be found at
http://home.fnal.gov/~dtucker/ugriz/index.html (new URL
Discrimination of a Single Dose of Morphine Followed by Naltrexone: Substitution of Other Agonists for Morphine and Other Antagonists for Naltrexone in a Rat Model of Acute Dependence
The u\u27g\u27r\u27i\u27z\u27 Standard Star Setwork
We present the 158 standard stars that define the u\u27g\u27r\u27i\u27z\u27 photometric system. These stars form the basis for the photometric calibration of the Sloan Digital Sky Survey (SDSS). The defining instrument system and filters, the observing process, the reduction techniques, and the software used to create the stellar network are all described. We briefly discuss the history of the star selection process, the derivation of a set of transformation equations for the UBVRcIc system, and plans for future work. (Refer to PDF file for exact formulas)
Discovery of Two Rare Rigidly Rotating Magnetosphere Stars in the APOGEE Survey
The Apache Point Observatory Galactic Evolution Experiment (APOGEE)---one of the Sloan Digital Sky Survey III programs---is using near-infrared (NIR) spectra of ~100,000 red giant branch star candidates to study the structure of the Milky Way. In the course of the survey, APOGEE also acquires spectra of hot field stars to serve as telluric calibrators for the primary science targets. We report the serendipitous discovery of two rare, fast-rotating B-stars of the sigma Ori E type among those blue field stars observed during the first year of APOGEE operations. Both of the discovered stars display the spectroscopic signatures of rigidly rotating magnetospheres (RRM) common to this class of highly magnetized (B ~ 10 kGauss) stars, increasing the number of known RRM stars by ~10%. One (HD 345439) is a main-sequence B-star with unusually strong He absorption (similar to sigma Ori E), while the other (HD 23478) fits a "He-normal" B3IV classification. We combine the APOGEE discovery spectra with other optical and NIR spectra of these two stars, and of sigma Ori E itself, to show how NIR spectroscopy can be a uniquely powerful tool for discovering more of these rare objects, which may show little/no RRM signatures in their optical spectra. We discuss the potential for further discovery of sigma Ori E type stars, as well as the implications of our discoveries for the population of these objects and insights into their origin and evolution
The effectiveness of interventions to change six health behaviours: a review of reviews
Background: Several World Health Organisation reports over recent years have highlighted the high incidence of chronic diseases such as diabetes, coronary heart disease and cancer. Contributory factors include unhealthy diets, alcohol and tobacco use and sedentary lifestyles. This paper reports the findings of a review of reviews of behavioural change interventions to reduce unhealthy behaviours or promote healthy behaviours. We included six different health-related behaviours in the review: healthy eating, physical exercise, smoking, alcohol misuse, sexual risk taking (in young people) and illicit drug use. We excluded reviews which focussed on pharmacological treatments or those which required intensive treatments (e. g. for drug or alcohol dependency).
Methods: The Cochrane Library, Database of Abstracts of Reviews of Effectiveness (DARE) and several Ovid databases were searched for systematic reviews of interventions for the six behaviours (updated search 2008). Two reviewers applied the inclusion criteria, extracted data and assessed the quality of the reviews. The results were discussed in a narrative synthesis.
Results: We included 103 reviews published between 1995 and 2008. The focus of interventions varied, but those targeting specific individuals were generally designed to change an existing behaviour (e. g. cigarette smoking, alcohol misuse), whilst those aimed at the general population or groups such as school children were designed to promote positive behaviours (e. g. healthy eating). Almost 50% (n = 48) of the reviews focussed on smoking (either prevention or cessation). Interventions that were most effective across a range of health behaviours included physician advice or individual counselling, and workplace- and school-based activities. Mass media campaigns and legislative interventions also showed small to moderate effects in changing health behaviours. Generally, the evidence related to short-term effects rather than sustained/longer-term impact and there was a relative lack of evidence on how best to address inequalities.
Conclusions: Despite limitations of the review of reviews approach, it is encouraging that there are interventions that are effective in achieving behavioural change. Further emphasis in both primary studies and secondary analysis (e.g. systematic reviews) should be placed on assessing the differential effectiveness of interventions across different population subgroups to ensure that health inequalities are addressed.</p
The Seventh Data Release of the Sloan Digital Sky Survey
This paper describes the Seventh Data Release of the Sloan Digital Sky Survey
(SDSS), marking the completion of the original goals of the SDSS and the end of
the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most
of the roughly 2000 deg^2 increment over the previous data release lying in
regions of low Galactic latitude. The catalog contains five-band photometry for
357 million distinct objects. The survey also includes repeat photometry over
250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A
coaddition of these data goes roughly two magnitudes fainter than the main
survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2
in the Northern Galactic Cap, closing the gap that was present in previous data
releases. There are over 1.6 million spectra in total, including 930,000
galaxies, 120,000 quasars, and 460,000 stars. The data release includes
improved stellar photometry at low Galactic latitude. The astrometry has all
been recalibrated with the second version of the USNO CCD Astrograph Catalog
(UCAC-2), reducing the rms statistical errors at the bright end to 45
milli-arcseconds per coordinate. A systematic error in bright galaxy photometr
is less severe than previously reported for the majority of galaxies. Finally,
we describe a series of improvements to the spectroscopic reductions, including
better flat-fielding and improved wavelength calibration at the blue end,
better processing of objects with extremely strong narrow emission lines, and
an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor
correction
The Fifth Data Release of the Sloan Digital Sky Survey
This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky
Survey (SDSS). DR5 includes all survey quality data taken through June 2005 and
represents the completion of the SDSS-I project (whose successor, SDSS-II will
continue through mid-2008). It includes five-band photometric data for 217
million objects selected over 8000 square degrees, and 1,048,960 spectra of
galaxies, quasars, and stars selected from 5713 square degrees of that imaging
data. These numbers represent a roughly 20% increment over those of the Fourth
Data Release; all the data from previous data releases are included in the
present release. In addition to "standard" SDSS observations, DR5 includes
repeat scans of the southern equatorial stripe, imaging scans across M31 and
the core of the Perseus cluster of galaxies, and the first spectroscopic data
from SEGUE, a survey to explore the kinematics and chemical evolution of the
Galaxy. The catalog database incorporates several new features, including
photometric redshifts of galaxies, tables of matched objects in overlap regions
of the imaging survey, and tools that allow precise computations of survey
geometry for statistical investigations.Comment: ApJ Supp, in press, October 2007. This paper describes DR5. The SDSS
Sixth Data Release (DR6) is now public, available from http://www.sdss.or
The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey
The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic
data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data
release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median
z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar
spectra, along with the data presented in previous data releases. These spectra
were obtained with the new BOSS spectrograph and were taken between 2009
December and 2011 July. In addition, the stellar parameters pipeline, which
determines radial velocities, surface temperatures, surface gravities, and
metallicities of stars, has been updated and refined with improvements in
temperature estimates for stars with T_eff<5000 K and in metallicity estimates
for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars
presented in DR8, including stars from SDSS-I and II, as well as those observed
as part of the SDSS-III Sloan Extension for Galactic Understanding and
Exploration-2 (SEGUE-2).
The astrometry error introduced in the DR8 imaging catalogs has been
corrected in the DR9 data products. The next data release for SDSS-III will be
in Summer 2013, which will present the first data from the Apache Point
Observatory Galactic Evolution Experiment (APOGEE) along with another year of
data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at
http://www.sdss3.org/dr
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