1,531 research outputs found
Lysine mediation of neuroendocrine food regulation in guinea fowl
In poultry, obesity is partly influenced by food intake, and is increasingly becoming a nationwide problem. Hypothalamic food intake mechanisms are involved metabolically and neurologically via two peptide hormones, leptin and ghrelin, and the amino acid glutamate, which is enzymatically derived from lysine metabolism. We hypothesize that lysine homeostasis mediates regulation of feed intake and performance characteristics via the brain–liver axis through glutamate sensing. The objective was to examine the effects of lysine homeostasis in avian food regulation and performance through neuroendocrine signaling. One-day-old male French Guinea fowl (GF) keets (n = 270) were weighed and randomly assigned to 5 dietary treatments (0.80%, 0.86%, 0.92%, 1.10% control, and 1.22% lysine) in 3 replicates. At 4 and 8 wk of age 20% of experimental birds were randomly selected, weighed and euthanatized. The liver, pancreas, and hypothalamus were excised, snap frozen in liquid nitrogen and stored at –80°C until use. Tissue mRNA was extracted and cDNA synthesized for qPCR assays. Lysine at 0.80 and 0.86% hindered growth, development of digestive organs, expression of brain and liver glutamate and leptin receptors, and caused high mortality in GF. The fold change for metabotropic glutamate receptor I was lower (P \u3c 0.05) in liver and higher in brain at 0.86 and 0.92% than the control (1.10%) and 1.22% lysine. The 1.22% lysine exhibited highest expression of ionotropic glutamate receptor, while brain ghrelin receptor expression was highest at 0.86 and 0.92% lysine. Therefore, dietary lysine concentration may influence signaling pathways regulating food intake in brain-liver axis via glutamate synthesis
Mental Fatigue Negatively Influences Manual Dexterity and Anticipation Timing but not Repeated High-intensity Exercise Performance in Trained Adults
Kepler-432: a red giant interacting with one of its two long period giant planets
We report the discovery of Kepler-432b, a giant planet ()
transiting an evolved star with an orbital period of days. Radial velocities (RVs) reveal that
Kepler-432b orbits its parent star with an eccentricity of , which we also measure independently with
asterodensity profiling (AP; ), thereby confirming
the validity of AP on this particular evolved star. The well-determined
planetary properties and unusually large mass also make this planet an
important benchmark for theoretical models of super-Jupiter formation.
Long-term RV monitoring detected the presence of a non-transiting outer planet
(Kepler-432c; days), and adaptive optics imaging revealed a nearby
(0\farcs87), faint companion (Kepler-432B) that is a physically bound M dwarf.
The host star exhibits high signal-to-noise asteroseismic oscillations, which
enable precise measurements of the stellar mass, radius and age. Analysis of
the rotational splitting of the oscillation modes additionally reveals the
stellar spin axis to be nearly edge-on, which suggests that the stellar spin is
likely well-aligned with the orbit of the transiting planet. Despite its long
period, the obliquity of the 52.5-day orbit may have been shaped by star-planet
interaction in a manner similar to hot Jupiter systems, and we present
observational and theoretical evidence to support this scenario. Finally, as a
short-period outlier among giant planets orbiting giant stars, study of
Kepler-432b may help explain the distribution of massive planets orbiting giant
stars interior to 1 AU.Comment: 22 pages, 19 figures, 5 tables. Accepted to ApJ on Jan 24, 2015
(submitted Nov 11, 2014). Updated with minor changes to match published
versio
Recognition and Accommodation at the Androgen Receptor Coactivator Binding Interface
Prostate cancer is a leading killer of men in the industrialized world. Underlying this disease is the aberrant action of the androgen receptor (AR). AR is distinguished from other nuclear receptors in that after hormone binding, it preferentially responds to a specialized set of coactivators bearing aromatic-rich motifs, while responding poorly to coactivators bearing the leucine-rich “NR box” motifs favored by other nuclear receptors. Under normal conditions, interactions with these AR-specific coactivators through aromatic-rich motifs underlie targeted gene transcription. However, during prostate cancer, abnormal association with such coactivators, as well as with coactivators containing canonical leucine-rich motifs, promotes disease progression. To understand the paradox of this unusual selectivity, we have derived a complete set of peptide motifs that interact with AR using phage display. Binding affinities were measured for a selected set of these peptides and their interactions with AR determined by X-ray crystallography. Structures of AR in complex with FxxLF, LxxLL, FxxLW, WxxLF, WxxVW, FxxFF, and FxxYF motifs reveal a changing surface of the AR coactivator binding interface that permits accommodation of both AR-specific aromatic-rich motifs and canonical leucine-rich motifs. Induced fit provides perfect mating of the motifs representing the known family of AR coactivators and suggests a framework for the design of AR coactivator antagonists
