8,670 research outputs found
Numerical Evidence for the Observation of a Scalar Glueball
We compute from lattice QCD in the valence (quenched) approximation the
partial decay widths of the lightest scalar glueball to pairs of pseudoscalar
quark-antiquark states. These predictions and values obtained earlier for the
scalar glueball's mass are in good agreement with the observed properties of
and inconsistent with all other observed meson resonances.Comment: 12 pages of Latex, 3 PostsScript figures as separate uufil
Hybrid meson decay from the lattice
We discuss the allowed decays of a hybrid meson in the heavy quark limit. We
deduce that an important decay will be into a heavy quark non-hybrid state and
a light quark meson, in other words, the de-excitation of an excited gluonic
string by emission of a light quark-antiquark pair.
We discuss the study of hadronic decays from the lattice in the heavy quark
limit and apply this approach to explore the transitions from a spin-exotic
hybrid to and where is a scalar meson. We obtain a
signal for the transition emitting a scalar meson and we discuss the
phenomenological implications.Comment: 18 pages, LATEX, 3 ps figure
Light hadron spectroscopy with O(a) improved dynamical fermions
We present the first results for the static quark potential and the light
hadron spectrum using dynamical fermions at using an O(a) improved
Wilson fermion action together with the standard Wilson plaquette action for
the gauge part. Sea quark masses were chosen such that the pseudoscalar-vector
mass ratio, m_PS/m_V$, varies from 0.86 to 0.67. Finite-size effects are
studied by using three different volumes, 8^3\cdot 24, 12^3\cdot 24 and
16^3\cdot 24. Comparing our results to previous ones obtained using the
quenched approximation, we find evidence for sea quark effects in quantities
like the static quark potential and the vector-pseudoscalar hyperfine
splitting.Comment: 38 pages, 14 Postscript figure, LaTe
Glueball calculations in large-N_c gauge theory
We use the light-front Hamiltonian of transverse lattice gauge theory to
compute from first principles the glueball spectrum and light-front
wavefunctions in the leading order of the 1/N_c colour expansion. We find
0^{++}, 2^{++}, and 1^{+-} glueballs having masses consistent with N_c=3 data
available from Euclidean lattice path integral methods. The wavefunctions
exhibit a light-front constituent gluon structure.Comment: 4 pages, 2 figures, uses macro boxedeps.tex, minor corrections in
revised versio
INFLUENCE OF PHOSPHATE SOURCE ON VESICULAR-ARBUSCULAR MYCORRHIZAE OF \u3ci\u3eBOUTELOUA GRACILIS\u3c/i\u3e
Non-mycorrhizal and vesicular-arbuscular mycorrhizal Bouteloua gracilis infected with Glomus fasciculatus were grown in defined media containing different phosphate sources and compared with respect to phosphate content and form, biomass, chlorophyll concentration, and root phosphatase activity. The phosphate sources were sodium monobasic phosphate, a mixture of sodium monobasic phosphate and calcium phytate, and calcium phytate. Inositol and inositol plus calcium were added to the sodium phosphate medium as additional treatments. Mycorrhizal infection was highest in roots of plants grown in the presence of phytate (75%). Lower root infection levels were noted in plants from the sodium phosphate (19%) and mixed phosphate (22%) media. No penetration by fungi occurred in plants from the sodium phosphate plus inositol or inositol and calcium media. Dry wts of non-mycorrhizal plants were highest when grown in media containing phytate and sodium phosphate plus inositol and calcium followed in decreasing order by sodium phosphate plus inositol, mixed phosphates, and sodium phosphate. Mycorrhizal infection increased leaf dry wt in plants from the sodium phosphate medium and root dry wt from the phytate medium. Phosphate concentrations in the plants were highest when grown in mixed phosphate medium followed by sodium phosphate and phytate. Mycorrhizal infection always increased significantly leaf phosphate concentrations but increased root phosphate concentrations only in the phytate medium. Phosphates were found predominantly as organicallybound compounds in leaves of mycorrhizal plants whereas in leaves of non-mycorrhizal plants, most of the phosphate was inorganic. Chlorophyll concentrations increased significantly with mycorrhizal infection with no change in a/b ratios. Mycorrhizal plants grown in the phytate medium had substantially higher alkaline phosphatase activity than did non-mycorrhizal plants; acid phosphatase activity was not affected by mycorrhizal condition.
