Radiating Shear-Free Gravitational Collapse with Charge

We present a new shear free model for the gravitational collapse of a spherically symmetric charged body. We propose a dissipative contraction with radiation emitted outwards. The Einstein field equations, using the junction conditions and an ansatz, are integrated numerically. A check of the energy conditions is also performed. We obtain that the charge delays the black hole formation and it can even halt the collapse.Comment: 22 pages, 9 figures. It has been corrected several typos and included several references. Accepted for publication in GR

Evaluating the capacity of human gut microorganisms to colonize the zebrafish larvae (Danio rerio)

Indexación: Scopus.In this study we evaluated if zebrafish larvae can be colonized by human gut microorganisms. We tested two strategies: (1) through transplantation of a human fecal microbiota and (2) by successively transplanting aerotolerant anaerobic microorganisms, similar to the colonization in the human intestine during early life. We used conventionally raised zebrafish larvae harboring their own aerobic microbiota to improve the colonization of anaerobic microorganisms. The results showed with the fecal transplant, that some members of the human gut microbiota were transferred to larvae. Bacillus, Roseburia, Prevotella, Oscillospira, one unclassified genus of the family Ruminococcaceae and Enterobacteriaceae were detected in 3 days post fertilization (dpf) larvae; however only Bacillus persisted to 7 dpf. Successive inoculation of Lactobacillus, Bifidobacterium and Clostridioides did not improve their colonization, compared to individual inoculation of each bacterial species. Interestingly, the sporulating bacteria Bacillus clausii and Clostridioides difficile were the most persistent microorganisms. Their endospores persisted at least 5 days after inoculating 3 dpf larvae. However, when 5 dpf larvae were inoculated, the proportion of vegetative cells in larvae increased, revealing proliferation of the inoculated bacteria and better colonization of the host. In conclusion, these results suggest that it is feasible to colonize zebrafish larvae with some human bacteria, such as C. difficile and Bacillus and open an interesting area to study interactions between these microorganisms and the host. © 2018 Valenzuela, Caruffo, Herrera, Medina, Coronado, Feijóo, Muñoz, Garrido, Troncoso, Figueroa, Toro, Reyes-Jara, Magne and Navarrete.https://www.frontiersin.org/articles/10.3389/fmicb.2018.01032/ful

Direct and indirect effects of vertical mixing, nutrients and ultraviolet radiation on the bacterioplankton metabolism in high-mountain lakes from southern Europe

As a consequence of global change, modifications in the interaction among abiotic stressors on aquatic ecosystems have been predicted. Among other factors, UVR transparency, nutrient inputs and shallower epilimnetic layers could alter the trophic links in the microbial food web. Currently, there are some evidences of higher sensitiveness of aquatic microbial organisms to UVR in opaque lakes. Our aim was to assess the interactive direct and indirect effects of UVR (through the excretion of organic carbon – EOC – by algae), mixing regime and nutrient input on bacterial metabolism. We performed in situ short-term experiments under the following treatments: full sunlight (UVR + PAR, >280 nm) vs. UVR exclusion (PAR only, >400 nm); ambient vs. nutrient addition (phosphorus (P; 30 μg PL−1) and nitrogen (N; up to final N : P molar ratio of 31)); and static vs. mixed regime. The experiments were conducted in three high-mountain lakes of Spain: Enol [LE], Las Yeguas [LY] and La Caldera [LC] which had contrasting UVR transparency characteristics (opaque (LE) vs. clear lakes (LY and LC)). Under ambient nutrient conditions and static regimes, UVR exerted a stimulatory effect on heterotrophic bacterial production (HBP) in the opaque lake but not in the clear ones. Under UVR, vertical mixing and nutrient addition HBP values were lower than under the static and ambient nutrient conditions, and the stimulatory effect that UVR exerted on HBP in the opaque lake disappeared. By contrast, vertical mixing and nutrient addition increased HBP values in the clear lakes, highlighting for a photoinhibitory effect of UVR on HBP. Mixed regime and nutrient addition resulted in negative effects of UVR on HBP more in the opaque than in the clear lakes. Moreover, in the opaque lake, bacterial respiration (BR) increased and EOC did not support the bacterial carbon demand (BCD). In contrast, bacterial metabolic costs did not increase in the clear lakes and the increased nutrient availability even led to higher HBP. Consequently, EOC satisfied BCD in the clear lakes, particularly in the clearest one [LC]. Our results suggest that the higher vulnerability of bacteria to the damaging effects of UVR may be particularly accentuated in the opaque lakes and further recognizes the relevance of light exposure history and biotic interactions on bacterioplankton metabolism when coping with fluctuating radiation and nutrient inputs.Fil: Durán, C.. Universidad de Granada; EspañaFil: Medina Sánchez, J. M.. Universidad de Granada; EspañaFil: Herrera, G.. Universidad de Granada; EspañaFil: Villar Argaiz , M.. Universidad de Granada; EspañaFil: Villafañe, Virginia Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Helbling, Eduardo Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Carrillo, P.. Universidad de Granada; Españ

