Slope Of Linear Regression Research Articles

Abstract CT097: Quantitative MR measurements in glioblastoma patients: Mean diffusivity with tumor treating fields plus standard therapy versus standard treatment alone

Abstract Introduction: Quantitative MR parameters, including those derived from diffusion imaging, may advance knowledge on the biological characteristics of gliomas in both diagnostic and treatment settings. We evaluated quantitative diffusion differences that could be detected in glioblastoma patients treated with standard therapy plus TTFields (Optune) versus standard therapy alone. Methods: Twelve patients with glioblastoma were subjected to surgical resection, radiotherapy and temozolomide. Six subjects were additionally treated with TTFields. All patients were followed by MRI every two months (range 210-1036 days) with standard imaging and diffusion tensor imaging until tumor progression. Results: Progression-free survival (PFS) was significantly longer in the subgroup treated by TTFields (mean 784 days ± 163 SD) as compared to standard therapy alone (443 days ± 249). No difference was detected between groups in the initial mean diffusivity values measured within the affected white matter near the resection cavity. However the linear regression slope describing mean diffusivity in this region over serial measurements was higher in the subgroup treated by TTFields than in the other group (5.43 ± 2.4 versus -3.77 ± 11.8). Furthermore, we detected significant positive correlation between mean diffusivity slope and PFS. Discussion: Our data demonstrate increasing mean diffusivity in the affected white matter of glioblastoma patients, which is favorable with positive correlation to PFS seen in steeper regression slopes. The patients treated with TTFields showed greater PFS in comparison to those who did not receive TTFields. There was a corresponding increase in mean diffusivity in the affected white matter of these patients. In the group that received standard therapy, the increase was not as apparent and, if present, the slope was not as steep. Changes in mean diffusivity likely reflect changes in tumor density in the white matter. Citation Format: Josef Vymazal, Radovan Zacek, Jan Sroubek, Jan Klener, Aaron M. Rulseh. Quantitative MR measurements in glioblastoma patients: Mean diffusivity with tumor treating fields plus standard therapy versus standard treatment alone [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT097.

O 005 – Inter-laboratory comparison of subject measurements as basic parameters for instrumented gait analysis

Step length and cadence (i.e., step frequency or steps/minute) maintain an invariant proportion across a range of walking speeds, known as the walk ratio (WR = step length/cadence). While step length is a difficult parameter to manipulate, cadence is readily modifiable using rhythmic auditory cuing (RAC; e.g., synchronizing step timing to a metronome or music tempo).The purpose of this study was to determine the effects of RAC-guided cadences on enacted cadence, step length, WR, and gait speed during overground walking.Sixteen healthy young adults repeatedly crossed a GAITRite electronic walkway while attempting to synchronize step timing to RAC-guided (metronome) tempos of 80 to 140 beats per minute. Mean absolute percent error (MAPE) was used to compare RAC tempos to enacted cadence. Repeated-measures analyses of variance were performed to test for the effects of RAC on cadence, step length, WR, and gait speed. Moreover, simple linear regressions were used to determine the precise stepwise relationship between RAC conditions and each variable.Participants successfully matched their cadence to RAC beats (MAPE < 1.1%). Cadence increased proportionally to RAC (linear regression slope = 1.02), while step length also increased but at a slower rate (slope = 0.40). These dissimilar slopes resulted in a modified WR that systematically decreased with increasing cadence, although ultimately gait speed increased with increasing cadence (slope = 1.41). This relationship indicates that every 10 steps/minute incremental increase in cadence corresponded with a 14 cm/s increase in gait speed.Gait speed appears to increase in a predictable manner when cadence is guided by RAC during overground walking irrespective of apparent changes to the WR.

O 071 – The intra-rater and inter-rater reliability of a method measuring the sagittal curvature of the spine using surface topography

