10,425 research outputs found
Chiral Corrections to Baryon Masses Calculated within Lattice QCD
Consideration of the analytic properties of pion-induced baryon self energies
leads to new functional forms for the extrapolation of light baryon masses.
These functional forms reproduce the leading non-analytic behavior of chiral
perturbation theory, the correct non-analytic behavior at the threshold
and the appropriate heavy-quark limit. They involve only three unknown
parameters, which may be obtained by fitting lattice QCD data. Recent dynamical
fermion results from CP-PACS and UKQCD are extrapolated using these new
functional forms. We also use these functions to probe the limit of
applicability of chiral perturbation theory.Comment: 4 pages, 2 figures, Contribution to the Proceedings of the 15th
Particles and Nuclei International Conference (PANIC 99), Uppsala, Sweden,
June 10-16, 199
Application of remote sensing to state and regional problems
The methods and procedures used, accomplishments, current status, and future plans are discussed for each of the following applications of LANDSAT in Mississippi: (1) land use planning in Lowndes County; (2) strip mine inventory and reclamation; (3) white-tailed deer habitat evaluation; (4) remote sensing data analysis support systems; (5) discrimination of unique forest habitats in potential lignite areas; (6) changes in gravel operations; and (7) determining freshwater wetlands for inventory and monitoring. The documentation of all existing software and the integration of the image analysis and data base software into a single package are now considered very high priority items
Ewald Sums for One Dimension
We derive analytic solutions for the potential and field in a one-dimensional
system of masses or charges with periodic boundary conditions, in other words
Ewald sums for one dimension. We also provide a set of tools for exploring the
system evolution and show that it's possible to construct an efficient
algorithm for carrying out simulations. In the cosmological setting we show
that two approaches for satisfying periodic boundary conditions, one overly
specified and the other completely general, provide a nearly identical
clustering evolution until the number of clusters becomes small, at which time
the influence of any size-dependent boundary cannot be ignored. Finally we
compare the results with other recent work with the hope of providing
clarification over differences these issues have induced. We explain that
modern formulations of physics require a well defined potential which is not
available if the forces are screened directly.Comment: 2 figures added references expanded discussion of algorithm corrected
figures added discussion of screened forc
Discovery of Bright Galactic R Coronae Borealis and DY Persei Variables: Rare Gems Mined from ACVS
We present the results of a machine-learning (ML) based search for new R
Coronae Borealis (RCB) stars and DY Persei-like stars (DYPers) in the Galaxy
using cataloged light curves from the All-Sky Automated Survey (ASAS) Catalog
of Variable Stars (ACVS). RCB stars - a rare class of hydrogen-deficient
carbon-rich supergiants - are of great interest owing to the insights they can
provide on the late stages of stellar evolution. DYPers are possibly the
low-temperature, low-luminosity analogs to the RCB phenomenon, though
additional examples are needed to fully establish this connection. While RCB
stars and DYPers are traditionally identified by epochs of extreme dimming that
occur without regularity, the ML search framework more fully captures the
richness and diversity of their photometric behavior. We demonstrate that our
ML method can use newly discovered RCB stars to identify additional candidates
within the same data set. Our search yields 15 candidates that we consider
likely RCB stars/DYPers: new spectroscopic observations confirm that four of
these candidates are RCB stars and four are DYPers. Our discovery of four new
DYPers increases the number of known Galactic DYPers from two to six;
noteworthy is that one of the new DYPers has a measured parallax and is m ~ 7
mag, making it the brightest known DYPer to date. Future observations of these
new DYPers should prove instrumental in establishing the RCB connection. We
consider these results, derived from a machine-learned probabilistic
classification catalog, as an important proof-of-concept for the efficient
discovery of rare sources with time-domain surveys.Comment: 18 pages, 2 new figures, accepted for publication in Ap
Superhero comics and the digital communications circuit: a case study of <i>Strong Female Protagonist</i>
This article examines the ongoing superhero webcomic Strong Female Protagonist (2012-present), by Brannon Lee Mulligan and Molly Ostertag and employs it as a case study to analyse the new communications circuit created by the digital production and delivery of comics. It adopts a perspective drawn from Book History to frame the communication model of print comics and to evaluate how webcomics such as Strong Female Protagonist redefine the role of readers, authors and publishers
Trait positive and negative emotionality differentially associate withdiurnal cortisol activity
