A new formulation of compartmental epidemic modelling for arbitrary distributions of incubation and removal times

The paradigm for compartment models in epidemiology assumes exponentially distributed incubation and removal times, which is not realistic in actual populations. Commonly used variations with multiple exponentially distributed variables are more flexible, yet do not allow for arbitrary distributions. We present a new formulation, focussing on the SEIR concept that allows to include general distributions of incubation and removal times. We compare the solution to two types of agent-based model simulations, a spatially homogeneous one where infection occurs by proximity, and a model on a scale-free network with varying clustering properties, where the infection between any two agents occurs via their link if it exists. We find good agreement in both cases. Furthermore a family of asymptotic solutions of the equations is found in terms of a logistic curve, which after a non-universal time shift, fits extremely well all the microdynamical simulations. The formulation allows for a simple numerical approach; software in Julia and Python is provided.Comment: 21 pages, 11 figures. v2 matches published version: improved presentation (including title, abstract and references), results and conclusions unchange

Football performance indicators review

Se ha realizado una revisión y selección de algunos de los factores que están implicados en el rendimiento deportivo en fútbol haciendo una recopilación de las variables que han tenido en cuenta otros investigadores y agrupándolas en diferentes bloques. En el primer bloque se presentan los factores físicos y fisiológicos, tanto los genéticos como los susceptibles de ser entrenados. En otro bloque hemos agrupado los factores contextuales en los que incluimos los psicológicos y sociales, ya que vienen a contextualizar las condiciones del partido y de los jugadores. Por último, desarrollamos los indicadores técnico tácticos más utilizados para estimar el rendimiento de los equipos de fútbol

Modeling dust emission in PN IC 418

We investigated the infrared (IR) dust emission from PN IC 418, using a detailed model controlled by a previous determination of the stellar properties and the characteristics of the photoionized nebula, keeping as free parameters the dust types, amounts and distributions relative to the distance of the central star. The model includes the ionized region and the neutral region beyond the recombination front (Photodissociation region, or PDR), where the [OI] and [CII] IR lines are formed. We succeeded in reproducing the observed infrared emission from 2 to 200~\mm. The global energy budget is fitted by summing up contributions from big grains of amorphous carbon located in the neutral region and small graphite grains located in the ionized region (closer to the central star). Two emission features seen at 11.5 and 30~\mm are also reproduced by assuming them to be due to silicon carbide (SiC) and magnesium and iron sulfides (Mg$_x$Fe$_{1-x}$S), respectively. For this, we needed to consider ellipsoidal shapes for the grains to reproduce the wavelength distribution of the features. Some elements are depleted in the gaseous phase: Mg, Si, and S have sub-solar abundances (-0.5 dex below solar by mass), while the abundance of C+N+O+Ne by mass is close to solar. Adding the abundances of the elements present in the dusty and gaseous forms leads to values closer to but not higher than solar, confirming that the identification of the feature carriers is plausible. Iron is strongly depleted (3 dex below solar) and the small amount present in dust in our model is far from being enough to recover the solar value. A remaining feature is found as a residue of the fitting process, between 12 and 25~\mm, for which we do not have identification.Comment: Accepted for publication in Astronomy & Astrophysics. V2: adding reference

Malnutrition as cause and consequence of sensory distorsiones

La malnutrición es una enfermedad provocada por un exceso o defecto en el consumo o aprovechamiento de los nutrientes. Habitualmente, se utiliza este término para referirse a la desnutrición, es decir, a un trastorno derivado del déficit de algún macro y o micronutrientes. Las alteraciones quimiosensoriales pueden reducir de forma importante la alimentación en el individuo, por lo que es importante verificar que el aporte de nutrientes y, de forma concreta, de algunos micronutrientes, sea suficiente, ya que alguno de ellos, como el zinc, desempeñan un papel primordial en las alteraciones del gusto y del olfato. Además, el paciente malnutrido o con una alimentación que excluya gran número de alimentos, tiene mayor riesgo de presentar déficits de dichos micronutrientes. Diversas enfermedades, tanto agudas como crónicas, se asocian a alteraciones de la percepción sensorial, y pueden llegar a afectar a más del 50% de las personas mayores de 65 años. Los efectos provocados por los fármacos y algunos tratamientos como la quimioterapia y la radioterapia, juegan también un papel muy importante en la distorsión sensorial y en la incidencia de malnutriciónMalnutrition is a pathological condition caused by an excess or deficiency in the consumption or the use of the nutrients. Usually this term refers to a lack of adequate nourishment, a disorder resulting from a deficiency of some macro and/or micronutrients. Chemo-sensory alterations can significantly reduce food choice and intake, so it is very important to verify that the supply of nutrients and specifically of some micronutrients are sufficient. Some of them, such as “zinc”, play a very important role in alterations in the sense of taste and smell. In addition malnutrition patients or a poorly-balanced diet or faulty utilization of foods have increased the risk of deficiencies in these micronutrients. Several types of diseases, both acute and chronic ones, are associated with sensory perception and can affect more than 50% of people over 65 years old. The effects caused by drugs and some treatments such as chemotherapy and radiation therapy play an important role in sensory distortion and the incidence of malnutritio