Step length and cadence (i.e., step frequency or steps/minute) maintain an invariant proportion across a range of walking speeds, known as the walk ratio (WR = step length/cadence). While step length is a difficult parameter to manipulate, cadence is readily modifiable using rhythmic auditory cuing (RAC; e.g., synchronizing step timing to a metronome or music tempo).The purpose of this study was to determine the effects of RAC-guided cadences on enacted cadence, step length, WR, and gait speed during overground walking.Sixteen healthy young adults repeatedly crossed a GAITRite electronic walkway while attempting to synchronize step timing to RAC-guided (metronome) tempos of 80 to 140 beats per minute. Mean absolute percent error (MAPE) was used to compare RAC tempos to enacted cadence. Repeated-measures analyses of variance were performed to test for the effects of RAC on cadence, step length, WR, and gait speed. Moreover, simple linear regressions were used to determine the precise stepwise relationship between RAC conditions and each variable.Participants successfully matched their cadence to RAC beats (MAPE < 1.1%). Cadence increased proportionally to RAC (linear regression slope = 1.02), while step length also increased but at a slower rate (slope = 0.40). These dissimilar slopes resulted in a modified WR that systematically decreased with increasing cadence, although ultimately gait speed increased with increasing cadence (slope = 1.41). This relationship indicates that every 10 steps/minute incremental increase in cadence corresponded with a 14 cm/s increase in gait speed.Gait speed appears to increase in a predictable manner when cadence is guided by RAC during overground walking irrespective of apparent changes to the WR.

O 009 – Robust locomotion detection and cadence estimation in children with cerebral palsy using a single trunk–mounted accelerometer

Step length and cadence (i.e., step frequency or steps/minute) maintain an invariant proportion across a range of walking speeds, known as the walk ratio (WR = step length/cadence). While step length is a difficult parameter to manipulate, cadence is readily modifiable using rhythmic auditory cuing (RAC; e.g., synchronizing step timing to a metronome or music tempo).The purpose of this study was to determine the effects of RAC-guided cadences on enacted cadence, step length, WR, and gait speed during overground walking.Sixteen healthy young adults repeatedly crossed a GAITRite electronic walkway while attempting to synchronize step timing to RAC-guided (metronome) tempos of 80 to 140 beats per minute. Mean absolute percent error (MAPE) was used to compare RAC tempos to enacted cadence. Repeated-measures analyses of variance were performed to test for the effects of RAC on cadence, step length, WR, and gait speed. Moreover, simple linear regressions were used to determine the precise stepwise relationship between RAC conditions and each variable.Participants successfully matched their cadence to RAC beats (MAPE < 1.1%). Cadence increased proportionally to RAC (linear regression slope = 1.02), while step length also increased but at a slower rate (slope = 0.40). These dissimilar slopes resulted in a modified WR that systematically decreased with increasing cadence, although ultimately gait speed increased with increasing cadence (slope = 1.41). This relationship indicates that every 10 steps/minute incremental increase in cadence corresponded with a 14 cm/s increase in gait speed.Gait speed appears to increase in a predictable manner when cadence is guided by RAC during overground walking irrespective of apparent changes to the WR.

Bias in Linear Regression Analysis of Compliance Measurements in Fatigue Crack Growth and Fracture Toughness Tests

Abstract When compliance methods are used to determine specimen crack size in fracture mechanics testing, accurate and unbiased determination of the slope of the linear region of the force versus the crack opening displacement (COD) curve is required. Often, the region of interest is isolated by truncation of data that lie outside either force or COD limits. Two decisions are required: which parameter to use for the truncation and which to use as the independent variable in the linear regression analysis. This article will demonstrate that the incorrect choice of independent variable for truncated data sets can lead to a systematic bias in the determination of the linear regression slope and intercept. It will be shown with Monte Carlo simulations that the independent variable for linear regression should always be the same as the truncation variable, and in this case the variation in slope will be random, with a zero mean. The magnitude of the slope bias is related to the relative noise in each variable. Not only will this lead to a bias in determining crack size, but large errors can occur when determining nonlinearity associated with crack-opening force and in the crack-compliance method for determining the crack driving force due to residual stress, Kres.

Mediterranean Diet, Its Components, and Amyloid Imaging Biomarkers.

