Heat flow in the postquasistatic approximation

We apply the postquasistatic approximation to study the evolution of spherically symmetric fluid distributions undergoing dissipation in the form of radial heat flow. For a model which corresponds to an incompressible fluid departing from the static equilibrium, it is not possible to go far from the initial state after the emission of a small amount of energy. Initially collapsing distributions of matter are not permitted. Emission of energy can be considered as a mechanism to avoid the collapse. If the distribution collapses initially and emits one hundredth of the initial mass only the outermost layers evolve. For a model which corresponds to a highly compressed Fermi gas, only the outermost shell can evolve with a shorter hydrodynamic time scale.Comment: 5 pages, 5 figure

Assessment of the application of enzymes in the production of sewage sludge in WWTP

Motivation: In the urban wastewater treatment plants (WWTP) a large volume of sewage sludge is produced due to the growth of microorganisms in the biological reactors. This sludge cannot spill directly to the environment, because it is legally forbidden (Directive 91/271/EEC). Nowadays, the searching of alternatives for treating/reducing this sludge is increasing. Some previous works [1] focused on different strategies for sewage sludge reduction in conventional activated sludge systems not interfering in the efficiency of the process. Among the different strategies, the use of hydrolytic enzymes seemed to be effective in the reduction of the excess sludge production (up to 30% reduction, [2]). On the other hand, the overgrowth of microorganisms and the accumulation of non-biodegradable organic matter in the filtering media of constructed wetlands produce the clogging and collapse of these natural treatment systems.The above mentioned problems could be mitigated if reducing the amount of refractory matter in the influent and limiting the growth of microorganisms by the use of enzymes’ technology. However, the application of enzymes is limited, mainly, by their high cost of acquisition. One alternative of commercial enzymes could be enzymes generated in the fermentation of sewage sludge or other by-products coming of WWTP [3]. This study aims at (1) the determination of the optimum conditions for the application of enzymes in the wastewater treatment and (2) the assessment of the effects on both intensive and extensive treatment systems.Methods: In this study, lab scale pilot plants are employed for the assessment of the application enzymes to biological reactors. One pilot plant works as an activated sludge system (intensive tech.) and the other will simulate a constructed wetland (extensive tech.). Both pilot plants are fed with real wastewater. Commercial enzymes will be tested initially, and later, with the by-product obtained in the fermentation of sewage sludge. Physicochemical and microbiological parameters will be monitored in both systems to assess the effect of enzyme’s addition on both systems. Besides, sludge production and “clogging” phenomena will be studied. According to the results of Lab scale tests, the study will continue extrapolating to a large- scale pilot plants, to verify the sewage sludge reduction and identify possible operative problems under real conditions

Biochemical and molecular characterization of olive β-glucosidase in seven olive varieties during the ripening process: the role of β-glucosidase in determining the phenolic content of virgin olive oil.

Virgin olive oil (VOO) is one of the essential components of the Mediterranean diet, which includes a series of cultural habits, especially alimentary, shared to a greater or lesser extent, by all countries lapped by Mediterranean Sea. VOO is enriched with bioactive compounds which are related to its unique organoleptic characteristics, and also to its antioxidant properties, which have been associated to with the reduction of risk to suffer cardiovascular diseases and to a protective effect against cancer. The most important bioactive components in VOO are phenolics compounds [2].The phenolic composition of VOO is closely related to the content of phenolic glycosides initially present in the olive tissue. In parallel, some studies indicate that there is a positive correlation between the activity levels of β-glucosidase in the olive fruit and the final content of phenolic compounds in VOO. This enzyme plays a key role hydrolyzing phenolic profile of VOO. In consequence, its biochemical and molecular characterization is of great interest from a biotechnological point of view [1, 2].In this study, seven olive varieties (Abou-Kanani, Dokkar, Klon-14, Menya, Picual, Piñonera y Shengeh) with different phenolic contents have been selected in the World Olive Germplasm Bank. The phenolic profiles of fruits harvested at different ripening stages and their oils have been analyzed by HPLC and at the same time β-glucosidase activity has been measured in olive fruits at different ripening stages. The methods for β-glucosidase extraction and activity assessment have been optimized. Spectrophotometric activity assays have been carried out with the synthetic substrate p-nitrophenyl galactoside (p-NPG) using a calculated molar extinction coefficient (ε=552,8 M-1cm-1) for the p-nitrophenyl liberated in the reaction medium. The results obtained show that olive varieties with the highest content of phenolic glycosides in the fruit such as Piñonera, Dokkar or Menya, also have the largest β-glucosidase activity levels, which usually decrease ripening process. These results will be completed with the pertinent studies of gene expression [3]

Concerns regarding the proposal for an ecological equation of state: an assessment starting from the organic biophysics of ecosystems (OBEC).

