Computing with quantized enveloping algebras: PBW-type bases, highest-weight modules, R-matrices

Let Uqg be the quantized enveloping algebra corresponding to the semisimple Lie algebra g We describe algorithms to obtain the multiplication table of a PBWtype basis of Uqg We use this to obtain an algorithm for calculating a Grobner basis of an ideal in the subalgebra U which leads to a general construction of irreducible highestweight modules over Uqg We also indicate how to compute the corresponding Rmatrice

Constructing canonical bases of quantized enveloping algebras

An algorithm for computing the elements of a given weight of the canonical basis of Uqg is described

Constructing faithful representations of finitely-generated torsion-free nilpotent groups

We formulate an algorithm for calculating a representation by unipotent matrices over the integers of a nitelygenerated torsionfree nilpotent group given by a polycyclic presentation The algorithm works along a polycyclic series of the group each step extending a representation of an element of that series to the next elemen

Flavor enhancement of food improves dietary intake and nutritional status of elderly nursing home residents

Taste and smell losses occur with aging. These changes may decrease the enjoyment of food and may subsequently reduce food consumption and negatively influence the nutritional status of elderly persons, especially those who are frail. The objective of this study was to determine if the addition of flavor enhancers to the cooked meals for elderly residents of a nursing home promotes food consumption and provides nutritional benefits. Methods. We performed a 16-week parallel group intervention consisting of sprinkling flavor enhancers over the cooked meals of the "flavor" group (n = 36) and not over the meals of the control group (n = 31). Measurements of intake of the cooked meals were taken before and after 8 and 16 weeks of intervention. Appetite, daily dietary intake, and anthropometry were assessed before and after the intervention. Results. On average, the body weight of the flavor group increased ( 1.1 ± 1.3 kg; p < .05) compared with that of the control group (-0.3 ± 1.6 kg: p < .05). Daily dietary intake decreased in the control group (-485 ± 1245 kJ; p < .05) but not in the flavor group (-208 ± 1115 kJ; p = .28). Intake of the cooked meal increased in the flavor group (133 ± 367 kJ; p < .05) but not in the control group (85 ± 392 kJ). A similar trend was observed for hunger feelings, which increased only in the flavor group. Conclusion. Adding flavor enhancers to the cooked meals was an effective way to improve dietary intake and body weight in elderly nursing home residents

Magnetic fingerprint of dithiazolyl-based molecule magnets

Magnetic bistability in organic-radical based materials has attracted significant interest due to its potential application in electronic devices. The First-Principles Bottom-Up study herein presented aims at elucidating the key factors behind the different magnetic response of the low and high temperature phases of four different switchable dithiazolyl (DTA)-based compounds. The drastic change in the magnetic response upon spin transition is always due to changes in the JAB magnetic interactions between adjacent radicals along the π-stacks of the crystal, which in turn are driven mostly by changes in interplanar distance and degree of lateral slippage, according to the interpretation of a series of magneto-structural correlation maps. Furthermore, specific geometrical dispositions have been recognized as a ferromagnetic fingerprint in such correlations. Our results thus show that a proper substitution of the chemical skeleton attached to the DTA ring could give rise to new organic materials with dominant ferromagnetic interactions

Calabi-Yau cones from contact reduction

We consider a generalization of Einstein-Sasaki manifolds, which we characterize in terms both of spinors and differential forms, that in the real analytic case corresponds to contact manifolds whose symplectic cone is Calabi-Yau. We construct solvable examples in seven dimensions. Then, we consider circle actions that preserve the structure, and determine conditions for the contact reduction to carry an induced structure of the same type. We apply this construction to obtain a new hypo-contact structure on S^2\times T^3.Comment: 30 pages; v2: typos corrected, presentation improved, one reference added. To appear in Ann. Glob. Analysis and Geometr

NPHP4 Variants Are Associated With Pleiotropic Heart Malformations

Rationale: Congenital heart malformations are a major cause of morbidity and mortality, especially in young children. Failure to establish normal left-right (L-R) asymmetry often results in cardiovascular malformations and other laterality defects of visceral organs. Objective: To identify genetic mutations causing cardiac laterality defects. Methods and Results: We performed a genome-wide linkage analysis in patients with cardiac laterality defects from a consanguineous family. The patients had combinations of defects that included dextrocardia, transposition of great arteries, double-outlet right ventricle, atrioventricular septal defects, and caval vein abnormalities. Sequencing of positional candidate genes identified mutations in NPHP4. We performed mutation analysis of NPHP4 in 146 unrelated patients with similar cardiac laterality defects. Forty-one percent of these patients also had laterality defects of the abdominal organs. We identified 8 additional missense variants that were absent or very rare in control subjects. To study the role of nphp4 in establishing L-R asymmetry, we used antisense morpholinos to knockdown nphp4 expression in zebrafish. Depletion of nphp4 disrupted L-R patterning as well as cardiac and gut laterality. Cardiac laterality defects were partially rescued by human NPHP4 mRNA, whereas mutant NPHP4 containing genetic variants found in patients failed to rescue. We show that nphp4 is involved in the formation of motile cilia in Kupffer's vesicle, which generate asymmetrical fluid flow necessary for normal L-R asymmetry. Conclusions: NPHP4 mutations are associated with cardiac laterality defects and heterotaxy. In zebrafish, nphp4 is essential for the development and function of Kupffer's vesicle cilia and is required for global L-R patterning