466 research outputs found
PRECISION: A Reconfigurable SIMD/MIMD Coprocessor for Computer Vision Systems-on-Chip
Computer vision applications have a large disparity in operations, data representation and memory access patterns from the early vision stages to the final classification and recognition stages. A hardware system for computer vision has to provide high flexibility without compromising performance, exploiting massively spatial-parallel operations but also keeping a high throughput on data-dependent and complex program flows. Furthermore, the architecture must be modular, scalable and easy to adapt to the needs of different applications. Keeping this in mind, a hybrid SIMD/MIMD architecture for embedded computer vision is proposed. It consists of a coprocessor designed to provide fast and flexible computation of demanding image processing tasks of vision applications. A 32-bit 128-unit device was prototyped on a Virtex-6 FPGA which delivers a peak performance of 19.6 GOP/s and 7.2 W of power dissipationThis work is funded by the Ministry of Science and Innovation, Government of Spain (projects TIN2013-41129-P and TEC2012-38921-C02-02) and the Xunta de Galicia (contract GRC 2014/008)S
Extended-spectrum beta-lactamaseproducing bacteria in a Tertiary Care Hospital in Madrid: Epidemiology, risk factors and antimicrobial susceptibility patterns
Introduction: Extended-spectrum beta-lactamase (ESBL) producing bacteria have been increasingly reported
as causal agents of nosocomial infection worldwide. Resistance patterns vary internationally, and even locally,
from one institution to the other. We investigated the clinical isolates positive for ESBL-producing bacteria in
our institution, a tertiary care hospital in Madrid (Spain), during a 2-year period (2007 2008).
Methods: Clinical and microbiological data were retrospectively reviewed. Two hundred and nineteen patients
were included in the study.
Results: Advanced age, diabetes, use of catheters, previous hospitalization and previous antibiotic treatment
were some of the risk factors found among patients. Escherichia coli was the most frequent isolate, and
urinary tract the most common site of isolation. Internal Medicine, Intensive Care Unit (ICU) and General
Surgery presented the highest number of isolates. There were no outbreaks during the study period. Antibiotic
patterns showed high resistance rates to quinolones in all isolates. There was 100% sensitivity to carbapenems.
Conclusion: Carbapenems continue to be the treatment of choice for ESBL-producing bacteria. Infection
control measures are of great importance to avoid the spread of these nosocomial infection
Distance Measurement Error in Time-of-Flight Sensors Due to Shot Noise
Unlike other noise sources, which can be reduced or eliminated by different signal processing techniques, shot noise is an ever-present noise component in any imaging system. In this paper, we present an in-depth study of the impact of shot noise on time-of-flight sensors in terms of the error introduced in the distance estimation. The paper addresses the effect of parameters, such as the size of the photosensor, the background and signal power or the integration time, and the resulting design trade-offs. The study is demonstrated with different numerical examples, which show that, in general, the phase shift determination technique with two background measurements approach is the most suitable for pixel arrays of large resolutionThis work has been partially funded by Spanish government Project TEC2012-38921-C02-02 MINECO(FEDER) and by the Xunta de Galicia with EM2013/038 and EM2014/012, AE CITIUS(CN2012/151, (FEDER)) and GPC2013/040 (FEDER)S
Ultralow power voltage reference circuit for implantable devices in standard CMOS technology
This is the peer reviewed version of the following article: Óscar Pereira-Rial, Paula López, Juan M. Carrillo, Victor M. Brea and Diego Cabello (2019) Ultralow power voltage reference circuit for implantable devices in standard CMOS technology. International journal of circuit theory and applications, 47 (7), 991-1005, which has been published in final form at https://doi.org/10.1002/cta.2643. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsAn ultralow power CMOS voltage reference for body implantable devices is presented in this paper. The circuit core consists of only regular threshold voltage PMOS transistors, thus leading to a very reduced output voltage dispersion, defined as σ/μ, and extremely low power consumption. A mathematical model of the generated reference voltage was obtained by solving circuit equations, and its numerical solution has been validated by extensive electrical simulations using a commercial circuit simulator. The proposed solution incorporates a passive RC low‐pass filter, to enhance power supply rejection (PSR) over a wide frequency range, and a speed‐up section, to accelerate the switching‐on of the circuit. The