There is accumulating evidence suggesting that diet may play a role in preventing or delaying cognitive decline and dementia, but the underlying biological mechanisms are not well understood. To examine the cross-sectional associations of the Mediterranean diet (MeDi) and its components with 11C-PiB-PET scan measures of amyloid-β (Aβ) deposition. The study consisted of 278 Mayo Clinic Study of Aging participants 70+ years old, who were cognitively unimpaired (CU) at the time of completion of the Food Frequency Questionnaire (FFQ) and when they underwent PET imaging. Adherence to the MeDi was assessed by computing the MeDi score for each participant. All scans were performed after the FFQ completion; median [IQR] time between FFQ and Aβ PET was 3.5 (1.4) years. Z-scores were created for component, macro- and micronutrients measured. Linear and logistic regression models were adjusted for age, sex, education, apolipoprotein E (APOE) ɛ4 allele carrier status, time interval between the FFQ completion and PET scan, and total energy intake. Participants' median age at FFQ was 77.7 years (55.8% men; 26.6% with an APOE ɛ4 allele). Higher MeDi score (linear regression slope (beta):-0.035, p = 0.012; per standard deviation increase), vegetable intake (beta:-0.043, p = 0.002), intake of vitamin A (beta:-0.041, p = 0.003) or β-carotene (beta: -0.039, p = 0.005) from food sources and moderate alcohol consumption (beta: -0.074, p = 0.03) were associated with lower 11C-PiB standardized uptake value ratio. Findings are consistent with previous studies suggesting that higher adherence to a MeDi pattern and higher vegetable consumption are associated with better neuroimaging biomarker profile. Prospective studies are needed to validate current findings.

Evaluation of BD Vacutainer® Barricor™ blood collection tubes for routine chemistry testing on a Roche Cobas® 8000 Platform

IntroductionBarricor™ Vacutainers® are a novel non-gel separator blood collection tube. These tubes enable faster pre-analytical processing which could reduce turnaround time and be beneficial in an acute care setting. We sought to evaluate the bias, stability, and integrity of plasma generated from these tubes compared to Plasma Separator Tubes™ (PST) for 50 routine chemistry analytes on a Roche Cobas® 8000 analyzer. MethodsPaired samples were collected from 150 patients originating in the emergency department and outpatient collections at the Saint John Regional Hospital. Barricor™ vacutainers were centrifuged for 3 min at 4000g and PST™ vacutainers for 10 min at 1300 g within two hours of collection. Plasma samples (n = 126) were then analyzed for 50 chemistry analytes and bias determined between tubes. Ten-day stability of AST, glucose, potassium, phosphate, and LDH was also assessed in a subset of paired samples (n = 4). Lastly, the quality of plasma (n = 20) was assessed through measurement of cell counts on a DxH Hematology Analyzer. ResultsAll 50 analytes demonstrated comparable results across a broad concentration range between Barricor™ and PST™ vacutainers (average percent bias −1.5% to 6.1%; Deming linear regression slopes 0.933–1.041; correlation coefficients ≥ 0.9144). AST, potassium, glucose and LDH were stable for 10 days in Barricor™ vacutainers (change from baseline < 10%) but <5 days in PST™ vacutainers while phosphate was stable for 4 days in Barricor™ vs 2 days in PST™ vacutainers. Platelet counts were statistically lower in Barricor™ compared to PST™ vacutainers. ConclusionOur data suggest that Barricor™ vacutainers are an acceptable alternative to PST™ vacutainers while offering the added benefit of decreased pre-analytical processing time, increased stability of certain analytes, and possibly less cellular contamination.

4-D Intracardiac Ultrasound Vector Flow Imaging-Feasibility and Comparison to Phase-Contrast MRI.

In vivo characterization of intracardiac blood velocity vector fields may provide new clinical information but is currently not available for bedside evaluation. In this paper, 4-D vector flow imaging for intracardiac flow assessment is demonstrated using a clinical ultrasound (US) system and a matrix array transducer, without the use of contrast agent. Two acquisition schemes were developed, one for full volumetric coverage of the left ventricle (LA) at 50 vps and a 3-D thick-slice setup with continuous frame acquisition (4000 vps), both utilizing ECG-gating. The 3-D vector velocity estimates were obtained using a novel method combining phase and envelope information. In vitro validation in a rotating tissue-mimicking phantom revealed velocity estimates in compliance with the ground truth, with a linear regression slope of 0.80, 0.77, and 1.03 for the , , and velocity components, and with standard deviations of 2.53, 3.19, and 0.95 cm/s, respectively. In vivo measurements in a healthy LV showed good agreement with PC-MRI. Quantitative analysis of energy loss (EL) and kinetic energy (KE) further showed similar trends, with peak KE at 1.5 and 2.4 mJ during systole and 3.6 and 3.1 mJ for diastole for US and PC-MRI. Similar for EL, 0.15- 0.2 and 0.7 mW was found during systole and 0.6 and 0.7 mW during diastole, for US and PC-MRI, respectively. Overall, a potential for US as a future modality for 4D cardiac vector flow imaging was demonstrated, which will be further evaluated in clinical studies.

