Identification of non-ordinary mesons from the dispersive connection between their poles and their Regge trajectories: the f0(500) resonance

We show how the Regge trajectory of a resonance can be obtained from its pole in a scattering process and analytic constraints in the complex angular momentum plane. The method is suited for resonances that dominate an elastic scattering amplitude. In particular, from the rho(770) resonance pole in pion-pion scattering, we obtain its linear Regge trajectory, characteristic of ordinary quark-antiquark states. In contrast, the f0(500) pole -the sigma meson- which dominates scalar isoscalar pion-pion scattering, yields a non-linear trajectory with a much smaller slope at the f0(500) mass. Conversely, imposing a linear Regge trajectory for the f0(500), with a slope of typical size, yields an elastic amplitude at odds with the data. This provides strong support for the non-ordinary nature of the sigma meson.Comment: 8 pages, 4 figure

Regge trajectory of the f_0(500) resonance from a dispersive connection to its pole

We report here our results on how to obtain the Regge trajectory of a resonance from its pole in a scattering process by imposing analytic constraints in the complex angular momentum plane. The method, suited for resonances that dominate an elastic scattering amplitude, has been applied to the {\rho}(770) and the f_0(500) resonances. Whereas for the former we obtain a linear Regge trajectory, characteristic of ordinary quark-antiquark states, for the latter we find a non-linear trajectory with a much smaller slope at the resonance mass. This provides a strong indication of the non-ordinary nature of the sigma meson.Comment: 4 pages, 2 figures, to appear in the proceedings of the "Seventh International Symposium on Chiral Symmetry in Hadrons and Nuclei

Peritoneal tuberculosis due to Mycobacterium caprae

The incidence of tuberculosis in humans due to Mycobacterium caprae is very low and is almost confined to Europe. We report a case of a previously healthy 41-year-old Moroccan with a 6 month history of abdominal pain, weight loss, fatigue and diarrhea. A diagnosis of peritoneal tuberculosis due to M. caprae was mad

Brote de eritema infeccioso en un centro de salud urbano

ObjetivosAnalizar las características clínicas y serológicas de un brote de eritema infeccioso en pacientes que acudieron a las 2 consultas de pediatría del Centro de Salud de Soria Norte.DiseñoEstudio descriptivo, transversal.EmplazamientoConsultas de pediatría del Centro de Salud de Soria Norte.PacientesUna vez sospechado el brote, se estudiaron niños con clínica sugestiva de eritema infeccioso que acudieron sucesivamente a las 2 consultas de pediatría de Soria Norte durante los meses de abril a agosto de 1998 y consintieron en la práctica de analítica.IntervencionesSe realizó registro de síntomas clínicos, serología, hemograma y evolución de 25 pacientes.ResultadosSe estudiaron 25 pacientes del total de casos, confirmando nuestra sospecha diagnóstica en un 84% de los casos. No se observaron diferencias en ambos sexos, con una edad media de 6,1 años, y DE, 2,015. El signo clínico más constante fue el exantema en mejillas, presente en un 100% de los casos confirmados, seguido de exantema en tronco y extremidades en un 57,1%, adenopatías en un 9,5% y fiebre en un 4,7%. En ningún caso se objetivaron complicaciones.ConclusionesLos resultados de este trabajo permiten confirmar la existencia de un brote de eritema infeccioso en nuestro medio. Consideramos útil la confirmación serológica para constatar la presencia de un brote y poder realizar un enfoque terapéutico (frente a complicaciones posibles) y preventivo adecuado. Destacamos el carácter, en general, benigno de la enfermedad.ObjectivesTo analyse the clinical and serological characteristics of an outbreak of infectious erythema in patients attending the two paediatrics clinics at the Soria Norte Health Centre.DesignCross-sectional, descriptive study.SettingPaediatrics clinics of the Soria Norte Health Centre.PatientsOnce the outbreak was suspected, the study was conducted on children with a clinical picture suggesting infectious erythema who attended successively two Soria Norte paediatrics clinics between April and August 1998 and who consented to the analyses.InterventionsThe clinical symptoms, serology, haemogram and evolution of 25 patients were recorded.Results25 patients of the total were studied and diagnostic suspicion was confirmed in 84% of the cases. There were no differences between sexes, with an average age of 6.1, SD 2.015. The most constant clinical sign was exanthem on the cheeks, present in 100% of the cases confirmed, followed by 57% exanthem on the trunk and limbs, 9.5% adenopathies and 4.7% temperature. No complications were found in any case.ConclusionsThe results of this study confirm the existence of an outbreak of infectious erythema in our area. Serological confirmation of an outbreak is useful and can lay the basis for a proper therapeutic and preventive focus (against possible complications). We highlight the generally benign nature of the disease

Astrocytic p38α MAPK drives NMDA receptor-dependent long-term depression and modulates long-term memory.

NMDA receptor-dependent long-term depression (LTD) in the hippocampus is a well-known form of synaptic plasticity that has been linked to different cognitive functions. The core mechanism for this form of plasticity is thought to be entirely neuronal. However, we now demonstrate that astrocytic activity drives LTD at CA3-CA1 synapses. We have found that LTD induction enhances astrocyte-to-neuron communication mediated by glutamate, and that Ca2+ signaling and SNARE-dependent vesicular release from the astrocyte are required for LTD expression. In addition, using optogenetic techniques, we show that low-frequency astrocytic activation, in the absence of presynaptic activity, is sufficient to induce postsynaptic AMPA receptor removal and LTD expression. Using cell-type-specific gene deletion, we show that astrocytic p38α MAPK is required for the increased astrocytic glutamate release and astrocyte-to-neuron communication during low-frequency stimulation. Accordingly, removal of astrocytic (but not neuronal) p38α abolishes LTD expression. Finally, this mechanism modulates long-term memory in vivo.post-print5316 K

The preliminary lattice QCD calculation of κ\kappa meson decay width

We present a direct lattice QCD calculation of the $\kappa$ meson decay width with the s-wave scattering phase shift for the isospin $I=1/2$ pion-kaon ($\pi K$) system. We employ a special finite size formula, which is the extension of the Rummukainen-Gottlieb formula for the $\pi K$ system in the moving frame, to calculate the scattering phase, which indicates a resonance around $\kappa$ meson mass. Through the effective range formula, we extract the effective $\kappa \to \pi K$ coupling constant $g_{\kappa \pi K} = 4.54(76)$ GeV and decay width $\Gamma = 293 \pm 101$ MeV. Our simulations are done with the MILC gauge configurations with $N_f=2+1$ flavors of the "Asqtad" improved staggered dynamical sea quarks on a $16^3\times48$ lattice at $(m_\pi + m_K) / m_\kappa \approx 0.8$ and lattice spacing $a \approx 0.15$ fm.Comment: To make it concise. arXiv admin note: text overlap with arXiv:1110.1422, but much of v1 text overlap with articles by same and other authors remove