Algebraic Linearization of Dynamics of Calogero Type for any Coxeter Group

Calogero-Moser systems can be generalized for any root system (including the non-crystallographic cases). The algebraic linearization of the generalized Calogero-Moser systems and of their quadratic (resp. quartic) perturbations are discussed.Comment: LaTeX2e, 13 pages, no figure

Sleep dysfunction and EEG alterations in mice overexpressing alpha-synuclein.

BackgroundSleep disruptions occur early and frequently in Parkinson's disease (PD). PD patients also show a slowing of resting state activity. Alpha-synuclein is causally linked to PD and accumulates in sleep-related brain regions. While sleep problems occur in over 75% of PD patients and severely impact the quality of life of patients and caregivers, their study is limited by a paucity of adequate animal models.ObjectiveThe objective of this study was to determine whether overexpression of wildtype alpha-synuclein could lead to alterations in sleep patterns reminiscent of those observed in PD by measuring sleep/wake activity with rigorous quantitative methods in a well-characterized genetic mouse model.MethodsAt 10 months of age, mice expressing human wildtype alpha-synuclein under the Thy-1 promoter (Thy1-aSyn) and wildtype littermates underwent the subcutaneous implantation of a telemetry device (Data Sciences International) for the recording of electromyograms (EMG) and electroencephalograms (EEG) in freely moving animals. Surgeries and data collection were performed without knowledge of mouse genotype.ResultsThy1-aSyn mice showed increased non-rapid eye movement sleep during their quiescent phase, increased active wake during their active phase, and decreased rapid eye movement sleep over a 24-h period, as well as a shift in the density of their EEG power spectra toward lower frequencies with a significant decrease in gamma power during wakefulness.ConclusionsAlpha-synuclein overexpression in mice produces sleep disruptions and altered oscillatory EEG activity reminiscent of PD, and this model provides a novel platform to assess mechanisms and therapeutic strategies for sleep dysfunction in PD

On the Lengths, Colours and Ages of Bars

In an effort to obtain further observational evidences for secular evolution processes in galaxies, as well as observational constraints to current theoretical models of secular evolution, we have used BVRI and Ks images of a sample of 18 barred galaxies to measure the lengths and colours of bars, create colour maps and estimate global colour gradients. In addition, applying a method we developed in a previous article, we could distinguish for 7 galaxies in our sample those whose bars have been recently formed from the ones with already evolved bars. We estimated an average difference in the optical colours between young and evolved bars that may be translated to an age difference of the order of 10 Gyr, meaning that bars may be long standing structures. Moreover, our results show that, on average, evolved bars are longer than young bars. This seems to indicate that, during its evolution, a bar grows longer by capturing stars from the disk, in agreement with recent numerical and analytical results.Comment: To appear in Galaxy Evolution Across the Hubble Time, proceedings of the IAU Symp. 235, F. Combes and J. Palous (eds.); 1 page; the poster can be found at http://www.mpa-garching.mpg.de/~dimitri/iauga.pd

Quadratic Algebra associated with Rational Calogero-Moser Models

Classical Calogero-Moser models with rational potential are known to be superintegrable. That is, on top of the r involutive conserved quantities necessary for the integrability of a system with r degrees of freedom, they possess an additional set of r-1 algebraically and functionally independent globally defined conserved quantities. At the quantum level, Kuznetsov uncovered the existence of a quadratic algebra structure as an underlying key for superintegrability for the models based on A type root systems. Here we demonstrate in a universal way the quadratic algebra structure for quantum rational Calogero-Moser models based on any root systems.Comment: 19 pages, LaTeX2e, no figure

Molecular Gas in the Powerful Radio Galaxies 3C~31 and 3C~264: Major or Minor Mergers?

