Acute respiratory infection: first clinical manifestation of active infection with cytomegalovirus in HIV patients presenting to the emergency department

Introduction. Traditionally, digestive and ophthalmic symptoms have been described as predominant in the clinical presentation of active infection with cytomegalovirus (AICMV). Nevertheless, it seems that this has changed following the introduction of antiretroviral therapy (ART). Nowadays, respiratory infection (RI) in HIV-infected patients is the first reason for consulting an Emergency Department (ED). Among these patients, the mortality is important. Aim. To determine if RI in HIV-infected patients is a common manifestation of AICMV and to describe the changes in clinical presentation of AICMV in relation to what was previously described. Methods. A single-center, retrospective study was conducted over the duration of nine years (2005-2015). All HIV patients who consulted our emergency department with respiratory symptoms and were diagnosed with AICMV were included. Isolation of other co-infecting microorganisms and mortality in the series are also described. Results. 56 HIV-infected patients with AICMV were identified. RI was diagnosed in 34 (61%), 31(91%) patients had pneumonia and 3(9%) pulmonary tuberculosis. The most frequently isolated microorganism was P. jirovecii, in 21 (68%) patients. Bacteria were isolated in five patients (15%). Five patients died from RI (9%). No patient had acute retinitis or any other ophthalmic involvement. Conclusion. Clinical manifestation of AICMV in HIV patients has changed, and RI is the most common manifestation, caused by opportunistic microorganisms with 9% mortality

Acute respiratory infection: first clinical manifestation of active infection with cytomegalovirus in HIV patients presenting to the emergency department

Introduction. Traditionally, digestive and ophthalmic symptoms have been described as predominant in the clinical presentation of active infection with cytomegalovirus (AICMV). Nevertheless, it seems that this has changed following the introduction of antiretroviral therapy (ART). Nowadays, respiratory infection (RI) in HIV-infected patients is the first reason for consulting an Emergency Department (ED). Among these patients, the mortality is important. Aim. To determine if RI in HIV-infected patients is a common manifestation of AICMV and to describe the changes in clinical presentation of AICMV in relation to what was previously described. Methods. A single-center, retrospective study was conducted over the duration of nine years (2005-2015). All HIV patients who consulted our emergency department with respiratory symptoms and were diagnosed with AICMV were included. Isolation of other co-infecting microorganisms and mortality in the series are also described. Results. 56 HIV-infected patients with AICMV were identified. RI was diagnosed in 34 (61%), 31(91%) patients had pneumonia and 3(9%) pulmonary tuberculosis. The most frequently isolated microorganism was P. jirovecii, in 21 (68%) patients. Bacteria were isolated in five patients (15%). Five patients died from RI (9%). No patient had acute retinitis or any other ophthalmic involvement. Conclusion. Clinical manifestation of AICMV in HIV patients has changed, and RI is the most common manifestation, caused by opportunistic microorganisms with 9% mortality

The escape problem under stochastic volatility: the Heston model

We solve the escape problem for the Heston random diffusion model. We obtain exact expressions for the survival probability (which ammounts to solving the complete escape problem) as well as for the mean exit time. We also average the volatility in order to work out the problem for the return alone regardless volatility. We look over these results in terms of the dimensionless normal level of volatility --a ratio of the three parameters that appear in the Heston model-- and analyze their form in several assymptotic limits. Thus, for instance, we show that the mean exit time grows quadratically with large spans while for small spans the growth is systematically slower depending on the value of the normal level. We compare our results with those of the Wiener process and show that the assumption of stochastic volatility, in an apparent paradoxical way, increases survival and prolongs the escape time.Comment: 29 pages, 12 figure

Stochastic volatility and leverage effect

We prove that a wide class of correlated stochastic volatility models exactly measure an empirical fact in which past returns are anticorrelated with future volatilities: the so-called ``leverage effect''. This quantitative measure allows us to fully estimate all parameters involved and it will entail a deeper study on correlated stochastic volatility models with practical applications on option pricing and risk management.Comment: 4 pages, 2 figure