The goal of testing the theoretical fruitfulness and empirical utility of the links between ecology and thermodynamics has been elusive. This could explain the breakdown of ecology into multiple branches, some of them intended to develop models in agreement with the principles of physics. The maximum entropy algorithm (MaxEnt) is one of the most frequently mentioned topics in this field. Within the MaxEnt framework, a quantitative relationship between various ecological parameters has recently been proposed as a seeming ecological equation of state (EESH; Harte et al. 2022. An equation of state unifies diversity, productivity, abundance and biomass. Commun. Biol. 5: 874). We analyze the EESH from the interdisciplinary perspective of Organic Biophysics of Ecosystems (OBEC). Consistent with this analysis, the EESH neglects the analytical similarity between key ecological variables and statistical mechanical variables, it does not include any intensive variable useful to determine the distance of ecological systems from equilibrium, it does not involve any constant useful to define the statistical range within which the system can be considered out of danger despite widespread effects of anthropogenic impact, and its general structure bears no resemblance to previous equations of state because it is based on a subjective approach devoid of physical content that is only useful as a tool for statistical inference. So, our conclusions are: (i) the EESH does not withstand comparison with prior knowledge and empirical evidence from both ecology and physics, and (ii) it cannot be considered an ecological equation of state

Nonadiabatic charged spherical evolution in the postquasistatic approximation

We apply the postquasistatic approximation, an iterative method for the evolution of self-gravitating spheres of matter, to study the evolution of dissipative and electrically charged distributions in General Relativity. We evolve nonadiabatic distributions assuming an equation of state that accounts for the anisotropy induced by the electric charge. Dissipation is described by streaming out or diffusion approximations. We match the interior solution, in noncomoving coordinates, with the Vaidya-Reissner-Nordstr\"om exterior solution. Two models are considered: i) a Schwarzschild-like shell in the diffusion limit; ii) a Schwarzschild-like interior in the free streaming limit. These toy models tell us something about the nature of the dissipative and electrically charged collapse. Diffusion stabilizes the gravitational collapse producing a spherical shell whose contraction is halted in a short characteristic hydrodynamic time. The streaming out radiation provides a more efficient mechanism for emission of energy, redistributing the electric charge on the whole sphere, while the distribution collapses indefinitely with a longer hydrodynamic time scale.Comment: 11 pages, 16 Figures. Accepted for publication in Phys Rev

Canines as a measuring tool for leaf tent construction in Dermanura watsoni

Many animals are capable of constructing structures to modify the environment for their own benefit. The design of these structures requires animals to perceive dimensions. However, how animals take measurements to achieve the final design of the structures they construct is known for only very few species. In the Neotropics, a few bat species build roosts or leaf tents that serve different purposes. Thomas’s fruit-eating bat (Dermanura watsoni) constructs tents that have complex designs, when compared to other tent building bats. The bifid tent is a design built by producing a long, J-shaped cut on each side of understory plant leaves. We expect that to accomplish this complex design bats would require precise measurements during tent construction. We measured several bat morphological traits to infer which of them, if any, was used by the bats as a measuring device. Dermanura watsoni uses the distance between their lower canines to increase the perpendicular distance of the J-cut to the central vein of the leaf along the J-cut. The bat adds the distance between the canines to each subsequent secondary vein cut. This is the first study to infer which body part D. watsoni most likely uses as a measuring tool. Our results provide new insight into the evolution of body parts as measuring devices during tent construction in related and unrelated tent-building bat species.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Conjunctival Melanoma: A New Clinical and Therapeutical Approach

Melanoma involving the conjunctiva is extremely rare. Graver prognosis has been reported with primary conjunctival melanoma than with their cutaneous counterparts [Collin et al.: Aust N Z J Ophthalmol 1986;14:29–34]. Among conjunctival melanomas, two significant risk factors for tumour-related death have been identified: (i) age older than 55 years and (ii) unfavourable tumour location (caruncle, cornea, fornix, palpebral conjunctiva) [Werschnik and Lommatzsch: Am J Clin Oncol 2002;25:248–255]. Here we present a rare case of lentigo maligna involving the palpebral, bulbar conjunctiva and the caruncle. We describe dermoscopic patterns observed and the use of a novel ocular melanoma therapy with topical imiquimod

Fructo-oligosaccharides (FOS) production by fungal submerged culture using aguamiel as a low-cost by-product