Inter-individual variability in metrics of hypothalamic-pituitary-adrenocortical (HPA) activity, such asthe slope of the diurnal decline in cortisol, cortisol awakening response (CAR), and total cortisol out-put, have been found to associate inversely with trait ratings of extraversion and positive affect (E/PA)and positively with neuroticism and negative affect (N/NA) in some, but not all, investigations. Theseinconsistencies may partly reflect varied intensity of cortisol sampling among studies and reliance onself-rated traits, which are subject to reporting biases and limitations of introspection. Here, we furtherexamined dispositional correlates of HPA activity in 490 healthy, employed midlife volunteers (M age = 43years; 54% Female; 86% white). Trait ratings were requested from participants and 2 participant-electedinformants using the Positive and Negative Affect Schedule (PANAS) and Extraversion and Neuroticismdimensions of NEO personality inventories. CAR was assessed as percent increase in cortisol levels fromawakening to 30 min after awakening; and the diurnal slope and total output of cortisol [Area Underthe Curve (AUC)] were determined from cortisol measurements taken at awakening, +4 and +9 h later,and bedtime, across 3 workdays. Structural equation modeling was used to estimate multi-informantE/PA and N/NA factors. We used 3 days of measurement as indicators to model each of the three latentcortisol factors (slope, CAR, and AUC). With the two latent emotionality and three latent cortisol indicesincluded there was good fit to the data ( 2(200)= 278.38, p = 0.0002; RMSEA = 0.028, 90% CI = 0.02–0.04;CFI/TLI = 0.97/0.96; SRMR = 0.04). After controlling for covariates (age, sex, race), results showed higherlatent E/PA associated with a steeper diurnal slope (Standardized ˇ = −0.19, p = 0.02) and smaller CAR(Standardized ˇ = −0.26, p = 0.004), whereas N/NA did not associate with any cortisol metric (Standard-ized ˇ’s = −0.12 to 0.13, p’s = 0.10 to 0.53). These findings suggest that positive emotionality may be moreclosely associated with indices of diurnal cortisol release than negative emotionality
Sequential Effects in Judgements of Attractiveness: The Influences of Face Race and Sex
In perceptual decision-making, a person’s response on a given trial is influenced by their response on the immediately preceding trial. This sequential effect was initially demonstrated in psychophysical tasks, but has now been found in more complex, real-world judgements. The similarity of the current and previous stimuli determines the nature of the effect, with more similar items producing assimilation in judgements, while less similarity can cause a contrast effect. Previous research found assimilation in ratings of facial attractiveness, and here, we investigated whether this effect is influenced by the social categories of the faces presented. Over three experiments, participants rated the attractiveness of own- (White) and other-race (Chinese) faces of both sexes that appeared successively. Through blocking trials by race (Experiment 1), sex (Experiment 2), or both dimensions (Experiment 3), we could examine how sequential judgements were altered by the salience of different social categories in face sequences. For sequences that varied in sex alone, own-race faces showed significantly less opposite-sex assimilation (male and female faces perceived as dissimilar), while other-race faces showed equal assimilation for opposite- and same-sex sequences (male and female faces were not differentiated). For sequences that varied in race alone, categorisation by race resulted in no opposite-race assimilation for either sex of face (White and Chinese faces perceived as dissimilar). For sequences that varied in both race and sex, same-category assimilation was significantly greater than opposite-category. Our results suggest that the race of a face represents a superordinate category relative to sex. These findings demonstrate the importance of social categories when considering sequential judgements of faces, and also highlight a novel approach for investigating how multiple social dimensions interact during decision-making
The effects of nicotine on laser Doppler measures of cochlear blood flow
Anesthetized guinea pigs were given arterial bolus injections of saline or varying nicotine concentrations. Blood flow through the cochlea and skin were measured via laser Doppler and arterial blood pressure via an arterial cannula. Cochlear blood flow increased with low doses of nicotine but decreased with the highest dose, while blood pressure increased and skin flow decreased with all doses of nicotine. Control injections of saline vehicle had only minor and transient effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25801/1/0000364.pd
Potential role of angiotensin II in noise-induced increases in inner ear blood flow
Guinea pigs were exposed to 120 dB white noise for 30 min and evidenced a four-fold elevation in plasma concentration of the potent vasoconstricting hormone angiotensin II (AII). Anesthetized animals received intra-arterial injections of All at doses that approximated the endogenous levels measured following noise exposure. A marked decrease in skin blood flow was observed with a concomitant increase in cochlear blood flow as measured by laser Doppler flowmeters. Increased cochlear blood flow appeared to be secondary to the increases in systemic blood pressure induced by AII. These findings suggest that cochlear blood flow may increase during periods of intense noise exposure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25806/1/0000369.pd
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