We report the detection of $^{12}$CO~($1 \to 0$) and $^{12}$CO~($2 \to 1$) emission from the central regions ($\lesssim 5$--$10 {\rm kpc}$) of the two powerful radio galaxies 3C~31 and 3C~264. Their individual CO emission exhibits a double-horned line profile that is characteristic of an inclined rotating disk with a central depression at the rising part of its rotation curve. The inferred disk or ring distributions of the molecular gas is consistent with the observed presence of dust disks or rings detected optically in the cores of both galaxies. For a CO to H$_2$ conversion factor similar to that of our Galaxy, the corresponding total mass in molecular hydrogen gas is $(1.3 \pm 0.2) \times 10^9 {\rm M_{\odot}}$ in 3C~31 and $(0.31 \pm 0.06) \times 10^9 {\rm M_{\odot}}$ in 3C~264. Despite their relatively large molecular-gas masses and other peculiarities, both 3C~31 and 3C~264, as well as many other powerful radio galaxies in the (revised) 3C catalog, are known to lie within the fundamental plane of normal elliptical galaxies. We reason that if their gas originates from the mergers of two gas-rich disk galaxies, as has been invoked to explain the molecular gas in other radio galaxies, then both 3C~31 and 3C~264 must have merged a long time (a few billion years or more) ago but their remnant elliptical galaxies only recently (last tens of millions of years or less) become active in radio. Instead, we argue that the cannibalism of gas-rich galaxies provides a simpler explanation for the origin of molecular gas in the elliptical hosts of radio galaxies. Given the transient nature of their observed disturbances, these galaxies probably become active in radio soon after the accretion event when sufficient molecular gas agglomerates in their nuclei.Comment: 16 pages, 1 JPEG figure attached, accepted for publication in ApJ

Influência da qualidade de vida percebida do dirigente colombiano sobre suas práticas de liderança

The influence of the leader's perceived quality of life, of his/her health habits and socioeconomic characteristics on his/her leadership practices was assessed. All of these dimensions are included in the framework of the quality of life model as an intervention strategy (Juárez, 2000, 2010). The Leadership Practices Inventory (version by Robles, de la Garza, & Medina, 2008), the Quality of Life Questionnaire -WHO (1998, 2004) and the Health Indicators Questionnaire (Jiménez, Martínez, Miró, & Sánchez, 2008) were administered to 60 participants in charge of personnel. Participants were grouped according to their socioeconomic characteristics. The increase in the overall quality of life and perceived health of the quality of life both augmented the transformational leadership practices of Modeling, Inspiring, Defying and Enabling and the transactional leadership practice of Encouraging. An increase in the perceived health of the Health Indicators Questionnaire augmented the transformational leadership practice of Modeling, while the increase in the behavior associated to alcoholic drinks intake reduced the leadership practice of Defying. No other variable was significant. Different theoretical explanations are discussed.Foi avaliada a influência sobre as práticas de liderança da qualidade de vida percebida do líder, de seus hábitos de saúde e das características socioeconômicas. Todas estas dimensões da qualidade de vida estão incluídas dentro do modelo de qualidade de vida como estratégia de intervenção (Juárez, 2000, 2010). A 60 participantes, com pessoal sob sua responsabilidade foi aplicado o Inventário de Práticas de Liderança (versão de Robles, de la Garza, & Medina, 2008), o questionário de Qualidade de Vida (WHO, 1998, 2004) e o de Indicadores de Saúde (Jiménez, Martínez, Miró, & Sánchez, 2008). Os participantes foram agrupados de acordo com suas características socioeconômicas. O aumento na qualidade de vida geral e a saúde psicológica da qualidade de vida, aumentaram as práticas da liderança transformacional de Modelar, Inspirar Desafiar e Habilitar e a da liderança transacional de Encorajar. O aumento na percepção de saúde do questionário de Indicadores de Saúde aumentou as práticas da liderança transformacional de Modelar, enquanto que o aumento na conduta associada ao consumo de bebidas alcoólicas reduziu a prática de liderança de Desafiar. Nenhuma outra variável foi significativa. Discutem-se diferentes explicações teóricas.Se evaluó la influencia sobre las prácticas de liderazgo, de la calidad de vida percibida del líder, de sus hábitos de salud y de las características socioeconómicas. Todas estas dimensiones de la calidad de vida están incluidas dentro del modelo de calidad de vida como estrategia de intervención (Juárez, 2000, 2010). A 60 participantes, con personal a su cargo, se les aplicó el Inventario de Prácticas de Liderazgo (versión de Robles, de la Garza, & Medina, 2008), el Cuestionario de Calidad de Vida (WHO, 1998, 2004) y el de Indicadores de Salud (Jiménez, Martínez, Miró, & Sánchez, 2008). Los participantes se agruparon según sus características socioeconómicas. El aumento en la calidad de vida general y la salud psicológica de la calidad de vida, incrementaron las prácticas del liderazgo transformacional de Modelar, Inspirar Desafiar y Habilitar y la del liderazgo transaccional de Alentar. El aumento en la percepción de salud del cuestionario de Indicadores de Salud incrementó las prácticas del liderazgo transformacional de Modelar, mientras que el aumento en la conducta asociada al consumo de bebidas alcohólicas redujo la práctica de liderazgo de Desafiar. Ninguna otra variable resultó significativa. Se discuten diferentes explicaciones teóricas