prototype was implemented in 0.18 μm standard CMOS technology and is able to operate with supply voltages ranging from 0.7 to 1.8 V providing a measured output voltage value of 584.2 mV at the target temperature of 36° C. The measured σ/μ dispersion of the reference voltage generated is 0.65% without the need of trimming. At the minimum supply of 0.7 V, the experimental power consumption is 64.5 pW, while the measured PSR is kept below –60 dB from DC up to the MHz frequency rangeThis work has been partially funded by the Spanish government projects TEC2015‐66878‐C3‐3‐R (MINECO/FEDER) and RTI2018‐097088‐B‐C32 (FEDER), by the Xunta de Galicia under project ED431C2017/69, by the Consellería de Cultura, Educación e Ordenación Universitaria (accreditation 2016‐2019, ED431G/08 and reference competitive group 2017‐2020, ED431C 2017/69), by the Junta de Extremadura R&D Plan, and the European Fund for Regional Development (EFRD) under Grant IB18079S
Wireless Sensor Network With Perpetual Motes for Terrestrial Snail Activity Monitoring
Wireless sensor networks (WSNs) are increasingly adopted in agriculture to monitor environmental variables to predict the presence of pests. Differently from these approaches, this paper introduces aWSN to detect the presence of snails in the field. The network can be used to both trigger an alarm of early pest presence and to further elaborate statistical models with the addition of environmental data as temperature or humidity to predict snail presence. In this paper we also design our own WSN simulator to account for real-life conditions as an uneven spacing of motes in the field or different currents generated by solar cells at the motes. This allows achieving more realistic network deployment in the field. Experimental tests are included in this paper, showing that our motes are perpetual in terms of energy consumptionConsellería de Cultura, Educación e Ordenación Universitaria (accreditation 2016-2019); European Regional Development Fund; Ministerio de Economía, Industria y Competitividad (TEC2015-66878-C3-3-R)S
Real time architectures for the scale Invariant feature transform algorithm
Feature extraction in digital image processing is a very intensive task for a CPU. In order to achieve real time image throughputs, hardware parallelism must be exploited. The speed-up of the system is constrained by the degree of parallelism of the implementation and this one at the same time, by programmable device size and the power dissipation. In this work, issues related to the synthesis of the Scale-Invariant Feature Transform (SIFT) algorithm on a FPGA to obtain target processing rates faster than 50 frames per second for VGA images, are analyzed. In order to increase the speedup of the algorithm, the work includes the analysis of feasible simplifications of the algorithm for a tracking application and the results are synthesized on an FPGA.This work has been partially funded by Spanish government projects TEC2015-66878-C3-2-R (MINECO/FEDER, UE) and TEC2015- 66878-C3-3-R (MINECO/FEDER, UE)
Effects of sevoflurane postconditioning on cell death, inflammation and TLR expression in human endothelial cells exposed to LPS
Background: Sevoflurane is an anesthetic agent which also participates in protective mechanisms in sepsis, likely
due to anti-inflammatory properties. A key tissue in sepsis is the endothelium, which expresses TLR2 and TLR4
receptors, known regulators of inflammatory mechanisms and potential therapeutic targets for this pathology. In
this context, we explored the effect of sevoflurane postconditioning in an in vitro sepsis model.
Methods: Primary cultures of human umbilical vein endothelial cells were used for two different experiments. In
the first set, cultures were placed in an airtight incubation chamber and exposed to different concentrations of
sevoflurane (0,1,3 or 7% vol,) for 1 hour. In the second set, lipopolysaccharide from Escherichia coli 0111:B4 (1 μg/
mL) was added to culture medium for 3 hours and cells were subsequently exposed to sevoflurane (0,1,3 or 7%
vol,) for 1 hour as explained before. In both cases, cell viability was measured by MTT and Trypan blue assays, TLR2
and TLR4 expression were analyzed by flow cytometry, and TNFα and IL-6 levels were quantified in cell culture
media by an immunoassay immediately after exposure, at 6 and 24 hours.
Results: Exposure to 3% sevoflurane decreased TLR2 at 24 hours and TLR4 at 6 and 24 hours (both p<0.05),
whereas exposure to 7% decreased TLR4 expression at 6 hours (p<0.05). Both 3 and 7% sevoflurane decreased
TNF-α and IL-6 levels at 24 hours (both p<0.05). In LPS-stimulated cultures, exposure to 3% sevoflurane was
cytoprotective at 6 and 24 hours (p<0.05) compared with control, and decreased TLR2 and TLR4 expression at 24
hours (p<0.05); whereas 7% decreased TLR4 expression at 24 hours (p<0.05). Both 3% and 7% sevoflurane
decreased TNF-α and IL-6 levels at 24 hours (both p<0.05).
