1,894 research outputs found
A multidomain enzyme, with glycerol-3-phosphate dehydrogenase and phosphatase activities, is involved in a chloroplastic pathway for glycerol synthesis in \u3ci\u3eChlamydomonas reinhardtii\u3c/i\u3e
Understanding the unique features of algal metabolism may be necessary to realize the full potential of algae as feedstock for the production of biofuels and biomaterials. Under nitrogen deprivation, the green alga C. reinhardtii showed substantial triacylglycerol (TAG) accumulation and up-regulation of a gene, GPD2, encoding a multidomain enzyme with a putative phosphoserine phosphatase (PSP) motif fused to glycerol-3-phosphate dehydrogenase (GPD) domains. Canonical GPD enzymes catalyze the synthesis of glycerol-3-phosphate (G3P) by reduction of dihydroxyacetone phosphate (DHAP). G3P forms the backbone of TAGs and membrane glycerolipids and it can be dephosphorylated to yield glycerol, an osmotic stabilizer and compatible solute under hypertonic stress. Recombinant Chlamydomonas GPD2 showed both reductase and phosphatase activities in vitro and it can work as a bifunctional enzyme capable of synthesizing glycerol directly from DHAP. In addition, GPD2 and a gene encoding glycerol kinase were up-regulated in Chlamydomonas cells exposed to high salinity. RNAmediated silencing of GPD2 revealed that the multidomain enzyme was required for TAG accumulation under nitrogen deprivation and for glycerol synthesis under high salinity. Moreover, a GPD2-mCherry fusion protein was found to localize to the chloroplast, supporting the existence of a GPD2-dependent plastid pathway for the rapid synthesis of glycerol in response to hyperosmotic stress. We hypothesize that the reductase and phosphatase activities of PSP-GPD multidomain enzymes may be modulated by post-translational modifications/mechanisms, allowing them to synthesize primarily G3P or glycerol depending on environmental conditions and/or metabolic demands in algal species of the core Chlorophytes
A multidomain enzyme, with glycerol-3-phosphate dehydrogenase and phosphatase activities, is involved in a chloroplastic pathway for glycerol synthesis in \u3ci\u3eChlamydomonas reinhardtii\u3c/i\u3e
Understanding the unique features of algal metabolism may be necessary to realize the full potential of algae as feedstock for the production of biofuels and biomaterials. Under nitrogen deprivation, the green alga C. reinhardtii showed substantial triacylglycerol (TAG) accumulation and up-regulation of a gene, GPD2, encoding a multidomain enzyme with a putative phosphoserine phosphatase (PSP) motif fused to glycerol-3-phosphate dehydrogenase (GPD) domains. Canonical GPD enzymes catalyze the synthesis of glycerol-3-phosphate (G3P) by reduction of dihydroxyacetone phosphate (DHAP). G3P forms the backbone of TAGs and membrane glycerolipids and it can be dephosphorylated to yield glycerol, an osmotic stabilizer and compatible solute under hypertonic stress. Recombinant Chlamydomonas GPD2 showed both reductase and phosphatase activities in vitro and it can work as a bifunctional enzyme capable of synthesizing glycerol directly from DHAP. In addition, GPD2 and a gene encoding glycerol kinase were up-regulated in Chlamydomonas cells exposed to high salinity. RNAmediated silencing of GPD2 revealed that the multidomain enzyme was required for TAG accumulation under nitrogen deprivation and for glycerol synthesis under high salinity. Moreover, a GPD2-mCherry fusion protein was found to localize to the chloroplast, supporting the existence of a GPD2-dependent plastid pathway for the rapid synthesis of glycerol in response to hyperosmotic stress. We hypothesize that the reductase and phosphatase activities of PSP-GPD multidomain enzymes may be modulated by post-translational modifications/mechanisms, allowing them to synthesize primarily G3P or glycerol depending on environmental conditions and/or metabolic demands in algal species of the core Chlorophytes
On the efficient delivery and storage of IoT data in edge-fog-cloud environments
This article belongs to the Special Issue Internet of Things, Sensing and Cloud ComputingCloud storage has become a keystone for organizations to manage large volumes of data produced by sensors at the edge as well as information produced by deep and machine learning applications. Nevertheless, the latency produced by geographic distributed systems deployed on any of the edge, the fog, or the cloud, leads to delays that are observed by end-users in the form of high response times. In this paper, we present an efficient scheme for the management and storage of Internet of Thing (IoT) data in edge-fog-cloud environments. In our proposal, entities called data containers are coupled, in a logical manner, with nano/microservices deployed on any of the edge, the fog, or the cloud. The data containers implement a hierarchical cache file system including storage levels such as in-memory, file system, and cloud services for transparently managing the input/output data operations produced by nano/microservices (e.g., a sensor hub collecting data from sensors at the edge or machine learning applications processing data at the edge). Data containers are interconnected through a secure and efficient content delivery network, which transparently and automatically performs the continuous delivery of data through the edge-fog-cloud. A prototype of our proposed scheme was implemented and evaluated in a case study based on the management of electrocardiogram sensor data. The obtained results reveal the suitability and efficiency of the proposed scheme.This research was funded by the project 41756 "Plataforma tecnológica para la gestión, aseguramiento, intercambio y preservación de grandes volúmenes de datos en salud y construcción de un repositorio nacional de servicios de análisis de datos de salud" by the PRONACES-CONACYT
