Good and stable reduction of abelian varieties

An abelian variety with sufficiently many complex multiplications has potentially good reduction; in case the residue class field is finite this was proved by Serre and Tate; in this paper we give a proof in the general case. An abelian variety has potentially stable reduction (at any discrete valuation of its field of definition); we show this theorem follows directly from the Igusa-Grothendieck orthogonality theorem.     

Collision induced absorption in the a1Δ(v = 2) ← X3Σg(-)(v = 0) band of molecular oxygen

Using cavity ring-down spectroscopy we measured the collision induced absorption spectrum associated with the a(1)Δ(v = 2) ←X(3)Σ(g)(-)(v = 0) band of oxygen near 922 nm both in pure oxygen and in mixtures of oxygen and nitrogen. For pure oxygen, we report for this band an integrated absorption of (1.56 - 0.04/+0.40) × 10(-5) cm(-2) amg(-2). We find that collisions between oxygen and nitrogen do not result in any measurable CIA signal. At 1 bar of oxygen, this collision induced transition is much stronger than the allowed magnetic dipole and electric quadrupole transitions.     

Evidence of vintage effects on grape wines using H NMR-based metabolomic study

The chemical composition of grape wines varies with grape variety, environmental factors of climate and soil, and bacterial strains, which can each affect the wine quality. Using ¹H NMR analysis coupled with multivariate statistical data sets, we investigated the effects of grape vintage on metabolic profiles of wine and the relationship between wine metabolites and meteorological data. Principal component analysis (PCA) showed a clear differentiation between Meoru wines that were vinified with the same yeast strain and Meoru grapes harvested from the same vineyard but with a different vintage. The metabolites contributing to the differentiation were identified as 2,3-butandiol, lactic acid, alanine, proline, γ-aminobutyric acid (GABA), choline, and polyphenols, by complementary PCA loading plot. Markedly higher levels of proline, lactic acid and polyphenols were observed in the 2006 vintage wines compared to those of 2007 vintage, showing excellent agreement with the meteorological data that the sun-exposed time and rainfall in 2006 were approximately two times more and four times less, respectively, than those in 2007. These results revealed the important role of climate during ripening period in the chemical compositions of the grape. This study highlights the reliability of NMR-based metabolomic data by integration with meteorological data in characterizing wine or grape.     

Synthesis,separation, and isomer-dependent packing in two dimensions--detected by scanning tunnelling microscopy--of a TTF derivative

The synthesis, isolation and STM imaging on graphite of the cis and trans isomers of a TTF reveal isomer-dependent packing, and constitutes a way to study the non-covalent interactions at play in these systems.     

Influence of variable selection and sample size on classification results with classy

To investigate the influence of selection of variables and sample size on the performance of the multivariate classification method CLASSY, these parameters were varied systematically. In addition to the usual classificatory performance, the reliability of the assigned probabilities is considered. A small training set with only about five variables was shown to yield satisfactory results. After the variables had been ranked according to decreasing utility for the classification, the inclusion of many variables made the probabilities more unreliable. This over-confidence was not easily remedied by adding training objects. The classificatory ability was not affected by using more variables than necessary.     

Polymers with quinoxaline units. II

A double chain or ladder polymer was obtained by the condensation of 1,2,4,5-tetraaminobenzene with 2,3,7,8-tetrasubstituted-1,4,6,9-tetraazaanthracene and self-condensation of 2,3-dihydroxy-6,7-diaminoquinoxaline and of 2,3-diphenoxy-6,7-diaminoquinoxaline. The polycondensations were carried out in solution or in melt. The polymers thus obtained were highly colored products which had inherent viscosities up to 2.5. The structures of the polymers were established by comparison with model compounds.