Interactive effects of vertical mixing, nutrients and ultraviolet radiation: In situ photosynthetic responses of phytoplankton from high mountain lakes of Southern Europe.

Global change, together with human activities, has resulted in increasing amounts of organic material (includ-ing nutrients) that water bodies receive. This input further attenuates the penetration of solar radiation, leading to the view that opaque lakes are more “protected” from solar ul-traviolet radiation (UVR) than clear ones. Vertical mixing, however, complicates this view as cells are exposed to fluc-tuating radiation regimes, for which the effects have, in gen-eral, been neglected. Furthermore, the combined impacts of mixing, together with those of UVR and nutrient inputs are virtually unknown. In this study, we carried out complex in situ experiments in three high mountain lakes of Spain (Lake Enol in the National Park Picos de Europa, Asturias, and lakes Las Yeguas and La Caldera in the National Park Sierra Nevada, Granada), used as model ecosystems to evaluate the joint impact of these climate change variables. The main goal of this study was to address the question of how short-term pulses of nutrient inputs, together with vertical mixing and increased UVR fluxes modify the photosynthetic responses of phytoplankton. The experimentation consisted in all pos-sible combinations of the following treatments: (a) solar radi-ation: UVR + PAR (280–700 nm) versus PAR (photosynthet-ically active radiation) alone (400–700 nm); (b) nutrient ad-dition (phosphorus (P) and nitrogen (N)): ambient versus ad-dition (P to reach to a final concentration of 30 µg P L−1, and N to reach N:P molar ratio of 31); and (c) mixing: mixed (one rotation from surface to 3 m depth (speed of 1 m 4 min−1, to-tal of 10 cycles)) versus static. Our findings suggest that un-der ambient nutrient conditions there is a synergistic effect between vertical mixing and UVR, increasing phytoplank-ton photosynthetic inhibition and excretion of organic carbon (EOC) from opaque lakes as compared to algae that received constant mean irradiance within the epilimnion. The opposite occurs in clear lakes where antagonistic effects were deter-mined, with mixing partially counteracting the negative ef-fects of UVR. Nutrient input, mimicking atmospheric pulses from Saharan dust, reversed this effect and clear lakes be-came more inhibited during mixing, while opaque lakes ben-efited from the fluctuating irradiance regime. These climate change related scenarios of nutrient input and increased mix-ing, would not only affect photosynthesis and production in lakes, but might also further influence the microbial loop and trophic interactions via enhanced EOC under fluctuat-ing UVR exposure.Fil: Helbling, Eduardo Walter. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina;Fil: Carrillo, P.. Universidad de Granada. Instituto Universitario de Investigación del Agua; España;Fil: Medina Sanchez, J. M.. Universidad de Granada. Facultad de Ciencias. Departamento de Ecología; España;Fil: Durán, C.. Universidad de Granada. Instituto Universitario de Investigación del Agua; España;Fil: Herrera, G.. Universidad de Granada. Instituto Universitario de Investigación del Agua; España;Fil: Villar Argaiz, M.. Universidad de Granada. Facultad de Ciencias. Departamento de Ecología; España;Fil: Villafañe, Virginia Estela. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina

Asynchronous processing for latent fingerprint identification on heterogeneous CPU-GPU systems

