481 research outputs found
Comparative Study on the Natural and Synthetic Hormones ofClarias gariepinus Broodstock
The study was carried out for six (6) weeks at the Department of Fisheries Teaching and Research farm, Modibbo Adama University, Yola, to compare the reproductive performance of Clarias gariepinus using synthetic (ovaprim) and natural (C. gariepinus pituitary extract) hormones . At the end of the feeding trial, the fecundity, percentage fertilization, hatchability, and survival rates of the hatchlings were estimated using standard procedure. The hatchlings were further raised for six weeks and the increase in weight was determined. The results showed that female broodstock injected with C. gariepinus pituitary extract (CgPE) had a higher fecundity (124,000) while the female injected with Ovaprim had 65,000 eggs. The weight of the testes significantly differed (p<0.05) across the treatments, the right lobe weighed 1.63g while the left lobe weighed 1.98g . Subsequently, a higher fertilization rate was recorded in CgPE (91.1%) while Ovaprim had 85.55% . However, Ovaprim had a higher percentage hatchability of 82.93% while CgPE had 82.73% . At the end of the six (6) weeks feeding period, the survival rate was higher in the fish treated with CgPE (82.31%) while the fish injected with Ovaprim had 79.68% . The research exposed the efficacy of using CgPE in the absence of synthetic hormone, CgPE is a preferred substitute that Hatchery managers can utilize for fingerlings production
Spiritual care for cancer patients in Iran
Background: Studies have shown that a return to spirituality is a major coping response in cancer patients so that therapists can adopt a holistic approach by addressing spirituality in their patient care. The present study was conducted to develop a guideline in the spiritual field for healthcare providers who serve cancer patients in Iran. Materials and Methods: Relevant statements were extracted from scientific documents that through study questions were reviewed and modified by a consensus panel. Results: The statements were arranged in six areas, including spiritual needs assessment, spiritual care candidates, the main components of spiritual care, spiritual care providers, the settings of spiritual care and the resources and facilities for spiritual care. Conclusions: In addition to the development and preparation of these guidelines, health policy-makers should also seek to motivate and train health service providers to offer these services and facilitate their provision and help with widespread implementation
QCD Corrections and the Endpoint of the Lepton Spectrum in Semileptonic B Decays
Recently, Neubert has suggested that a certain class of nonperturbative
corrections dominates the shape of the electron spectrum in the endpoint region
of semileptonic decay. Perturbative QCD corrections are important in the
endpoint region. We study the effects of these corrections on Neubert's
proposal. The connection between the endpoint of the electron spectrum in
semileptonic decay and the photon spectrum in is
outlined.Comment: 18 pages, uses REVTeX, UCSD/PTH 93-38, CALT-68-1910, JHU-TIPAC-930029
(some changes to the discussion of subleading radiative corrections, and
minor typos fixed
Branching ratio and CP asymmetry of decays in the perturbative QCD approach
In this paper, we calculate the decay rate and CP asymmetry of the decay in perturbative QCD approach with Sudakov resummation. Since
none of the quarks in final states is the same as those of the initial
meson, this decay can occur only via annihilation diagrams in the standard
model. Besides the current-current operators, the contributions from the QCD
and electroweak penguin operators are also taken into account. We find that (a)
the branching ratio is about ; (b) the penguin diagrams
dominate the total contribution; and (c) the direct CP asymmetry is small in
size: no more than ; but the mixing-induced CP asymmetry can be as large
as ten percent testable in the near future LHC-b experiments.Comment: 12 pages, 4 figures included, RevTe
Measurement of hybrid content of heavy quarkonia using lattice NRQCD
Using lowest-order lattice NRQCD to create heavy meson propagators and
applying the spin-dependent interaction, , at varying intermediate time slices, we
compute the off-diagonal matrix element of the Hamiltonian for the
quarkonium-hybrid two-state system. Thus far, we have results for one set of
quenched lattices with an interpolation in quark mass to match the bottomonium
spectrum. After diagonalization of the two-state Hamiltonian, we find the
ground state of the to show a (with ) probability admixture of hybrid, .Comment: 11 pages, 4 figures, to appear in Phys Rev
Two-loop matching of the dipole operators for and
The order corrections to the Wilson coefficients of the dipole
operators () at the matching scale are a crucial ingredient
for a complete next- to-leading logarithmic calculation of the branching ratio
for . Given the phenomenological relevance and the fact that
this two-loop calculation has been done so far only by one group [1], we
present a detailed re-calculation using a different method. Our results are in
complete agreement with those in ref. [1].Comment: 24 pages, latex, 6 figures include
Recalculation of QCD Corrections to Decay
We give a more complete calculation of decay, including
leading log QCD corrections from to in addition to corrections
from to . We have included the full set of dimension-6 operators
and corrected numerical mistakes of anomalous dimensions in a previous
paper\cite{Cho}. Comparing with the calculations without QCD running from
to \cite{Mis}, the inclusive decay rate is found to be enhanced.