Supplementary data to this article can be found online at https:// doi.org/10.1016/j.lwt.2018.12.020.Fructooligosaccharides (FOS) are important ingredients in the functional food industry because they have different biological properties such as decrease level of triglycerides, cholesterol and phospholipids and stimulate growth of probiotics for enhancement of microflora in large intestine. However, current strategies for the FOS production through simple and economical bioprocess has been necessary. The aim of this work was evaluated the capacity of three fungal strains (Aspergillus niger GH1, Aspergillus niger PSH and Aspergillus oryzae DIA-MF) to produce fructooligosaccharides (FOS) using aguamiel from Agave salmiana as an economical substrate. In addition, Czapek Dox medium supplemented with sucrose as carbon source was used as a control medium for the FOS production. A. oryzae DIA-MF was a fungi producer of FOS using aguamiel or Czapek Dox medium as substrate at 24?h of fermentation. However, the yield of FOS was increased two folds (20.30?g/L), with a productivity of 0.84?g FOS/l.h when aguamiel was used as substrate. On the other hand, A. niger GH1 and A. niger PSH showing only hydrolytic activity on sucrose under the studied conditions. In conclusion, this study shown excellent compatibility of A. oryzae DIA-MF using aguamiel as an economical substrate for the FOS production under a simple bioprocess.Authors thank all technical support and comments made by Dra. Adriana C. Flores-Gallegos and Dra. Abril Flores-Maltos. Authors thank National Council for Science and Technology (CONACYT) of Mexico by the financial support through the project No. CB-2011-C01-167764. Author D. B. Muñiz-Márquez also thank CONACYT for the financial support during her postgraduate program (Doctorate) in Food Science and Technology offered by the University Autonomous of Coahuila, Mexico.info:eu-repo/semantics/publishedVersio

Quadratic Time-dependent Quantum Harmonic Oscillator

We present a Lie algebraic approach to a Hamiltonian class covering driven, parametric quantum harmonic oscillators where the parameter set -- mass, frequency, driving strength, and parametric pumping -- is time-dependent. Our unitary-transformation-based approach provides a solution to the general quadratic time-dependent quantum harmonic model. As an example, we show an analytic solution to the periodically driven quantum harmonic oscillator without the rotating wave approximation; it works for any given detuning and coupling strength regime. For the sake of completeness, we provide an analytic solution to the historical Caldirola--Kanai quantum harmonic oscillator that, in a suitable reference frame, is just a time-independent parametric quantum harmonic oscillator.Comment: 22 pages, 4 figure

Estudio de mutantes resistentes a los antiretrovirales en pacientes con VIH con falla terapeutica y efecto de los factores de riesgo en el tratamiento

INTRODUCTION: Information about HIV phenotypes of resistant to available ART and the influence of different risk factors on virological failures (VF) in Costa Rican HIV positive patients prior or during HAART is unknown. MATERIALS AND METHODS: Eighty nine samples, 72 VF and 17 basal (before treatment) were analyzed by examining resistant mutants in reverse transcriptase (RT) and protease (PT) regions using Trugene or LIPA genotyping kits. Sixty eight control patients were selected and relevant information was collected in a questionnaire. RESULTS: Poor adherence, presence of resistant mutations and number of treatment's changes were the only significant factors found (p = 0.006, 0.04 and 0.01 respectively). From 66 sequenced samples, 78%, 50% and 50% showed resistance to NRTI (nucleoside reverse transcriptase inhibitors), NNRT (non-nucleoside reverse transcriptase inhibitors) and PI (protease inhibitors), respectively. The most frequent mutations were M41L, M184V, and T215FY in RT and L62PI, L10FIRV and M36I in PT. DISCUSSION: The most important factor related to treatment response in this study was adherence to treatment. Mutations in RT were related to the treatment failure while the ones found in PT were secondary mutations which have been previously described to influence the selection of primary resistance mutations in these regions. The study reveals the urgency to detect resistant mutations in VF to be considered by physicians for selection of treatment schedule, to analyze basal HIV patients for monitoring of the spread of resistant mutations and the importance to reinforce the adherence in the patients for overall treatment outcome.En Costa Rica no se tiene información a cerca de genotipos de resistencia para los tratamientos anti-retrovirales disponibles y la influencia de diferentes factores de riego en la falla virológica (FV) de pacientes VIH positivos previo o durante su tratamiento. Ochenta y nueve muestras, 72 FV y 17 basales, fueron analizadas con Trugene o LIPA para la detección de mutantes de resistencia en la transcriptasa reversa (TR) y en la proteasa (PT) del VIH. Se seleccionaron sesenta y ocho controles y se recolectó información relevante en un cuestionario. La mala adherencia, la presencia de mutaciones y el número de cambios de tratamiento fueron los únicos factores con significancia encontrados. (p = 0.03, 0.04 and 0.04 respectively). De 66 muestras secuenciadas, 78%, 50% y 50% mostraron resistencia a los inhibidores análogos y no análogos de nucleótidos para la TR y la PT respectivamente. La mutaciones más frecuentes fueron M41L, M184V, y T215FY en la TR y L62PI, L10FIRV y M36I en la PT. La adherencia fue el factor más importante relacionado con la respuesta al tratamiento. Las mutaciones encontradas en la TR estaban relacionadas al tratamiento mientras que las de la PT fueron mutaciones secundarias que propician la aparición de las mutaciones asociadas a resistencia en esa región. Este estudio revela la necesidad de detectar mutantes de resistencia en pacientes con FV y de estudiar las muestras basales. Además la importancia de reforzar la adherencia en los pacientes para una mejor respuesta al tratamiento