Spatio-temporal analysis of groundwater levels and projection of future trend of Agra city, Uttar Pradesh, India

Access to water resources is one of the major challenges being faced worldwide. Water scarcity, particularly groundwater resource, is the major ubiquitous concern for the country. Almost half of the country is reeling under severe ground water crisis due to anthropogenic and natural reasons (basalt rock surface). Agra region situated in the western part of Uttar Pradesh state of India has a semi-arid climate. The study area, which has a history of water scarcity since medieval ages, has seen a spurt of acute water shortage in recent times owing to the expansion of a very dense built-up area and excessive haulage accompanied by decline in rainfall. A study was under taken for identifying the trends in pre- and post-monsoon groundwater levels for Agra city, Uttar Pradesh. Pre-monsoon and post-monsoon groundwater depth data of 16 observation wells for the 2007–2016 period were collected and analyzed using ARC GIS 10.2 software. The rainfall trend during the study period was also studied to understand its role in groundwater fluctuation level. Statistical tests like Mann-Kendall, Sen’s slope estimator, and linear regression model were applied to understand the trend and rate of change in groundwater level. The land use/land cover map of the study area was integrated with groundwater map to have a primary understanding of the spatial trend of groundwater scenario of the study area. The result obtained is quite alarming for the city’s groundwater scenario. Results showed that the groundwater levels had significantly declined during 2007–2016. Average rates of water level decline were 0.228 and 0.267 m/year during pre- and post-monsoon seasons, respectively. There was a rapid decline in water level between 2008 and 2009 and between 2013 and 2014. The average rate of decline of pre- and post-monsoon groundwater level in the city during this period is 0.32 and 0.30 m/year, respectively. Significant decrease in groundwater level is found in 84.21% of wells for pre- and post-monsoon as obtained through Mann-Kendall analysis at 95% confidence level. During pre-monsoon season, the rate of decline according to Sen’s slope estimator varied between 0.74 and 2.05 m/year. Almost similar picture of decline is portrayed through linear regression slope wherein the computed rate of decline varied between 0.75 and 2.05 m/year. During post-monsoon, the rate of decline according to Sen’s slope varied between 0.13 and 1.94 m/year. Similar trend statistic is obtained through linear regression method where the declining rate is between 0.14 and 1.91 m/year. Comparison of the three statistical tests indicates similar nature of declining trend. The result of this research raises concern about the future of groundwater resources in Agra city. The findings of this study will assist planners and decision-makers in developing better land use and water resource management.

Thermal acclimation of the temperature dependence of the V&lt;sub&gt;Cmax&lt;/sub&gt; of Rubisco in quinoa

Changes in the temperature dependence of the maximum carboxylation capacity (VCmax) of Rubisco during thermal acclimation of PN remain controversial. I tested for acclimation of the temperature dependence of VCmax in quinoa, wheat, and alfalfa. Plants were grown with day/night temperatures of 12/6, 20/14, and 28/22°C. Responses of PN to substomatal CO2 (Ci) and CO2 at Rubisco (Cc) were measured at leaf temperatures of 10-30°C. VCmax was determined from the initial slope of the PNvs. Ci or Cc curve. Slopes of linear regressions of 1/VCmaxvs. 1/T [K] provided estimates the activation energy. In wheat and alfalfa the increases in activation energy with growth temperature calculated using Ci did not always occur when using Cc, indicating the importance of mesophyll conductance when estimating the activation energy. However, in quinoa, the mean activation energy approximately doubled between the lowest and highest growth temperatures, whether based on Ci or Cc.

Effects of Landcover, Soil Property, and Temperature on Covariations of DOC and CDOM in Inland Waters

