56 research outputs found
Performance of MIMO systems
Demand in high data rate communications, driven by internet and cellular mobile, have increased, specially in wireless local area networks, emerging home audio visual networks and multimedia services in general. The limitation of the available radio spectrum makes it impossible for the data rate needs to be accomplished by an increase in the bandwidth. The deployment of multiple antennas in the transmitter and the receiver, multiple input multiple output (MIMO), a cost effective technology, makes it feasible to meet the high data rate demands. In this work, several scenarios such as the transmission under Rayleigh and Rice channel conditions are analyzed. Different transmission schemes are used, using different numbers of transmit and receive antennas. The focus of the project is an investigation of the fundamental performance tradeoff between bit error probability and bit rate in these systems, related to the number of antennas deployed and the SNR. ______________________________________________________________La demanda de la alta velocidad de datos ha crecido
considerablemente debido a internet y a los teléfonos móviles
especialmente en redes wifi, en las redes audiovisuales de los hogares y
servicios multimedia. La limitación del espectro de radio disponible hace
imposible que la velocidad de datos aumente aumentando el ancho de
banda. El desarrollo de múltiples antenas transmitiendo y múltiples antenas
recibiendo, multiple input multiple output (MIMO), tiene un bajo coste y
hace factible el aumento de alta velocidad de datos.
En el trabajo, varios tipos de de condiciones de transmisión, como los
canales Rayleigh y Rice se han analizado. Se han usado diferentes modelos
de transmisión, utilizando numerosas antenas en transmisión y recepción.
El objetivo del proyecto es la investigación del rendimiento que se obtiene
entre sacrificar la probabilidad de bit y la tasa de transmisión en estos
sistemas, relacionándolo con el número de antenas en transmisión y
recepción y la SNR.Ingeniería de Telecomunicació
La educación inclusiva en la educación infantil: Propuestas basadas en la evidencia
La educación Inclusiva es un proceso de transformación de la escuela,
especialmente de la escuela infantil, cuyo propósito es lograr una oferta
educativa de calidad, universal y sin exclusiones que requiere reestructurar las
culturas, políticas y prácticas educativas de manera que los centros educativos
sean sensibles a la diversidad de todos los niños (Booth, Ainscow y Kingston,
2007). Si bien se ha avanzado mucho en el cambio cultural y político, aún no es
una realidad consolidada en las aulas. Desde el presente artículo se pretende
aglutinar las prácticas educativas (estructuras, recursos y estrategias) que se
están poniendo en marcha en las escuelas de infantil y que han demostrado su
capacidad para dar respuesta a la diversidad desde un enfoque inclusivo de la
educación.Inclusive Education is a process of transformation of school, especially
kindergarten, whose purpose is to offer a quality education and universal
education, so it needs to restructuring of cultural, policies and educational
practices in order to achieve that schools will be sensitive the diversity of all
children (Booth, Ainscow and Kingston, 2007). While progress has been made
in the cultural and political change, however it is not established in the
classroom reality yet. This article is intended to bring educational practices
(structures, resources and strategies) that are being put in place in schools for
children and who have demonstrated their ability to respond to diversity from an
inclusive education approach
Spin-wave excitations in ribbon-shaped Fe nanoparticles
It has been found that in highly anisometric ribbon-shaped Fe particles with nanoscale dimensions that the magnetization decreases with temperature markedly faster than in bulk bcc Fe. This anomalous dependence, which becomes more remarkable as the length-to-cross section ratio increases, arises from the elongated shape of the particles. The analytical approximation performed on the thermal spectrum of magnons, compatible with the sample dimensions, unravels the correlated influences of shape and size on the thermal decreasing rate of magnetization
Nutraceutical Potential of Phenolics from `Brava´ and `Mansa´ Extra-Virgin Olive Oils on the Inhibition of Enzymes Associated to Neurodegenerative Disorders in Comparison with Those of `Picual´ and `Cornicabra´