Sobre la presencia de Powellita, Mo O4 Ca, en Gualba de Dalt (Barcelona)

Se cita por primera vez la powellita, Mo O, Ca, en Catalunya (Gualba de Dalt, Barcelona). Los ejemplares recolectados se estudiaron mediante las técnicas siguientes: analisis quimico, picnometria, difractometria y espectrografia por fluorescencia de rayos X. Se consideran las posibles relaciones entre la powellita y la molibdenita, S, Mo, presente en el mismo yacimiento

Accounting for risk of non linear portfolios: a novel Fourier approach

The presence of non linear instruments is responsible for the emergence of non Gaussian features in the price changes distribution of realistic portfolios, even for Normally distributed risk factors. This is especially true for the benchmark Delta Gamma Normal model, which in general exhibits exponentially damped power law tails. We show how the knowledge of the model characteristic function leads to Fourier representations for two standard risk measures, the Value at Risk and the Expected Shortfall, and for their sensitivities with respect to the model parameters. We detail the numerical implementation of our formulae and we emphasizes the reliability and efficiency of our results in comparison with Monte Carlo simulation.Comment: 10 pages, 12 figures. Final version accepted for publication on Eur. Phys. J.

Entropy of the Nordic electricity market: anomalous scaling, spikes, and mean-reversion

The electricity market is a very peculiar market due to the large variety of phenomena that can affect the spot price. However, this market still shows many typical features of other speculative (commodity) markets like, for instance, data clustering and mean reversion. We apply the diffusion entropy analysis (DEA) to the Nordic spot electricity market (Nord Pool). We study the waiting time statistics between consecutive spot price spikes and find it to show anomalous scaling characterized by a decaying power-law. The exponent observed in data follows a quite robust relationship with the one implied by the DEA analysis. We also in terms of the DEA revisit topics like clustering, mean-reversion and periodicities. We finally propose a GARCH inspired model but for the price itself. Models in the context of stochastic volatility processes appear under this scope to have a feasible description.Comment: 16 pages, 7 figure

Sobre la presencia de Powellita, Mo O4 Ca, en Gualba de Dalt (Barcelona)

Se cita por primera vez la powellita, Mo O, Ca, en Catalunya (Gualba de Dalt, Barcelona). Los ejemplares recolectados se estudiaron mediante las técnicas siguientes: analisis quimico, picnometria, difractometria y espectrografia por fluorescencia de rayos X. Se consideran las posibles relaciones entre la powellita y la molibdenita, S, Mo, presente en el mismo yacimiento

Neuritis por virus zoster simulando una lesión yatrogénica del nervio ciático

Se describe un caso de fractura-luxación posterior de cadera sin alteraciones neurovasculares asociadas, que a las 2 semanas de la intervención se presentó un cuadro de radiculalgia. Inicialmente se sospechó una lesión neurológica relacionada con el acto quirúrgico con el proceso de cicatrización de la herida. El estudio electromiográfico, las características clínicas y la respuesta al tratamiento con aciclovir permitieron identificar la neuritis del nervio ciático por virus varicela zoster. Ante una radiculopatía postoperatoria no se debe olivar la posibilidad de un origen inflamatorio o infeccioso. El acto quirúrgico puede provocar una reactivación de la infección latente por virus varicela zoster.One case of posterior fracture-dislocation of the hip without neurovascular injury is presented. Radicular pain bean two weeks after surgery. It was initially attributed to surgery, or to the would healing process. Electromyography, clinical appearance and response to the treatment with acyclovir led to the diagnosis of neuritis of the sciatic nerve by varicela-zoster virus. Whenever a postoperative radiculalgia appears, one must consider the possibility of an inflammatory or infectious origin. Surgical manipulation could induce the reactivation of a latent infection by varicela-zoster virus