Multiple Order Dual-Band Active Ring Filters with Composite Right/Left Handed Cells

In this paper, a novel dual-band active filter topology is presented. The non-linear phase response of a composite right/left-handed cell is used to achieve the desired dual-band performance. Additionally, the proposed structure based on coupled ring resonators yields a very compact solution in which high-order implementations can be easily obtained by cascading multiple rings. The theoretical principles of this type of filters are analyzed in detail. Finally, three prototypes based on first-, second- and third-order structures validate the feasibility of this type of filters. Good agreement between simulations and measurements has been achieved

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

Modelling and Terrestrial Laser Scanning Methodology (2009–2018) on Debris Cones in Temperate High Mountains

Producción CientíficaDebris cones are a very common landform in temperate high mountains. They are the most representative examples of the periglacial and nival processes. This work studies the dynamic behavior of two debris cones (Cone A and Cone B) in the Picos de Europa, in the north of the Iberian Peninsula. Their evolution was measured uninterruptedly throughout each August for 10 years (2009–2018) using the Terrestrial Laser Scanning (TLS) technique. The observations and calculations of the two debris cones were treated independently, but both showed the same behavior. Therefore, if these results are extrapolated to other debris cones in similar environments (temperate high mountain), they should show behavior similar to that of the two debris cones analyzed. Material falls onto the cones from the walls, and transfer of sediments follows linear trajectories according to the maximum slope. In order to understand the linear evolution of the two debris cones, profiles were created along the maximum slope lines of the Digital Elevation Model (DEM) of 2009, and these profile lines were extrapolated to the remaining years of measurement. In order to determine volumetric surface behavior in the DEMs, each year for the period 2009–2018 was compared. In addition, the statistical predictive value for position (Z) in year 2018 was calculated for the same planimetric position (X,Y) throughout the profiles of maximum slopes. To do so, the real field data from 2009–2017 were interpolated and used to form a sample of curves. These curves are interpreted as the realization of a functional random variable that can be predicted using statistical techniques. The predictive curve obtained was compared with the 2018 field data. The results of both coordinates (Z), the real field data, and the statistical data are coherent within the margin of error of the data collection.Fondo Europeo de Desarrollo Regional - Agencia Estatal de Investigación (grant TIN2016-76843-C4-2-R)Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (grant CGL2015-68144-R

Autophagic flux is required for the synthesis of triacylglycerols and ribosomal protein turnover in Chlamydomonas

Autophagy is an intracellular catabolic process that allows cells to recycle unneeded or damaged material to maintain cellular homeostasis. This highly dynamic process is characterized by the formation of double-membrane vesicles called autophagosomes, which engulf and deliver the cargo to the vacuole. Flow of material through the autophagy pathway and its degradation in the vacuole is known as autophagic flux, and reflects the autophagic degradation activity. A number of assays have been developed to determine autophagic flux in yeasts, mammals, and plants, but it has not been examined yet in algae. Here we analyzed autophagic flux in the model green alga Chlamydomonas reinhardtii. By monitoring specific autophagy markers such as ATG8 lipidation and using immunofluorescence and electron microscopy techniques, we show that concanamycin A, a vacuolar ATPase inhibitor, blocks autophagic flux in Chlamydomonas. Our results revealed that vacuolar lytic function is needed for the synthesis of triacylglycerols and the formation of lipid bodies in nitrogen- or phosphate-starved cells. Moreover, we found that concanamycin A treatment prevented the degradation of ribosomal proteins RPS6 and RPL37 under nitrogen or phosphate deprivation. These results indicate that autophagy might play an important role in the regulation of lipid metabolism and the recycling of ribosomal proteins under nutrient limitation in ChlamydomonasEspaña, MINECO BFU2015-68216-PEspaña, Junta de Andalucía CVI-7336 (to JLC), BIO2015-74432-JIN (to MEPP

Noise Figure Measurement of Differential Amplifiers Using non-Ideal Baluns

This paper analyzes the noise and gain measurement of microwave differential amplifiers using two passive baluns. A general model of the baluns is considered, including potential losses and phase/amplitude unbalances. This analysis allows de-embedding the actual gain and noise performance of the isolated amplifier by using single-ended measurements of the cascaded system and baluns. Finally, measured results from two amplifier prototypes are used to validate the theoretical principles

In-silico modeling to compare radiofrequency-induced thermal lesions created on myocardium and thigh muscle

