Effect of the sampling parameters in FOCV-MPPT circuits for fast-varying EH sources

The fractional open-circuit voltage (FOCV) method is extensively used in low-power energy harvesting (EH) sources to extract maximum power. For fast-varying EH sources, a fast sampling rate is required. This work theoretically analyzes the influence of the sampling time and period on the harvested power of sinusoidal EH sources. In addition, the circuit limitations to achieve a fast sampling rate are presented and circuits to deal with them proposed and implemented. Furthermore, one of the circuits is based on a novel pseudoFOCV method and achieves the fastest sampling rate. Experimental tests are performed with a 2 Hz, 1 to 3 V sinusoidal source having an output resistance of 127 Ω, and the results are shown to agree with theoretical predictions. It is shown that the harvested power increases with the sampling rate when the sampling time is negligible (sampling 15 times faster than the source frequency extracts around 99% of the maximum), and for fixed sampling times, there is an optimum sampling rate where the harvested power is maximum. The first result is generic and valid for methods other than the FOCV. Tests were also performed with a small-scale wave energy converter placed in a linear shaker emulating a sea environment. Harvested power increases by 25% with respect using a commercial FOCV unit with a low sampling rate

Enhancing large-scale docking simulation on heterogeneous systems: An MPI vs rCUDA study

[EN] Virtual Screening (VS) methods can considerably aid clinical research by predicting how ligands interact with pharmacological targets, thus accelerating the slow and critical process of finding new drugs. VS methods screen large databases of chemical compounds to find a candidate that interacts with a given target. The computational requirements of VS models, along with the size of the databases, containing up to millions of biological macromolecular structures, means computer clusters are a must. However, programming current clusters of computers is no easy task, as they have become heterogeneous and distributed systems where various programming models need to be used together to fully leverage their resources. This paper evaluates several strategies to provide peak performance to a GPU-based molecular docking application called METADOCK in heterogeneous clusters of computers based on CPU and NVIDIA Graphics Processing Units (GPUs). Our developments start with an OpenMP, MPI and CUDA METADOCK version as a baseline case of cluster utilization. Next, we explore the virtualized GPUs provided by the rCUDA framework in order to facilitate the programming process. rCUDA allows us to use remote GPUs, i.e. installed in other nodes of the cluster, as if they were installed in the local node, so enabling access to them using only OpenMP and CUDA. Finally, several load balancing strategies are analyzed in a search to enhance performance. Our results reveal that the use of middleware like rCUDA is a convincing alternative to leveraging heterogeneous clusters, as it offers even better performance than traditional approaches and also makes it easier to program these emerging clusters.This work is jointly supported by the Fundacion Seneca (Agencia Regional de Ciencia y Tecnologia, Region de Murcia) under grant 18946/JLI/13, and by the Spanish MEC and European Commission FEDER under grants TIN2015-66972-C5-3-R and TIN2016-78799-P (AEI/FEDER, UE). We also thank NVIDIA for hardware donation under GPU Educational Center 2014-2016 and Research Center 2015-2016. Furthermore, researchers from Universitat Politecnica de Valencia are supported by the Generalitat Valenciana under Grant PROMETEO/2017/077. Authors are also grateful for the generous support provided by Mellanox Technologies Inc.Imbernón, B.; Prades Gasulla, J.; Gimenez Canovas, D.; Cecilia, JM.; Silla Jiménez, F. (2018). Enhancing large-scale docking simulation on heterogeneous systems: An MPI vs rCUDA study. Future Generation Computer Systems. 79:26-37. https://doi.org/10.1016/j.future.2017.08.050S26377

Vertebrate fauna at the Allosaurus fossil-site of Andrés (Upper Jurassic), Pombal, Portugal

