Characterization of TrxC, an Atypical Thioredoxin Exclusively Present in Cyanobacteria

Cyanobacteria form a diverse group of oxygenic photosynthetic prokaryotes considered to be the antecessor of plant chloroplast. They contain four different thioredoxins isoforms, three of them corresponding to m, x and y type present in plant chloroplast, while the fourth one (named TrxC) is exclusively found in cyanobacteria. TrxC has a modified active site (WCGLC) instead of the canonical (WCGPC) present in most thioredoxins. We have purified it and assayed its activity but surprisingly TrxC lacked all the classical activities, such as insulin precipitation or activation of the fructose-1,6-bisphosphatase. Mutants lacking trxC or over-expressing it were generated in the model cyanobacterium Synechocystis sp. PCC 6803 and their phenotypes have been analyzed. The ΔtrxC mutant grew at similar rates to WT in all conditions tested although it showed an increased carotenoid content especially under low carbon conditions. Overexpression strains showed reduced growth under the same conditions and accumulated lower amounts of carotenoids. They also showed lower oxygen evolution rates at high light but higher Fv’/Fm’ and Non-photochemical-quenching (NPQ) in dark adapted cells, suggesting a more oxidized plastoquinone pool. All these data suggest that TrxC might have a role in regulating photosynthetic adaptation to low carbon and/or high light conditions.España, MINECO BIO2016-75634-PJunta de Andalucía P12-BIO-1119 , BIO-28

Chloroplast damage induced by the inhibition of fatty acid synthesis triggers autophagy in chlamydomonas

Fatty acids are synthesized in the stroma of plant and algal chloroplasts by the fatty acid synthase complex. Newly synthesized fatty acids are then used to generate plastidial lipids that are essential for chloroplast structure and function. Here, we show that inhibition of fatty acid synthesis in the model alga Chlamydomonas reinhardtii activates autophagy, a highly conserved catabolic process by which cells degrade intracellular material under adverse conditions to maintain cell homeostasis. Treatment of Chlamydomonas cells with cerulenin, a specific fatty acid synthase inhibitor, stimulated lipidation of the autophagosome protein ATG8 and enhanced autophagic flux. We found that inhibition of fatty acid synthesis decreased monogalactosyldiacylglycerol abundance, increased lutein content, down-regulated photosynthesis, and increased the production of reactive oxygen species. Electron microscopy revealed a high degree of thylakoid membrane stacking in cerulenin-treated cells. Moreover, global transcriptomic analysis of these cells showed an up-regulation of genes encoding chloroplast proteins involved in protein folding and oxidative stress and the induction of major catabolic processes, including autophagy and proteasome pathways. Thus, our results uncovered a link between lipid metabolism, chloroplast integrity, and autophagy through a mechanism that involves the activation of a chloroplast quality control system.Ministerio de Economía y Competitividad BFU2015-68216-PJunta de Andalucía CVI-7336, BIO2015-74432-JI

Development of an Emergency Radio Beacon for Small Unmanned Aerial Vehicles

Emergency locator transmitters (ELTs) used to locate manned aircrafts are not well suited to find and recover small crashed unmanned aerial vehicles (UAVs). ELTs utilize an international satellite system for search and rescue (Cospas-Sarsat System), which should leverage its expensive resources to save lives as a priority. Besides, ELTs are too big and heavy to be used within small UAVs. Some of the existing solutions for this problem are based on receivers that detect signal strength, which may be a long and tedious process not suitable for user needs. Others do not have enough range or require radio license and expensive amateur radio receivers. This paper presents an emergency radio beacon specifically designed to locate small UAVs. It is triggered automatically in the event of a crash and allows finding and recovering a crashed UAV in a fast and simple way. It meets not only the required specifications of user-friendliness, size and weight of this kind of application, but also it is a high precision and low cost device. Besides, it has enough range and endurance. The experiments carried out show the operation of the proposed system

Osteoglycin as a Potential Biomarker of Mild Kidney Function Impairment in Type 2 Diabetes Patients

