scholarly journals Characterization of Mayer wave oscillations in functional near-infrared spectroscopy using a physiologically informed model of the neural power spectra

2021 ◽  
Author(s):  
Robert Luke ◽  
Maureen Shader ◽  
David McAlpine

Significance: Mayer waves are spontaneous oscillations in arterial blood pressure that can mask cortical hemodynamic responses associated with neural activity of interest. Aim: To characterize the properties of oscillations in the fNIRS signal generated by Mayer waves in a large sample of fNIRS recordings. Further, we aim to determine the impact of short-channel correction for the attenuation of these unwanted signal components. Approach: Mayer wave oscillation parameters were extracted from 310 fNIRS measurements using the Fitting Oscillations & One-Over-F (FOOOF) method to compute normative values. The effect of short-channel correction on Mayer wave oscillation power was quantified on 222 measurements. The practical benefit of the short-channel correction approach for reducing Mayer waves and improving response detection was also evaluated on a subgroup of 17 fNIRS measurements collected during a passive auditory speech detection experiment. Results: Mayer wave oscillations had a mean frequency of 0.108 Hz, bandwidth of 0.075 Hz, and power of 3.5 μM2/Hz. The distribution of oscillation signal power was positively skewed, with some measurements containing large Mayer waves. Short-channel correction significantly reduced the amplitude of these undesired signals; greater attenuation was observed for measurements containing larger Mayer wave oscillations. Conclusions: A robust method for quantifying Mayer wave oscillations in the fNIRS signal spectrum was presented and used to provide normative parameterization. Short-channel correction is recommended as an approach for attenuating Mayer waves, particularly in participants with large oscillations.

2019 ◽  
Vol 9 (4) ◽  
pp. 504-511
Author(s):  
Sikha Mishra ◽  
Urmila Bhanja ◽  
Guru Prasad Mishra

Introduction: A new analytical model is designed for Workfunction Modulated Rectangular Recessed Channel-Silicon On Insulator (WMRRC-SOI) MOSFET that considers the concept of groove gate and implements an idea of workfunction engineering. Methods: The impact of Negative Junction Depth (NJD) and oxide thickness (tox) are analyzed on device performances such as Sub-threshold Slope (SS), Drain Induced Barrier Lowering (DIBL) and threshold voltage. Results: The results of the proposed work are evaluated with the Rectangular Recessed Channel-Silicon On Insulator (RRC-SOI) MOSFET keeping the metal workfunction constant throughout the gate region. Furthermore, an analytical model is developed using 2D Poisson’s equation and threshold voltage is estimated in terms of minimum surface potential. Conclusion: In this work, the impact of Negative Junction Depth (NJD) on minimum surface potential and the drain current are also evaluated. It is observed from the analysis that the analog switching performance of WMRRC-SOI MOSFET surpasses RRC-SOI MOSFET in terms of better driving capability, high Ion/Ioff ratio, minimized Short Channel Effects (SCEs) and hot carrier immunity. Results are simulated using 2D Sentaurus TCAD simulator for validation of the proposed structure.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Eman Sobh ◽  
Fatma Elhussieny ◽  
Taghreed Ismail

Abstract Background Nasal obstruction is a significant medical problem. This study aimed to examine the effect of nasal obstruction and nasal packing on arterial blood gases and pulmonary function indices, and the impact of the elimination of nasal obstruction on preoperative values. Results The mean age of the study population was 26.6 ± 10.1 years, males represented 50.8%. Spirometric indices showed statistically significant improvement (preoperative forced expiratory volume in 1st second 66.9 ± 13.9 vs 79.6 ± 14.9 postoperative and preoperative forced vital capacity 65.5 ± 12.7 vs 80.4 ± 13.8 postoperative). Oxygen saturation was significantly lower during nasal packing (95.6 ± 1.6 preoperative vs 94.7 ± 2.8 with nasal pack), and significant improvement (97.2 ± 1.4) was observed after removal of the nasal pack. Nasal obstruction scores significantly improved. Conclusion The results of this study indicate that either simple nasal obstruction or nasal packing may cause hypoxemia and abnormalities in lung function tests. Hypoxemia was more evident with nasal packing.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A247-A248
Author(s):  
Alyson Hanish ◽  
Abbey Jo Klein ◽  
Therese Mathews ◽  
Ann Berger ◽  
Kevin Kupzyk ◽  
...  