The increasing interest in theMediterranean diet is based on the protective effects against several
diseases, including neurodegenerative disorders. Polyphenol-rich functional foods have been proposed to
be unique supplementary and nutraceutical treatments for these disorders. Extra-virgin olive oils (EVOOs)
obtained from 0Brava0 and 0Mansa0, varieties recently identified from Galicia (northwestern Spain), were
selected for in vitro screening to evaluate their capacity to inhibit key enzymes involved in Alzheimer0s
disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and 5-lipoxygenase (5-LOX)),
major depressive disorder (MDD) and Parkinson0s disease (PD) (monoamine oxidases: hMAO-A and
hMAO-B respectively). 0Brava0 oil exhibited the best inhibitory activity against all enzymes, when they
are compared to 0Mansa0 oil: BuChE (IC50 = 245 ± 5 and 591 ± 23 mg.mL-1), 5-LOX (IC50 = 45 ± 7 and
106±14 mg.mL-1), hMAO-A (IC50 = 30 ± 1 and 72 ± 10 mg.mL-1) and hMAO-B (IC50 = 191 ± 8 and
208 ±14 mg.mL-1), respectively. The inhibitory capacity of the phenolic extracts could be associated
with the content of secoiridoids, lignans and phenolic acids.This work received financial support from Programa de
Cooperación Interreg V-A España—Portugal (POCTEP) 2014–2020 (projects Ref.: 0181_NANOEATERS_01_E and
Ref: 0377_IBERPHENOL_6_E)
Evaluation of the neuroprotective and antidiabetic potential of phenol-rich extracts from virgin olive oils by in vitro assays
In this work, phenol-rich extracts from ‘Cornicabra’ and ‘Picual’ virgin-olive oils (EVOOs) were examined, for the first time, to establish their capacity to inhibit key enzymes involved in Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and 5-lipoxygenase (LOX)), major depressive disorder (MDD) and Parkinson's disease (PD) (monoamine oxidases: hMAO-A and hMAO-B respectively), and diabetes mellitus (DM) (α-glucosidase and α-amylase). ‘Cornicabra’ displayed the best inhibitory activity against all enzymes, when compared to ‘Picual’: BuChE (IC50 = 156 ± 4 and 308 ± 33 mg mL−1), LOX (IC50 = 26 ± 0.5 and 37 ± 3 mg mL−1), hMAO-A (IC50 = 20 ± 2 and 37 ± 0.2 mg mL−1), hMAO-B (IC50 = 131 ± 7 and 215 ± 13 mg mL−1) and α-glucosidase (IC50 = 154 ± 17 and 251 ± 31 mg mL−1), respectively. The behaviour observed can be associated with the higher content of secoiridoids, lignans and phenolic acids in ‘Cornicabra’ EVOO.POCTEP | Ref. 0377_IBERPHENOL_6_EFundação para a Ciência e a Tecnologia | Ref. UID/QUI/50006/2013Norte Portugal Regional Operational Programme | Ref. NORTE-01-0145-FEDER-000024Xunta de Galici
Characterization of virgin olive oils produced with autochthonous Galician varieties
The interest of Galician oil producers (NW Spain) in recovering the ancient autochthonous olive varieties Brava and Mansa has increased substantially in recent years. Virgin olive oils produced by co-crushing both varieties in two different proportions, reflecting the usual and most common practice adopted in this region, have gradually emerged for the production of virgin olive oils. Herein, the sensory and chemical characteristics of such oils were characterized by quality and genuineness-related parameters. The results of chemical analysis are discussed in terms of their effective contribution to the sensory profile, which suggests useful recommendations for olive oil producers to improve the quality of oils. Antioxidant compounds, together with aromas and coloured pigments were determined, and their contribution in determining the functional value and the sensory properties of oils was investigated. In general, given the high levels of phenolic compounds (ranging between 254 and 375 mg/kg oil), tocopherols (about 165 mg/kg oil) and carotenoids (10-12 mg/kg oil); these are oils with long stability, especially under dark storage conditions, because stability is reinforced with the contribution of chlorophylls (15-22 mg/kg oil). A major content of phenolic compounds, as well as a predominance of trans-2-hexen-1-al within odor-active compounds (from 897 to 1645 μg/kg oil), responsible for bitter sensory notes. This characterization allows to developing new antioxidant-rich and flavour-rich VOOs, when co-crushing with a higher proportion of Brava olives, satisfying the consumers' demand in having access to more healthy dishes and peculiar sensory attributes
Singular olive oils from a recently discovered Spanish North-Western cultivar: an exhaustive 3-year study of their chemical composition and in-vitro antidiabetic potential
