Modelling the light-curve of KIC 12557548b: an extrasolar planet with a comet like tail

An object with a very peculiar light-curve was discovered recently using Kepler data. Authors argue that this object may be a transiting disintegrating planet with a comet like dusty tail. We calculate the light-curves of stars with such planets and take into account the Mie absorption and scattering on spherical dust grains of various sizes assuming realistic dust opacities and phase functions and finite radius of the source of the scattered light. The planet light-curve is reanalysed using long and short cadence Kepler observations from the first 14 quarters. Orbital period of the planet was improved. We prove that the peculiar light-curve of this objects is in agreement with the idea of a planet with a comet like tail. There is an evidence of a quasi periodic long term evolution of the tail. Light-curve has a prominent pre-transit brightening and a less prominent post-transit brightening. Both are caused by the forward scattering and are a strong function of the particle size. This feature enabled us to estimate a typical particle size (radius) in the dust tail of about 0.1-1 micron. However, there is an indication that the particle size changes along the tail. Larger particles better reproduce the pre-transit brightening and transit core while smaller particles are more compatible with the egress and post-transit brightening. Dust density in the tail is a steep decreasing function of the distance from the planet which indicates a significant tail destruction caused by the star. We also argue that the 'planet' does not show uniform behaviour but may have at least two constituents. This light-curve with pre-transit brightening is analogous to the light-curve of $\epsilon$ Aur with mid-eclipse brightening and forward scattering plays a significant role in such eclipsing systems.Comment: Version 2: Submitted to A&A, any comments are welcome. Version 1: Presented at the meeting: The Most Mysterious Binaries: Significance for Astrophysics, Hvar, Croatia, July 2-6, 201

PROTOTYPE TOOL OF IEEE 802.11AC WIRELESS NETWORKS PROPAGATION IN INDOOR ENVIRONMENTS

This research pretends to be useful for the future deployment of the wireless network of the Universidad Miguel Hernández, specifically at the campus of Elche. In terms of capacity, in short term we will need more capacity in the wireless network, for this reason we are testing some aspects of the protocol IEEE 802.11ac (Wi-Fi ac). This protocol works in the 5 GHz band and provides us more channels and capacity with channel bonding and MIMO. Before the deployment of the wireless network, we need to know the propagation model of the signal in different scenarios and conditions. We analyse the results obtained by a developed software tool capable of representing different measurements of the signal strength with LOS and NLOS scenarios and comparing with indoor propagation models. For measuring the signal level we have used an emitter 3x4 MIMO and a receiver 3x3 MIMO, both compatible with Wi-Fi ac

Simulation tool of IEEE 802.11ac wireless networks propagation in indoor environments

This research pretends to be useful for the future deployment of the wireless network of the Universidad Miguel Hernández, specifically at the campus of Elche. In terms of capacity, in short term we will need more capacity in the wireless network, for this reason we are testing some aspects of the protocol IEEE 802.11ac (Wi-Fi 5). This protocol works in the 5 GHz band and provides us more channels and capacity with channel bonding and MIMO. Before the deployment of the wireless network, we need to know the propagation model of the signal in different scenarios and conditions. We analyse the results obtained by a developed software tool capable of representing different measurements of the signal strength with LOS and NLOS scenarios and comparing with indoor propagation models. For measuring the signal level we have used an emitter 3x4 MIMO and a receiver 3x3 MIMO, both compatible with Wi-Fi ac

Salivary Parameters (Salivary Flow, pH and Buffering Capacity) in Stimulated Saliva of Mexican Elders 60 Years Old and Older

Objective: To compare a limited array of chewing-stimulated saliva features (salivary flow, pH and buffer capacity) in a sample of elderly Mexicans with clinical, sociodemographic and socio-economic variables. Subjects and Methods: A cross-sectional study was carried out in 139 adults, 60 years old and older, from two retirement homes and a senior day care centre in the city of Pachuca, Mexico. Sociodemographic, socio-economic and behavioural variables were collected through a questionnaire. A trained and standardized examiner obtained the oral clinical variables. Chewing-stimulated saliva (paraffin method) was collected and the salivary flow rate, pH and buffer capacity were measured. The analysis was performed using non-parametric tests in Stata 9.0. Results: Mean age was 79.1 ± 9.8 years. Most of the subjects included were women (69.1%). Mean chewing-stimulated salivary flow was 0.75 ± 0.80 mL/minute, and the pH and buffer capacity were 7.88 ± 0.83 and 4.20 ± 1.24, respectively. Mean chewing-stimulated salivary flow varied (p < 0.05) across type of retirement home, tooth brushing frequency, number of missing teeth and use of dental prostheses. pH varied across the type of retirement home (p < 0.05) and marginally by age (p = 0.087); buffer capacity (p < 0.05) varied across type of retirement home, tobacco consumption and the number of missing teeth. Conclusions: These exploratory data add to the body of knowledge with regard to chewing-stimulated salivary features (salivary flow rate, pH and buffer capacity) and outline the variability of those features across selected sociodemographic, socio-economic and behavioural variables in a group of Mexican elders

