7,567 research outputs found
Meson spectroscopy and properties using Dyson-Schwinger equations
We study pseudoscalar and scalar mesons using a practical and symmetry
preserving truncation of QCD's Dyson-Schwinger equations. We investigate and
compare properties of ground and radially excited meson states. In addition to
exact results for radial meson excitations we also present results for meson
masses and decay constants from the chiral limit up to the charm-quark mass, e.
g., the mass of the chi_{c0} (2P) meson.Comment: 8 pages, 3 figures, To appear in the proceedings of 9th International
Workshop on Meson Production, Properties and Interaction (Meson2006), Krakow,
Poland, 9 - 13 June 200
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Hydropyrolysis of high molecular weight organic matter in Murchison
Hydropyrolysis of the Murchison macromolecular material releases polyaromatic compounds including phenanthrene, carbazole, fluoranthene, pyrene, chrysene, perylene, benzoperylene and coronene units with varying degrees of alklyation
Pharmacist-led management of chronic pain in primary care:results from a randomised controlled exploratory trial
To compare the effectiveness of pharmacist medication review, with or without pharmacist prescribing, with standard care, for patients with chronic pain
A cohort study of influences, health outcomes and costs of patients' health-seeking behaviour for minor ailments from primary and emergency care settings
To compare health-related and cost-related outcomes of consultations for symptoms suggestive of minor ailments in emergency departments (EDs), general practices and community pharmacies
Gas-phase CO2 emission toward Cepheus A East: the result of shock activity?
We report the first detection of gas-phase CO2 emission in the star-forming
region Cepheus A East, obtained by spectral line mapping of the v2 bending mode
at 14.98 micron with the Infrared Spectrograph (IRS) instrument onboard the
Spitzer Space Telescope. The gaseous CO2 emission covers a region about 35'' x
25'' in extent, and results from radiative pumping by 15 micron continuum
photons emanating predominantly from the HW2 protostellar region. The gaseous
CO2 exhibits a temperature distribution ranging from 50 K to 200 K. A
correlation between the gas-phase CO2 distribution and that of H2 S(2), a
tracer of shock activity, indicates that the CO2 molecules originate in a cool
post-shock gas component associated with the outflow powered by HW2. The
presence of CO2 ice absorption features at 15.20 micron toward this region and
the lack of correlation between the IR continuum emission and the CO2 gas
emission distribution further suggest that the gaseous CO2 molecules are mainly
sputtered off grain mantles -- by the passage of slow non-dissociative shocks
with velocities of 15-30 km/s -- rather than sublimated through grain heating.Comment: 11 pages, 6 figures, accepted for publication in ApJ
The Relationship Between HR Practices and Firm Performance: Examining Causal Order
Significant research attention has been devoted to examining the relationship between HR practices and firm performance, and the research support has assumed HR as the causal variable. Using data from 45 business units (with 62 data points), this study examines how measures of HR practices correlate with past, concurrent, and future operational performance measures. The results indicate that correlations with performance measures at all three times are both high and invariant, and that controlling for past or concurrent performance virtually eliminates the correlation of HR with future performance. Implications are discussed
How many neutrophils are enough (redux, redux)?
Many chemotherapeutic regimens produce neutropenia, which predisposes to microbial infection. However, not all neutropenic individuals develop infections, so the ability to predict this outcome would be a powerful clinical tool. In this issue of the JCI, Malka et al. describe a dynamic system model of neutrophil bactericidal activity that confirms and extends the concept of critical neutrophil concentration. The authors demonstrate that when the neutrophil concentration approaches the critical concentration, bacterial populations in contact with them exhibit bistability. Their experimental findings raise the intriguing possibility of greater variability in bactericidal activity of neutrophils from healthy adults than heretofore recognized; their model predicts that this could have life-and-death consequences
Bifidobacterium breve reduces apoptotic epithelial cell shedding in an exopolysaccharide and MyD88-dependent manner
Certain members of the microbiota genus Bifidobacterium are known to positively influence host well-being. Importantly, reduced bifidobacterial levels are associated with inflammatory bowel disease (IBD) patients, who also have impaired epithelial barrier function, including elevated rates of apoptotic extrusion of small intestinal epithelial cells (IECs) from villiâa process termed âcell sheddingâ. Using a mouse model of pathological cell shedding, we show that mice receiving Bifidobacterium breve UCC2003 exhibit significantly reduced rates of small IEC shedding. Bifidobacterial-induced protection appears to be mediated by a specific bifidobacterial surface exopolysaccharide and interactions with host MyD88 resulting in downregulation of intrinsic and extrinsic apoptotic responses to protect epithelial cells under highly inflammatory conditions. Our results reveal an important and previously undescribed role for B. breve, in positively modulating epithelial cell shedding outcomes via bacterial- and host-dependent factors, supporting the notion that manipulation of the microbiota affects intestinal disease outcomes
Rotation periods of exoplanet host stars
The stellar rotation periods of ten exoplanet host stars have been determined
using newly analysed Ca II H & K flux records from Mount Wilson Observatory and
Stromgren b, y photometric measurements from Tennessee State University's
automatic photometric telescopes (APTs) at Fairborn Observatory. Five of the
rotation periods have not previously been reported, with that of HD 130322 very
strongly detected at Prot = 26.1 \pm 3.5 d. The rotation periods of five other
stars have been updated using new data. We use the rotation periods to derive
the line-of-sight inclinations of the stellar rotation axes, which may be used
to probe theories of planet formation and evolution when combined with the
planetary orbital inclination found from other methods. Finally, we estimate
the masses of fourteen exoplanets under the assumption that the stellar
rotation axis is aligned with the orbital axis. We calculate the mass of HD
92788 b (28 MJ) to be within the low-mass brown dwarf regime and suggest that
this object warrants further investigation to confirm its true nature.Comment: Accepted for publication in MNRAS. 15 pages, 11 figure
Adolescentsâ preferences for sexual dimorphism are influenced by relative exposure to male and female faces
Exposure to a particular population of faces can increase ratings of the normality and attractiveness of similar-looking faces. Such exposure can also refine the perceived boundaries of that face population, such that other faces are more readily perceived as dissimilar. We predicted that relatively less exposure to opposite-sex faces, as experienced by children at single-sex compared with mixed-sex schools, would decrease ratings of the attractiveness of sexual dimorphism in opposite-sex faces (that is, boys at single-sex schools would show a decreased preference for feminised faces, and girls at single-sex schools would show a decreased preference for masculinised faces). Consistent with this prediction, girls at single-sex compared with mixed-sex schools demonstrated significantly stronger preferences for facial femininity in both male and female faces. Boys at single-sex compared with mixed-sex schools demonstrated marginally stronger preferences for facial masculinity in male faces, but did not differ in their ratings of female faces. These effects were attenuated among some single-sex school pupils by the presence of adolescent opposite-sex siblings. These data add to the evidence that long-term exposure to a particular face population can influence judgements of other faces, and contribute to our understanding of the factors leading to individual differences in face preferences
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