Leptogenesis in SO(10) models with a left-right symmetric seesaw mechanism

We study leptogenesis in supersymmetric SO(10) models with a left-right symmetric seesaw mechanism, including flavour effects and the contribution of the next-to-lightest right-handed neutrino. Assuming M_D = M_u and hierarchical light neutrino masses, we find that successful leptogenesis is possible for 4 out of the 8 right-handed neutrino mass spectra that are compatible with the observed neutrino data. An accurate description of charged fermion masses appears to be an important ingredient in the analysis.Comment: Submitted for the SUSY07 proceedings, 4 pages, 9 figure

Hot methane line lists for exoplanet and brown dwarf atmospheres

We present comprehensive experimental line lists of methane (CH4) at high temperatures obtained by recording Fourier transform infrared emission spectra. Calibrated line lists are presented for the temperatures 300 - 1400 degC at twelve 100 degC intervals spanning the 960 - 5000 cm-1 (2.0 - 10.4 microns) region of the infrared. This range encompasses the dyad, pentad and octad regions, i.e., all fundamental vibrational modes along with a number of combination, overtone and hot bands. Using our CH4 spectra, we have estimated empirical lower state energies (Elow in cm-1) and our values have been incorporated into the line lists along with line positions (cm-1) and calibrated line intensities (S' in cm molecule-1). We expect our hot CH4 line lists to find direct application in the modeling of planetary atmospheres and brown dwarfs.Comment: Supplementary material is provided via the Astrophysical Journal referenc

Genetics of Chronic Lymphocytic Leukemia: Practical Aspects and Prognostic Significance

status: publishe

Can tooth differentiation help to understand species coexistence? The case of wood mice in China

Five wood mice Apodemus species occur across China, in allopatry but also in sympatry up to cases of syntopy. They all share a similar external appearance, similar habitats of grasslands and forests and a generalist feeding behaviour. This overall similarity raises questions about the mechanisms insuring competition avoidance and allowing the coexistence of the species. In this context, a morphometric analysis of two characters related to feeding (mandible and molar) addressed the following issues: (1) Were the species actually different in size and/or shape of these characters, supporting their role in resource partitioning? (2) Did this pattern of phenotypic divergence match the neutral genetic differentiation, suggesting that differentiation might have occurred in a former phase of allopatry as a result of stochastic processes? (3) Did the species provide evidence of character displacement when occurring in sympatry, supporting an ongoing role of competition in the interspecific divergence? Results evidenced first that different traits, here mandibles and molars, provided discrepant pictures of the evolution of the Apodemus group in China. Mandible shape appeared as prone to vary in response to local conditions, blurring any phylogenetic or ecological pattern, whereas molar shape evolution appeared to be primarily driven by the degree of genetic differentiation. Molar size and shape segregated the different species in the morphospace, suggesting that these features may be involved in a resource partitioning between Apodemus species. The morphological segregation of the species, likely achieved by processes of differentiation in isolation promoted by the complex landscape of China, could contribute to competition avoidance and hence explain why no evidence was found of character displacement. © 2012 Blackwell Verlag GmbH

Finite dimensional quantizations of the (q,p) plane : new space and momentum inequalities

We present a N-dimensional quantization a la Berezin-Klauder or frame quantization of the complex plane based on overcomplete families of states (coherent states) generated by the N first harmonic oscillator eigenstates. The spectra of position and momentum operators are finite and eigenvalues are equal, up to a factor, to the zeros of Hermite polynomials. From numerical and theoretical studies of the large $N$ behavior of the product $\lambda\_m(N) \lambda\_M(N)$ of non null smallest positive and largest eigenvalues, we infer the inequality $\delta\_N(Q) \Delta\_N(Q) = \sigma\_N \overset{<}{\underset{N \to \infty}{\to}} 2 \pi$ (resp. $\delta\_N(P) \Delta\_N(P) = \sigma\_N \overset{<}{\underset{N \to \infty}{\to}} 2 \pi$) involving, in suitable units, the minimal ($\delta\_N(Q)$) and maximal ($\Delta\_N(Q)$) sizes of regions of space (resp. momentum) which are accessible to exploration within this finite-dimensional quantum framework. Interesting issues on the measurement process and connections with the finite Chern-Simons matrix model for the Quantum Hall effect are discussed