484 research outputs found
The use of Ektacolor Paper as a pre-press color proof
To test the usefulness of Ektacolor Professional Paper as a pre-press color proofing method, one set of three predictor equations for each of the four primary printing inks was derived relating additive exposures on Ektacolor to colorimetric solid ink densities. These relationship would not yield to simultaneous solution.
Chromaticity coordinates of several sets of solid inks were matched on Ektacolor with an error of 2-10 MacAdam noticeability units. Probably because of the differences in surface characteristics of Ektacolor and newsprint, a visual match was not achieved
The Ursinus Weekly, April 3, 1903
Like the ripples • Home rule for cities • Alumni notes • Among the colleges • Philadelphia letter • Racquet lovers meet • Locals • Zwinglian anniversary • Audubon science program • Athleticshttps://digitalcommons.ursinus.edu/weekly/3081/thumbnail.jp
The Ursinus Weekly, December 19, 1902
Literary department: Poetry and philosophy • Immensee • A pipe dream • Philadelphia letter • Schaff Society • Among the colleges • National Civil Service Reform League • Alumni notes • Week in Congresshttps://digitalcommons.ursinus.edu/weekly/3068/thumbnail.jp
Consumption-Based Conservation Targeting: Linking Biodiversity Loss to Upstream Demand through a Global Wildlife Footprint.
Although most conservation efforts address the direct, local causes of biodiversity loss, effective long-term conservation will require complementary efforts to reduce the upstream economic pressures, such as demands for food and forest products, which ultimately drive these downstream losses. Here, we present a wildlife footprint analysis that links global losses of wild birds to consumer purchases across 57 economic sectors in 129 regions. The United States, India, China, and Brazil have the largest regional wildlife footprints, while per-person footprints are highest in Mongolia, Australia, Botswana, and the United Arab Emirates. A US$100 purchase of bovine meat or rice products occupies approximately 0.1 km2 of wild bird ranges, displacing 1-2 individual birds, for 1 year. Globally significant importer regions, including Japan, the United Kingdom, Germany, Italy, and France, have large footprints that drive wildlife losses elsewhere in the world and represent important targets for consumption-focused conservation attention
Stressor- and Corticotropin releasing Factor-induced Reinstatement and Active Stress-related Behavioral Responses are Augmented Following Long-access Cocaine Self-administration by Rats
Rationale Stressful events during periods of drug abstinence likely contribute to relapse in cocaine-dependent individuals. Excessive cocaine use may increase susceptibility to stressor-induced relapse through alterations in brain corticotropin-releasing factor (CRF) responsiveness.
Objectives This study examined stressor- and CRF-induced cocaine seeking and other stress-related behaviors in rats with different histories of cocaine self-administration (SA).
Materials and methods Rats self-administered cocaine under short-access (ShA; 2 h daily) or long-access (LgA; 6 h daily) conditions for 14 days or were provided access to saline and were tested for reinstatement by a stressor (electric footshock), cocaine or an icv injection of CRF and for behavioral responsiveness on the elevated plus maze, in a novel environment and in the light–dark box after a 14- to 17-day extinction/withdrawal period.
Results LgA rats showed escalating patterns of cocaine SA and were more susceptible to reinstatement by cocaine, EFS, or icv CRF than ShA rats. Overall, cocaine SA increased activity in the center field of a novel environment, on the open arms of the elevated plus maze, and in the light compartment of a light–dark box. In most cases, the effects of cocaine SA were dependent on the pattern/amount of cocaine intake with statistically significant differences from saline self-administering controls only observed in LgA rats.
Conclusions When examined after several weeks of extinction/ withdrawal, cocaine SA promotes a more active pattern of behavior during times of stress that is associated with a heightened susceptibility to stressor-induced cocaine-seeking behavior and may be the consequence of augmented CRF regulation of addiction-related neurocircuitry
Aitchison's Compositional Data Analysis 40 Years On: A Reappraisal
The development of John Aitchison's approach to compositional data analysis
is followed since his paper read to the Royal Statistical Society in 1982.
Aitchison's logratio approach, which was proposed to solve the problematic
aspects of working with data with a fixed sum constraint, is summarized and
reappraised. It is maintained that the principles on which this approach was
originally built, the main one being subcompositional coherence, are not
required to be satisfied exactly -- quasi-coherence is sufficient, that is near
enough to being coherent for all practical purposes. This opens up the field to
using simpler data transformations, such as power transformations, that permit
zero values in the data. The additional principle of exact isometry, which was
subsequently introduced and not in Aitchison's original conception, imposed the
use of isometric logratio transformations, but these are complicated and
problematic to interpret, involving ratios of geometric means. If this
principle is regarded as important in certain analytical contexts, for example
unsupervised learning, it can be relaxed by showing that regular pairwise
logratios, as well as the alternative quasi-coherent transformations, can also
be quasi-isometric, meaning they are close enough to exact isometry for all
practical purposes. It is concluded that the isometric and related logratio
transformations such as pivot logratios are not a prerequisite for good
practice, although many authors insist on their obligatory use. This conclusion
is fully supported here by case studies in geochemistry and in genomics, where
the good performance is demonstrated of pairwise logratios, as originally
proposed by Aitchison, or Box-Cox power transforms of the original compositions
where no zero replacements are necessary.Comment: 26 pages, 18 figures, plus Supplementary Material. This is a complete
revision of the first version of this paper, placing the geochemical example
upfront and adding a large section on CoDA of wide matrice
A Population of Metal-Poor Galaxies with ~L* Luminosities at Intermediate Redshifts
We present new spectroscopy and metallicity estimates for a sample of 15
star-forming galaxies with redshifts in the range 0.29 - 0.42. These objects
were selected in the KPNO International Spectroscopic Survey via their strong
emission lines seen in red objective-prism spectra. Originally thought to be
intermediate-redshift Seyfert 2 galaxies, our new spectroscopy in the far red
has revealed these objects to be metal-poor star-forming galaxies. These
galaxies follow a luminosity-metallicity (L-Z) relation that parallels the one
defined by low-redshift galaxies, but is offset by a factor of more than ten to
lower abundances. The amount of chemical and/or luminosity evolution required
to place these galaxies on the local L-Z relation is extreme, suggesting that
these galaxies are in a very special stage of their evolution. They may be
late-forming massive systems, which would challenge the current paradigm of
galaxy formation. Alternatively, they may represent intense starbursts in
dwarf-dwarf mergers or a major infall episode of pristine gas into a
pre-existing galaxy. In any case, these objects represent an extreme stage of
galaxy evolution taking place at relatively low redshift.Comment: 6 pages, 3 figures; to appear in 10 April 2009 ApJ
Prospectus, October 8, 1986
https://spark.parkland.edu/prospectus_1986/1024/thumbnail.jp
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