Osteoglycin (OGN) could be a biomarker of mild kidney function impairment in type 2 diabetes (T2D). Our study aimed to determine the association between serum OGN and impaired kidney function risk in T2D patients and to analyze its potential role as an estimator of kidney disturbances in this population. This cross-sectional study included 147 T2D patients (65 ± 8 years, 58.5% males), and 75 healthy controls (63 ± 10 years, 36% males). Circulating OGN levels were determined by ELISA. Linear regression modeling was performed to determine the variables influencing circulating OGN, and an ROC curve was plotted to assess the usefulness of OGN as an estimator of diabetic kidney disease risk. Circulating OGN was significantly increased in T2D patients compared to controls (18.41 (14.45–23.27) ng/mL vs. 8.74 (7.03–12.35) ng/mL; p < 0.001). We found a progressive increase in serum OGN according to the severity of kidney impairment in T2D patients (normal kidney function: 16.14 (12.13–20.48) ng/mL; mildly impaired kidney function: 19.15 (15.78–25.90) ng/mL; moderate impaired kidney function: 21.80 (15.06–29.22) ng/mL; p = 0.006). Circulating OGN was an independent estimator of mildly impaired kidney function risk in T2D patients. We suggest that serum OGN could act as an albuminuria-independent biomarker of incipient kidney dysfunction in T2D patients.Junta de Andalucía grants (PI-0207-2016 and PI0268-2019)Instituto de Salud Carlos III grants (PI18-00803 and PI18-01235)European Regional Development Fund (FEDER)Instituto de Salud Carlos III (FI19/00118; CD20/00022

Correction of errors and harmonic distortion in pulse-width modulation of digital signals

Article number 153991Pulse-Width (PW) modulation is widely used in those applications where an analog or digital signal has to be encoded in the time domain as a binary stream, such as switched-mode power amplifiers in transmitters of modern telecommunication standards, high-resolution digital signal conversion using single-bit digital-to-analog converters, and many others. Due to the fact that digital signals are sampled in the time domain, the quality of the resulting PW modulated waveforms is worsened by harmonic distortion. Multilevel PW modulation has been proposed to reduce these adverse effects, but the modulated waveform is no longer binary. In this paper, the mechanisms by which harmonic distortion is produced are analyzed. As a result, the distortion terms are mathematically quantified and used to correct the errors. Note that a correction network based on a simple subtraction of the distortion terms from the PW modulated signal would produce a waveform that would no longer be binary. The proposed correction network is implemented in the digital domain and, by means of a sigma-delta modulator, preserves the binary feature of the PW modulated output.Ministerio de Ciencia, Innovación y Universidades (España) RTI201- 099189-B-C2

Estrategias de aprendizaje y afrontamiento en estudiantes con elevada ansiedad frente a los exámenes

La elevada ansiedad frente a los exámenes (AE) frecuentemente esta asociada a bajo rendimiento académico, escasa habilidad para el estudio y tendencia a afrontar de manera poco adaptativa las situaciones generadoras de estrés. En el presente estudio se exploraron las relaciones entre estos constructos, definidos desde una perspectiva multidimensional, y evaluados mediante autoinformes, en una muestra de 816 estudiantes universitarios. Los resultados indican que los estudiantes de mayor AE recurren con mas frecuencia a la repetición y utilizan menos estrategias reflexivas que los de menos ansiosos. En cuanto al afrontamiento, los primeros presentan mayor tendencia a la autoculpabilización y la rumiacion autofocalizada mientras que los segundos se orientan hacia el problema buscando su resolución o su aceptación y reevaluación en términos más positivos. Cada dimensión de la AE se relaciona de manera particular con las estrategias de aprendizaje y los estilos de afrontamiento. La preocupación se correlaciona en forma positiva con las estrategias de repetición y regulación del esfuerzo y con estilos más o menos adaptativos de afrontamiento, mientras que la falta de confianza y la interferencia se relacionan negativamente con estrategias de aprendizaje reflexivo y crítico y positivamente con los estilos menos eficaces para afrontar el estrés. Los hallazgos se discuten en el marco de la teoría de la eficiencia en el procesamiento, y permiten inferencias útiles para el diseño de programas de asistencia a estudiantes con elevada AE

The Contribution of Wnt Signaling to Vascular Complications in Type 2 Diabetes Mellitus

