143 research outputs found

    White noise reduction for wideband linear array signal processing

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    The performance of wideband array signal processing algorithms is dependent on the noise level in the system. A method is proposed for reducing the level of white noise in wideband linear arrays via a judiciously designed spatial transformation followed by a bank of highpass filters. A detailed analysis of the method and its effect on the spectrum of the signal and noise is presented. The reduced noise level leads to a higher signal to noise ratio (SNR) for the system, which can have a significant beneficial effect on the performance of various beamforming methods and other array signal processing applications such as direction of arrival (DOA) estimation. Here we focus on the beamforming problem and study the improved performance of two well-known beamformers, namely the reference signal based (RSB) and the linearly constrained minimum variance (LCMV) beamformers. Both theoretical analysis and simulation results are provided

    Physically attractive faces attract us physically

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    When interacting with other humans, facial expressions provide valuable information for approach or avoid decisions. Here, we consider facial attractiveness as another important dimension upon which approach-avoidance behaviours may be based. In Experiments 1–3, we measured participants' responses to attractive and unattractive women's faces in an approach-avoidance paradigm in which there was no explicit instruction to evaluate facial attractiveness or any other stimulus attribute. Attractive faces were selected more often, a bias that may be sensitive to response outcomes and was reduced when the faces were inverted. Experiment 4 explored an entirely implicit measure of approach, with participants passively viewing single faces while standing on a force platform. We found greater lean towards attractive faces, with this pattern being most obvious in male participants. Taken together, these results demonstrate that attractiveness activates approach-avoidance tendencies, even in the absence of any task demand

    Efficacy and patient satisfaction with autoadjusting CPAP with variable expiratory pressure vs standard CPAP: a two-night randomized crossover trial

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    Expiratory pressure relief (C-Flex) technology monitors the patient’s airflow during expiration and reduces the pressure in response to the patient. Increased comfort levels associated with C-Flex therapy have potential to improve patient adherence to therapy. The purpose of this study was to assess the combination of autoadjusting CPAP (APAP) and C-Flex in terms of (1) treatment efficacy, and (2) patient preference when compared to standard CPAP. Fifteen patients who had previously undergone formal CPAP titration polysomnography were treated with either one night of the APAP with C-Flex or one night of conventional CPAP, in a crossover trial. Patient satisfaction levels were recorded using visual analog scales (VAS) on the morning after the study. Mean patient age was 50 ± 12 years, body mass index (BMI) was 36 ± 6 kg/m(2), baseline AHI was 53 ± 31 events/h, and CPAP Pressure was 11 ± 2 cm/H(2)O. APAP with C-Flex was as effective as CPAP, with no differences detected in sleep latency (17 ± 5 vs 12.3 ± 3 min, p = 0.4), or respiratory indices (AHI of 4.2 ± 2 vs 2.4 ± 0.7 events/h, p = 0.1). VAS scores (scale 0–10) indicated a trend towards increased patient satisfaction while using APAP with C-Flex (7.9 vs 7.2, p = 0.07). 10 patients expressed a preference for APAP with C-Flex (VAS, 0 to10) over standard CPAP (total positive score of 68, mean score of 4.8 ± 4.3). One patient expressed no preference. Four patients expressed a preference for CPAP (total positive score of 13, mean score of 0.9 ± 1.9) (APAP with C-Flex vs standard CPAP, p < 0.01 paired t test). APAP with C-Flex eliminates sleep disordered breathing as effectively as standard CPAP. Patients indicated a preference for APAP with C-Flex suggesting a possible advantage in terms of patient adherence for this mode of treatment

    Reliability of home CPAP titration with different automatic CPAP devices

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    <p>Abstract</p> <p>Background</p> <p>CPAP titration may be completed by automatic apparatus. However, differences in pressure behaviour could interfere with the reliability of pressure recommendations. Our objective was to compare pressure behaviour and effective pressure recommendations between three Automatic CPAP machines (Autoset Spirit, Remstar Auto, GK 420).</p> <p>Methods</p> <p>Sixteen untreated obstructive sleep apnea patients were randomly allocated to one of the 3 tested machines for a one-week home titration trial in a crossover design with a 10 days washout period between trials.</p> <p>Results</p> <p>The median pressure value was significantly lower with machine GK 420 (5.9 +/- 1.8 cm H<sub>2</sub>O) than with the other devices both after one night and one week of CPAP titration (7.4 +/- 1.3 and 6.6 +/- 1.9 cm H<sub>2</sub>O). The maximal pressure obtained over the one-week titration was significantly higher with Remstar Auto (12.6 +/- 2.4 cm H<sub>2</sub>O, Mean +/- SD) than with the two other ones (10.9 +/- 1.0 and 11.0 +/- 2.4 cm H<sub>2</sub>O). The variance in pressure recommendation significantly differed between the three machines after one night and between Autoset Spirit and the two other machines after 1 week.</p> <p>Conclusion</p> <p>Pressure behaviour and pressure recommendation significantly differ between Auto CPAP machines both after one night and one week of home titration.</p

