Superluminality in the Bi- and Multi- Galileon

We re-explore the Bi- and Multi-Galileon models with trivial asymptotic conditions at infinity and show that propagation of superluminal fluctuations is a common and unavoidable feature of these theories, unlike previously claimed in the literature. We show that all Multi-Galileon theories containing a Cubic Galileon term exhibit superluminalities at large distances from a point source, and that even if the Cubic Galileon is not present one can always find sensible matter distributions in which there are superluminal modes at large distances. In the Bi-Galileon case we explicitly show that there are always superluminal modes around a point source even if the Cubic Galileon is not present. Finally, we briefly comment on the possibility of avoiding superluminalities by modifying the asymptotic conditions at infinity.Comment: 32 pages, minor changes, few references adde

Por que usar agulhas atraumaticas em puncao lombar?

Diagnostic lumbar puncture is essential to the diagnosis of central nervous system infections, subarachnoid haemorrhage and others neurological diseases. Myeloradicular involvement or life-threatening adverse events due to the procedure are rare, but less severe complications are more frequent. Post-lumbar puncture headache is the most common complication, by spinal fluid leakage due to delayed closure of a dural defect. Therefore, the development of fine needles, with differentiated atraumatic bevel, has contributed to minimize that problem. These generically called atraumatic needles cause less deformation of the dura mater then the Quincke® ones. So, why don't we use these atraumatic needles?A punção lombar é essencial para o diagnóstico de infecções do sistema nervoso central, hemorragia subaracnoídea e outras doenças neurológicas. O comprometimento mielorradicular ou efeitos adversos que envolvam risco de vida como consequência do procedimento são raros, mas complicações leves são mais frequentes. Cefaléia pós-punção lombar é a complicação mais comum, secundária a escoamento do líquido cefalorraquiano por fechamento tardio de uma lesão dural. Consequentemente, o desenvolvimento de agulhas finas, com bisel atraumático, tem contribuído para minimizar o problema. Estas agulhas, chamadas genericamente de atraumáticas, causam menos deformação da dura-mater que as agulhas tipo Quincke®. Então, porque não usar estas agulhas atraumáticas?Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Senne Liquor DiagnosticoUNIFESP, EPM, Senne Liquor DiagnosticoSciEL

Auditory evoked potentials and multiple sclerosis

Multiple sclerosis (MS) is an inflammatory, demyelinating disease that can affect several areas of the central nervous system. Damage along the auditory pathway can alter its integrity significantly. Therefore, it is important to investigate the auditory pathway, from the brainstem to the cortex, in individuals with MS. Objective: the aim of this study was to characterize auditory evoked potentials in adults with MS of the remittent-recurrent type. Method: the study comprised 25 individuals with MS, between 25 and 55 years, and 25 age- and gender-matched healthy controls (research and control groups). Subjects underwent audiological and electrophysiological evaluations. Results: Statistically significant differences were observed between the groups regarding the results of the auditory brainstem response and the latency of the Na and P300 waves. Conclusion: Individuals with MS present abnormalities in auditory evoked potentials indicating dysfunction of different regions of the central auditory nervous system.Univ São Paulo FMUSP, Auditory Evoked Potentials Lab, Sch Med, Speech Pathol & Audiol Course, São Paulo, BrazilUniv São Paulo FMUSP, Speech Pathol & Audiol Course, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo Hosp, São Paulo, BrazilFMUSP, Rehabil Sci Program, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo Hosp, São Paulo, BrazilWeb of Scienc

Interacció VHC-hoste: Estudi genètic i clínic en pacients coinfectats amb VHC-VIH

L’Organització Mundial de la Salut (OMS) estima que fins a un 3% de la població mundial ha estat infectada pel virus de l’hepatitis C i és la causa més important d’hepatitis crònica, cirrosi i de malaltia hepàtica terminal, que finalment acaba conduint a un transplantament de fetge. La relació entre la variabilitat en la seqüència del virus de l’hepatitis C i el desenvolupament de la malaltia hepàtica és de tipus multifactorial. La infecció crònica causa fibrosi hepàtica, fet que es veu accelerat per mecanismes desconeguts en el cas de pacients coinfectats amb VIH. La progressió de la malaltia produïda pel VHC en pacients coinfectats, està influenciada no només per factors demogràfics, epidemiològics o pels antecedents clínics dels pacients, si no també per diferències genètiques entre els diferents virus i els hostes

Kalman reduced form and pole placement by state feedback for multi‐input linear systems over Hermite rings

[EN] A Kalman reduced form is obtained for linear systems over Hermite rings. This reduced form gives information of the set of assignable polynomials to a given linear system.S