Micobacteriosis en una tortuga mediterránea

Se describe un caso de Micobacteriosis en una tortuga mediterránea mantenida en cautividad. Se presenta el cuadro clínico y los hallazgos microbiológicos y anatornopatológicos, haciendo hincapié en las posibles repercusiones epidemiológicas para la salud humana.A case of Mycobacteriosis in a captive Hermann Tortoise is described. The clinical, microbiological and anatomopathological findings are presented With especial reference to posible consequences for human health

Remnants of Sagittarius Dwarf Spheroidal Galaxy around the young globular cluster Palomar 12

Photometry of a large field around the young globular cluster Palomar 12 has revealed the main-sequence of a low surface-brightness stellar system. This main-sequence is indicative of a stellar population that varies significantly in metallicity and/or age, but in the mean is more metal poor than Pal 12. Under different assumptions for the properties of this population, we find distances from the Sun in the range 17-24 kpc, which encompasses the distance to Pal 12, $19.0\pm0.9$ kpc. The stellar system is also detected in a field 2\arcdeg North of Pal 12, which indicates it has a minimum diameter of $\sim0.9$ kpc. The orbit of Pal 12 (Dinescu et al. 2000), the color-magnitude diagram of the stellar system, their positions on the sky, and their distances suggest that they are debris from the tidal disruption of the Sgr dSph galaxy. We discuss briefly the implications for the evolution of Sgr and the Galactic halo.Comment: 16 pages, 2 figures, accepted for ApJ Letters. Some importante changes after revision, including a new figur

Study on the vibration characteristics of the telescope T80 in the Javalambre astrophysical observatory (JAO) aimed at detecting invalid images

The location of large telescopes, generally far from the data processing centers, represents a logistical problem for the supervision of the capture of images. In this work, we carried out a preliminary study of the vibration signature of the T80 telescope at the Javalambre Astrophysical Observatory (JAO). The study analyzed the process of calculating the displacement that occurs because of the vibration in each of the frequencies in the range of interest. We analyzed the problems associated with very low frequencies by means of simulation, finding the most critical vibrations below 20 Hz, since they are the ones that generate greater displacements. The work also relates previous studies based on simulation with the real measurements of the vibration of the telescope taken remotely when it is subjected to different positioning movements (right ascension and/or declination) or when it performs movement actions such as those related to filter trays or mirror cover. The obtained results allow us to design a remote alarm system to detect invalid images (taken with excess vibration)

Modified filtered-x hierarchical lms algorithm with sequential partial updates for active noise control

In the field of active noise control (ANC), a popular method is the modified filtered-x LMS algorithm. However, it has two drawbacks: Its computational complexity higher than that of the conventional FxLMS, and its convergence rate that could still be improved. Therefore, we propose an adaptive strategy which aims at speeding up the convergence rate of an ANC system dealing with periodic disturbances. This algorithm consists in combining the organization of the filter weights in a hierarchy of subfilters of shorter length and their sequential partial updates (PU). Our contribution is threefold: (1) we provide the theoretical basis of the existence of a frequency-depend-ent parameter, called gain in step-size. (2) The theoretical upper bound of the step-size is compared with the limit obtained from simulations. (3) Additional experiments show that this strategy results in a fast algorithm with a computational complexity close to that of the conventional FxLMS

Evidence of strong antiferromagnetic coupling between localized and itinerant electrons in ferromagnetic Sr2FeMoO6