In this work, the quality and physicochemical parameters, phenolic composition, and antidiabetic potential of olive oils obtained from olives belonging to centenarian olive trees of the so-called ‘Mansa de Figueiredo’ cultivar were evaluated during three consecutive crop seasons (2017–2019). The oils produced during the three crop years were classified as extra virgin based on the quality-related indices, sensory analysis, and the genuineness-related parameters. In addition, LC-ESI-TOF MS was used to get a comprehensive characterisation of the phenolic fraction while LC-ESI-IT MS was applied for quantitation purposes. The content of phenolic compounds (ranging from 1837 to 2434 mg/kg) was significantly affected by the harvest year due to the environmental conditions and ripening index. Furthermore, although significant differences in the inhibitory effects against the α-glucosidase enzyme for the EVOOs extracted throughout the three successive years were detected, all the studied EVOOs exhibited a stronger inhibitor effect than that found for acarbose.Agencia Estatal de Investigación | Ref. RTI2018-098633-B-I00FEDER/Junta de Andalucía | Ref. P20_00263FEDER/Junta de Andalucía | Ref. B-AGR-416-UGR18Ministerio de Universidades | Ref. FPU19/0070
Radiomics analysis of bone marrow biopsy locations in [18F]FDG PET/CT images for measurable residual disease assessment in multiple myeloma.
The combination of visual assessment of whole body [18F]FDG PET images and evaluation of bone marrow samples by Multiparameter Flow Cytometry (MFC) or Next-Generation Sequencing (NGS) is currently the most common clinical practice for the detection of Measurable Residual Disease (MRD) in Multiple Myeloma (MM) patients. In this study, radiomic features extracted from the bone marrow biopsy locations are analyzed and compared to those extracted from the whole bone marrow in order to study the representativeness of these biopsy locations in the image-based MRD assessment. Whole body [18F]FDG PET of 39 patients with newly diagnosed MM were included in the database, and visually evaluated by experts in nuclear medicine. A methodology for the segmentation of biopsy sites from PET images, including sternum and posterior iliac crest, and their subsequent quantification is proposed. First, starting from the bone marrow segmentation, a segmentation of the biopsy sites is performed. Then, segmentations are quantified extracting SUV metrics and radiomic features from the [18F]FDG PET images and are evaluated by Mann-Whitney U-tests as valuable features differentiating PET+/PET- and MFC+ /MFC- groups. Moreover, correlation between whole bone marrow and biopsy sites is studied by Spearman ρ rank. Classification performance of the radiomics features is evaluated applying seven machine learning algorithms. Statistical analyses reveal that some images features are significant in PET+/PET- differentiation, such as SUVmax, Gray Level Non-Uniformity or Entropy, especially with a balanced database where 16 of the features show a p value < 0.001. Correlation analyses between whole bone marrow and biopsy sites results in significant and acceptable coefficients, with 11 of the variables reaching a correlation coefficient greater than 0.7, with a maximum of 0.853. Machine learning algorithms demonstrate high performances in PET+/PET- classification reaching a maximum AUC of 0.974, but not for MFC+/MFC- classification. The results demonstrate the representativeness of sample sites as well as the effectiveness of extracted features (SUV metrics and radiomic features) from the [18F]FDG PET images in MRD assessment in MM patients.The author E.M. received financial support through a predoctoral Fellowship (ayuda del Programa Propio de I+D+i 2020) from Universidad Politecnica de Madrid. The project was partially supported by COVITECH-CM (Plataforma cientifico-tecnologica para alerta, diagnostico, pronostico, terapia y seguimiento de la enfermedad COVID19 y futuras pandemias) and REACT-UE through the European Regional Development Fund (ERDF), the European Social Fund (EFS) and the Fund for European Aid to the Most Deprived (FEAD).Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The authors declare that no funds, grants, or other support were received during the preparation of this manuscriptS
CASSIA (cardiology software suite for image analysis): a potential new tool for the evaluation of [18F]FDG PET/CT in the setting of infective endocarditis.