At GeV, it results in 12\% enhancement, and for GeV, 15\% is
found. The total QCD effect makes an enhanced factor of 4.2 at GeV,
and 3.2 for GeV.Comment: 16 pages, 7 figures (uuencoded ps files), Changes of description. To
appear in Phys. Rev.
Scaling of the B and D meson spectrum in lattice QCD
We give results for the and the meson spectrum using NRQCD on the
lattice in the quenched approximation. The masses of radially and orbitally
excited states are calculated as well as -wave hyperfine and -wave fine
structure. Radially excited -states are observed for the first time. Radial
and orbital excitation energies match well to experiment, as does the
strange-non-strange -wave splitting. We compare the light and heavy quark
mass dependence of various splittings to experiment. Our -results cover a
range in lattice spacings of more than a factor of two. Our -results are
from a single lattice spacing and we compare them to numbers in the literature
from finer lattices using other methods. We see no significant dependence of
physical results on the lattice spacing.
PACS: 11.15.Ha 12.38.Gc 14.40.Lb 14.40.NdComment: 78 pages, 29 tables, 30 figures Revised version. Minor corrections to
spelling and wordin
Charmonium Spectrum from Quenched Anisotropic Lattice QCD
We present a detailed study of the charmonium spectrum using anisotropic
lattice QCD. We first derive a tree-level improved clover quark action on the
anisotropic lattice for arbitrary quark mass. The heavy quark mass dependences
of the improvement coefficients, i.e. the ratio of the hopping parameters
and the clover coefficients , are examined at the tree
level. We then compute the charmonium spectrum in the quenched approximation
employing anisotropic lattices. Simulations are made with
the standard anisotropic gauge action and the anisotropic clover quark action
at four lattice spacings in the range =0.07-0.2 fm. The clover
coefficients are estimated from tree-level tadpole improvement. On
the other hand, for the ratio of the hopping parameters , we adopt both
the tree-level tadpole-improved value and a non-perturbative one. We calculate
the spectrum of S- and P-states and their excitations. The results largely
depend on the scale input even in the continuum limit, showing a quenching
effect. When the lattice spacing is determined from the splitting, the
deviation from the experimental value is estimated to be 30% for the
S-state hyperfine splitting and 20% for the P-state fine structure. Our
results are consistent with previous results at obtained by Chen when
the lattice spacing is determined from the Sommer scale . We also address
the problem with the hyperfine splitting that different choices of the clover
coefficients lead to disagreeing results in the continuum limit.Comment: 43 pages, 49 eps figures, revtex; minor changes, version to appear in
Physical Review
Strong Phases and Factorization for Color Suppressed Decays
We prove a factorization theorem in QCD for the color suppressed decays B0->
D0 M0 and B0-> D*0 M0 where M is a light meson. Both the color-suppressed and
W-exchange/annihilation amplitudes contribute at lowest order in LambdaQCD/Q
where Q={mb, mc, Epi}, so no power suppression of annihilation contributions is
found. A new mechanism is given for generating non-perturbative strong phases
in the factorization framework. Model independent predictions that follow from
our results include the equality of the B0 -> D0 M0 and B0 -> D*0 M0 rates, and
equality of non-perturbative strong phases between isospin amplitudes,
delta(DM) = delta(D*M). Relations between amplitudes and phases for M=pi,rho
are also derived. These results do not follow from large Nc factorization with
heavy quark symmetry.Comment: 38 pages, 6 figs, typos correcte
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