Measurement of the Branching Fraction for B- --> D0 K*-
We present a measurement of the branching fraction for the decay B- --> D0
K*- using a sample of approximately 86 million BBbar pairs collected by the
BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is
detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the
K*- through its decay to K0S pi-. We measure the branching fraction to be
B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid
Communications
A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)
We present a measurement of time-dependent CP-violating asymmetries in
neutral B meson decays collected with the BABAR detector at the PEP-II
asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data
sample consists of 29.7 recorded at the
resonance and 3.9 off-resonance. One of the neutral B mesons,
which are produced in pairs at the , is fully reconstructed in
the CP decay modes , , , () and , or in flavor-eigenstate
modes involving and (). The flavor of the other neutral B meson is tagged at the time of
its decay, mainly with the charge of identified leptons and kaons. The proper
time elapsed between the decays is determined by measuring the distance between
the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample
finds . The value of the asymmetry amplitude is determined from
a simultaneous maximum-likelihood fit to the time-difference distribution of
the flavor-eigenstate sample and about 642 tagged decays in the
CP-eigenstate modes. We find , demonstrating that CP violation exists in the neutral B meson
system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review
Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions
The weak nucleon axial-vector form factor for quasi-elastic interactions is
determined using neutrino interaction data from the K2K Scintillating Fiber
detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of
which half are charged-current quasi-elastic interactions nu-mu n to mu- p
occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for
oxygen and assume the form factor is approximately a dipole with one parameter,
the axial vector mass M_A, and fit to the shape of the distribution of the
square of the momentum transfer from the nucleon to the nucleus. Our best fit
result for M_A = 1.20 \pm 0.12 GeV. Furthermore, this analysis includes updated
vector form factors from recent electron scattering experiments and a
discussion of the effects of the nucleon momentum on the shape of the fitted
distributions.Comment: 14 pages, 10 figures, 6 table
Study of e+e- --> pi+ pi- pi0 process using initial state radiation with BABAR
The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass
energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with
the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum
we have obtained the products of branching fractions for the omega and phi
mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0.06 +/- 0.27)10-5 and
B(phi --> e+e-)B(phi --> 3pi)=(4.30 +/- 0.08 +/- 0.21)10-5, and evaluated the
e+e- --> pi+ pi- pi0 cross section for the e+e- center-of-mass energy range
1.05 to 3.00 GeV. About 900 e+e- --> J/psi gamma --> pi+ pi- pi0 gamma events
have been selected and the branching fraction B(J/psi --> pi+ pi- pi0)=(2.18
+/- 0.19)% has been measured.Comment: 21 pages, 37 postscript figues, submitted to Phys. Rev.
Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction
We present evidence for the flavor-changing neutral current decay and a measurement of the branching fraction for the related
process , where is either an or
pair. These decays are highly suppressed in the Standard Model,
and they are sensitive to contributions from new particles in the intermediate
state. The data sample comprises
decays collected with the Babar detector at the PEP-II storage ring.
Averaging over isospin and lepton flavor, we obtain the branching
fractions and , where the
uncertainties are statistical and systematic, respectively. The significance of
the signal is over , while for it is .Comment: 7 pages, 2 postscript figues, submitted to Phys. Rev. Let
Measurement of Branching Fraction and Dalitz Distribution for B0->D(*)+/- K0 pi-/+ Decays
We present measurements of the branching fractions for the three-body decays
B0 -> D(*)-/+ K0 pi^+/-B0 -> D(*)-/+ K*+/- using
a sample of approximately 88 million BBbar pairs collected by the BABAR
detector at the PEP-II asymmetric energy storage ring.
We measure:
B(B0->D-/+ K0 pi+/-)=(4.9 +/- 0.7(stat) +/- 0.5 (syst)) 10^{-4}
B(B0->D*-/+ K0 pi+/-)=(3.0 +/- 0.7(stat) +/- 0.3 (syst)) 10^{-4}
B(B0->D-/+ K*+/-)=(4.6 +/- 0.6(stat) +/- 0.5 (syst)) 10^{-4}
B(B0->D*-/+ K*+/-)=(3.2 +/- 0.6(stat) +/- 0.3 (syst)) 10^{-4}
From these measurements we determine the fractions of resonant events to be :
f(B0-> D-/+ K*+/-) = 0.63 +/- 0.08(stat) +/- 0.04(syst) f(B0-> D*-/+ K*+/-) =
0.72 +/- 0.14(stat) +/- 0.05(syst)Comment: 7 pages, 3 figures submitted to Phys. Rev. Let
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