Thermodynamics of a Trapped Unitary Fermi Gas

We present the first model-independent comparison of recent measurements of the entropy and of the critical temperature of a unitary Fermi gas, performed by Luo et al., with the most complete results currently available from finite temperature Monte Carlo calculations. The measurement of the critical temperature in a cold fermionic atomic cloud is consistent with a value $T_c=0.23(2)epsilon_F$ in the bulk, as predicted by the present authors in their Monte Carlo calculations.Comment: 5 pages, 4 figures, published versio

Calculating and resumming the classical virial expansion using automated algebra

Using schematic model potentials, we calculate exactly the virial coefficients of a classical gas up to sixth order and use them to assess the convergence properties of the virial expansion of basic thermodynamic quantities such as pressure, density, and compressibility. At sufficiently strong couplings, as expected, the virial expansion fails to converge. However, at least for the interactions and parameter ranges we explored, we find that Pad\'e-Borel resummation methods are extremely effective in improving the convergence of the expansion.Comment: 9 pages, 12 figure

Universality in one-dimensional fermions at finite temperature: Density, pressure, compressibility, and contact

We present finite-temperature, lattice Monte Carlo calculations of the particle number density, compressibility, pressure, and Tan's contact of an unpolarized system of short-range, attractively interacting spin-1/2 fermions in one spatial dimension, i.e., the Gaudin-Yang model. In addition, we compute the second-order virial coefficients for the pressure and the contact, both of which are in excellent agreement with the lattice results in the low-fugacity regime. Our calculations yield universal predictions for ultracold atomic systems with broad resonances in highly constrained traps. We cover a wide range of couplings and temperatures and find results that support the existence of a strong-coupling regime in which the thermodynamics of the system is markedly different from the noninteracting case. We compare and contrast our results with identical systems in higher dimensions.Comment: 6 pages, 7 figures; improved, published versio

Pseudoartrosis de radio en un niño con Neurofibromatosis tipo 1(NF1)

La Neurofibromatosis tipo 1 (NF1) es una enfermedad AD que asocia lesiones óseas entre las que se incluye la displasia de huesos largos, más frecuentemente la tibia, con o sin pseudoartrosis. Presentamos un caso de un niño de 9 años con pseudoartrosis de radio y NF1. El examen histológico del material de la zona mostró cartílago y tejido fibroso con inmunohistoquímica negativa para S-100, descartando un componente de la enfermedad básica en la lesión. Si bien en la literatura hay referencias de NF1 y pseudoartrosis de huesos largos sólo se mencionan aislados ejemplos de pacientes pediátricos con pseudoartrosis de radio. Se desconoce el mecanismo por el que la NF1 favorece el desarrollo de pseudoartrosis.Neurofibromatosis type 1 (NF1) is an AD disease which may associate bone lesions including long bone dysplasia, more frequently at the tibia, with or without pseudoarthrosis. We are reporting the case of a 9-year-old boy with ulnar pseudoarthrosis and NF1. Histological study of samples from the lesion revealed cartilage and fibrous tissue resulting immunohistochemically negative for S-100. This result indicated absence of neurofibromatous tissue in the lesion. Although the literature contains several reports of the association between NF1 and pseudoarthrosis of long bones there are but a few of this combination in the ulna in children. It is unknown how NF1 favors the development of pseudoarthrosis

Spin 1/2 Fermions in the Unitary Regime: A Superfluid of a New Type

We have studied, in a fully non-perturbative calculation, a dilute system of spin 1/2 interacting fermions, characterized by an infinite scattering length at finite temperatures. Various thermodynamic properties and the condensate fraction were calculated and we have also determined the critical temperature for the superfluid-normal phase transition in this regime. The thermodynamic behavior appears as a rather surprising and unexpected melange of fermionic and bosonic features. The thermal response of a spin 1/2 fermion at the BCS-BEC crossover should be classified as that of a new type of superfluid.Comment: 4 pages, 1 figure, published versio

Next-to-next-to-leading-order epsilon expansion for a Fermi gas at infinite scattering length

We extend previous work on applying the epsilon-expansion to universal properties of a cold, dilute Fermi gas in the unitary regime of infinite scattering length. We compute the ratio xi = mu/epsilon_F of chemical potential to ideal gas Fermi energy to next-to-next-to-leading order (NNLO) in epsilon=4-d, where d is the number of spatial dimensions. We also explore the nature of corrections from the order after NNLO.Comment: 28 pages, 14 figure

A newborn with partial pure trisomy of chromosome 7q inherited from paternal balanced translocation with congenital anomalies. a mini review

We report on a familial translocation t(3;7)(3q29::7q22) leading to pure trisomy 7q22 --> 7qter in a 21-days-old boy: 46,XY,der(3;7)(3pter--> 3q29::7q22--> 7pter). By conventional citogenetic techniques including fluorescence in situ hybridization (FISH) analysis, the patient was found to have inherited a derivative chromosome 3 from his father: 46,XY,t(3;7)(3pter--> 3q29::7q22--> 7qter;7pter--> 7q22). As a consequence, pure duplications of chromosome 7q have been classified in 4 groups on the basis of the involved region. The present case is included in group 2 which involves large duplications spanning from proximal bands to telomere duplication. In the literature, only one case with a pure duplication of the same region has been described. Despite this, the phenotype is different. Moreover, our patient shares some phenotypic features, such as wide fontanelle, retrognathia, epicathal fold, hypertelorism, pulmonary hypoventilation and early postnatal death. However, the absence of physical characterization in most of the reported cases could justify the lacking phenotype-genotype correlation in patients with partial 7q duplication. Further studies using recent molecular approaches such as array-CGH might permit a more clinically useful grouping of 7q duplications.Fil: Siewert, Susana Elfrida. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; ArgentinaFil: Della Vedova, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Guillamondegui, M. J.. Provincia de Mendoza. Hospital Pediátrico Dr. Humberto J. Notti; ArgentinaFil: Drut, M.. Laboratorio Privado; ArgentinaFil: Brezigar A.. Provincia de San Luis. Clinic Cerhu; ArgentinaFil: Cardetti, M.. Provincia de San Luis. Clinic Cerhu; ArgentinaFil: Marsá, S.M.. Laboratorio Genes; Argentin

Estudio inmunohistoquímico del osteosarcoma post-tratamiento con quimioterapia

Basados en la observación de un caso original se decidió investigar la composición celular del tejido “neoplásico remanente” en 6 casos de osteosarcoma, 3 tratados y 3 sin tratamiento previo, determinando la presencia de macrófagos mediante inmunohistoquímica (IHQ) para CD68.Facultad de Ciencias Médica

Open problems in nuclear density functional theory

This note describes five subjects of some interest for the density functional theory in nuclear physics. These are, respectively, i) the need for concave functionals, ii) the nature of the Kohn-Sham potential for the radial density theory, iii) a proper implementation of a density functional for an "intrinsic" rotational density, iv) the possible existence of a potential driving the square root of the density, and v) the existence of many models where a density functional can be explicitly constructed.Comment: 10 page

Fermi point in graphene as a monopole in momentum space

We consider the effective field theory of graphene monolayer with the Coulomb interaction between fermions taken into account. The gauge field in momentum space is introduced. The position of the Fermi point coincides with the position of the corresponding monopole. The procedure of extracting such monopoles during lattice simulations is suggested.Comment: Latex, 12 page