Vascular complications are the leading cause of morbidity and mortality among patients with type 2 diabetes mellitus (T2DM). These vascular abnormalities result in a chronic hyperglycemic state, which influences many signaling molecular pathways that initially lead to increased oxidative stress, increased inflammation, and endothelial dysfunction, leading to both microvascular and macrovascular complications. Endothelial dysfunction represents the initial stage in both types of vascular complications; it represents “mandatory damage” in the development of microvascular complications and only “introductory damage” in the development of macrovascular complications. Increasing scientific evidence has revealed an important role of the Wnt pathway in the pathophysiology of the vascular wall. It is well known that the Wnt pathway is altered in patients with T2DM. This review aims to be an update of the current literature related to the Wnt pathway molecules that are altered in patients with T2DM, which may also be the cause of damage to the vasculature. Both microvascular complications (retinopathy, nephropathy, and neuropathy) and macrovascular complications (coronary artery disease, cerebrovascular disease, and peripheral arterial disease) are analyzed. This review aims to concisely concentrate all the evidence to facilitate the view on the vascular involvement of the Wnt pathway and its components by highlighting the importance of exploring possible therapeutic strategy for patients with T2DM who develop vascular pathologies.Instituto de Salud Carlos III European Commission PI18-00803 PI21-01069 PI18-01235 CD20/00022 FI19/00118European CommissionJunta de Andalucia PI-0268-2019University of GranadaEuropean Commission 811

Cancion primera de Bart. Martinez de Quintana ...

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2013Según Méndez Aparicio, el impresor es Giovanni Antonio de FranceschiSign.: A-G

Structural quality in single crystalline CdSe ingots grown by PVT: Qualidade estrutural em lingotes de CdSe monocristalinos crescidos por PVT

CdSe is II-VI semiconductor with compact hexagonal structure. It has a band gap of 1.82 eV and a high stopping power for nuclear radiation. Single crystalline CdSe ingots were grown by Physical Vapor Transport (PVT) employing a horizontal reactor. As devices critically depend on material properties its single crystalline quality was determined by chemical etching and transmission electron microscopy. Results were compared to those corresponding to Bridgman High Pressure (HPB) grown material and also to PVT material grown in a vertical reactor.O CdSe é um semicondutor II-VI com estrutura hexagonal compacta. Tem uma banda proibida de 1,82 eV e um alto poder de freamento de radiação nuclear. Os monocristais de CdSe foram crescidos por transporte físico de vapor (PVT), empregando um reator horizontal. Como os dispositivos dependem criticamente das propriedades do material, sua qualidade cristalina foi determinada por ataque químico e microscopia eletrônica de transmissão. Os resultados foram comparados com aqueles correspondentes ao material crescido pelo método Bridgman vertical de alta pressão (HPB) e também com o material PVT crescido em um reator vertical.Fil: D'Elía, Raúl Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Aguirre Myriam Haydee. Universidad de Zaragoza. Facultad de Ciencias. Departamento de Física de la Materia Condensada; EspañaFil: Di Stefano, María Cristina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; ArgentinaFil: Heredia, Eduardo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Martínez, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; ArgentinaFil: Canepa, Horacio Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Núñez García, Javier Luis Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; ArgentinaFil: Trigubo, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentin

Diagnóstico del aislamiento principal de bobinas estatóricas sometidas a esfuerzos termoeléctricos en laboratorio

El estudio de los mecanismos de degradación del sistema de aislamiento del estator de máquinas eléctricas de alto voltaje es la base fundamental para la propuesta, validación y aplicación de criterios de diagnóstico en campo. A nivel mundial la principal herramienta para la reproducción controlada de los mecanismos de degradación del aislamiento ha sido la implementación de programas de envejecimiento acelerado. En estos, se someten bobinas de prueba a esfuerzos tipo TEAM (térmicos, eléctricos, ambientales y mecánicos) y por medio de técnicas de medición se estiman las probables causas que llevaron a la obtención de los resultados de las mediciones. Por décadas, los centros de investigación han aplicado esta metodología lo cual ha llevado al establecimiento de los criterios de diagnóstico hoy empleados en campo. Esta investigación doctoral contribuyó al estado del arte con el desarrollo de un nuevo índice para evaluación de la degradación del aislamiento que permitió relacionar las pruebas de capacitancia/factor de disipación y descargas parciales, cuyos resultados predominantemente se han interpretado de forma independiente. Así mismo, la investigación aplicó técnicas de medición no convencionales, como el análisis fisicoquímico, buscando complementar la información de diagnóstico que se puede extraer con las técnicas convencionales: mediciones dieléctricas