Anisotropic Topological Hall Effect with Real and Momentum Space Berry Curvature in the Antiskrymion Hosting Heusler Compound Mn1.4_{1.4}PtSn

The topological Hall effect (THE) is one of the key signatures of topologically non-trivial magnetic spin textures, wherein electrons feel an additional transverse voltage to the applied current. The magnitude of THE is often small compared to the anomalous Hall effect. Here, we find a large THE of 0.9 $\mu\Omega$cm that is of the same order of the anomalous Hall effect in the single crystalline antiskyrmion hosting Heusler compound Mn$_{1.4}$PtSn, a non-centrosymmetric tetragonal compound. The THE is highly anisotropic and survives in the whole temperature range where the spin structure is noncoplanar (<170 K). The THE is zero above the spin reorientation transition temperature of 170 K, where the magnetization will have a collinear and ferromagnetic alignment. The large value of the THE entails a significant contribution from the momentum space Berry curvature along with real space Berry curvature, which has never been observed earlier

Identification of major factors influencing ELISpot-based monitoring of cellular responses to antigens from mycobacterium tuberculosis

A number of different interferon-c ELISpot protocols are in use in laboratories studying antigen-specific immune responses. It is therefore unclear how results from different assays compare, and what factors most significantly influence assay outcome. One such difference is that some laboratories use a short in vitro stimulation period of cells before they are transferred to the ELISpot plate; this is commonly done in the case of frozen cells, in order to enhance assay sensitivity. Other differences that may be significant include antibody coating of plates, the use of media with or without serum, the serum source and the number of cells added to the wells. The aim of this paper was to identify which components of the different ELISpot protocols influenced assay sensitivity and inter-laboratory variation. Four laboratories provided protocols for quantifying numbers of interferon-c spot forming cells in human peripheral blood mononuclear cells stimulated with Mycobacterium tuberculosis derived antigens. The differences in the protocols were compared directly. We found that several sources of variation in assay protocols can be eliminated, for example by avoiding serum supplementation and using AIM-V serum free medium. In addition, the number of cells added to ELISpot wells should also be standardised. Importantly, delays in peripheral blood mononuclear cell processing before stimulation had a marked effect on the number of detectable spot forming cells; processing delay thus should be minimised as well as standardised. Finally, a pre-stimulation culture period improved the sensitivity of the assay, however this effect may be both antigen and donor dependent. In conclusion, small differences in ELISpot protocols in routine use can affect the results obtained and care should be given to conditions selected for use in a given study. A pre-stimulation step may improve the sensitivity of the assay, particularly when cells have been previously frozen