Abstract Introduction: Introduction Sleep disturbances are common in adolescents with neurodevelopmental disorders (NDDs). Inclusion of vulnerable populations such as adolescents with NDDs into sleep intervention efforts is essential as they are at high-risk for poor physical/mental health outcomes. The objective of this study is to pilot a sequential, multiple assignment, randomized trial (SMART) design to compare the impact of a sequence of sleep interventions, based on treatment response, to optimize sleep health in adolescents with NDDs. Methods: Methods Recruitment began June 2019 using convenience sampling. The SMART pilot feasibility study includes 1-week of baseline sleep data, and two 4-week periods of a sleep intervention (9-week total study enrollment). Interventions include exogenous melatonin, The Bedtime Bank, and their combination. Exogenous melatonin (liquid, immediate release, 3mg) is administered 30 minutes before bedtime. The Bedtime Bank, a behavioral sleep intervention, is based upon contingency contracting that relies on a credit- or debt-based system to hold adolescents accountable for maintaining a consistent bedtime. At baseline participants completed demographics, PROMIS pediatric sleep questionnaires, the Cleveland Adolescent Sleepiness Questionnaire (CASQ), salivary & urinary endogenous melatonin measurement, and one week of actigraphy. Upon enrollment, participants were randomly assigned to either melatonin or The Bedtime Bank. Participants who respond (nightly increase in total sleep time (TST) ≥18 minutes) remain on the assigned intervention; if non-responsive participants are re-randomized to a different sleep intervention or combination. Results: Results At baseline, participants (n=29, aged 10–18 years) had an average TST of 7 hours 11 minutes. PROMIS Sleep Disturbance (M=64.3, SE=2.5), PROMIS Sleep-Related Impairment scores (M=58.9, SE=2.2), and CASQ scores (M=40.0, SD= 10.5) were higher than reported normative values. Salivary DLMO & urinary 6-sulfatoyxmelatonin analysis is ongoing. For participants who completed the full 9-week trial, nearly 30% (n=7/24) were responsive (increased baseline TST ≥18 minutes) to one of the 4-week interventions. Conclusion: Conclusion Baseline data of the enrolled participants demonstrates poor indicators of TST, sleep disturbance, and sleep related impairment. Preliminary results of this SMART indicate some adolescents are responsive to sleep interventions aimed to improve their TST. Support (if any) Support: This clinical trial is funded by the National Institute of Nursing Research, National Institutes of Health (1K01NR017465-01A1).


2021 ◽  
Vol 11 (5) ◽  
pp. 2118
Author(s):  
Jan Feher ◽  
Jozef Cambal ◽  
Blazej Pandula ◽  
Julian Kondela ◽  
Marian Sofranko ◽  
...  

Vibrations caused by blasting works have an impact not only on buildings but also the internal environment of the buildings. If these buildings are situated in the surroundings of quarries, the citizens can perceive these vibrations negatively. By applying an appropriate millisecond timing interval, it is possible to lower the intensity of vibrations to the levels that the citizens will not perceive as negative effects inside the buildings. The limit values for this vibration intensity have not been defined to date. For the protection of the building from the vibrations, normative values of the particle velocity and frequency were determined. Hygienic standards for the inhabitants of the housing were applied, which assessed the impact of the vibration on humans through the measurement of the vibration acceleration in the housing. In this article, the results of the research carried out in Trebejov Quarry are presented. The experimental blasts carried out in Trebejov Quarry proved that the reduction in the vibration intensity under the value 2 mm.s−1 led to the satisfaction of the inhabitants.