Magnetic dc susceptibility ($\chi$) and electron spin resonance (ESR) measurements in the paramagnetic regime, are presented. We found a Curie-Weiss (CW) behavior for $\chi$(T) with a ferromagnetic $\Theta = 446(5)$ K and $\mu_{eff} = 4.72(9) \mu_{B}/f.u.$, this being lower than that expected for either $Fe^{3+}(5.9\mu_{B})$ or $Fe^{2+}(4.9\mu_{B})$ ions. The ESR g-factor $g = 2.01(2)$, is associated with $Fe^{3+}$. We obtained an excellent description of the experiments in terms of two interacting sublattices: the localized $Fe^{3+}$ ($3d^{5}$) cores and the delocalized electrons. The coupled equations were solved in a mean-field approximation, assuming for the itinerant electrons a bare susceptibility independent on $T$. We obtained $\chi_{e}^{0} = 3.7$ $10^{-4}$ emu/mol. We show that the reduction of $\mu_{eff}$ for $Fe^{3+}$ arises from the strong antiferromagnetic (AFM) interaction between the two sublattices. At variance with classical ferrimagnets, we found that $\Theta$ is ferromagnetic. Within the same model, we show that the ESR spectrum can be described by Bloch-Hasegawa type equations. Bottleneck is evidenced by the absence of a $g$-shift. Surprisingly, as observed in CMR manganites, no narrowing effects of the ESR linewidth is detected in spite of the presence of the strong magnetic coupling. These results provide evidence that the magnetic order in $Sr_{2}FeMoO_{6}$ does not originates in superexchange interactions, but from a novel mechanism recently proposed for double perovskites

Effect of Melatonin as an Antioxidant Drug to Reverse Hepatic Steatosis: Experimental Model

Introduction. The hepatic steatosis of the nonalcoholic origin or NAFLD is increasing at present, particularly in Western countries, parallel to the increase in obesity, constituting one of the most prevalent hepatic processes in the Western society. Melatonin has been successfully tested in experimental models in mice as a drug capable of reversing steatosis. The effect of melatonin on fat metabolism can be summarized as a decrease in lipid peroxidation and a decrease in oxidative stress, biochemical phenomena intimately related to fat deposition in the hepatocyte. There are hardly any studies in large animals. Objective. In this study, we investigate the effects of melatonin administered orally at a dose of 10 mg/kg/day to reverse established hepatic steatosis induced by a special diet in a porcine animal model. Materials and Methods. We analyze the parameters of oxidative stress: malondialdehyde (MDA), 4-hydroxyalkenals (4-HDA), and carbonyls, degree of fat infiltration (analyzed by direct vision by a pathologist and by means of a computer program of image treatment), and serological parameters of lipid metabolism and hepatic damage. These parameters were analyzed in animals to which hepatic steatosis was induced by means of dietary modifications. Results. We have not been able to demonstrate globally a beneficial effect of melatonin in the improvement or reversal of liver steatosis once established, induced by diet in a porcine animal model. However, we have found several signs of improvement at the histological level, at the level of lipid metabolism, and at the level of oxidative stress parameters. We have verified in our study that, in the histological analysis of the liver sample by means of the program image treatment (free of subjectivity) of the animals that continue with the diet, those that consume melatonin do not increase steatosis as much as those that do not consume it significantly (p=0.002). Regarding the parameters of oxidative stress, MDA modifies in a significant manner within the group of animals that continue with the diet and take melatonin (p=0.004). As for lipid metabolism, animals that maintain the steatotic diet and take melatonin lower total and LDL cholesterol levels and increase HDL levels, although these results do not acquire statistical significance. Conclusions. In this study, it has not been possible to demonstrate a beneficial effect of melatonin in the improvement or reversal of liver steatosis once established and induced by diet in the porcine model. It is true that signs of improvement have been found at the histological level, at the level of lipid metabolism, and at the level of oxidative stress phenomena, when comparing animals with established steatosis that are treated with melatonin with those who do not take it. This work is the first study conducted in a large animal model in which the effect of melatonin is studied as a treatment in the reversal of established hepatic steatosis

Comparación del efecto de la concentración de polvo de neumático reciclado y polímeros en el comportamiento de ligantes para mezclas bituminosas