These results suggest that form of the phosphate in the root environment influences naycorrhizal establishment and effect of mycorrhizae on plant growth
INFLUENCE OF PHOSPHATE SOURCE ON VESICULAR-ARBUSCULAR MYCORRHIZAE OF \u3ci\u3eBOUTELOUA GRACILIS\u3c/i\u3e
Non-mycorrhizal and vesicular-arbuscular mycorrhizal Bouteloua gracilis infected with Glomus fasciculatus were grown in defined media containing different phosphate sources and compared with respect to phosphate content and form, biomass, chlorophyll concentration, and root phosphatase activity. The phosphate sources were sodium monobasic phosphate, a mixture of sodium monobasic phosphate and calcium phytate, and calcium phytate. Inositol and inositol plus calcium were added to the sodium phosphate medium as additional treatments. Mycorrhizal infection was highest in roots of plants grown in the presence of phytate (75%). Lower root infection levels were noted in plants from the sodium phosphate (19%) and mixed phosphate (22%) media. No penetration by fungi occurred in plants from the sodium phosphate plus inositol or inositol and calcium media. Dry wts of non-mycorrhizal plants were highest when grown in media containing phytate and sodium phosphate plus inositol and calcium followed in decreasing order by sodium phosphate plus inositol, mixed phosphates, and sodium phosphate. Mycorrhizal infection increased leaf dry wt in plants from the sodium phosphate medium and root dry wt from the phytate medium. Phosphate concentrations in the plants were highest when grown in mixed phosphate medium followed by sodium phosphate and phytate. Mycorrhizal infection always increased significantly leaf phosphate concentrations but increased root phosphate concentrations only in the phytate medium. Phosphates were found predominantly as organicallybound compounds in leaves of mycorrhizal plants whereas in leaves of non-mycorrhizal plants, most of the phosphate was inorganic. Chlorophyll concentrations increased significantly with mycorrhizal infection with no change in a/b ratios. Mycorrhizal plants grown in the phytate medium had substantially higher alkaline phosphatase activity than did non-mycorrhizal plants; acid phosphatase activity was not affected by mycorrhizal condition.
These results suggest that form of the phosphate in the root environment influences naycorrhizal establishment and effect of mycorrhizae on plant growth
Providing Feedback Following Leadership Walkrounds is Associated with Better Patient Safety Culture, Higher Employee Engagement and Lower Burnout
Background There is a poorly understood relationship between Leadership WalkRounds (WR) and domains such as safety culture, employee engagement, burnout and work-life balance. Methods This cross-sectional survey study evaluated associations between receiving feedback about actions taken as a result of WR and healthcare worker assessments of patient safety culture, employee engagement, burnout and work-life balance, across 829 work settings. Results 16 797 of 23 853 administered surveys were returned (70.4%). 5497 (32.7% of total) reported that they had participated in WR, and 4074 (24.3%) reported that they participated in WR with feedback. Work settings reporting more WR with feedback had substantially higher safety culture domain scores (first vs fourth quartile Cohen’s d range: 0.34–0.84; % increase range: 15–27) and significantly higher engagement scores for four of its six domains (first vs fourth quartile Cohen’s d range: 0.02–0.76; % increase range: 0.48–0.70). Conclusion This WR study of patient safety and organisational outcomes tested relationships with a comprehensive set of safety culture and engagement metrics in the largest sample of hospitals and respondents to date. Beyond measuring simply whether WRs occur, we examine WR with feedback, as WR being done well. We suggest that when WRs are conducted, acted on, and the results are fed back to those involved, the work setting is a better place to deliver and receive care as assessed across a broad range of metrics, including teamwork, safety, leadership, growth opportunities, participation in decision-making and the emotional exhaustion component of burnout. Whether WR with feedback is a manifestation of better norms, or a cause of these norms, is unknown, but the link is demonstrably potent
Adaptive Step Size for Hybrid Monte Carlo Algorithm
We implement an adaptive step size method for the Hybrid Monte Carlo a
lgorithm. The adaptive step size is given by solving a symmetric error
equation. An integr ator with such an adaptive step size is reversible.
Although we observe appreciable variations of the step size, the overhead of
the method exceeds its benefits. We propose an explanation for this phenomenon.Comment: 13 pages, 5 Postscript figures, late
Role of Asian summer monsoon subsystems in the inter-hemispheric progression of deglaciation
The responses of Asian monsoon subsystems to both hemispheric climate forcing and external orbital forcing are currently issues of vigorous debate. The Indian summer monsoon is the dominant monsoon subsystem in terms of energy flux, constituting one of Earth’s most dynamic expressions of ocean–atmosphere interactions. Yet, the Indian summer monsoon is grossly under-represented in Asian monsoon palaeoclimate records. Here, we present high-resolution records of Indian summer monsoon- induced rainfall and fluvial runoff recovered in a sediment core from the Bay of Bengal across Termination II, 139–127 thousand years ago, including coupled measurements of the oxygen isotopic composition and Mg/Ca, Mn/Ca, Nd/Ca and U/Ca ratios in surface-ocean-dwelling foraminifera. Our data reveal a millennial-scale transient strengthening of the Asian monsoon that punctuates Termination II associated with an oscillation of the bipolar seesaw. The progression of deglacial warming across Termination II emerges first in the Southern Hemisphere, then the tropics in tandem with Indian summer monsoon strengthening, and finally the Northern Hemisphere. We therefore suggest that the Indian summer monsoon was a conduit for conveying Southern Hemisphere latent heat northwards, thereby promoting subsequent Northern Hemisphere deglaciation
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