Polarized indoor MIMO measurements at 2,45 GHz Molina-Garcia-Pardo, J.-M.; Castillo Olmo, I.; Egea-Garcia, F. ...
2007 IEEE Antennas and Propagation Society International Symposium,
2007-June
Conference Proceeding
MIMO (Multiple-Input Multiple-Output) has recently appeared as a firm candidate to improve the performance of wireless systems. It is based on the use of multiple antennas at both sides of radio ...interface, and with an appropriate coding the spectral efficiency can be importantly increased. In fact, nowadays many efforts are towards the development of MIMO technologies in international standards. For instance, 3GPP is actively working in a recommendation for using MIMO in UMTS and IEEE also includes in their wireless local area network recommendations MIMO solutions. Apart from that, the use of polarization has recently been accepted as a cost effective solution to increase the number of antenna elements and to obtain more uncorrelated channels. At the same position, one can use, for instance, vertical and horizontal polarization, and provided that the different channels are uncorrelated, it can be effectively used. In this work, a MIMO measurement campaign has been performed in the underground level of one of the buildings of the Technical University of Cartagena. In these measurements, the impact on the polarization has been studied.
Freezing of gait (FOG) is one of the most troublesome symptoms of Parkinson's disease, affecting more than 50% of patients in advanced stages of the disease. Wearable technology has been widely used ...for its automatic detection, and some papers have been recently published in the direction of its prediction. Such predictions may be used for the administration of cues, in order to prevent the occurrence of gait freezing. The aim of the present study was to propose a wearable system able to catch the typical degradation of the walking pattern preceding FOG episodes, to achieve reliable FOG prediction using machine learning algorithms and verify whether dopaminergic therapy affects the ability of our system to detect and predict FOG.
A cohort of 11 Parkinson's disease patients receiving (on) and not receiving (off) dopaminergic therapy was equipped with two inertial sensors placed on each shin, and asked to perform a timed up and go test. We performed a step-to-step segmentation of the angular velocity signals and subsequent feature extraction from both time and frequency domains. We employed a wrapper approach for feature selection and optimized different machine learning classifiers in order to catch FOG and pre-FOG episodes.
The implemented FOG detection algorithm achieved excellent performance in a leave-one-subject-out validation, in patients both on and off therapy. As for pre-FOG detection, the implemented classification algorithm achieved 84.1% (85.5%) sensitivity, 85.9% (86.3%) specificity and 85.5% (86.1%) accuracy in leave-one-subject-out validation, in patients on (off) therapy. When the classification model was trained with data from patients on (off) and tested on patients off (on), we found 84.0% (56.6%) sensitivity, 88.3% (92.5%) specificity and 87.4% (86.3%) accuracy.
Machine learning models are capable of predicting FOG before its actual occurrence with adequate accuracy. The dopaminergic therapy affects pre-FOG gait patterns, thereby influencing the algorithm's effectiveness.
In December of 2019, there was an outbreak of a severe acute respiratory syndrome caused by the Coronavirus 2 (SARS-CoV-2 or COVID-19) in China. The virus rapidly spread into the whole World causing ...an unprecedented pandemic and forcing governments to impose a global quarantine, entering an extreme unknown situation. The organizational consequences of quarantine/isolation are: absence of organized training and competition, lack of communication among athletes and coaches, inability to move freely, lack of adequate sunlight exposure, inappropriate training conditions. Based on the current scientific, we strongly recommend encouraging the athlete to reset their mindset to understand quarantine as an opportunity for development, organizing appropriate guidance, educating and encourage athletes to apply appropriate preventive behavior and hygiene measures to promote immunity and ensuring good living isolation conditions. The athlete's living space should be equipped with cardio and resistance training equipment (portable bicycle or rowing ergometer). Some forms of body mass resistance circuit-based training could promote aerobic adaptation. Sports skills training should be organized based on the athlete's needs. Personalized conditioning training should be carried out with emphasis on neuromuscular performance. Athletes should also be educated about nutrition (Vitamin D and proteins) and hydration. Strategies should be developed to control body composition. Mental fatigue should be anticipated and mental controlled. Adequate methods of recovery should be provided. Daily monitoring should be established. This is an ideal situation in which to rethink personal life, understanding the situation, that can be promoted in these difficult times that affect practically the whole world.