Due to the high morbidity and mortality of infective endocarditis (IE), medical imaging techniques are combined to ensure a correct diagnosis. [18F]FDG PET/CT has demonstrated the ability to improve diagnostic accuracy compared with the conventional modified Duke criteria in patients with suspected IE, especially those with prosthetic valve infective endocarditis (PVIE). The aim of this study is to provide an adjunctive diagnostic tool to improve the diagnostic accuracy in cardiovascular infections, specifically PVIE.
A segmentation tool to extract quantitative measures of [18F]FDG PET/CT image studies of prosthetic heart valve regions was developed and validated in 20 cases of suspected PVIE, of which 9 were confirmed. For that, Valvular Heterogeneity Index (VHI) and Ring-to-Center Ratio (RCR) were defined.
Results show an overall increase in the metabolic uptake of the prosthetic valve ring in the studies with confirmed PVIE diagnosis (SUVmax from 1.70 to 3.20; SUVmean from 0.86 to 1.50). The VHI and RCR showed areas under the curve of 0.727 and 0.808 in the receiver operating characteristics curve analyses, respectively, for PVIE diagnosis. Mann-Whitney U tests showed statistically significant differences between groups for RCR (p = 0.02). Visual analyses and clinical reports were concordant with the extracted quantitative metrics.
The proposed new method and presented software solution (CASSIA) provide the capability to assess quantitatively myocardial metabolism along the prosthetic valve region in routine [18F]FDG PET/CT scans for evaluating heart valve infectious processes. VHI and RCR are proposed as new potential adjunctive measures for PVIE diagnosis.The project was partially funded by Sociedad
Española de Cardiología (SEC/FEC-INVBAS 21/022).
Open Access funding provided thanks to the CRUE-CSIC
agreement with Springer Nature.S
Texture-Based Analysis of 18F-Labeled Amyloid PET Brain Images
Amyloid positron emission tomography (PET) brain imaging with radiotracers like [18F]florbetapir (FBP) or [18F]flutemetamol (FMM) is frequently used for the diagnosis of Alzheimer’s disease. Quantitative analysis is usually performed with standardized uptake value ratios (SUVR), which are calculated by normalizing to a reference region. However, the reference region could present high variability in longitudinal studies. Texture features based on the grey-level co-occurrence matrix, also called Haralick features (HF), are evaluated in this study to discriminate between amyloid-positive and negative cases. A retrospective study cohort of 66 patients with amyloid PET images (30 [18F]FBP and 36 [18F]FMM) was selected and SUVRs and 6 HFs were extracted from 13 cortical volumes of interest. Mann–Whitney U-tests were performed to analyze differences of the features between amyloid positive and negative cases. Receiver operating characteristic (ROC) curves were computed and their area under the curve (AUC) was calculated to study the discriminatory capability of the features. SUVR proved to be the most significant feature among all tests with AUCs between 0.692 and 0.989. All HFs except correlation also showed good performance. AUCs of up to 0.949 were obtained with the HFs. These results suggest the potential use of texture features for the classification of amyloid PET image
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