2002 ◽  
Vol 716 ◽  
Author(s):  
Nihar R. Mohapatra ◽  
Madhav P. Desai ◽  
Siva G. Narendra ◽  
V. Ramgopal Rao

AbstractThe impact of technology scaling on the MOS transistor performance is studied over a wide range of dielectric permittivities using two-dimensional (2-D) device simulations. It is found that the device short channel performance is degraded with increase in the dielectric permittivity due to an increase in dielectric physical thickness to channel length ratio. For Kgate greater than Ksi, we observe a substantial coupling between source and drain regions through the gate dielectric. We provide extensive 2-D device simulation results to prove this point. Since much of the coupling between source and drain occurs through the gate dielectric, it is observed that the overlap length is an important parameter for optimizing DC performance in the short channel MOS transistors. The effect of stacked gate dielectric and spacer dielectric on the MOS transistor performance is also studied to substantiate the above observations.


Author(s):  
Patricia Chiril ◽  
Endang Wahyu Pamungkas ◽  
Farah Benamara ◽  
Véronique Moriceau ◽  
Viviana Patti

AbstractHate Speech and harassment are widespread in online communication, due to users' freedom and anonymity and the lack of regulation provided by social media platforms. Hate speech is topically focused (misogyny, sexism, racism, xenophobia, homophobia, etc.), and each specific manifestation of hate speech targets different vulnerable groups based on characteristics such as gender (misogyny, sexism), ethnicity, race, religion (xenophobia, racism, Islamophobia), sexual orientation (homophobia), and so on. Most automatic hate speech detection approaches cast the problem into a binary classification task without addressing either the topical focus or the target-oriented nature of hate speech. In this paper, we propose to tackle, for the first time, hate speech detection from a multi-target perspective. We leverage manually annotated datasets, to investigate the problem of transferring knowledge from different datasets with different topical focuses and targets. Our contribution is threefold: (1) we explore the ability of hate speech detection models to capture common properties from topic-generic datasets and transfer this knowledge to recognize specific manifestations of hate speech; (2) we experiment with the development of models to detect both topics (racism, xenophobia, sexism, misogyny) and hate speech targets, going beyond standard binary classification, to investigate how to detect hate speech at a finer level of granularity and how to transfer knowledge across different topics and targets; and (3) we study the impact of affective knowledge encoded in sentic computing resources (SenticNet, EmoSenticNet) and in semantically structured hate lexicons (HurtLex) in determining specific manifestations of hate speech. We experimented with different neural models including multitask approaches. Our study shows that: (1) training a model on a combination of several (training sets from several) topic-specific datasets is more effective than training a model on a topic-generic dataset; (2) the multi-task approach outperforms a single-task model when detecting both the hatefulness of a tweet and its topical focus in the context of a multi-label classification approach; and (3) the models incorporating EmoSenticNet emotions, the first level emotions of SenticNet, a blend of SenticNet and EmoSenticNet emotions or affective features based on Hurtlex, obtained the best results. Our results demonstrate that multi-target hate speech detection from existing datasets is feasible, which is a first step towards hate speech detection for a specific topic/target when dedicated annotated data are missing. Moreover, we prove that domain-independent affective knowledge, injected into our models, helps finer-grained hate speech detection.


2007 ◽  
Vol 32 (4) ◽  
pp. 670-676 ◽  
Author(s):  
Fleur Poelkens ◽  
Mark Rakobowchuk ◽  
Kirsten A. Burgomaster ◽  
Maria T.E. Hopman ◽  
Stuart M. Phillips ◽  
...  

An increase in age coincides with a decrease in arterial compliance, which is related to a higher risk for cardiovascular accidents. Evidence regarding the effects of resistance training on arterial compliance is conflicting. Currently, little information is available about the effect of resistance training on arterial compliance in elderly men. We assessed the impact of 10 weeks of unilateral arm and leg resistance training on carotid, brachial, and femoral arterial compliance in 12 healthy elderly men (mean age ± SD, 71 ± 7 y). Arterial compliance was evaluated before, after 4 weeks, and after 10 weeks of unilateral resistance training by simultaneously measuring arterial diameter and blood pressure in each artery. There were no significant differences in arterial compliance or stiffness index in any of the arteries examined after 10 weeks of training. However, after 10 weeks of resistance training, resting heart rate decreased from 76 ± 4 beats/min to 61 ± 3 beats/min (p < 0.05), plasma glucose decreased from 6.0 ± 0.9 to 5.1 ± 0.9 mmol/L (mean ± SE) (p < 0.05), and carotid artery peak blood flow increased from 1831 mL/min to 2245 mL/min (p < 0.05). There were no significant changes in resting arterial blood pressure. Unilateral resistance training for 10 weeks does not alter peripheral and central arterial compliance elderly men.