Thermal behavior evaluation of solar dryers in a passive regime
Se presenta la evaluación del comportamiento térmico de tres secadores solares en régimen pasivo de flujo, diseñados para ser utilizados en las condiciones ambientales de la Costa Caribe Colombiana. Se realizaron experiencias de campo que proporcionaron resultados de eficiencia térmica que se comparan con los proporcionados por una simulación computacional. La simulación se realiza a partir de los balances de energía en cada componente de los secadores. Datos atmosféricos de la locación correspondientes a los días en que se hicieron las pruebas de campo se utilizaron para alimentar la simulación que se realizó usando software específico de licencia de uso libre. Se observa coherencia entre los resultados procedentes de la simulación y los obtenidos a partir de la medición directa.This article presents the evaluation of the thermal behavior of three solar dryers in a passive flow regime designed for the environmental conditions of the Colombian Caribbean Coast. Field experiments were conducted to obtain thermal efficiency results that were compared with those supplied by a computer simulation. The latter was based on energy balances in each component of the dryers. Atmospheric data of the location on the days the field tests were carried out were used as input for a simulation created using specific open-source software. Consistency is observed between the results from the simulation and those obtained from direct measurement
Validation of a questionnaire on emotional eating for use in cases of obesity : the Emotional Eater Questionnaire (EEQ)
Introduction: Emotions have a powerful effect on our choice of food and eating habits. It has been found that in some people there is relationship between eating, emotions and the increased energy intake. This relationship should be measurable to better understand how food is used to deal with certain mood states and how these emotions affect the effectiveness of weight loss programs. Objective: To develop and analyze the psychometric characteristics of a questionnaire on emotional eating for obesity easy to apply in clinical practice. Subjects and methods: A ten-item questionnaire called Emotional-Eater-Questionnaire (EEQ) was developed and administered to a total of 354 subjects (body mass index, 31 ± 5), aged 39 ± 12, who were subjected to a weight-reduction program. The questionnaire was specifically designed for obesity. Analysis of the internal structure, internal consistency, test-retest reliability and convergent validity with Mindful-Eater-Questionnaire (MEQ) were conducted. Results: After principal components analysis, the questionnaire was classified in three different dimensions that explained 60% of the total variance: Disinhibition, Type-of-food and Guilt. Internal consistency showed that Cronbach's alpha was 0.773 for the "Dishinibition" subscale, 0.656 for the "Type of food" subscale and 0.612 for the "Guilt" subscale. The test-retest stability was r =0.70. The data showed that the percentage of agreement between the EEQ and the MEQ was around 70% with a Kappa index of 0.40; P < 0.0001. Conclusion: We have presented a new questionnaire, which classifies individuals as a function of the relation between food intake and emotions. Such information will permit personalised treatments to be designed by drawing up early strategies from the very beginning of treatment programmesIntroducción: Las emociones tienen un poderoso efecto sobre la elección de alimentos y los hábitos alimentarios. Existe una relación entre comer, emociones y el aumento del aporte calórico. Esta relación debería ser medible para comprender mejor cómo utilizamos los alimentos en determinados estados de ánimo y cómo las emociones afectan a la eficacia de los programas de pérdida de peso. Objetivo: Desarrollar y analizar las características psicométricas de un cuestionario para identificar la ingesta emocional en la obesidad de fácil aplicación en la práctica clínica. Material y métodos: Se ha desarrollado y administrado un cuestionario de diez ítems llamado Cuestionario-de-Comedor-Emocional (CCE) a un total de 354 sujetos (Índice de Masa Corporal: 31 ± 5), (Edad: 39 ± 12 años), pertenecientes a un programa de reducción de peso. Se llevó a cabo un análisis de la estructura interna del cuestionario, de la consistencia interna, la fiabilidad testretest y la validez convergente con el Mindful-Eater- Questionnaire (MEQ). Resultados: El análisis de componentes principales del cuestionario encontró tres dimensiones diferentes que explicaban el 60% de la varianza: desinhibición, tipo de alimento y culpa. La consistencia interna mostró que el alfa de Cronbach fue de 0,773 para la subescala "Desinhibición", 0,656 para "Tipo de alimentos" y 0,612 para "culpa". La estabilidad test-retest fue de r = 0,70. Los datos mostraron que el porcentaje de acuerdo entre el CCE y MEQ era del 70% con un índice Kappa de 0,40, P < 0,0001. Conclusión: Hemos presentado un nuevo cuestionario, que clasifica a los individuos en función de la relación entre la ingesta de alimentos y las emociones. Esta información permitirá el diseño de tratamientos personalizados desde el inicio para la obesida