Background:
Mental health stigma is a relevant phenomenon with implications for the people who suffer from it. Despite its importance, no studies have been carried out in Spain at national level with ...a representative sample of the population.
Aims:
The aim of this research is to analyze the stigma associated with MHPs in a representative sample of the Spanish population for the first time.
Method:
A cross-sectional quantitative descriptive study was carried out with a representative sample of the population (N = 2746). Descriptive analyses and regressions are carried out on the different dimensions of stigma such as attitude, attribution and intention of social distance.
Results:
Medium levels of stigma are obtained in stigmatizing attitudes and attributions, and medium-low levels in the intention of social distance. The best predictors of stigma in its different dimensions are attitudes, attributions and intention of social distance themselves. Progressive political ideology is related to less stigma in all dimensions. Knowing someone with mental health problems and talking openly about it together with higher education are also relevant protectors. Mixed results are obtained regarding age, gender and help-seeking.
Conclusion:
National programs and campaigns focused on attitudes, attributions and behavioral intentions are necessary to reduce the stigma still present in Spanish society.
In this work, we evaluated the influence of a novel hybrid 3D-printed porous composite scaffold based on poly(ε-caprolactone) (PCL) and β-tricalcium phosphate (β-TCP) microparticles in the process of ...adhesion, proliferation, and osteoblastic differentiation of multipotent adult human bone marrow mesenchymal stem cells (
-BM-MSCs) cultured under basal and osteogenic conditions. The in vitro biological response of
-BM-MSCs seeded on the scaffolds was evaluated in terms of cytotoxicity, adhesion, and proliferation (AlamarBlue Assay
) after 1, 3, 7, and 14 days of culture. The osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity, mineralization (Alizarin Red Solution, ARS), expression of surface markers (CD73, CD90, and CD105), and reverse transcription-quantitative polymerase chain reaction (qRT-PCR) after 7 and 14 days of culture. The scaffolds tested were found to be bioactive and biocompatible, as demonstrated by their effects on cytotoxicity (viability) and extracellular matrix production. The mineralization and ALP assays revealed that osteogenic differentiation increased in the presence of PCL/β-TCP scaffolds. The latter was also confirmed by the gene expression levels of the proteins involved in the ossification process. Our results suggest that similar bio-inspired hybrid composite materials would be excellent candidates for osteoinductive and osteogenic medical-grade scaffolds to support cell proliferation and differentiation for tissue engineering, which warrants future in vivo research.
Allyl cyanide, CH2CHCH2CN, is a volatile organic compound that is emitted by biogenic and anthropogenic sources. Daytime atmospheric degradation of CH2CHCH2CN may be initiated by reaction with OH ...radicals, Cl atoms and O3. In this work, we report the gas-phase rate coefficients for the reaction of these atmospheric oxidants with CH2CHCH2CN (k1, k2 and k3, respectively) determined in an atmospheric simulation chamber at 298 ± 2 K and 760 ± 5 Torr of air, in a NOx-free environment. A relative kinetic method was employed for OH and Cl kinetic studies, obtaining k1 = (1.58 ± 0.39) × 10−11 cm3 molecule−1 s−1 and k2 = (2.26 ± 0.30) × 10−10 cm3 molecule−1 s−1. For the O3+CH2CHCH2CN reaction, k3 = (6.01 ± 0.24) × 10−19 cm3 molecule−1 s−1 was obtained using an absolute kinetic method under pseudo-first order conditions (excess of allyl cyanide). In both cases, Fourier Transform Infrared (FTIR) spectroscopy was used for monitoring the loss of CH2CHCH2CN relative to the loss of a reference compound and the loss of ozone, respectively. The estimated tropospheric lifetime considering all the homogeneous processes evaluated in this work is 16 h, with the major degradation route being the reaction with OH radicals. Gas-phase products detected in the IR spectrum have been identified by comparison with IR experimental spectra and/or theoretical spectra computed using density functional theory (DFT) calculations. In the Cl and O3 reactions, among others, HC(O)CN, HC(O)CH2CN, HC(O)H, and CO were identified as products, indicating that these reactions proceed mainly by addition of the oxidant to the double bond of CH2CHCH2CN. Even though allyl cyanide absorbs in the atmospheric IR window, due to its short lifetime it has a negligible contribution to the radiative forcing of climate. The formation of secondary organic aerosols (SOAs) has been investigated in the Cl reaction by a Fast Particle Mobility Sizer spectrometer. The determined SOA yield is lower than 6%, which could indicate a negligible impact on human health that could also be extrapolated to the OH reaction.