An overview of the faunistic diversity of the Andres fossil-site from the Portuguese Upper Jurassic is presented. This work provides a preliminary approach on the vertebrate fauna known at present. Although this quarry is known since the 1990’s, due to the description on the first robust evidence of a member of the neotetanuran genus Allosaurus outside North America, the results presented here are mainly derived from the analysis of the elements found during the second and third field seasons in 2005. At the moment, among the material collected from Andrés it was identified remains that represent a diverse vertebrate fauna, including fishes, sphenodonts, crocodrylomorphs, pterosaurs, and at least, seven distinct dinosaur forms. The recovery of this diverse and abundant osteological collection from one unique fossil-site is noteworthy for the Upper Jurassic Portuguese record, and only comparable with those from the Guimarota coalmine. Due to these two features plus the good preservation of the fossils, the Andres quarry may be a site of reference for the analysis of vertebrate ecosystems from the Portuguese Upper Jurassic. Dinosaur elements are the most abundant fossils, and among them it is particulary common the presence of remains identified as Allosaurus. These new evidences allow testing the previus phylogenetical hypothesys ascribing the firsts theropod remains from Andrés to A. fragilis, a species described in synchronic levels of the North American Morrison Formation. The similarity between the Allosaurus remains collected in Andres and some specimens from the Morrison Formation seems to point the existence of a genetic flow between some continental vertebrates on both sides of the proto-north Atlantic during the Upper Jurassic. Favourable tectonic conditions for the occurrence of punctual contacts between the two continents is, at present, the best scenario for explain this situation.Se presenta un analisis de la diversidad faunistica del yacimiento de Andrés en el Jurasico Superior de la Cuenca Lusitanica. El presente trabajo pretende establecer un análisis preliminar de la fauna de vertebrados identificada en el yacimiento hasta la fecha. Aunque conocido desde la decada de 1990, debido a la descripcion de la primera evidencia robusta de un neotetanuro del genero Allosaurus fuera de Norteamerica, los resultados presentados derivan principalmente del analisis de elementos encontrados durante la segunda y tercera campanas de excavacion en 2005. Hasta el momento han sido identificados entre el material recogido en Andrés, representantes de diversos taxones de vertebrados que incluyen que incluyen peces, esfenodontos, crocodilomorfos, pterosaurios y, al menos, siete formas distintas de dinosaurios. La presencia de esta diversidad y abundancia de restos osteologicos en el mismo yacimiento representa una situacion unica en el registro del Jurasico Superior portugues, tan solo comparable a la del yacimiento clasico de la mina de carbon de Guimarota. Atendiendo a estas dos caracteristicas y a la buena preservacion de los fosiles, el yacimiento de Andres puede ser considerado como una localidad de referencia para el estudio de los ecosistemas con vertebrados del Jurasico Superior portugues. Los restos de dinosaurios son los fosiles mas abundantes y, entre ellos, son particularmente comunes los asignables a Allosaurus. Estas nuevas evidencias proporcionan a A. fragilis, una especie descrita en niveles sincronicos de la Formacion Morrison en Norteamerica. La similitud entre los restos de Allosaurus recogidos en Andres y algunos de los ejemplares de la Formacion Morrison, sugiere la existencia de un flujo genético entre algunos vertebrados continentales de ambos lados del proto-Atlántico norte durante el Jurásico Superior. La existencia de condiciones tectonicas favorables para la existencia de contactos puntuales entre los dos continentes es actualmente el mejor escenario para explicar esta situacion

The programmable processor

[EN] Reconfigurable optical chips made from 2D meshes of connected waveguides could pave the way for programmable, general purpose microwave photonics processors.Capmany Francoy, J.; Gasulla Mestre, I.; Pérez-López, D. (2016). The programmable processor. Nature Photonics. 10:6-8. doi:10.1038/nphoton.2015.254S6810Waterhouse, R. & Novak, D. IEEE Microwave Mag. 16, 84–92 (2015).Skubic, B., Bottari, G., Rostami, A., Cavaliere, F. & Ölen, P. IEEE J. Lightwave Technol. 33, 1084–1091 (2015).Nature Photonics Technology Focus http://www.nature.com/nphoton/journal/v5/n12/techfocus/index.html (2011).Marpaung, D. et al. Lasers Phot. Rev. 7, 506–538 (2013).Pérez, D., Gasulla, I. & Capmany, J. Opt. Express 23, 14640–14654 (2015).Zhuang, L. et al. Optica 2, 854–859 (2015).Smit, M. et al. Semicond. Sci. Technol. 28, 083001 (2014).Guan, B. B. et al. IEEE J. Sel. Top. Quantum Electron. 20, 359–368 (2014).Wang, J. et al. Nature Commun. 6, 5957 (2015).Miller, D. A. B. Optica 2, 747–750 (2015)

