The Spin of Holographic Electrons at Nonzero Density and Temperature

We study the Green's function of a gauge invariant fermionic operator in a strongly coupled field theory at nonzero temperature and density using a dual gravity description. The gravity model contains a charged black hole in four dimensional anti-de Sitter space and probe charged fermions. In particular, we consider the effects of the spin of these probe fermions on the properties of the Green's function. There exists a spin-orbit coupling between the spin of an electron and the electric field of a Reissner-Nordstrom black hole. On the field theory side, this coupling leads to a Rashba like dispersion relation. We also study the effects of spin on the damping term in the dispersion relation by considering how the spin affects the placement of the fermionic quasinormal modes in the complex frequency plane in a WKB limit. An appendix contains some exact solutions of the Dirac equation in terms of Heun polynomials.Comment: 27 pages, 11 figures; v2: minor changes, published versio

Differences in clinicopathologic variables between Borrelia C6 antigen seroreactive and Borrelia C6 seronegative glomerulopathy in dogs.

BackgroundRapidly progressive glomerulonephritis has been described in dogs that seroreact to Borrelia burgdorferi, but no studies have compared clinicopathologic differences in Lyme-seroreactive dogs with protein-losing nephropathy (PLN) versus dogs with Borrelia-seronegative PLN.Hypothesis/objectivesDogs with Borrelia C6 antigen-seroreactive PLN have distinct clinicopathologic findings when compared to dogs with Borrelia seronegative PLN.AnimalsForty dogs with PLN and Borrelia C6 antigen seroreactivity and 78 C6-seronegative temporally matched dogs with PLN.MethodsRetrospective prevalence case-control study. Clinical information was retrieved from records of dogs examined at the University of California, Davis, Veterinary Medical Teaching Hospital. Histopathologic findings in renal tissue procured by biopsy or necropsy of dogs with PLN were reviewed.ResultsRetrievers and retriever mixes were overrepresented in seroreactive dogs (P < .001). Seroreactive dogs were more likely to have thrombocytopenia (P < .001), azotemia (P = .002), hyperphosphatemia (P < .001), anemia (P < .001), and neutrophilia (P = .003). Hematuria, glucosuria, and pyuria despite negative urine culture were more likely in seroreactive dogs (all P ≤ .002). Histopathologic findings were consistent with immune-complex glomerulonephritis in 16 of 16 case dogs and 7 of 23 control dogs (P = 006). Prevalence of polyarthritis was not different between groups (P = .17).Conclusions and clinical importanceC6 seroreactivity in dogs with PLN is associated with a clinicopathologically distinct syndrome when compared with other types of PLN. Early recognition of this syndrome has the potential to improve outcomes through specific aggressive and early treatment

Monopoles and Holography

We present a holographic theory in AdS_4 whose zero temperature ground state develops a crystal structure, spontaneously breaking translational symmetry. The crystal is induced by a background magnetic field, but requires no chemical potential. This lattice arises from the existence of 't Hooft-Polyakov monopole solitons in the bulk which condense to form a classical object known as a monopole wall. In the infra-red, the magnetic field is screened and there is an emergent SU(2) global symmetry.Comment: 33 pages, 16 figures; v2: ref adde

Thermodynamics of Dyonic Lifshitz Black Holes

Black holes with asymptotic anisotropic scaling are conjectured to be gravity duals of condensed matter system close to quantum critical points with non-trivial dynamical exponent z at finite temperature. A holographic renormalization procedure is presented that allows thermodynamic potentials to be defined for objects with both electric and magnetic charge in such a way that standard thermodynamic relations hold. Black holes in asymptotic Lifshitz spacetimes can exhibit paramagnetic behavior at low temperature limit for certain values of the critical exponent z, whereas the behavior of AdS black holes is always diamagnetic.Comment: 26 pages, 4 figure

Duración y calidad de la analgesia postoperatoria después del bloqueo del plexo braquial para cirugía del hombro: ropivacaína 0,5% frente a ropivacaína 0,5% con clonidina

Resumen OBJETIVOS: Algunos estudios han demostrado que la duración de los bloqueos nerviosos realizados con anestésicos locales puede ser prolongada con clonidina. En este estudio evaluamos la duración y la calidad de la analgesia proporcionada por el bloqueo del plexo braquial por vía interescalénica para cirugía del hombro, comparando la ropivacaína 0,5% con la ropivacaína 0,5% asociada a clonidina. PACIENTES Y MÉTODOS: Treinta pacientes fueron distribuidos en dos grupos en un estudio doble ciego. Grupo A - bloqueo realizado con ropivacaína 0,5%, 40 ml, y grupo B - ropivacaína 0,5%, 40 ml con clonidina (40 μg). Se procedió a la anestesia general con la administración de propofol e introducción de la mascarilla laríngea, siendo los pacientes mantenidos en ventilación espontánea con propofol en perfusión continua. Después de la estimulación nerviosa del plexo braquial fue administrado el (los) fármaco(s) seleccionado(s). El paciente fue instruido para recordar la hora de la reversión del bloqueo motor y sensitivo, y la analgesia postoperatoria fue evaluada a través de la escala visual analógica (EVA) a las 2, 4, 6, 8 y 24 horas. RESULTADOS: El tiempo medio de reversión del bloqueo sensitivo y motor y la evaluación del grado de dolor (EVA 0-10) a las 4, 6, 8 y 24 horas, no mostró diferencias estadísticamente significativas. CONCLUSIONES: La asociación de 40 μg de clonidina a 200 mg de ropivacaína 0,5% no prolonga el bloqueo sensitivo y motor y no mejora la calidad de la analgesia en el postoperatorio inmediato