•Kinetics of the OH, Cl and O3 reactions with allyl cyanide are studied at 298 K.•Gas-phase products detected by FTIR and computed by DFT method.•Secondary organic aerosols are observed and quantified for the Cl reaction.•Estimated tropospheric lifetime of allyl cyanide is 16 h mainly due to OH radicals.•Negligible impact on the radiative forcing of climate and human health.
The Tilburg Frailty Indicator (TFI) is one of the most prominent multidimensional frailty assessment instruments. This review aimed to critically appraise and summarise its measurement properties.
...Reports were eligible if they included results of studies aimed at developing the TFI or evaluating its measurement properties. We performed a literature search in MEDLINE, CINAHL, and PsycINFO databases from their inception until December 8, 2021. We also searched grey literature databases. We assessed the methodological quality of the included studies using the “COSMIN Risk of Bias”. The measurement properties were evaluated using specific criteria. We graded the quality of the evidence using a GRADE approach.
Sixty-three studies were included. We found moderate sufficient evidence for TFI content validity, although it is still insufficient for the comprehensiveness of its items. TFI construct validity was based on sufficient evidence from two studies of its structural validity as well as multiple hypothesis-testing for construct validity studies with inconsistent results. We did not find any studies that assessed cross-cultural validity. Only one of TFI’s three dimensions showed sufficient evidence for the internal consistency of its scores, and results in test-retest reliability were inconsistent. The TFI showed high sufficient concurrent validity with the comprehensive geriatric assessment. We identified several studies assessing its predictive validity for adverse frailty-related outcomes, although most of the evidence from these studies was insufficient. We did not find any studies that assessed the responsiveness of TFI scores.
The TFI had evidence gaps in several relevant measurement properties. Further research is needed to strengthen its usefulness as a clinical decision-making tool.
•63 studies on the Tilburg Frailty Indicator were included in this review.•This review used a rigorous and up-to-date psychometric review methodology.•Content validity should be studied further, mainly the comprehensiveness of its items.•No evidence is available for some of its measurement properties.•More evidence is needed to strengthen its usefulness as a measurement tool.
Current telemedicine approaches lack standardised procedures for the remote assessment of axial impairment in Parkinson's disease (PD). Unobtrusive wearable sensors may be a feasible tool to provide ...clinicians with practical medical indices reflecting axial dysfunction in PD. This study aims to predict the postural instability/gait difficulty (PIGD) score in PD patients by monitoring gait through a single inertial measurement unit (IMU) and machine-learning algorithms.
Thirty-one PD patients underwent a 7-m timed-up-and-go test while monitored through an IMU placed on the thigh, both under (ON) and not under (OFF) dopaminergic therapy. After pre-processing procedures and feature selection, a support vector regression model was implemented to predict PIGD scores and to investigate the impact of L-Dopa and freezing of gait (FOG) on regression models.
Specific time- and frequency-domain features correlated with PIGD scores. After optimizing the dimensionality reduction methods and the model parameters, regression algorithms demonstrated different performance in the PIGD prediction in patients OFF and ON therapy (r = 0.79 and 0.75 and RMSE = 0.19 and 0.20, respectively). Similarly, regression models showed different performances in the PIGD prediction, in patients with FOG, ON and OFF therapy (r = 0.71 and RMSE = 0.27; r = 0.83 and RMSE = 0.22, respectively) and in those without FOG, ON and OFF therapy (r = 0.85 and RMSE = 0.19; r = 0.79 and RMSE = 0.21, respectively).
Optimized support vector regression models have high feasibility in predicting PIGD scores in PD. L-Dopa and FOG affect regression model performances. Overall, a single inertial sensor may help to remotely assess axial motor impairment in PD patients.
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