AbstractSignificant uncertainty exists in the estimation of dissolved organic carbon (DOC) concentration via remote sensing from colored dissolved organic matter (CDOM) absorption in inland waters pointing to a need for more process‐based understanding of the relationship between CDOM and DOC. In this study, we examine the factors affecting the covariations of DOC and CDOM using controlled experiments combined with field measurements at subbasin scale that have varying environmental and biological conditions. Our analysis reveals that the DOC:CDOM ratio is mainly related to landcover types. Higher DOC:CDOM linear regression slopes observed in evergreen leaf litter leachate suggest that CDOM comprises a smaller fraction of the DOC pool in evergreen sites in comparison to agricultural and deciduous leaf litter leachates. Given the same DOC concentrations, the range of CDOM levels from deciduous forest plant varied 3 times greater than that from other plant types. Results indicate that soil narrows the slope differences in the linear regressions of DOC from CDOM for all plant types (by 19% of evergreen, 18% of agriculture, and 77% of deciduous). Raising soil temperature by 5°C could double the range of DOC concentration and CDOM absorption for all scenarios. We present a mathematical model to estimate DOC concentration in freshwater environment via CDOM variations with reference to land cover and soil effects. The model was able to explain 95% of field measurements of multiple years in four subbasins. This improved understanding is critical for the remote sensing of DOC directly via observations of CDOM.

A comparison of energy partitioning and evapotranspiration over closed maize and sparse grapevine canopies in northwest China

Energy exchanges and turbulent fluxes were simultaneously measured using eddy covariance technique over closed maize and sparse grapevine canopies during two growth seasons in an arid region of northwest China. Canopy conductance (Gc) and decoupling coefficient (Ω) were calculated to evaluate differences of fluxes and controlling factors over the two types of canopies. Atmosphere over grapevine canopy was drier, higher evaporative demand and aerodynamical transfer than maize canopy because air temperature, vapor pressure deficit and wind speed over grapevine were higher. Seasonal averaged net radiation (Rn) and soil heat flux (G) over maize canopy was higher and lower, respectively, than grapevine, resulting in that averaged available energy (Rn – G) was higher for maize than grapevine canopies, with 125.0 and 85.6 W m−2 in 2009 and 121.9 and 99.5 W m−2 in 2010, respectively. Energy partitioning of available energy to latent heat flux (λET) was higher for maize than grapevine canopies, with seasonal averaged ratio of 79.8% and 75.0% for maize and 62.3% and 59.8% for grapevine for both years, respectively. Seasonal averaged Bowen ratio (β) was lower for maize than grapevine canopies, with 0.26 and 0.72, respectively. Gc for maize canopy was higher than grapevine, varying nearly from 1 to above 30 mm s−1 and from 0 to above 15 mm s−1, respectively. Ω of maize canopy was higher than grapevine, with averaged values of 0.52 and 0.30, respectively, suggesting that there was a stronger coupling between grapevine canopy and the above air. The slope of linear regression between evapotranspiration (ET) and Rn were higher for maize canopy, indicating that maize ET was mostly controlled by Rn. The relationship between the Priestley-Taylor coefficient (α) and Gc fits an exponential increase for both types of crop canopies, suggesting that grapevine ET was more controlled by Gc because most grapevine Gc was lower than the threshold of 15 mm s−1. The slope of linear regression between α and leaf area index (LAI) <2.8 m2 m−2 was higher for maize canopy, indicating that maize ET was more sensitive to LAI below the threshold. These results are important for water management and agricultural sustainable development across similar croplands in arid regions.

Preoperative [18F]FDG PET/CT tumour heterogeneity index in patients with uterine leiomyosarcoma: a multicentre retrospective study.

We investigated the prognostic value of the tumour heterogeneity index determined on preoperative [18F]FDG PET/CT in patients with uterine leiomyosarcoma (LMS). We retrospectively reviewed patients with uterine LMS who underwent preoperative [18F]FDG PET/CT scans at three tertiary referral hospitals. The PET/CT parameters maximum standardized uptake value of the primary tumour (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis were assessed. The negative values of the MTV linear regression slope (nMLRS) according to the SUV thresholds of 2.5 and 3.0 were determined as the tumour heterogeneity index. The value of PET/CT-derived parameters in predicting progression-free survival (PFS) and overall survival (OS) were determined in regression analyses. Clinicopathological and PET/CT data from 16 patients were reviewed. The median postsurgical follow-up was 21months (range 4-82months), and 12 patients (75.0%) experienced recurrence. Tumour size (P = 0.017), SUVmax (P = 0.019), MTV (P = 0.016) and nMLRS (P = 0.008) were significant prognostic factors for recurrence. MTV (P = 0.048) and nMLRS (P = 0.045) were significant prognostic factors for patient survival. nMLRS was correlated with clinicopathological parameters including tumour size (Pearson's correlation coefficient γ = 0.825, P < 0.001) and lymph node metastasis (γ = 0.721, P = 0.004). Patient groups categorized according to the nMLRS cut-off value showed significant differences in PFS (P = 0.033) and OS (P = 0.044). The preoperative tumour heterogeneity index obtained using the MTV linear regression slope may be a novel and useful prognostic marker in uterine LMS.