Spatial Division Multiplexed Microwave Signal processing by selective grating inscription in homogeneous multicore fibers

[EN] The use of Spatial Division Multiplexing for Microwave Photonics signal processing is proposed and experimentally demonstrated, for the first time to our knowledge, based on the selective inscription of Bragg gratings in homogeneous multicore fibers. The fabricated devices behave as sampled true time delay elements for radiofrequency signals offering a wide range of operation possibilities within the same optical fiber. The key to processing flexibility comes from the implementation of novel multicavity configurations by inscribing a variety of different fiber Bragg gratings along the different cores of a 7-core fiber. This entails the development of the first fabrication method to inscribe high-quality gratings characterized by arbitrary frequency spectra and located in arbitrary longitudinal positions along the individual cores of a multicore fiber. Our work opens the way towards the development of unique compact fiber-based solutions that enable the implementation of a wide variety of 2D (spatial and wavelength diversity) signal processing functionalities that will be key in future fiber-wireless communications scenarios. We envisage that Microwave Photonics systems and networks will benefit from this technology in terms of compactness, operation versatility and performance stability.We thank Prof. Jose Capmany for the thoughtful discussions and recommendations that greatly contribute to this work. This research was supported by the Spanish MINECO Projects TEC2014-60378-C2-1-R and TEC2015-62520-ERC, the Valencian Research Excellency Award Program GVA PROMETEO 2013/012, the Spanish MECD FPU Scholarship (FPU13/04675) for J. Hervas, and the Spanish MINECO Ramon y Cajal Program (RYC-2014-16247) for I. Gasulla.Gasulla Mestre, I.; Barrera Vilar, D.; Hervás-Peralta, J.; Sales Maicas, S. (2017). Spatial Division Multiplexed Microwave Signal processing by selective grating inscription in homogeneous multicore fibers. Scientific Reports. 7(41727):1-10. https://doi.org/10.1038/srep41727S110741727Samsung Electronics Co, “5G Vision”, available at http://www.samsung.com/global/business-images/insights/2015/Samsung-5G-Vision-0.pdf (2015).Technology Focus on Microwave Photonics. Nat. Photonics 5, 723 (2011).J. Capmany, J. Mora, I. Gasulla, J. Sancho, J. Lloret & S. Sales . Microwave photonic signal processing. IEEE J. Lightw. Technol. 31, 571–586 (2013).Y. Long & J. Wang . Ultra-high peak rejection notch microwave photonic filter using a single silicon microring resonator. Opt. Express 23, 17739–17750 (2015).Y. Long & J. Wang . All-optical tuning of a nonlinear silicon microring assisted microwave photonic filter: theory and experiment. Opt. Express 23, 17758–17771 (2015).Y. Long, L. Zhou & J. Wang . Photonic-assisted microwave signal multiplication and modulation using a silicon Mach–Zehnder modulator. Sci. Reports 6, 20215 (2016).J. Sancho, J. Bourderionnet, J. Lloret, S. Combrié, I. Gasulla, S. Xavier, S. Sales, P. Colman, G. Lehoucq, D. Dolfi, J. Capmany & A. De Rossi . Integrable microwave filter based on a photonic crystal delay line. Nat. Commun. 