Let V be a K3 surface defined over a number field k. The BatyrevManin conjecture for V states that for every nonempty open subset U of V , there exists a finite set ZU of accumulating rational curves such that the density of rational points on U − ZU is strictly less than the density of rational points on ZU . Thus, the set of rational points of V conjecturally admits a stratification correspon...

Let V be a generic quintic threefold in the 4-dimensional complex projective space P. A well-known conjecture of Clemens says that V has only a finite number of rational curves in each degree. Although Clemens’ conjecture is still quite open at this moment (it is known to be true for degree up to 7 by S. Katz [K]), recently physicists, based on the mirror symmetry principle, have proposed a for...

In patients with atrioventricular (A-V) nodal re-entrant paroxysmal supraventricular tachycardia (PSVT), atrial extrastimulus technique frequently reveals discontinuous A1-A2, H1-H2 curves suggestive of dual A-V nodal pathways. To further test the hypothesis that these curves in fact reflect dual A-V nodal pathways, a ventricular extrastimulus (VS) was coupled either to A2 at a fixed A1-A2 inte...

We discuss a natural way to deene barycentric coordinates associated with circular arcs. This leads to a theory of Bernstein-B ezier polynomials which parallels the familiar interval case, and which has close connections to trigonometric polynomials. x1. Introduction Bernstein-B ezier (BB-) polynomials deened on an interval are useful tools for constructing piecewise functional and parametric c...

The serotonin 5-HT(3) receptor native to rat hippocampal CA1 stratum radiatum interneurons is blocked by Ca(2+) ions in a dose- and voltage-dependent manner, which is reflected by a region of negative slope conductance in the I-V curve. The steep dependence on the extracellular Ca(2+) concentration suggests that the channel contains more than one binding site for Ca(2+). A three barrier-two sit...

We present V and B-band CCD photometry of 35 RR Lyr stars in the southern hemisphere globular cluster NGC 6362. Fourier decomposition of the light curves was used to estimate the basic properties of these variables. From the analysis of the RRc stars we obtain a mean mass of M = 0.531 ± 0.014 M⊙, luminosity logL/L⊙ = 1.656 ± 0.006, effective temperature Teff = 7429 ± 20, and helium abundance Y ...

Van Hooft, Johannes A. and Wytse J. Wadman. Ca ions block and permeate serotonin 5-HT3 receptor channels in rat hippocampal interneurons. J Neurophysiol 89: 1864–1869, 2003. First published December 18, 2002; 10.1152/jn.00948.2002. The serotonin 5-HT3 receptor native to rat hippocampal CA1 stratum radiatum interneurons is blocked by Ca ions in a doseand voltage-dependent manner, which is reflec...

Spectroscopic observations of the soft X-ray transient 4U 1543-47 reveal a radial velocity curve with a period of P = 1.123 ± 0.008 days and a semi-amplitude of K2 = 124± 4 km s. The resulting mass function is f(M) = 0.22± 0.02M⊙. We classify the secondary star as A2V, in agreement with previous work, and measure Teff = 9000±500 K and E(B − V ) = 0.50 ± 0.05 from fits to synthetic spectra. We d...

In this work, electrical characterization of the current-voltage and capacitance-voltage curves for the Metal/InN/InP Schottky structures are investigated. We have studied electrically thin InN films realized by the nitridation of InP (100) substrates using a Glow Discharge Source (GDS) in ultra high vacuum. The I (V) curves have exhibited anomalous two-step (kink) forward bias behaviour; a sui...