1,432 research outputs found

    Prediction of Fall Risk Among Community-Dwelling Older Adults Using a Wearable System

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    Falls are among the most common cause of decreased mobility and independence in older adults and rank as one of the most severe public health problems with frequent fatal consequences. In the present study, gait characteristics from 171 community-dwelling older adults were evaluated to determine their predictive ability for future falls using a wearable system. Participants wore a wearable sensor (inertial measurement unit, IMU) affixed to the sternum and performed a 10-m walking test. Measures of gait variability, complexity, and smoothness were extracted from each participant, and prospective fall incidence was evaluated over the following 6-months. Gait parameters were refined to better represent features for a random forest classifier for the fall-risk classification utilizing three experiments. The results show that the best-trained model for faller classification used both linear and nonlinear gait parameters and achieved an overall 81.6 ± 0.7% accuracy, 86.7 ± 0.5% sensitivity, 80.3 ± 0.2% specificity in the blind test. These findings augment the wearable sensor\u27s potential as an ambulatory fall risk identification tool in community-dwelling settings. Furthermore, they highlight the importance of gait features that rely less on event detection methods, and more on time series analysis techniques. Fall prevention is a critical component in older individuals’ healthcare, and simple models based on gait-related tasks and a wearable IMU sensor can determine the risk of future falls

    Dynamical Properties of Postural Control in Obese Community-Dwelling Older Adults

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    Postural control is a key aspect in preventing falls. The aim of this study was to determine if obesity affected balance in community-dwelling older adults and serve as an indicator of fall risk. The participants were randomly assigned to receive a comprehensive geriatric assessment followed by a longitudinal assessment of their fall history. The standing postural balance was measured for 98 participants with a Body Mass Index (BMI) ranging from 18 to 63 kg/m2, using a force plate and an inertial measurement unit affixed at the sternum. Participants’ fall history was recorded over 2 years and participants with at least one fall in the prior year were classified as fallers. The results suggest that body weight/BMI is an additional risk factor for falling in elderly persons and may be an important marker for fall risk. The linear variables of postural analysis suggest that the obese fallers have significantly higher sway area and sway ranges, along with higher root mean square and standard deviation of time series. Additionally, it was found that obese fallers have lower complexity of anterior-posterior center of pressure time series. Future studies should examine more closely the combined effect of aging and obesity on dynamic balance

    Clinical trials for elderly patients with multiple diseases (CHROMED) pilot study

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    The problem COPD (Chronic Obstructive Pulmonary Disease) is a significant socioeconomic burden which, particularly when associated with comorbidities such as Chronic Heart Failure (CHF), markedly affects patient outcomes. Care models based on telemedicine systems that enable early diagnosis and treatment of exacerbations are advocated to reduce the impact of chronic diseases on patient outcomes and health service costs. CHROMED (www.chromed.eu) is an international EU-funded project aimed at developing a multi-centre clinical trial to evaluate the impact of a new integrated home care approach to reduce care costs and improve quality of life in COPD. The approach We collaborated in a pilot study prior to the main trial which will include 300 patients from seven European countries (Italy, Spain, UK, Estonia, Slovenia, Sweden and Norway) with nine partners. The home monitoring system includes a novel forced oscillation technique (FOT) device for self-measurement of lung mechanics (RESMONPRO DIARY, Restech srl, Italy), a touch screen for collecting patients' symptoms and, where COPD is associated with CHF, by a device for measuring heart rate (HR), blood pressure (BP), pulse oximetry (SpO2) and body temperature (WRIST CLINIC, Medic4all, Israel). Findings The pilot included 16 patients (n=11 COPD, 5 COPD+CHF). The average monitoring period was 48.3±23.4 days resulting in a total of 504 patient days. The percentage of data correctly received within the period was: lung impedance and breathing pattern 90.0%; HR 91.7%, BP 91.7%; SpO2 74.0% and body temperature 71.4%. During the pilot, one patient was treated pharmacologically for an exacerbation of COPD. Offline processing demonstrated that the system identified warning of an exacerbation five days prior to admission. We also analysed qualitative data from patients and professionals about the acceptability of the telemedicine system and the interaction between patients, professionals and the monitoring system. Consequences The data suggest good acceptability and short-term compliance among patients with COPD. Lung function, HR and BP provided the most reliable data. The full RCT is currently under way and will be completed in August 2015

    A simple method to increase the current range of the TERA chip in charged particle therapy applications

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    The development of the next generation of accelerators for charged particle radiotherapy aims to reduce dimensions and operational complexity of the machines by engineering pulsed beams accelerators. The drawback is the increased difficulty to monitor the beam delivery. Within each pulse, instantaneous currents larger by two to three orders of magnitude than present applications are expected, which would saturate the readout of the monitor chambers. In this paper, we report of a simple method to increase by almost two orders of magnitude the current range of an Application Specific Integrated Circuit chip previously developed by our group to read out monitor ionization chambers. & 2015 Elsevier B.V. All rights reserved