Lesion topographies in multiple sclerosis diagnosis

To assess the contributions of cortico-juxtacortical and corpus callosum lesions to multiple sclerosis diagnosis and to compare the value of ≥1 vs ≥3 periventricular lesions in clinically isolated syndromes (CIS). Step 1: We evaluated lesion topography classifications in 657 patients with CIS with stepwise Cox proportional hazards regression models considering second attack as the outcome. Step 2: We established 2 dissemination in space (DIS) versions according to the periventricular lesion cutoffs of ≥1 and ≥3 and assessed their performance at 10 years with second attack as the outcome, first individually and then combined with dissemination in time (DIT) in all cases (n = 326), by age, and by CIS topography. Step 1: The models (hazard ratios [95% confidence interval]) favored ≥1 over ≥3 periventricular lesions (2.5 [1.7-3.6]) and cortico-juxtacortical over juxtacortical lesions (1.4 [1.0-1.8]). Callosal lesions were not selected. Step 2: DIS specificity with ≥1 periventricular lesions was slightly lower than with ≥3 (59.1 vs 61.4) and the same after adding DIT (88.6). Regarding age, ≥3 periventricular lesions improved DIS specificity over ≥1 lesions in the 40-49 years of age bracket (66.7 vs 58.3). This difference disappeared when adding DIT (83.3). Optic neuritis had a similar pattern when evaluating CIS topographies. Our results comply with the Magnetic Resonance Imaging in Multiple Sclerosis (MAGNIMS) consensus recommendation of combining cortical and juxtacortical lesions into a single term when possible. Concerning periventricular lesions, maintaining the current ≥1 cutoff in the McDonald criteria does not compromise specificity in typical CIS cases, but attention should be paid to older patients or optic neuritis cases

Biosensores multienzimáticos para el análisis multiparamétrico con un solo dispositivo

In this work, the simulation of the voltammetric and chronoamperometric response of a multi-enzyme biosensor for the simultaneous analysis of glucose, cholesterol and triglycerides with a single device is reported. The results were processed using MLR multiple linear regression, PCR principal components regression and PLS partial least squares regression, finding that the best results are obtained with MLR processing the voltammetric information, obtaining relative error percentages of less than 10% on averageEn el presente trabajo se reporta la simulación de la respuesta voltamperométrica y cronoamperométrica de un biosensor multienzimático para la cuantificación simultánea de glucosa, colesterol y triglicéridos con un solo dispositivo. Los resultados fueron procesados mediante regresión lineal múltiple MLR, regresión de componentes principales PCR y regresión de mínimos cuadrados parciales PLS, encontrando que se obtienen los mejores resultados con MLR procesando la información voltamperométrica, obteniendo porcentajes de error relativo menores al 10% en promedi

Oral contraceptives do not modify the risk of a second attack and disability accrual in a prospective cohort of women with a clinically isolated syndrome and early multiple sclerosis

To evaluate whether oral contraceptive (OC) use is associated with the risk of a second attack and disability accrual in women with a clinically isolated syndrome (CIS) and early multiple sclerosis (MS). Reproductive information from women included in the Barcelona CIS prospective cohort was collected through a self-reported cross-sectional survey. We examined the relationship of OC exposure with the risk of a second attack and confirmed Expanded Disability Status Scale of 3.0 using multivariate Cox regression models, adjusted by age, topography of CIS, oligoclonal bands, baseline brain T2 lesions, body size at menarche, smoking, and disease-modifying treatment (DMT). OC and DMT exposures were considered as time-varying variables. Findings were confirmed with sensitivity analyses using propensity score models. A total of 495 women were included, 389 (78.6%) referred to ever use OC and 341 (68.9%) started OC before the CIS. Exposure to OC was not associated with a second attack (adjusted hazard ratio (aHR) = 0.73, 95% confidence interval (CI) = 0.33-1.61) or disability accrual (aHR = 0.81, 95% CI = 0.17-3.76). Sensitivity analyses confirmed these results. OC use does not modify the risk of second attack or disability accrual in patients with CIS and early MS, once considered as a time-dependent exposure and adjusted by other potential confounders

Optic Nerve Topography in Multiple Sclerosis Diagnosis

To assess the added value of the optic nerve region (by using visual evoked potentials [VEPs]) to the current diagnostic criteria. From the Barcelona clinically isolated syndrome (CIS) cohort, patients with complete information to assess dissemination in space (DIS), the optic nerve region, and dissemination in time at baseline (n = 388) were selected. Modified DIS (modDIS) criteria were constructed by adding the optic nerve to the current DIS regions. The DIS and modDIS criteria were evaluated with univariable Cox proportional hazard regression analyses with the time to the second attack as the outcome. A subset of these patients who had at least 10 years of follow-up or a second attack occurring within 10 years (n = 151) were selected to assess the diagnostic performance. The analyses were also performed according to CIS topography (optic neuritis vs non-optic neuritis). The addition of the optic nerve as a fifth region improved the diagnostic performance by slightly increasing the accuracy (2017 DIS 75.5%, modDIS 78.1%) and the sensitivity (2017 DIS 79.2%, modDIS 82.3%) without lowering the specificity (2017 DIS 52.4%, modDIS 52.4%). When the analysis was conducted according to CIS topography, the modDIS criteria performed similarly in both optic neuritis and non-optic neuritis CIS. The addition of the optic nerve, assessed by VEP, as a fifth region in the current DIS criteria slightly improves the diagnostic performance because it increases sensitivity without losing specificity

Proposta de metodologia a seguir per la presa de decisions davant les diferents alternatives de millora en l'accessibilitat d'una estació

En la presa de decisió d'execució de proj~ctes d'accessibilitat cal que intervinguin, a mes deis aspectes c1assicsde minimització de cost, nous criteris com la maximització del benefici social. Així, aquest article proposa a partir de I'avaluació individual de nivell d'accessibilitat de cada estació, un mecanisme de presa de decisions per tal d'obtenir un millor benefici social amb menys costo Amb aquest sistema es pretén aconseguir una avaluació de les diferents alternatives objectiva i quantitativa en un món de característiques qualitatives, assegurant una correcte relació cost/benefici social.Postprint (published version