26,858 research outputs found

    Interaction of Human Chorionic Gonadotropin (hCG) and Asialo-hCG with Recombinant Human Thyrotropin Receptor.

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    hCG is a putative thyroid stimulator. The present studies were undertaken to examine its interaction and that of its desialylated variant asialo-hCG with recombinant human TSH (hTSH) receptor (hTSHr). To this end, we transfected a human thyroid carcinoma cell line (HTC) lacking endogenous TSHr with the full-length cDNA of the hTSHr. Unlike the wild type, the transfected cells, termed HTC-TSHr cells, were able to bind bovine TSH (bTSH) with high affinity and increase cAMP production in response to bTSH stimulation. Of the hCG forms, intact hCG displayed a weak activity to inhibit [125I] bTSH binding to HTC-TSHr cells, with 100 mg/L (2.6 x 10(-6) mol/L) producing maximally a 20% inhibition, whereas asialo-hCG achieved half-maximum binding inhibition at a concentration of 8 mg/L (2.3 x 10(-7) mol/L). The inhibitory constant (Ki) of asialo-hCG for recombinant hTSHr was calculated from saturation experiments in the presence of variable doses of bTSH and a fixed concentration of asialo-hCG to be approximately 8 x 10(-8) mol/L. The interaction of asialo-hCG with TSHr was further assessed by studies of the direct binding of the radioactively labeled hormone to both HTC and HTC-TSHr cells. [125I]Asialo-hCG binding to HTC-TSHr cells was 4.7%, compared to 1.5% in the wild-type cells lacking TSHr and was displaceable by bTSH (0.1-100 IU/L), indicating specific binding of the tracer to TSHr. Functionally, hCG (up to 100 mg/L; 2.6 x 10(-6) mol/L) proved unable to evoke any significant cAMP response over basal values in HTC-TSHr cells, as did asialo-hCG. Asialo-hCG, but not hCG, inhibited bTSH-stimulated adenylate cyclase activity in the cells in a dose-dependent manner. In conclusion, the present data show that intact hCG binds only weakly to HTC-TSHr cells and produces no significant cAMP stimulation, which is at variance with data obtained in FRTL-5 and Chinese hamster ovary-TSHr cells, but in good accord with previous findings in human thyroid membranes. Asialo-hCG, on the other hand, strongly binds to recombinant TSHr and inhibits the cAMP response to bTSH in HTC-TSHr cells, indicating that the desialylated hCG variant directly interacts with the receptor and truly is an antagonist of the hTSHr

    The proteome of the calcified layer organic matrix of turkey (Meleagris gallopavo) eggshell

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    Background: Chicken eggshell mineralization is a prominent model for biomineralization not only because of its importance for avian reproduction but also because of the commercial interest associated with eggshell quality. An analysis and comparison of the protein constituents of eggshells of several species would contribute to a better understanding of the shell mineralization process. The recent publication of the turkey genome sequence now provides a basis for the in-depth analysis of the turkey eggshell proteome. Results: Proteomic analysis of turkey acid-soluble and acid-insoluble organic eggshell matrix yielded 697 identified proteins/protein groups. However, intensity-based absolute quantification (iBAQ) results indicated that the 47 most abundant identified proteins already constituted 95% of the total turkey eggshell matrix proteome. Forty-four of these proteins were also identified in chicken eggshell matrix previously. Despite these similarities there were important and unexpected differences. While ovocleidin-116 and ovocalyxin-36 were major proteins constituting approximately 37% of the identified proteome, other members of the group of so-called eggshell-specific proteins were not identified. Thus ovocalyxin-21 and ovocalyxin-32 were missing among matrix proteins. Conversely, major turkey eggshell proteins were not detected in chicken, such as the bone protein periostin, the mammalian counterpart of which is involved in many aspects of bone metabolism and which represented 10-11% of the total identified proteome. Conclusions: Even members of the same avian family show important differences in eggshell matrix composition and more studies on the proteome and the transcriptome level will be necessary to identify a common toolkit of eggshell mineralization and to work out species differences among functional eggshell protein sets and their role in eggshell production

    Research and development at ORNL/CESAR towards cooperating robotic systems for hazardous environments

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    One of the frontiers in intelligent machine research is the understanding of how constructive cooperation among multiple autonomous agents can be effected. The effort at the Center for Engineering Systems Advanced Research (CESAR) at the Oak Ridge National Laboratory (ORNL) focuses on two problem areas: (1) cooperation by multiple mobile robots in dynamic, incompletely known environments; and (2) cooperating robotic manipulators. Particular emphasis is placed on experimental evaluation of research and developments using the CESAR robot system testbeds, including three mobile robots, and a seven-axis, kinematically redundant mobile manipulator. This paper summarizes initial results of research addressing the decoupling of position and force control for two manipulators holding a common object, and the path planning for multiple robots in a common workspace