    Dynamical Properties of Postural Control in Obese Community-Dwelling Older Adults

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    Postural control is a key aspect in preventing falls. The aim of this study was to determine if obesity affected balance in community-dwelling older adults and serve as an indicator of fall risk. The participants were randomly assigned to receive a comprehensive geriatric assessment followed by a longitudinal assessment of their fall history. The standing postural balance was measured for 98 participants with a Body Mass Index (BMI) ranging from 18 to 63 kg/m2, using a force plate and an inertial measurement unit affixed at the sternum. Participants€™ fall history was recorded over 2 years and participants with at least one fall in the prior year were classified as fallers. The results suggest that body weight/BMI is an additional risk factor for falling in elderly persons and may be an important marker for fall risk. The linear variables of postural analysis suggest that the obese fallers have significantly higher sway area and sway ranges, along with higher root mean square and standard deviation of time series. Additionally, it was found that obese fallers have lower complexity of anterior-posterior center of pressure time series. Future studies should examine more closely the combined effect of aging and obesity on dynamic balance

    Iron, copper and manganese complexes with in vitro superoxide dismutase and/or catalase activities that keep Saccharomyces cerevisiae cells alive under severe oxidative stress

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    Due to their aerobic lifestyle, eukaryotic organisms have evolved different strategies to overcome oxidative stress. The recruitment of some specific metalloenzymes such as superoxide dismutases (SODs) and catalases (CATs) is of great importance for eliminating harmful reactive oxygen species (hydrogen peroxide and superoxide anion). Using the ligand HPCINOL {1-[bis(pyridin-2-ylmethyl)amino]-3-chloropropan-2-ol}, we have synthesized three coordination compounds containing iron(III), copper(II), and manganese(II) ions, which are also present in the active site of the above-noted metalloenzymes. These compounds were evaluated as SOD and CAT mimetics. The manganese and iron compounds showed both SOD and CAT activities, while copper showed only SOD activity. The copper and manganese in vitro SOD activities are very similar (IC50 similar to 0.4 mu mol dm(-3)) and about 70-fold higher than those of iron. The manganese compound showed CAT activity higher than that of the iron species. Analyzing their capacity to protect Saccharomyces cerevisiae cells against oxidative stress (H2O2 and the O-2(center dot-) radical), we observed that all compounds act as antioxidants, increasing the resistance of yeast cells mainly due to a reduction of lipid oxidation. Especially for the iron compound, the data indicate complete protection when wild-type cells were exposed to H2O2 or O-2(center dot-) species. Interestingly, these compounds also compensate for both superoxide dismutase and catalase deficiencies; their antioxidant activity is metal ion dependent, in the order iron(III) > copper(II) > manganese(II). The protection mechanism employed by the complexes proved to be independent of the activation of transcription factors (such as Yap1, Hsf1, Msn2/Msn4) and protein synthesis. There is no direct relation between the in vitro and the in vivo antioxidant activities. (C) 2014 Elsevier Inc. All rights reserved

    Unveiling a Rich System of Faint Dwarf Galaxies in the Next Generation Fornax Survey

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    We report the discovery of 158 previously undetected dwarf galaxies in the Fornax cluster central regions using a deep coadded u,gu, g and ii-band image obtained with the DECam wide-field camera mounted on the 4-meter Blanco telescope at the Cerro Tololo Interamerican Observatory as part of the {\it Next Generation Fornax Survey} (NGFS). The new dwarf galaxies have quasi-exponential light profiles, effective radii 0.1 ⁣< ⁣re ⁣< ⁣2.80.1\!<\!r_e\!<\!2.8 kpc and average effective surface brightness values 22.0 ⁣< ⁣μi ⁣< ⁣28.022.0\!<\!\mu_i\!<\!28.0 mag arcsec2^{-2}. We confirm the existence of ultra-diffuse galaxies (UDGs) in the Fornax core regions that resemble counterparts recently discovered in the Virgo and Coma galaxy clusters.~We also find extremely low surface brightness NGFS dwarfs, which are several magnitudes fainter than the classical UDGs. The faintest dwarf candidate in our NGFS sample has an absolute magnitude of Mi ⁣= ⁣8.0M_i\!=\!-8.0\,mag. The nucleation fraction of the NGFS dwarf galaxy sample appears to decrease as a function of their total luminosity, reaching from a nucleation fraction of > ⁣75%>\!75\% at luminosities brighter than Mi ⁣ ⁣15.0M_i\!\simeq\!-15.0 mag to 0%0\% at luminosities fainter than Mi ⁣ ⁣10.0M_i\!\simeq\!-10.0 mag. The two-point correlation function analysis of the NGFS dwarf sample shows an excess on length scales below  ⁣100\sim\!100 kpc, pointing to the clustering of dwarf galaxies in the Fornax cluster core.Comment: 6 pages, 3 figures. Accepted for publication in The Astrophysical Journal Letters. Download the high-resolution version of the paper from the following link: https://www.dropbox.com/s/xb9vz8s29wlzjgf/ms.pdf?dl=
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