Crumb rubber modified binders are environmental-friendly alternatives to polymer modified bitumens in asphalt mixtures. This paper compares the performance of both types of binders with different modifier contents. Six binders were characterised by conventional tests and analysed using the UCL method. This method evaluates different properties of binders regarding their role in asphalt mixtures (cohesion, water and thermal sensitivity and resistance to ageing). Results showed that i) crumb rubber concentration has to be higher than that of SBS-polymers in order to obtain a similar performance to that of SBS-polymer modified bitumen; ii) crumb rubber modified binders are more stable than SBS-polymer modified binders in terms of modifier concentration; iii) crumb rubber modified binders exhibited less water sensitivity and similar thermal and ageing susceptibility to SBS-polymer modified binders; iv) linear relationships have been found between modifier concentration and the properties studied for both kind of binders.Los betunes modificados con polvo de neumático (PN) son alternativas ambientalmente sostenibles a los betunes modificados con polímeros. Este artículo compara el comportamiento de ambos tipos de betunes con varios contenidos de modificador. Para ello, se caracterizaron seis betunes mediante ensayos convencionales y método UCL. Este método evalúa propiedades de ligantes para su uso en mezclas bituminosas (cohesión, sensibilidad al agua, térmica y al envejecimiento). Los resultados muestran que i) la concentración de PN ha de ser más elevada que la de polímeros para obtener comportamiento semejante; ii) los betunes con PN son más estables ante cambios en la concentración de modificador que los betunes con polímeros; iii) los betunes con PN presentan menor sensibilidad al agua y equivalente susceptibilidad térmica y al envejecimiento que los betunes con polímeros; iv) se encontraron buenos ajustes lineales entre la concentración de modificadores y la evolución de las propiedades estudiadas

Assessment of the Production of Value-Added Chemical Compounds from Sewage Sludge Pyrolysis Liquids

A procedure to analyze sewage sludge (SS) pyrolysis liquids based on solvent fractionation has been developed. Pyrolysis liquids are separated into three different fractions: heptane soluble (Hep-sol), dichloromethane soluble (DCM-sol), and hydrochloric acid soluble (HCl-sol). Diverse techniques (GC-MS, UPLC-TOF-MS) were employed to qualitatively and quantitatively analyze liquid fractions to assess the potential production of value-added chemicals. Aliphatic hydrocarbons, aliphatic nitriles, and steroids were mostly separated in the Hep-sol fraction, phenols and fatty acids in the DCM-sol fraction, and carboxylic acids and amides in the HCl-sol fraction. The largest production was obtained for ammonia (10–14 kg per tonne of SS) and a-olefins (8–9 kg per tonne of SS). The potential production of some of these value-added chemicals from SS pyrolysis liquid was compared with their current European production. In the case of a-olefins, 16 % of their European production could be achieved by SS pyrolysis

Experimental and numerical analysis of quench propagation on MgB 2 tapes and pancake coils

In the design and feasibility of electric power applications with MgB2 conductors, thermal conductivity plays an important role. In composite wires and tapes it is mainly determined by the amount of stabilizer (usually copper), while for coils the electric insulation and epoxy binder characteristics are added. In this paper we present results on quench development and propagation on isolated superconducting tapes and small single pancake coils cooled by thermal conduction, for three types of MgB2 tape with different stabilizations. The quench parameters at different temperatures, such as minimum quench energy (MQE), minimum propagation zone (MPZ) and quench propagation velocity (vp), are reported. A complete electrical and thermal characterization of the superconducting tapes and of non-superconducting materials used in the coil manufacture has been made. With these data, numerical computational models using finite element simulations have been performed for isolated wires and single pancake coils, and the results of the relevant quench parameters have been compared with the measured values

West Nile virus in the New World: potential impacts on bird species

The past five years have seen the arrival and extremely rapid expansion of West Nile virus (WNV) in the Western Hemisphere. The rapid sweep across North America has permitted little time for developing knowledge of the virus’s potential impacts on wildlife in the New World. Given this information gap, we here summarize for the ornithological community what is known or can be anticipated for WNV’s effect on bird communities in coming years. Our particular focus is on impacts of WNV on the conservation status of birds, the principal vertebrate reservoir for the virus