    Intermediate left-right gauge symmetry, unification of couplings and fermion masses in SUSY SO(10)×S4SO(10)\times S_4

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    If left-right gauge theory occurs as an intermediate symmetry in a GUT then, apart from other advantages, it is possible to obtain the see-saw scale necessary to understand small neutrino masses with Majorana coupling of order unity. Barring threshold or non-renormalizable gravitational effects, or assumed presence of additional light scalar particles of unprescribed origin, all other attempts to achieve manifest one-loop gauge coupling unification in SUSY SO(10) with left-right intermediate symmetry have not been successful so far. Attributing this failure to lack of flavor symmetry in the GUT, we show how the spontaneous symmetry breaking of SO(10)×S4SO(10)\times S_4 leads to such intermediate scale extending over a wide range, MR≃5×109M_R \simeq 5\times 10^{9} GeV to 101510^{15} GeV. All the charged fermion masses are fitted at the see-saw scale, MN≃MR≃4×1013M_N\simeq M_R \simeq 4 \times 10^{13} GeV which is obtained with Majorana coupling f0≃1f_0 \simeq 1. Using a constrained parametrization in which CP-violation originates only from quark sector, besides other predictions made in the neutrino sector, the reactor mixing angle is found to be θ13≃3∘−5∘\theta_{13} \simeq 3^{\circ} - 5^{\circ} which is in the range accessible to ongoing and planned experiments. The leptonic Dirac phase turns out to be δ∼2.9−3.1\delta \sim 2.9- 3.1 radians with Jarlskog invariant J∼2.95×10−5−10−3J \sim 2.95 \times 10^{-5} - 10^{-3}.Comment: Minor clarification and few references added to match the published versio

    Proteome Sci.

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    Hawking Radiation in the Dilaton Gravity with a Non-Minimally Coupled Scalar Field

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    We discuss the two-dimensional dilaton gravity with a scalar field as the source matter where the coupling with the gravity is given, besides the minimal one, through an external field. This coupling generalizes the conformal anomaly in the same way as those found in recent literature, but with a diferent motivation. The modification to the Hawking radiation is calculated explicity and shows an additional term that introduces a dependence on the (effective) mass of the black-hole.Comment: 13 pages, latex file, no figures, to be published in IJM

    Reactor antineutrino spectra and their application to antineutrino-induced reactions. II

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    The antineutrino and electron spectra associated with various nuclear fuels are calculated. While there are substantial differences between the spectra of different uranium and plutonium isotopes, the dependence on the energy and flux of the fission-inducing neutrons is very weak. The resulting spectra can be used for the calculation of the antineutrino and electron spectra of an arbitrary nuclear reactor at various stages of its refueling cycle. The sources of uncertainties in the spectrum are identified and analyzed in detail. The exposure time dependence of the spectrum is also discussed. The averaged cross sections of the inverse neutron β decay, weak charged and neutral-current-induced deuteron disintegration, and the antineutrino-electron scattering are then evaluated using the resulting ν̅_e spectra. [RADIOACTIVITY, FISSION 235U, 238U, (^239)Pu, (^240)Pu, (^241)Pu, antineutrino and electron spectra calculated. σ for ν̅ induced reactions analyzed.

    Higgs triplets at like-sign linear colliders and neutrino mixing

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    We study the phenomenology of the type-II seesaw model at a linear e^-e^- collider. We show that the process e^-e^- \rightarrow alpha^-beta^- (alpha, beta = e, mu, tau being charged leptons) mediated by a doubly charged scalar is very sensitive to the neutrino parameters, in particular the absolute neutrino mass scale and the Majorana CP-violating phases. We identify the regions in parameter space in which appreciable collider signatures in the channel with two like-sign muons in the final state are possible. This includes Higgs triplet masses beyond the reach of the LHC.Comment: 8 pages, 6 figure

    Hierarchical neutrino masses and mixing in non minimal-SU(5)

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    We consider the problem of neutrino masses and mixing within the framework of a non-minimal supersymmetric SU(5) model extended by adding a set of 1,24 chiral superfields accommodating three right-handed neutrinos. A Type I+III see-saw mechanism can then be realized giving rise to a hierarchical mass spectrum for the light neutrinos of the form m_3> m_2>> m_1 consistent with present data. The extra colored states are pushed to the unification scale by proton stability constraints, while the intermediate see-saw energy scale and the unification scale are maintained in phenomenologically acceptable ranges. We also examine the issue of large neutrino mixing hierarchy \theta_{23}> \theta_{12}>> \theta_{13} in the above framework of hierarchical neutrino masses.Comment: 12 pages, 1 figure, 1 table. Captions inserted, 2 sentences for clarification added, 2 references adde

    Study of a soft lander/support module for Mars missions. Volume 3 - Appendixes Final summary report

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    Soft lander support module for Mars missions - lunar module radar evaluation and vernier phase simulatio
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