Latent fingerprint identification is one of the most essential identification procedures in criminal investigations. Addressing this task is challenging as (i) it requires analyzing massive databases in reasonable periods and (ii) it is commonly solved by combining different methods with very complex data-dependencies, which make fully exploiting heterogeneous CPU-GPU systems very complex. Most efforts in this context focus on improving the accuracy of the approaches and neglect reducing the processing time. Indeed, the most accurate approach was designed for one single thread. This work introduces the fastest methodology for latent fingerprint identification maintaining high accuracy called Asynchronous processing for Latent Fingerprint Identification (ALFI). ALFI fully exploits all the resources of CPU-GPU systems using asynchronous processing and fine-coarse parallelism for analyzing massive databases. Our approach reduces idle times in processing and exploits the inherent parallelism of comparing latent fingerprints to fingerprint impressions. We analyzed the performance of ALFI on Linux and Windows operating systems using the well-known NIST/FVC databases. Experimental results reveal that ALFI is in average 22x faster than the state-of-the-art algorithm, reaching a value of 44.7x for the best-studied case

Evaluación de la mezcla de sustratos en un cultivo de lechuga (Lactuca sativa L.) var. Verónica

The production of vegetables on substrates has become a great alternative. Therefore, different substrates were evaluated in a greenhouse lettuce culture. A completely randomized block design (BCA) with three treatments was used as follows: T1: peat 30% coconut peat 70%, T2: peat 70% coconut peat 30% and T3: peat 50 % Coconut peat 50%, for a total of 9 experimental units each consisting of 10 plants. Every 8 days, during 32 days, the height of the plant, fresh and dry mass of leaves and root, leaf area and every 2 days, the SPAD units and the stomatal conductivity (SC) were determined. There were significant differences in the SPAD units in time for day 11 ddt with a value of 20.7. The SC presented the highest values in T3 and T2 with values of 354.2 and 366.2 mol m-2 s–1, respectively. T1 presented the highest value of stomatal resistance (RE) with 7.5 m2 s mol–1. The leaf area and height did not show significant differences. T2 at 15 days after transplant showed the highest values of fresh root mass (MFR), dry root mass (MSR) and fresh leaf mass (MFH) with 3.1 g, 0.106 g and 13.19 g respectively. In harvest, T3 showed 10% and 15% more production of MFH in lettuce than treatments T2 and T1, respectivelyLa producción de hortalizas en sustratos se ha convertido en una gran alternativa. Por lo anterior, se evaluaron diferentes sustratos en un cultivo de lechuga en invernadero. Se utilizó un diseño en bloques completamente al azar (BCA) donde el factor de bloqueo fueron los sustratos y se establecieron tres tratamientos: T1: turba negra 30%, turba de coco 70%, T2: turba negra 70%, turba de coco 30% y T3: turba negra 50% y turba de coco 50%, para un total de 9 unidades experimentales, cada unidad experimental estuvo conformada por 10 plantas. Cada 8 días, durante 32 días, se determinó la altura de planta, masa fresca y seca de hojas y raíz, área foliar y cada 2 días, las unidades SPAD y la conductividad estomática (CE). Se presentaron diferencias significativas en las Unidades SPAD en el tiempo con un valor de 20,7. La CE presentó los mayores valores en T3 y T2 con valores de 354,2 y 366,2 mmol m-2 s–1, respectivamente. El T1 presentó el mayor valor de resistencia estomática (RE) con 7,5 m2 s mol–1. El área foliar y la altura no presentaron diferencias significativas. El T2 a los 15 días después de trasplante mostró los mayores valores de masa fresca de raíz (MFR), masa seca de raíz (MSR) y masa fresca de hojas (MFH) con 3,1 g, 0,106 g y 13,19 g, respectivamente. En la cosecha, el T3 mostró un 10% y 15% más de producción de MFH de lechuga, que los tratamientos T2 y T1, respectivamente.&nbsp

Training Reading Skills in Central Field Loss Patients: Impact of Clinical Advances and New Technologies to Improve Reading Ability

