1,140 research outputs found
Effects of Monensin on metabolic profile and feeding behavior of transition dairy cows
Thirty-two Holstein transition cows were used to determine the effects of monensin (Rumensin, Elanco Animal Health, Greenfield, IN; 400 mg/cow daily) on metabolism and feeding behavior. Cows were assigned randomly, based on calving date, to control or monensin treatments (n = 16 per treatment) 21 days before their expected calving date, and cows remained on treatments through 21 days in milk. Feeding behavior and water intake data were collected daily. Blood samples were collected at 8 different time points during the experimental period. Monensin decreased mean and peak plasma ketone concentrations, and also decreased time between meals before and after calving. No effects of monensin supplementation were observed on milk production or other metabolic traits. Furthermore, we observed no treatment effects on disease incidence, although sample size was small for detecting such effects.; Dairy Day, 2011, Kansas State University, Manhattan, KS, 2011; Dairy Research, 2011 is known as Dairy Day, 201
Propagators on the two-dimensional light-cone
Light-cone quantization procedure recently presented is applied to the
two-dimensional light-cone theories. By introducing the two distinct null
planes it is shown that the modification term in the two-dimensional massless
light-cone propagators suggested about twenty years ago vanishs.Comment: LATEX, 9page
The One-loop Open Superstring Massless Five-point Amplitude with the Non-Minimal Pure Spinor Formalism
We compute the massless five-point amplitude of open superstrings using the
non-minimal pure spinor formalism and obtain a simple kinematic factor in pure
spinor superspace, which can be viewed as the natural extension of the
kinematic factor of the massless four-point amplitude. It encodes bosonic and
fermionic external states in supersymmetric form and reduces to existing
bosonic amplitudes when expanded in components, therefore proving their
equivalence. We also show how to compute the kinematic structures involving
fermionic states.Comment: 38 pages, harvmac TeX, v2: fix typo in (4.2) and add referenc
The Product Replacement Prospector
AbstractWe present a heuristic extension to the product replacement algorithm, called the Prospector. The aim is to find hopefully good quality ârandomâ elements with short straight line programs in the given generators. This is achieved by saving the random state at certain points and later restoring it. Statistical tests are employed in order to determine when to save the state. We also give evidence for the surprisingly good effect of using an accelerator. The Prospector has been implemented in Magma, and experimental evidence is provided which indicates that it is a very practical method
Excited B mesons from the lattice
We determine the energies of the excited states of a heavy-light meson
, with a static heavy quark and light quark with mass approximately
that of the strange quark from both quenched lattices and with dynamical
fermions. We are able to explore the energies of orbital excitations up to L=3,
the spin-orbit splitting up to L=2 and the first radial excitation. These mesons will be very narrow if their mass is less than 5775 MeV -- the
threshold. We investigate this in detail and present evidence that the
scalar meson (L=1) will be very narrow and that as many as 6
excited states will have energies close to the threshold and should also
be relatively narrow.Comment: 17 pages, 6 ps figure
Exactly solvable model of superstring in Ramond-Ramond plane wave background
We describe in detail the solution of type IIB superstring theory in the
maximally supersymmetric plane-wave background with constant null Ramond-Ramond
5-form field strength. The corresponding light-cone Green-Schwarz action found
in hep-th/0112044 is quadratic in both bosonic and fermionic coordinates. We
find the spectrum of the light-cone Hamiltonian and the string representation
of the supersymmetry algebra. The superstring Hamiltonian has a
``harmonic-oscillator'' form in both the string-oscillator and the zero-mode
parts and thus has discrete spectrum in all 8 transverse directions. We analyze
the structure of the zero-mode sector of the theory, establishing the precise
correspondence between the lowest-lying ``massless'' string states and the type
IIB supergravity fluctuation modes in the plane-wave background. The zero-mode
spectrum has certain similarity to the supergravity spectrum in AdS_5 x S^5 of
which the plane-wave background is a special limit. We also compare the
plane-wave string spectrum with expected form of the light-cone gauge spectrum
of superstring in AdS_5 x S^5.Comment: 33 pages, latex. v4: minor sign corrections in (1.5) and (3.62), to
appear in PR
Baryogenesis in Cosmological Model with Superstring-Inspired E_6 Unification
We have developed a concept of parallel existence of the ordinary (O) and
hidden (H) worlds with a superstring-inspired E_6 unification, broken at the
early stage of the Universe into SO(10) X U(1) - in the O-world, and SU(6)' X
SU(2)' - in the H-world. As a result, we have obtained in the hidden world the
low energy symmetry group G'_SM X SU(2)'_\theta, instead of the Standard Model
group G_SM. The additional non-Abelian SU(2)'_\theta group with massless gauge
fields, "thetons", is responsible for the dark energy. We present a
baryogenesis mechanism with the B-L asymmetry produced by the conversion of
ordinary leptons into particles of the hidden sector.Comment: 15 pages, 2 figure
Pure Spinor Superspace Identities for Massless Four-point Kinematic Factors
Using the pure spinor formalism we prove identities which relate the
tree-level, one-loop and two-loop kinematic factors for massless four-point
amplitudes. From these identities it follows that the complete supersymmetric
one- and two-loop amplitudes are immediately known once the tree-level
kinematic factor is evaluated. In particular, the two-loop equivalence with the
RNS formalism (up to an overall coefficient) is obtained as a corollary.Comment: 10 pages, harvmac TeX. v2: Updated affiliation and Report-no
Some Superstring Amplitude Computations with the Non-Minimal Pure Spinor Formalism
We use the non-minimal pure spinor formalism to compute in a super-Poincare
covariant manner the four-point massless one and two-loop open superstring
amplitudes, and the gauge anomaly of the six-point one-loop amplitude. All of
these amplitudes are expressed as integrals of ten-dimensional superfields in a
"pure spinor superspace" which involves five coordinates covariantly
contracted with three pure spinors. The bosonic contribution to these
amplitudes agrees with the standard results, and we demonstrate identities
which show how the and tensors naturally emerge from
integrals over pure spinor superspace.Comment: 20 pages, harvmac te
DDF Construction and D-Brane Boundary States in Pure Spinor Formalism
Open string boundary conditions for non-BPS D-branes in type II string
theories discussed in hep-th/0505157 give rise to two sectors with integer (R
sector) and half-integer (NS sector) modes for the combined fermionic matter
and bosonic ghost variables in pure spinor formalism. Exploiting the manifest
supersymmetry of the formalism we explicitly construct the DDF (Del Giudice, Di
Vecchia, Fubini) states in both the sectors which are in one-to-one
correspondence with the states in light-cone Green-Schwarz formalism. We also
give a proof of validity of this construction. A similar construction in the
closed string sector enables us to define a physical Hilbert space in pure
spinor formalism which is used to project the covariant boundary states of both
the BPS and non-BPS instantonic D-branes. These projected boundary states take
exactly the same form as those found in light-cone Green-Schwarz formalism and
are suitable for computing the cylinder diagram with manifest open-closed
duality.Comment: 37 pages, typos corrected, some organisational changes mad
- âŠ