3, 1075 (2012).F. Ohman, K. Yvind & J. Mørk . Slow Light in a Semiconductor Waveguide for True-Time Delay Applications in Microwave Photonics. IEEE Photon. Technol. Lett. 19, 1145–1157 (2007).P. A. Morton & J. B. Khurgin. Microwave photonic delay line with separate tuning of the optical carrier. IEEE Photon. Technol. Lett. 21, 1686–1688 (2009).D. Marpaung, C. Roeloffzen, R. Heideman, A. Leinse, S. Sales & J. Capmany . Integrated microwave photonics. Lasers Photon. Rev. 7, 506–538 (2013).I. Gasulla & J. Capmany . Microwave photonics applications of multicore fibers. Photonics J. 4, 877–888 (2012).S. Garcia & I. Gasulla . Design of Heterogeneous Multicore fibers as sampled True Time Delay Lines. Opt. Lett. 40, 621–624 (2015).F. Zeng & J. Yao . All-optical microwave filters using uniform fiber Bragg gratings with identical reflectivities. IEEE J. Lightw. Technol. 23, 1410 (2005).C. Wang & J. Yao . Fiber Bragg gratings for microwave photonics subsystems. Opt. Express 21, 22868–22884 (2013).I. Gasulla, D. Barrera & S. Sales . Microwave photonic devices based on multicore fibers. 16th International Conference on Transparent Optical Networks (ICTON), Graz, Austria, 2014.I. Gasulla, D. Barrera, J. Hervás, S. García & S. Sales . Multi-cavity Microwave Photonics devices built upon multicore fibres. 18th International Conference on Transparent Optical Networks (ICTON), Trento (Italy), pp. 1–4, 2016.K. O. Hill & G. Meltz . Fiber Bragg grating technology fundamentals and overview. IEEE J. Lightw. Technol. 15, 1263–1276 (1997).T. Erdogan . Fiber grating spectra. IEEE J. Lightw. Technol. 15, 1277–1294 (1997).D. Barrera, I. Gasulla & S. Sales . Multipoint two-dimensional curvature optical fiber sensor based on a non-twisted homogeneous four-core fiber. IEEE J. Lightw. Technol. 33, 2445–2450 (2015).T. Birks, B. Mangan, A. Diez, J. Cruz, S. Leon-Saval, J. Bland-Hawthorn & D. Murphy . Multicore optical fibres for astrophotonics. In CLEO/Europe and EQEC 2011 Conference Digest, OSA Technical Digest (CD)d (Optical Society of America, 2011), paper JSIII2_1.C. Wang, Z. Yan, Q. Sun, Z. Sun, C. Mou, J. Zhang, A. Badmos & L. Zhang . Fibre Bragg gratings fabrication in four core fibres. Proc. SPIE 9886, Micro-Structured and Specialty Optical Fibres IV, 98860H (2016).M. J. Cole, W. H. Loh, R. I. Laming, M. N. Zervas & S. Barcelos . Moving fibre/phase mask-scanning beam technique for enhanced flexibility in producing fibre gratings with uniform phase mask. Electron. Lett. 31, 1488–1490 (1995).M. Gallagher & U. Österberg . Time resolved 3.10 eV luminescence in germanium-doped silica glass. Appl. Phys. Lett. 63, 2987–2988 (1993).T. Komukai & M. Nakazawa . Fabrication of high-quality long fiber Bragg grating by monitoring 3.1 eV radiation (400 nm) from GeO defects. IEEE Photon. Tech. Lett. 8, 1495–1497 (1996).R. R. Thomson, H. T. Bookey, N. D. Psaila, A. Fender, S. Campbell, W. N. MacPherson, J. S. Barton, D. T. Reid & A. K. Kar . Ultrafast-laser inscription of a three dimensional fan-out device for multicore fiber coupling applications. Opt. Express 15, 11691–11697 (2007)

