A combination of l-arabinose and chromium lowers circulating glucose and insulin levels after an acute oral sucrose challenge

<p>Abstract</p> <p>Background</p> <p>A growing body of research suggests that elevated circulating levels of glucose and insulin accelerate risk factors for a wide range of disorders. Low-risk interventions that could suppress glucose without raising insulin levels could offer significant long-term health benefits.</p> <p>Methods</p> <p>To address this issue, we conducted two sequential studies, the first with two phases. In the first phase of Study 1, baseline fasting blood glucose was measured in 20 subjects who consumed 70 grams of sucrose in water and subsequently completed capillary glucose measurements at 30, 45, 60 and 90 minutes (Control). On day-2 the same procedure was followed, but with subjects simultaneously consuming a novel formula containing l-arabinose and a trivalent patented food source of chromium (LA-Cr) (Treatment). The presence or absence of the LA-Cr was blinded to the subjects and testing technician. Comparisons of changes from baseline were made between Control and Treatment periods. In the second phase of Study 1, 10 subjects selected from the original 20 competed baseline measures of body composition (DXA), a 43-blood chemistry panel and a Quality of Life Inventory. These subjects subsequently took LA-Cr daily for 4 weeks completing daily tracking forms and repeating the baseline capillary tests at the end of each of the four weeks. In Study 2, the same procedures used in the first phase were repeated for 50 subjects, but with added circulating insulin measurements at 30 and 60 minutes from baseline.</p> <p>Results</p> <p>In both studies, as compared to Control, the Treatment group had significantly lower glucose responses for all four testing times (AUC = <it>P </it>< 0.0001). Additionally, the Treatment was significantly more effective in lowering circulating insulin after 60 minutes from baseline (AUC = <it>P </it>= < 0.01). No adverse effects were found after acute sucrose challenge or in those who consumed LA-Cr daily for four weeks.</p> <p>Conclusions</p> <p>As compared to a placebo control, consumption of a LA-Cr formula after a 70-gram sucrose challenge was effective in safely lowering both circulating glucose and insulin levels.</p> <p>Trial Registration</p> <p>Clinical Trials.gov, <a href="http://www.clinicaltrials.gov/ct2/show/NCT0110743">NCT0110743</a></p

Kink Structure in the Quasiparticle Band of Doped Hubbard Systems

By making use of the self-consistent projection operator method with high-momentum and high-energy resolutions, we find a kink structure in the quasiparticle excitation spectrum of the two-dimensional Hubbard model in the underdoped regime. The kink is caused by a mixing between the quasiparticle state and excitations with short-range antiferromagnetic order. We suggest that this might be the origin of the strong concentration dependence of the 'kink' found in La_{2-x}Sr_{x}CuO_{4} (x=0.03-0.07).Comment: 3 pages, 4 figures. to be published in J. Phys. Soc. Jpn., Vol. 74, No. 9, September 15, 200

Strong-Coupling Expansion for the Hubbard Model

A strong-coupling expansion for models of correlated electrons in any dimension is presented. The method is applied to the Hubbard model in $d$ dimensions and compared with numerical results in $d=1$. Third order expansion of the Green function suffices to exhibit both the Mott metal-insulator transition and a low-temperature regime where antiferromagnetic correlations are strong. It is predicted that some of the weak photoemission signals observed in one-dimensional systems such as $SrCuO_2$ should become stronger as temperature increases away from the spin-charge separated state.Comment: 4 pages, RevTex, 3 epsf figures include

Tidal Dynamics in Cosmological Spacetimes

We study the relative motion of nearby free test particles in cosmological spacetimes, such as the FLRW and LTB models. In particular, the influence of spatial inhomogeneities on local tidal accelerations is investigated. The implications of our results for the dynamics of the solar system are briefly discussed. That is, on the basis of the models studied in this paper, we estimate the tidal influence of the cosmic gravitational field on the orbit of the Earth around the Sun and show that the corresponding temporal rate of variation of the astronomical unit is negligibly small.Comment: 12 pages, no figures, REVTeX 4.0; appendix added, new references, and minor changes throughout; to appear in Classical and Quantum Gravity; v4: error in (A24) of Appendix A corrected, results and conclusions unchanged. We thank L. Iorio for pointing out the erro

Shadow band in the one-dimensional large UU Hubbard model

We show that the factorized wave-function of Ogata and Shiba can be used to calculate the $k$ dependent spectral functions of the one-dimensional, infinite $U$ Hubbard model, and of some extensions to finite $U$. The resulting spectral function is remarkably rich: In addition to low energy features typical of Luttinger liquids, there is a well defined band, which we identify as the shadow band resulting from $2k_F$ spin fluctuations. This band should be detectable experimentally because its intensity is comparable to that of the main band for a large range of momenta.Comment: Latex file. 4 pages. Figures upon reques

Critical Properties of Spectral Functions for the 1D Anisotropic t-J Models with an Energy Gap

We exactly calculate the momentum-dependent critical exponents for spectral functions in the one-dimensional anisotropic t-J models with a gap either in the spin or charge excitation spectrum. Our approach is based on the Bethe ansatz technique combined with finite-size scaling techniques in conformal field theory. It is found that the spectral functions show a power-law singularity, which occurs at frequencies determined by the dispersion of a massive spin (or charge) excitation.We discuss how the nontrivial contribution of a massive excitation controls the singular behavior in optical response functions.Comment: 4 pages, REVTeX, 2 figures(available upon request), accepted for publication in JPSJ 66 (1997) No.

Spectral function of the 1D Hubbard model in the U→+∞U\to +\infty limit

We show that the one-particle spectral functions of the one-dimensional Hubbard model diverge at the Fermi energy like $|\omega-\varepsilon_F|^{-3/8}$ in the $U\to +\infty$ limit. The Luttinger liquid behaviour $|\omega-\varepsilon_F|^\alpha$, where $\alpha \to 1/8$ as $U\to +\infty$, should be limited to $|\omega-\varepsilon_F| \sim t^2/U$ (for $U$ large but finite), which shrinks to a single point, $\omega=\varepsilon_F$,in that limit. The consequences for the observation of the Luttinger liquid behaviour in photoemission and inverse photoemission experiments are discussed.Comment: 4 pages, RevTeX, 2 figures on reques

Cosmic Swarms: A search for Supermassive Black Holes in the LISA data stream with a Hybrid Evolutionary Algorithm

We describe a hybrid evolutionary algorithm that can simultaneously search for multiple supermassive black hole binary (SMBHB) inspirals in LISA data. The algorithm mixes evolutionary computation, Metropolis-Hastings methods and Nested Sampling. The inspiral of SMBHBs presents an interesting problem for gravitational wave data analysis since, due to the LISA response function, the sources have a bi-modal sky solution. We show here that it is possible not only to detect multiple SMBHBs in the data stream, but also to investigate simultaneously all the various modes of the global solution. In all cases, the algorithm returns parameter determinations within $5\sigma$ (as estimated from the Fisher Matrix) of the true answer, for both the actual and antipodal sky solutions.Comment: submitted to Classical & Quantum Gravity. 19 pages, 4 figure

Quasiparticle structure and coherent propagation in the t−Jz−J⊥t-J_{z}-J_{\perp} model

Numerical studies, from variational calculation to exact diagonalization, all indicate that the quasiparticle generated by introducing one hole into a two-dimensional quantum antiferromagnet has the same nature as a string state in the $t-J_{z}$ model. Based on this observation, we attempt to visualize the quasiparticle formation and subsequent coherent propagation at low energy by studying the generalized $t-J_{z}-J_{\perp}$ model in which we first diagonalize the $t-J_{z}$ model and then perform a {\em degenerate} perturbation in $J_{\perp}$. We construct the quasiparticle state and derive an effective Hamiltonian describing the coherent propagation of the quasiparticle and its interaction with the spin wave excitations in the presence of the N\'{e}el order. We expect that qualitative properties of the quasiparticle remain intact when analytically continuing $J_{\perp}$ from the anisotropic $J_{\perp} < J_{z}$ to the isotropic $J_{\perp} = J_{z}$ limit, despite the fact that the spin wave excitations change from gapful to gapless. Extrapolating to $J_{\perp}=J_{z}$, our quasiparticle dispersion and spectral weight compare well with the exact numerical results for small clusters.Comment: Revised with minor changes and references updated. To appear in Phys. Rev. B., Jan. 1996. 10 pages, The complete PostScript file including figures can be obtained via ftp at ftp://serval.berkeley.edu/tjzjp.ps . It is also posted in the WEB site of Niels Bohr Institute at http://roemer.fys.ku.dk/recent.ht