    Acute-Phase-HDL Remodeling by Heparan Sulfate Generates a Novel Lipoprotein with Exceptional Cholesterol Efflux Activity from Macrophages

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    During episodes of acute-inflammation high-density lipoproteins (HDL), the carrier of so-called good cholesterol, experiences a major change in apolipoprotein composition and becomes acute-phase HDL (AP-HDL). This altered, but physiologically important, HDL has an increased binding affinity for macrophages that is dependent on cell surface heparan sulfate (HS). While exploring the properties of AP-HDL∶HS interactions we discovered that HS caused significant remodeling of AP-HDL. The physical nature of this change in structure and its potential importance for cholesterol efflux from cholesterol-loaded macrophages was therefore investigated. In the presence of heparin, or HS, AP-HDL solutions at pH 5.2 became turbid within minutes. Analysis by centrifugation and gel electrophoresis indicated that AP-HDL was remodeled generating novel lipid poor particles composed only of apolipoprotein AI, which we designate β2. This remodeling is dependent on pH, glycosaminoglycan type, is promoted by Ca2+ and is independent of protease or lipase activity. Compared to HDL and AP-HDL, remodeled AP-HDL (S-HDL-SAA), containing β2 particles, demonstrated a 3-fold greater cholesterol efflux activity from cholesterol-loaded macrophage. Because the identified conditions causing this change in AP-HDL structure and function can exist physiologically at the surface of the macrophage, or in its endosomes, we postulate that AP-HDL contains latent functionalities that become apparent and active when it associates with macrophage cell surface/endosomal HS. In this way initial steps in the reverse cholesterol transport pathway are focused at sites of injury to mobilize cholesterol from macrophages that are actively participating in the phagocytosis of damaged membranes rich in cholesterol. The mechanism may also be of relevance to aspects of atherogenesis

    A randomised-controlled trial investigating potential underlying mechanisms of a functionality-based approach to improving women’s body image

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    Focusing on body functionality is a promising technique for improving women's body image. This study replicates prior research in a large novel sample, tests longer-term follow-up effects, and investigates underlying mechanisms of these effects (body complexity and body-self integration). British women (N = 261) aged 18–30 who wanted to improve their body image were randomised to Expand Your Horizon (three online body functionality writing exercises) or an active control. Trait body image was assessed at Pretest, Posttest, 1-week, and 1-month Follow-Up. To explore whether changes in body complexity and body-self integration ‘buffer’ the impact of negative body-related experiences, participants also completed beauty-ideal media exposure. Relative to the control, intervention participants experienced improved appearance satisfaction, functionality satisfaction, body appreciation, and body complexity at Posttest, and at both Follow-Ups. Neither body complexity nor body-self integration mediated intervention effects. Media exposure decreased state body satisfaction among intervention and control participants, but neither body complexity nor body-self integration moderated these effects. The findings underscore the value of focusing on body functionality for improving body image and show that effects persist one month post-intervention

    Data enhancement for co-morbidity measurement among patients referred for sleep diagnostic testing: an observational study

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    <p>Abstract</p> <p>Background</p> <p>Observational outcome studies of patients with obstructive sleep apnea (OSA) require adjustment for co-morbidity to produce valid results. The aim of this study was to evaluate whether the combination of administrative data and self-reported data provided a more complete estimate of co-morbidity among patients referred for sleep diagnostic testing.</p> <p>Methods</p> <p>A retrospective observational study of 2149 patients referred for sleep diagnostic testing in Calgary, Canada. Self-reported co-morbidity was obtained with a questionnaire; administrative data and validated algorithms (when available) were also used to define the presence of these co-morbid conditions within a two-year period prior to sleep testing.</p> <p>Results</p> <p>Patient self-report of co-morbid conditions had varying levels of agreement with those derived from administrative data, ranging from substantial agreement for diabetes (κ = 0.79) to poor agreement for cardiac arrhythmia (κ = 0.14). The enhanced measure of co-morbidity using either self-report or administrative data had face validity, and provided clinically meaningful trends in the prevalence of co-morbidity among this population.</p> <p>Conclusion</p> <p>An enhanced measure of co-morbidity using self-report and administrative data can provide a more complete measure of the co-morbidity among patients with OSA when agreement between the two sources is poor. This methodology will aid in the adjustment of these coexisting conditions in observational studies in this area.</p

    Combination of RGD Compound and Low-Dose Paclitaxel Induces Apoptosis in Human Glioblastoma Cells

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    ) peptide, to human glioblastoma U87MG cells with combination of low dose Paclitaxel (PTX) pre-treatment to augment therapeutic activity for RGD peptide-induced apoptosis. peptide induced U87MG programmed cell death. The increased expression of PTX-induced integrin-αvβ3 was correlated with the enhanced apoptosis in U87MG cells.This study provides a novel concept of targeting integrin-αvβ3 with RGD peptides in combination with low-dose PTX pre-treatment to improve efficiency in human glioblastoma treatment

    Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.

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    The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.
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