Lichen rehydration in heavy metal polluted environments: Pb modulates the oxidative response of both Ramalina farinacea thalli and its isolated microalgae

Lichens are adapted to desiccation/rehydration and accumulate heavy metals, which induce ROS especially from the photobiont photosynthetic pigments. Although their mechanisms of abiotic stress tolerance are still to be unravelled, they seem related to symbionts' reciprocal upregulation of antioxidant systems. With the aim to study the effect of Pb on oxidative status during rehydration, the kinetics of intracellular ROS, lipid peroxidation and chlorophyll autofluorescence of whole Ramalina farinacea thalli and its isolated microalgae (Trebouxia TR1 and T. TR9) was recorded. A genetic characterization of the microalgae present in the thalli used was also carried out in order to assess possible correlations among the relative abundance of each phycobiont, their individual physiological responses and that of the entire thallus. Unexpectedly, Pb decreased ROS and lipid peroxidation in thalli and its phycobionts, associated with a lower chlorophyll autofluorescence. Each phycobiont showed a particular pattern, but the oxidative response of the thallus paralleled the TR1's, agreeing with the genetic identification of this strain as the predominant phycobiont. We conclude that: (1) the lichen oxidative behaviour seems to be modulated by the predominant phycobiont and (2) Pb evokes in R. farinacea and its phycobionts strong mechanisms to neutralize its own oxidant effects along with those of rehydration

Metabolomic Response of Calotropis procera Growing in the Desert to Changes in Water Availability

Water availability is a major limitation for agricultural productivity. Plants growing in severe arid climates such as deserts provide tools for studying plant growth and performance under extreme drought conditions. The perennial species Calotropis procera used in this study is a shrub growing in many arid areas which has an exceptional ability to adapt and be productive in severe arid conditions. We describe the results of studying the metabolomic response of wild C procera plants growing in the desert to a one time water supply. Leaves of C. procera plants were taken at three time points before and 1 hour, 6 hours and 12 hours after watering and subjected to a metabolomics and lipidomics analysis. Analysis of the data reveals that within one hour after watering C. procera has already responded on the metabolic level to the sudden water availability as evidenced by major changes such as increased levels of most amino acids, a decrease in sucrose, raffinose and maltitol, a decrease in storage lipids (triacylglycerols) and an increase in membrane lipids including photosynthetic membranes. These changes still prevail at the 6 hour time point after watering however 12 hours after watering the metabolomics data are essentially indistinguishable from the prewatering state thus demonstrating not only a rapid response to water availability but also a rapid response to loss of water. Taken together these data suggest that the ability of C. procera to survive under the very harsh drought conditions prevailing in the desert might be associated with its rapid adjustments to water availability and losses

One-year longitudinal association between changes in dietary choline or betaine intake and cardiometabolic variables in the PREvención con DIeta MEDiterránea-Plus (PREDIMED-Plus) trial

Choline and betaine intakes have been related to cardiovascular health. We aimed to explore the relation between 1-y changes in dietary intake of choline or betaine and 1-y changes in cardiometabolic and renal function traits within the frame of the PREDIMED (PREvención con DIeta MEDiterránea)-Plus trial. We used baseline and 1-y follow-up data from 5613 participants (48.2% female and 51.8% male; mean ± SD age: 65.01 ± 4.91 y) to assess cardiometabolic traits, and 3367 participants to assess renal function, of the Spanish PREDIMED-Plus trial. Participants met ≥3 criteria of metabolic syndrome and had overweight or obesity [BMI (in kg/m 2) ≥27 and ≤40]. These criteria were similar to those of the PREDIMED parent study. Dietary intakes of choline and betaine were estimated from the FFQ. The greatest 1-y increase in dietary choline or betaine intake (quartile 4) was associated with improved serum glucose concentrations (−3.39 and −2.72 mg/dL for choline and betaine, respectively) and HbA1c levels (−0.10% for quartile 4 of either choline or betaine intake increase). Other significant changes associated with the greatest increase in choline or betaine intake were reduced body weight (−2.93 and −2.78 kg, respectively), BMI (−1.05 and −0.99, respectively), waist circumference (−3.37 and −3.26 cm, respectively), total cholesterol (−4.74 and −4.52 mg/dL, respectively), and LDL cholesterol (−4.30 and −4.16 mg/dL, respectively). Urine creatinine was reduced in quartile 4 of 1-y increase in choline or betaine intake (−5.42 and −5.74 mg/dL, respectively). Increases in dietary choline or betaine intakes were longitudinally related to improvements in cardiometabolic parameters. Markers of renal function were also slightly improved, and they require further investigation. This trial was registered at as ISRCTN89898870

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation