Compatible Discrete Series

Several very interesting results connecting the theory of abelian ideals of Borel subalgebras, some ideas of D. Peterson relating the previous theory to the combinatorics of affine Weyl groups, and the theory of discrete series are stated in a recent paper (\cite{Ko2}) by B. Kostant. In this paper we provide proofs for most of Kostant's results extending them to $ad$-nilpotent ideals and develop one direction of Kostant's investigation, the compatible discrete series.Comment: AmsTex file, 27 Pages; minor corrections; to appear in Pacific Journal of Mathematic

On the structure of Borel stable abelian subalgebras in infinitesimal symmetric spaces

Let g=g_0+g_1 be a Z_2-graded Lie algebra. We study the posets of abelian subalgebras of g_1 which are stable w.r.t. a Borel subalgebra of g_0. In particular, we find out a natural parametrization of maximal elements and dimension formulas for them. We recover as special cases several results of Kostant, Panyushev, Suter.Comment: Latex file, 35 pages, minor corrections, some examples added. To appear in Selecta Mathematic

Closed-Loop Targeted Memory Reactivation during Sleep Improves Spatial Navigation

Sounds associated with newly learned information that are replayed during non-rapid eye movement (NREM) sleep can improve recall in simple tasks. The mechanism for this improvement is presumed to be reactivation of the newly learned memory during sleep when consolidation takes place. We have developed an EEG-based closed-loop system to precisely deliver sensory stimulation at the time of down-state to up-state transitions during NREM sleep. Here, we demonstrate that applying this technology to participants performing a realistic navigation task in virtual reality results in a significant improvement in navigation efficiency after sleep that is accompanied by increases in the spectral power especially in the fast (12\u201315 Hz) sleep spindle band. Our results show promise for the application of sleep-based interventions to drive improvement in real-world tasks

Potencialidad de la cosecha y rendimiento industrial de bosques de Nothofagus antarctica en Tierra del Fuego (Argentina)

Martínez Pastur, G.; Lencinas, M.V. CADIC-CONICET. Casilla 92 (9410) Ushuaia, Argentina. Cellini, J.M. Cátedra de Biometría. Universidad Nacional de La Plata, La Plata, Argentina. Peri, P. UNPA-INTA-CONICET, Río Gallegos, Argentina.La propuesta silvícola para bosques de Nothofagus antarctica es el manejo silvopastoril, siendo la limitante para su implementación la falta de mercado para los productos madereros generados durante su aplicación. En Tierra del Fuego (Argentina) existen más de 180 mil ha, de las cuales 23% pertenecen a sitios medio-altos (>11,5 m de altura). El potencial de cosecha y el rendimiento industrial fueron analizados en 12 parcelas de 500 m², cuya área basal fue 58,7±11,5 m².ha-1 (promedio ± desvío estándar) con un remanente de 29,9±7,6 m².ha-1 luego de la aplicación de raleos. El volumen cosechado fue 102,2±29,0 m3.ha-1. El rendimiento en aserradero (127 trozas en 20 paquetes de muestreo) varió con la calidad y el tamaño de las trozas. Trozas >30 cm presentaron rendimientos del 34, 10, y 4% para calidades alta, media y baja, respectivamente. Trozas <30 cm de alta calidad presentaron rendimientos del 27%, y 10% para la de calidad media. Las trozas >30 cm de mejor calidad produjeron 9% de tablones, 21% de tablas, 49% de tirantes, 5% de madera corta y 16% de madera para pallet y las trozas <30 cm produjeron 0-1, 8-11%, 30-53%, 7- 16% y 32-43%, respectivamente. Los rendimientos sugieren la posibilidad de incorporar al aserrado solo trozas de alta calidad de cualquier diámetro, lo que representa rendimientos de cosecha de 50,0±27,9 m3.ha-1 para bosques de calidad de sitio media-alta. Considerando solo el punto de vista maderero, los rendimientos obtenidos pueden solventar la aplicación de los tratamientos silvopastoriles con ingresos brutos de hasta U$S 3500 por hectárea.Proyecto PID2005 35648 (SECYT-Argentina

Fat Mass and Obesity-Associated Gene (FTO) in Eating Disorders: Evidence for Association of the rs9939609 Obesity Risk Allele with Bulimia nervosa and Anorexia nervosa

Objective: The common single nucleotide polymorphism (SNP) rs9939609 in the fat mass and obesity-associated gene (FTO) is associated with obesity. As genetic variants associated with weight regulation might also be implicated in the etiology of eating disorders, we evaluated whether SNP rs9939609 is associated with bulimia nervosa (BN) and anorexia nervosa (AN). Methods: Association of rs9939609 with BN and AN was assessed in 689 patients with AN, 477 patients with BN, 984 healthy non-population-based controls, and 3,951 population-based controls (KORA-S4). Based on the familial and premorbid occurrence of obesity in patients with BN, we hypothesized an association of the obesity risk A-allele with BN. Results: In accordance with our hypothesis, we observed evidence for association of the rs9939609 A-allele with BN when compared to the non-population-based controls (unadjusted odds ratio (OR) = 1.142, one-sided 95% confidence interval (CI) 1.001-infinity; one-sided p = 0.049) and a trend in the population-based controls (OR = 1.124, one-sided 95% CI 0.932-infinity; one-sided p = 0.056). Interestingly, compared to both control groups, we further detected a nominal association of the rs9939609 A-allele to AN (OR = 1.181, 95% CI 1.027-1.359, two-sided p = 0.020 or OR = 1.673, 95% CI 1.101-2.541, two-sided p = 0.015,). Conclusion: Our data suggest that the obesity-predisposing FTO allele might be relevant in both AN and BN. Copyright (C) 2012 S. Karger GmbH, Freibur

Clinical and genetic analysis of 29 Brazilian patients with Huntington’s disease-like phenotype

Huntington’s disease (HD) is a neurodegenerative disorder characterized by chorea, behavioral disturbances and dementia, caused by a pathological expansion of the CAG trinucleotide in the HTT gene. Several patients have been recognized with the typical HD phenotype without the expected mutation. The objective of this study was to assess the occurrence of diseases such as Huntington’s disease-like 2 (HDL2), spinocerebellar ataxia (SCA) 1, SCA2, SCA3, SCA7, dentatorubral-pallidoluysian atrophy (DRPLA) and choreaacanthocytosis (ChAc) among 29 Brazilian patients with a HD-like phenotype. In the group analyzed, we found 3 patients with HDL2 and 2 patients with ChAc. The diagnosis was not reached in 79.3% of the patients. HDL2 was the main cause of the HD-like phenotype in the group analyzed, and is attributable to the African ancestry of this population. However, the etiology of the disease remains undetermined in the majority of the HD negative patients with HD-like phenotype. Key words: Huntington’s disease, Huntington’s disease-like, chorea-acanthocytosis, Huntington’s disease-like 2

Ultrahard carbon film from epitaxial two-layer graphene

Atomically thin graphene exhibits fascinating mechanical properties, although its hardness and transverse stiffness are inferior to those of diamond. To date, there hasn't been any practical demonstration of the transformation of multi-layer graphene into diamond-like ultra-hard structures. Here we show that at room temperature and after nano-indentation, two-layer graphene on SiC(0001) exhibits a transverse stiffness and hardness comparable to diamond, resisting to perforation with a diamond indenter, and showing a reversible drop in electrical conductivity upon indentation. Density functional theory calculations suggest that upon compression, the two-layer graphene film transforms into a diamond-like film, producing both elastic deformations and sp2-to-sp3 chemical changes. Experiments and calculations show that this reversible phase change is not observed for a single buffer layer on SiC or graphene films thicker than 3 to 5 layers. Indeed, calculations show that whereas in two-layer graphene layer-stacking configuration controls the conformation of the diamond-like film, in a multilayer film it hinders the phase transformation.Comment: Published online on Nature Nanotechnology on December 18, 201

Managerial delegation in a dynamic renewable resource oligopoly

I propose a differential oligopoly game of resource extraction under (quasi-static) open-loop and nonlinear feedback strategies, where firms are managerial and two alternative types of delegation contract are considered. Under open-loop information, delegation expands the residual steady state resource stock. Conversely, under nonlinear feedback information the outcome depends on the structure of managerial incentives. If sales are used, once again delegation favours resource preservation. On the contrary, if market shares are included in the delegation contract, this combines with an underlying voracity effect in shrinking the steady state volume of the resource