The primary goal of patients with central field loss attending to visual rehabilitation (VR) offices is to get adapted to daily life activities in near vision, mainly looking for recovering their ability to read again. The disparity in the functionality of these patients, due to the new advances in medical treatment and the increasing number of new apps and technological devices in the market, implies a heterogeneity in the reading training programs to be applied, and consequently a variability in the results obtained. Currently, with the increasing access to information and communication technologies and social networks, the opportunities for improving their access to information and communication is taken an important role. For this reason, the basis of ad-hoc evidence-based reading training programs is needed to standardized the clinical practice in reading rehabilitation for visual impaired and blind patients. This chapter will go in depth into these topics offering an exhaustive state of the art of reading rehabilitation for central field loss patients that will be useful for clinicians dedicated to the rehabilitation of visual impaired and blind people

Catalytic pyrolysis of used tires on noble-metal-based catalysts to obtain high-value chemicals: Reaction pathways

A systematic study on the use of noble metals (Pd, Pt, Au) supported on titanate nanotubes (NT-Ti) for selectively producing BTX and p-cymene from waste tire pyrolysis is provided here. All the materials were characterized for chemical, textural and structural properties using a range of analytical techniques. The M/NT-Ti (M: Pd, Pt, or Au) catalysts exhibit low nanoparticle sizes (1.8 Pt ≈ Au > support > non-catalyst. The Py-GC/MS suggest that the catalysts participate in the secondary reactions of dealkylation, dehydrogenation, isomerization, aromatization, and cyclization leading to a higher formation of BTX than the uncatalyzed reaction. Finally, a comprehensive reaction pathway describing the catalytic pyrolysis of WT over Pd/NT-Ti was proposed by studying the catalytic pyrolysis of individual polymers constituting the waste tires, and D,L-Limonene.Puede accederse a los datos primarios de este trabajo haciendo clic en "Documentos relacionados".Centro de Investigación y Desarrollo en Ciencias Aplicada

Nonadiabatic charged spherical gravitational collapse

We present a complete set of the equations and matching conditions required for the description of physically meaningful charged, dissipative, spherically symmetric gravitational collapse with shear. Dissipation is described with both free-streaming and diffusion approximations. The effects of viscosity are also taken into account. The roles of different terms in the dynamical equation are analyzed in detail. The dynamical equation is coupled to a causal transport equation in the context of Israel-Stewart theory. The decrease of the inertial mass density of the fluid, by a factor which depends on its internal thermodynamic state, is reobtained, with the viscosity terms included. In accordance with the equivalence principle, the same decrease factor is obtained for the gravitational force term. The effect of the electric charge on the relation between the Weyl tensor and the inhomogeneity of energy density is discussed.Comment: 23 pages, Latex. To appear in Phys. Rev. D. Some references correcte

Patrones de comportamiento de la malaria en el departamento de Risaralda, Colombia, 2007-2009

Introducción: La malaria es la enfermedad parasitaria de mayor morbimortalidad en Latinoamérica, especialmente en países de la cuenca amazónica, incluido Colombia. Risaralda, uno de sus departamentos con baja carga, requiere vigilancia y evaluación periódicas con el fin de contribuir a mayor control. Materiales y métodos: Estudio epidemiológico de evaluación de incidencia, etiología, distribución geográfica y mortalidad por malaria en el período 2007-2009, en Risaralda, Colombia. Resultados: Durante el período se registraron 2640 casos (promedio 880±290/año). La incidencia osciló entre 60,01 (2008) a 122,87 (2011) casos/100.000 hab (IPA, 0,6-1,23 casos/1.000 hab). Del total de casos, 93,4% correspondieron a P. vivax, 3,7% a P. falciparum y 2,9% a P. vivax/P. falciparum, siendo 68,9% de los casos del municipio Pueblo Rico, 14,0% Mistrató y 3,1% Pereira, adicionalmente 13% fueron importados de otros departamentos. La mortalidad fue constante, 0,1 muertes/100.000 hab/año. Discusión: La carga de la malaria en Risaralda se explica en parte por las condiciones sociales de los municipios así como ambientales, los cuales se han visto reflejados en ésta y otras enfermedades transmitidas por vectores en Colombia, Latinoamérica y el Mundo. Por ello deben hacerse mayores esfuerzos en investigación operativa que permitan profundizar actividades orientadas al mayor control y reducción de la enfermedad en el departamento