The somatogravic illusion during centrifugation: sex differences

Maintaining orientation in an environment with non-Earth gravity (1 g) is critical for an astronaut's operational performance. Such environments present a number of complexities for balance and motion. For example, when an astronaut tilts due to ascending or descending an inclined plane on the moon, the gravity vector will be tilted correctly, but the magnitude will be different from on earth. If this results in a mis-perceived tilt, then that may lead to postural and perceptual errors, such as mis-perceiving the orientation of oneself or the ground plane and corresponding errors in task judgment.

Impaired Visual Habituation in Idiopathic Generalized Epilepsy with Photosensitivity Patients.

In this study, our goal was to analyze further the cortical excitability levels in idiopathic generalized epilepsy (IGE) patients with and without photosensitivity. Forty-two patients (16 men and 26 women; mean age 30±8 years; range: 18-43 years) with IGE and thirty healthy age-matched control subjects (15 men and 15 women; mean age 35±3 years; range: 20-45 years) were enrolled for the investigation. We investigated the following two groups: 18 subjects with IGE with photosensitivity (IGE+PS), and 24 patients with IGE without photosensitivity (IGE-PS). Pattern reversal and potential inter-peak amplitudes, N75-P100 and P100-N145, as well as the corresponding latencies (N75, P100, and N145) for one hundred responses were measured 6 times. A linear regression slope was used for N75-P100 and P100-N145. Statistical analysis showed difference between groups where the IGE+PS had reduced N75-P100 compared to IGE-PS and controls. In IGE+PS group, the amplitude of N75-P100 was drastically reduced receiving antiepileptic therapy compared to those not receiving any anti-epileptic treatment (p=0.035). These results show that the IGE+PS group has a different photoparoxysmal response phenotype driven by an unknown and distinct molecular mechanism. Pre-activation cortical excitability may be increased in IGE+PS patients compared to the IGE-PS or in healthy group. PR-VEP habituation may project the pathophysiological mechanisms underlying photosensitivity and it may be potential biomarker in patients with IGE+PS.

Serum cortisol as a moderator of the relationship between serum testosterone and Olympic weightlifting performance in real and simulated competitions.

Some equivocality exists regarding the effect of testosterone (T) on competitive performance with cortisol (C) implicated as a moderating factor. This study investigated whether C is moderating the T relationship with Olympic weightlifting (OWL) performance during real and simulated competitions. We monitored 105 male athletes (age 19.3±3.7 years); 46 during real OWL competitions (e.g., national age championships) and 59 across simulated events (e.g., talent identification). Serum T and C were assessed before warming up and within 15 minutes of event completion. Performance was indexed by the total combined load across the snatch and clean and jerk exercises. Hierarchical linear regression and simple slopes were employed to test the hormone and performance relationships. Pre-competition T (pre-T) and C (pre-C) were unrelated to OWL performance when controlling for competition type, time of day, age, and body mass (model=75.6% variance). However, the pre-T × pre-C interaction was significant (model=77% variance). Upon exploring this interaction, different pre-T and performance relationships emerged for males with high pre-C (β=-9.96) and low pre-C levels (β=9.04), with diverging slopes (p=0.006). The assessment of T changes and pre-C produced similar results. The association between male T and performance during OWL competition was determined by C activity, which could explain conflicting reports of T as a correlate of competitive abilities. Our results imply that T and C are not strictly anabolic and catabolic biomarkers of performance, respectively, but rather they exert complementary actions that could depend on task, situational and environmental needs.

Wireless ECG Monitoring System using IoT based Signal Conditioning Module For Real Time Signal Acquisition

Recently, in human health care scenario most of the people are suffering by arrhythmia which is a type of the cardiovascular diseases and it occurs during a person has irregular or abnormal heart rate. To diagnose such condition, there should be continuous monitoring of electrocardiogram signal irrespective of the location confined to the subject and the appropriate physician. In this research, wireless ECG monitoring system using AD8232 signal conditioning module for real time signal acquisition was proposed. The proposed system performs continuous ECG signal monitoring that integrates Wi-Fi technology which acquires the ECG signal and transmit it to cloud wirelessly. Also, feature extraction algorithm has been developed to extract features such as RMSSD, SDNN, Mean RR, Ratio SR and slope of linear regression of IBI from ECG signal of BioVid Heat pain database for different pain levels. The same feature extraction algorithm can be applied on real time ECG signal to extract the features. From the results, it is clear that the proposed system is advantageous for the physicians to provide the right health care to the subject without being in close proximity.