2000 ◽  
Vol 93 (5) ◽  
pp. 1184-1187 ◽  
Author(s):  
Jonathan H. Waters ◽  
Clifford A. Bernstein

Background The intent of this study was to evaluate the impact of the commonly used colloids-hetastarch and albumin-on in vivo acid-base balance. From this evaluation, a better understanding of the mechanism of dilutional acidosis was expected. Methods In a prospective, randomized fashion, 11 healthy volunteers were administered 15 ml/kg hetastarch solution, 6%, or 15 ml/kg albumin, 5%, intravenously over 30 min. Four weeks later, the study subjects were administered the other colloid. Arterial blood gas and electrolyte parameters were measured at baseline and at 30, 60, 90, 120, 210, and 300 min after colloid administration. Pre- and postlaboratory values were compared within groups using a paired t test and a Wilcoxon signed rank test and between groups using repeated-measures analysis of variance and a Wilcoxon rank sum test. Results Thirty min after infusion, subjects who were administered hetastarch showed statistically significant changes (P &lt; 0.05) in base excess (from 2.5 +/- 0.9 mEq/l to 0.7 +/- 1.1 mEq/l), HCO3- concentration (from 27 +/- 1.0 mEq/l to 25 +/- 1.3 mEq/l), Cl- concentration (from 108 +/- 2 mEq/l to 112 +/- 2 mEq/l), albumin concentration (from 4.4 +/- 0.2 g/dl to 3.5 +/- 0.5 g/dl), and arterial carbon dioxide tension (Paco2; from 40.8 +/- 2.3 mmHg to 39. 2 +/- 3.2 mmHg), whereas only the albumin concentration (from 4.4 +/- 0.2 g/dl to 4.8 +/- 0.6 g/dl) changed significantly in the albumin-treated group. Conclusions Decreases in base excess were observed for 210 min after hetastarch administration but not after albumin. The mechanism for this difference is discussed.


2015 ◽  
Vol 1084 ◽  
pp. 515-518
Author(s):  
Nina I. Martemyanova ◽  
Natalia D. Turgunova ◽  
Aleksandr N. Aleinik

Reflectance pulse oximeter is designed to determine arterial blood oxygen saturation during a radiation therapy. Proposed solutions promote to reduce the impact of sensor motion on the readings. Experimentally obtained optimal contact pressure of the sensor on the body is 0.7 N. The preliminary results show that the device has good resolution and high reliability.


2021 ◽  
Vol 12 ◽  
Author(s):  
Abdrabo Soliman ◽  
Abdel-Salam G. Abdel-Salam ◽  
Mervat Ahmed

Background: The Bene-Anthony Family Relations Test (BAFRT) is one of the most widely used measures of family dynamics seen from a child’s perspective. However, the most common issue surrounding this test is the lack of accurate normative scores for use with non-white ethnic groups. The purpose of this study was to examine the BAFRT’s reliability and validity for use with Arab children, as well as to provide normative data for this group. Methods: The BAFRT was translated into Arabic and back-translated to ensure accuracy. The test was administered to a cohort of 394 Arab children, consisting of both cognitively normal children (n = 269) and children diagnosed with a psychological disorder (n = 125), all aged 5–8 years old. Test-retest reliability was assessed using a sub-set of children and validity was tested against clinical status as well as CBCL and SDQ measures. Normative measures were calculated after examining the impact of influencing variables such as age and gender. Results: Statistical analyses showed that in our cohort of Arab children the BAFRT has good test-retest reliability, correlates well with measures of emotional and behavioral adjustment, and discriminates accurately between clinical and non-clinical children. Age, gender, and clinical status all significantly impacted upon BAFRT scores and therefore normative values are presented from our cohort when considering these variables. Conclusion: The normative scores we present will provide researchers and clinicians an appropriate reference point for the comparison of scores from Arab children and a starting point for future research into this area.


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