Extremely Metal-Poor Galaxies: The HI Content
Extremely metal-poor (XMP) galaxies are chemically, and possibly dynamically,
primordial objects in the local Universe. Our objective is to characterize the
HI content of the XMP galaxies as a class, using as a reference the list of 140
known local XMPs compiled by Morales-Luis et al. (2011). We have observed 29
XMPs, which had not been observed before at 21 cm, using the Effelsberg radio
telescope. This information was complemented with HI data published in
literature for a further 53 XMPs. In addition, optical data from the literature
provided morphologies, stellar masses, star-formation rates and metallicities.
Effelsberg HI integrated flux densities are between 1 and 15 Jy km/s, while
line widths are between 20 and 120 km/s. HI integrated flux densities and line
widths from literature are in the range 0.1 - 200 Jy km/s and 15 - 150 km/s,
respectively. Of the 10 new Effelsberg detections, two sources show an
asymmetric double-horn profile, while the remaining sources show either
asymmetric (7 sources) or symmetric (1 source) single-peak 21 cm line profiles.
An asymmetry in the HI line profile is systematically accompanied by an
asymmetry in the optical morphology. Typically, the g-band stellar
mass-to-light ratios are ~0.1, whereas the HI gas mass-to-light ratios may be
up to 2 orders of magnitude larger. Moreover, HI gas-to-stellar mass ratios
fall typically between 10 and 20, denoting that XMPs are extremely gas-rich. We
find an anti-correlation between the HI gas mass-to-light ratio and the
luminosity, whereby fainter XMPs are more gas-rich than brighter XMPs,
suggesting that brighter sources have converted a larger fraction of their HI
gas into stars. The dynamical masses inferred from the HI line widths imply
that the stellar mass does not exceed 5% of the dynamical mass, while the
\ion{H}{i} mass constitutes between 20 and 60% of the dynamical mass.
(abridged)Comment: 30 pages, accepted for A&
Cobalt oxide nanomaterials prepared by CVD as negative electrodes in lithium batteries
III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce
Positioning systems in Minkowski space-time: from emission to inertial coordinates
The coordinate transformation between emission coordinates and inertial
coordinates in Minkowski space-time is obtained for arbitrary configurations of
the emitters. It appears that a positioning system always generates two
different coordinate domains, namely, the front and the back emission
coordinate domains. For both domains, the corresponding covariant expression of
the transformation is explicitly given in terms of the emitter world-lines.
This task requires the notion of orientation of an emitter configuration. The
orientation is shown to be computable from the emission coordinates for the
users of a `central' region of the front emission coordinate domain. Other
space-time regions associated with the emission coordinates are also outlined.Comment: 20 pages; 1 figur
Analysis by Finite Element Calculations of Light Scattering in Laser-textured AZO Films for PV thin-film Solar Cells
In the thin-film photovoltaic industry, to achieve a high light scattering in one or more of the cell interfaces is one of the strategies that allow an enhancement of light absorption inside the cell and, therefore, a better device behavior and efficiency. Although chemical etching is the standard method to texture surfaces for that scattering improvement, laser light has shown as a new way for texturizing different materials, maintaining a good control of the final topography with a unique, clean, and quite precise process. In this work AZO films with different texture parameters are fabricated. The typical parameters used to characterize them, as the root mean square roughness or the haze factor, are discussed and, for deeper understanding of the scattering mechanisms, the light behavior in the films is simulated using a finite element method code. This method gives information about the light intensity in each point of the system, allowing the precise characterization of the scattering behavior near the film surface, and it can be used as well to calculate a simulated haze factor that can be compared with experimental measurements. A discussion of the validation of the numerical code, based in a comprehensive comparison with experimental data is include
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