Medicaid waivers and public sector mental health service penetration rates for youth.

To assist families of youth with serious emotional disturbance in financing youth's comprehensive care, some states have sought and received Medicaid waivers. Medicaid waivers waive or relax the Medicaid means test for eligibility to provide insurance coverage to nonpoor families for expensive, otherwise out-of-reach treatment for youth with Serious Emotional Disturbance (SED). Waivers promote treatment access for the most troubled youth, and the present study investigated whether any of several Medicaid waiver options-and those that completely omit the means test in particular-are associated with higher state-wide public sector treatment penetration rates. The investigators obtained data from the U.S. Census, SAMHSA's Uniform Reporting System, and the Centers for Medicare and Medicaid Services. Analysis employed random intercept and random slope linear regression models, controlling for a variety of state demographic and fiscal variables, to determine whether a relationship between Medicaid waiver policies and state-level public sector penetration rates could be observed. Findings indicate that, whether relaxing or completely waiving Medicaid's qualifying income limits, waivers increase public sector penetration rates, particularly for youth under age 17. However, completely waiving Medicaid income limits did not uniquely contribute to penetration rate increases. States offering Medicaid waivers that either relax or completely waive Medicaid's means test to qualify for health coverage present higher public sector treatment rates for youth with behavioral health care needs. There is no evidence that restricting the program to waiving the means test for accessing Medicaid would increase treatment access. (PsycINFO Database Record

Prognostic Utility of Morning Blood Pressure Surge for 20-Year All-Cause and Cardiovascular Mortalities: Results of a Community-Based Study.

BackgroundMorning blood pressure (BP) surge (MS), defined by the MS amplitude, is an independent prognostic factor of cardiovascular outcomes in some, but not all, populations.Method and ResultsWe enrolled 2020 participants (1029 men; aged 30–79 years) with 24‐hour ambulatory BP data. During a median 19.7‐year follow‐up, 607 deaths (182 by cardiovascular causes) were confirmed from the National Death Registry. The amplitude of sleep‐trough MS (STMS) was derived from the difference between morning systolic BP (SBP) and lowest nighttime SBP. The rate of STMS was derived as the slope of linear regression of sequential SBP measures on time intervals within the STMS period. Thresholds for high STMS amplitude and rate were determined by the 95th percentiles (43.7 mm Hg and 11.3 mm Hg/h, respectively). Multivariable Cox models, adjusting for age, sex, body mass index, smoking, alcohol, low‐density lipoprotein cholesterol, 24‐hour SBP, night:day SBP ratio, and antihypertensive treatment, revealed that a high STMS rate (hazard ratio, 1.666; 95% confidence interval, 1.185–2.341), but not STMS amplitude (hazard ratio, 1.245; 95% confidence interval, 0.984–1.843), was significantly associated with a greater mortality risk. Similarly, STMS rate (hazard ratio, 2.608; 95% confidence interval, 1.554–4.375), but not STMS amplitude, was significantly associated with the risk of cardiovascular mortality (hazard ratio, 0.966; 95% confidence interval, 0.535–1.747). Moreover, the prognostic values of STMS rate were comparable in subjects with or without morning and nocturnal hypertension (P>0.05 for interaction for all). In simulation studies, STMS rate was less susceptible to measurement errors of the sleep‐trough SBP than STMS amplitude.Conclusions STMS rate could independently help identify subjects with an increased cardiovascular risk.

Inference about the slope in linear regression: an empirical likelihood approach

We present a new, efficient maximum empirical likelihood estimator for the slope in linear regression with independent errors and covariates. The estimator does not require estimation of the influence function, in contrast to other approaches, and is easy to obtain numerically. Our approach can also be used in the model with responses missing at random, for which we recommend a complete case analysis. This suffices thanks to results by Muller and Schick (Bernoulli 23:2693–2719, 2017), which demonstrate that efficiency is preserved. We provide confidence intervals and tests for the slope, based on the limiting Chi-square distribution of the empirical likelihood, and a uniform expansion for the empirical likelihood ratio. The article concludes with a small simulation study.