Conclusions: Postconditioning with the halogenated anesthetic agent sevoflurane after LPS stimulation shows a
cytoprotective effect in an in vitro model, decreasing cell death and reducing TLR2 and TLR4 expression as well as
levels of the inflammatory mediators TNF-α and IL-6 in human endothelial cellsS
Membrane-disrupting iridium(III) oligocationic organometallopeptides
NOTICE: This is the peer reviewed version of the following article: Salvadó, I, Gamba, I, Montenegro J, Martínez-Costas J, Brea JM, Loza MI, Vázquez López M, Vázquez M.E. Membrane-disrupting iridium(III) oligocationic organometallopeptides. Chem. Commun., 2016,52, 11008-11011. DOI: 10.1039/C6CC05537K. This article may be used for non-commercial purposes in accordance with RSC Terms and Conditions for self-archivingA series of oligoarginine peptide derivatives containing cyclometallated iridium(III) units display remarkable cytotoxicity, comparable to that of cisplatin. In vitro studies with unilamellar vesicles support a membrane-disrupting mechanism of actionWe are thankful for the support given by the Spanish grants SAF2013-41943-R, CTQ2015-70698-R, CTQ2013-49317-EXP,CTQ2014-59646-R, and BFU2013-43513-R, and the Xunta de Galicia GRC2013-041. Support from COST Action CM1105 and the orfeo-cinqa network (CTQ2014-51912-REDC) is kindly acknowledgedS
Quality, oxidative markers and DNA damage (DNA) fragmentation of red deer thawed spermatozoa after incubation at 37 °C in presence of several antioxidants
P. 1005-1019Antioxidants may be useful for supplementing sperm extenders. We have tested dehydroascorbic acid (DHA), TEMPOL, N-acetyl-cysteine (NAC) and rutin on epididymal spermatozoa from red deer, during incubation at 37 °C. Cryopreserved spermatozoa were thawed, washed and incubated with 1 mm or 0.1 mm of each antioxidant, including oxidative stress (Fe2+/ascorbate). Motility (CASA and clustering of subpopulations), viability, mitochondrial membrane potential, and acrosomal status were assessed at 2 and 4 h. Lipoperoxidation, intracellular reactive oxygen species (ROS) and DNA damage (DNA) status (TUNEL) were checked at 4 h. Oxidative stress increased ROS, lipoperoxidation and DNA damage. Overall, antioxidants negatively affected motility and physiological parameters. Only DHA 1 mm protected motility, increasing the fast and progressive subpopulation. However, it had a detrimental effect on acrosomal and DNA status, in absence of oxidative stress. Tempol and rutin efficiently reduced lipoperoxidation, ROS, and DNA damage in presence of oxidative stress. NAC was not as efficient as TEMPOL or rutin reducing lipoperoxidation or protecting DNA, and did not reduce ROS, but its negative effects were lower than the other antioxidants when used at 1 mm, increasing the subpopulation of hyperactivated-like spermatozoa at 2 h. Our results show that these antioxidants have mixed effects when spermatozoa are incubated at physiological temperatures. DHA may not be suitable because of prooxidant effects, but TEMPOL, NAC and rutin may be considered for cryopreservation trials. In general, exposure of red deer spermatozoa to these antioxidants should be limited to low temperatures, when only protective effects may develop.S
Improving the effect of incubation and oxidative stress on thawed spermatozoa from red deer by using different antioxidant treatments
P. 856-870Antioxidants could improve sperm media, extending the viability of spermatozoa and protecting their DNA. The protective ability of lipoic acid, melatonin, Trolox and crocin was tested on red deer spermatozoa incubated at 37°C. Cryopreserved spermatozoa were thawed and incubated with 1 mM or 0.1 mM of each antioxidant, with or without oxidative stress (100 μM Fe2+). Motility (CASA), viability, mitochondrial membrane potential and acrosomal status were assessed. Lipoperoxidation (malondialdehyde production), intracellular reactive oxygen species (ROS) and DNA status (TUNEL) were checked at 4 h. Incubation alone increased ROS and decreased motility. Oxidative stress intensified these effects, increasing lipoperoxidation and DNA damage. Lipoic acid had little protective effect, whereas 1 mM melatonin showed limited protection. Trolox lowered ROS and lipoperoxidation both in oxidised and non-oxidised samples. In oxidised samples, Trolox prevented DNA and acrosomal damage, and ameliorated motility. Crocin at 1 mM showed similar results to Trolox, but noticeably stimulated motility and had no effect on lipoperoxidation. In a second experiment, a broader range of crocin and melatonin concentrations were tested, confirming the effects of crocin (positive effects noticeable at 0.5–0.75 mM), but showing an increase in lipoperoxidation at 2 mM. Melatonin was increasingly effective at 2.5 and 5 mM (ROS, lipoperoxidation and DNA status). Crocin seems a promising new antioxidant, but its particular effects on sperm physiology must be further studied, especially the consequences of motility stimulation and confirming its effect on lipoperoxidation. Melatonin might be useful at relatively high concentrations, compared to Trolox.S
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