[EN] Beating heart (BH) and thigh muscle (TM) are two pre-clinical models aimed at studying the lesion sizes created by radiofrequency (RF) catheters in cardiac ablation. Previous experimental results have shown that thermal lesions created in the TM are slightly bigger than in the BH. Our objective was to use in-silico modeling to elucidate some of the causes of this difference. In-silico RF ablation models were created using the Arrhenius function to estimate lesion size under different energy settings (25 W/20 s, 50 W/6 s and 90 W/4 s) and parallel, 45 degrees and perpendicular catheter positions. The models consisted of homogeneous tissue: myocardium in the BH model and striated muscle in the TM model. The computer results showed that the lesion sizes were generally bigger in the TM model and the differences depended on the energy setting, with hardly any differences at 90 W/4 s but with differences of 1 mm in depth and 1.5 m in width at 25 W/20 s. The higher electrical conductivity of striated muscle (0.446 S/m) than that of the myocardium (0.281 S/m) is possibly one of the causes of the higher percentage of RF energy delivered to the tissue in the TM model, with differences between models of 2-5% at 90 W/4 s, similar to 9% at 50 W/6 s and similar to 10% at 25 W/20 s. Proximity to the air-blood interface (just 2 cm from the tissue surface) artificially created in the TM model to emulate the cardiac cavity had little effect on lesion size. In conclusion, the TM-based experimental model creates fairly similar-sized lesions to the BH model, especially in high-power short-duration ablations (50 W/6 s and 90 W/4 s). Our computer results suggest that the higher electrical conductivity of striated muscle could be one of the causes of the slightly larger lesions in the TM model.This research was funded by the Spanish Ministerio de Ciencia, Innovacion y Universidades/Agencia Estatal de Investigacion MCIN/AEI/10.13039/501100011033 (Grant number: RTI2018-094357-B-C21)Pérez, JJ.; Berjano, E.; González-Suárez, A. (2022). In-silico modeling to compare radiofrequency-induced thermal lesions created on myocardium and thigh muscle. Bioengineering. 9(7):1-13. https://doi.org/10.3390/bioengineering9070329S1139

How far the zone of heat-induced transient block extends beyond the lesion during RF catheter cardiac ablation

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Hyperthermia on 02-01-2023, available online: http://www.tandfonline.com/ https://doi.org/10.1080/02656736.2022.2163310[EN] Purpose While radiofrequency catheter ablation (RFCA) creates a lesion consisting of the tissue points subjected to lethal heating, the sublethal heating (SH) undergone by the surrounding tissue can cause transient electrophysiological block. The size of the zone of heat-induced transient block (HiTB) has not been quantified to date. Our objective was to use computer modeling to provide an initial estimate. Methods and materials We used previous experimental data together with the Arrhenius damage index (omega) to fix the omega values that delineate this zone: a lower limit of 0.1-0.4 and upper limit of 1.0 (lesion boundary). An RFCA computer model was used with different power-duration settings, catheter positions and electrode insertion depths, together with dispersion of the tissue's electrical and thermal characteristics. Results The HiTB zone extends in depth to a minimum and maximum distance of 0.5 mm and 2 mm beyond the lesion limit, respectively, while its maximum width varies with the energy delivered, extending to a minimum of 0.6 mm and a maximum of 2.5 mm beyond the lesion, reaching 3.5 mm when high energy settings are used (25 W-20s, 500 J). The dispersion of the tissue's thermal and electrical characteristics affects the size of the HiTB zone by +/- 0.3 mm in depth and +/- 0.5 mm in maximum width. Conclusions Our results suggest that the size of the zone of heat-induced transient block during RFCA could extend beyond the lesion limit by a maximum of 2 mm in depth and approximately 2.5 mm in width.This work was supported by Spanish Ministerio de Ciencia, Innovacion y Universidades/Agencia Estatal de Investigacion IMCIN/AEI/10.13039/ 501100011033 (Grant RTI2018-094357-B-C21).Pérez, JJ.; Berjano, E.; González Suárez, A. (2023). How far the zone of heat-induced transient block extends beyond the lesion during RF catheter cardiac ablation. International Journal of Hyperthermia. 40(1):1-10. https://doi.org/10.1080/02656736.2022.216331011040

Mariano Peset, historiador de las universidades, historiador de la Universidad de México

En este trabajo analizamos a partir de las obras de Mariano Peset sobre la Universidad de México, su aportación a la historia de las universidades hispánicas

El desarrollo de las carreras de posgrado en la Facultad de Ciencias Económicas y Sociales de la UNMDP. Su relación con la agenda de investigación

La formación de posgrado conducente a título en las Universidades de gestión pública, a partir de la década del '90, es una de las actividades del sistema de educación superior que experimenta notables transformaciones. En su dinámica de crecimiento se observarán rasgos de expansión, de mercantilización, de heterogeneidad y de segmentación. Distintos estudios que abordan el sistema de educación superior (Barsky, García de Fanelli, Mollis, Gentille, Trombetta, Follari, Jeppesen, Marquis, Vera Santillan, Zarur, Castro Lamas) dan cuenta de la complejidad de la actividad que se analiza desde perspectivas mayoritariamente convergentes. En el presente trabajo, en el marco de la investigación actualmente en desarrollo -a través de un diseño de investigación cuantitativo y cualitativo- se presenta un avance de la composición del perfil de las carreras de posgrado de las distintas Facultades de Ciencias Económicas de las Universidades de gestión pública con especial énfasis en el caso específico de la Facultad de Ciencias Económicas y Sociales de la UNMDP, especialmente en la articulación de las ofertas de las carreras de posgrado y su vinculación con grupos y proyectos de investigación y el tratamiento de la formación del posgrado en la agenda institucional.Fil: González Carella, María Inés. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Pérez, Pedro Enrique. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Hammond, Fernando. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina