scholarly journals A Rapid Motor Task-Based Screening Tool for Parkinsonism in Community-Based Studies

2021 ◽  
Vol 12 ◽  
Author(s):  
Wendy W. Dlamini ◽  
Searles Nielsen ◽  
Mwiza Ushe ◽  
Gill Nelson ◽  
Brad A. Racette
Keyword(s):  
Standard Deviation ◽  
Predictive Model ◽  
Screening Tool ◽  
Motor Task ◽  
Population Based ◽  
Validation Dataset ◽  
Motor Tasks ◽  
Test Dataset ◽  
The Mean ◽  
Summary Measures

Background: The prevalence of parkinsonism in developing countries is largely unknown due to difficulty in ascertainment because access to neurologists is often limited.Objective: Develop and validate a parkinsonism screening tool using objective motor task-based tests that can be administered by non-clinicians.Methods: In a cross-sectional population-based sample from South Africa, we evaluated 315 adults, age >40, from an Mn-exposed (smelter) community, using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3), Purdue grooved pegboard, and kinematic-UPDRS3-based motor tasks. In 275 participants (training dataset), we constructed a linear regression model to predict UPDRS3. We selected motor task summary measures independently associated with UPDRS3 (p < 0.05). We validated the model internally in the remaining 40 participants from the manganese-exposed community (test dataset) using the area under the receiver operating characteristic curve (AUC), and externally in another population-based sample of 90 participants from another South African community with only background levels of environmental Mn exposure.Results: The mean UPDRS3 score in participants from the Mn-exposed community was 9.1 in both the training and test datasets (standard deviation = 6.4 and 6.1, respectively). Together, 57 (18.1%) participants in this community had a UPDRS3 ≥ 15, including three with Parkinson's disease. In the non-exposed community, the mean UPDRS3 was 3.9 (standard deviation = 4.3). Three (3.3%) had a UPDRS3 ≥ 15. Grooved pegboard time and mean velocity for hand rotation and finger tapping tasks were strongly associated with UPDRS3. Using these motor task summary measures and age, the UPDRS3 predictive model performed very well. In the test dataset, AUCs were 0.81 (95% CI 0.68, 0.94) and 0.91 (95% CI 0.81, 1.00) for cut points for neurologist-assessed UPDRS3 ≥ 10 and UPDRS3 ≥ 15, respectively. In the external validation dataset, the AUC was 0.85 (95% CI 0.73, 0.97) for UPDRS3 ≥ 10. AUCs were 0.76–0.82 when excluding age.Conclusion: A predictive model based on a series of objective motor tasks performs very well in assessing severity of parkinsonism in both Mn-exposed and non-exposed population-based cohorts.

scholarly journals Automated Classification of Colorectal Neoplasms in White-Light Colonoscopy Images via Deep Learning

2020 ◽  
Vol 9 (5) ◽  
pp. 1593 ◽  
Author(s):  
Young Joo Yang ◽  
Bum-Joo Cho ◽  
Myung-Je Lee ◽  
Ju Han Kim ◽  
Hyun Lim ◽  
...  
Keyword(s):  
Deep Learning ◽  
Colorectal Neoplasms ◽  
White Light ◽  
External Validation ◽  
Validation Dataset ◽  
Tubular Adenoma ◽  
Colonoscopic Examination ◽  
Test Dataset ◽  
The Mean

Background: Classification of colorectal neoplasms during colonoscopic examination is important to avoid unnecessary endoscopic biopsy or resection. This study aimed to develop and validate deep learning models that automatically classify colorectal lesions histologically on white-light colonoscopy images. Methods: White-light colonoscopy images of colorectal lesions exhibiting pathological results were collected and classified into seven categories: stages T1-4 colorectal cancer (CRC), high-grade dysplasia (HGD), tubular adenoma (TA), and non-neoplasms. The images were then re-classified into four categories including advanced CRC, early CRC/HGD, TA, and non-neoplasms. Two convolutional neural network models were trained, and the performances were evaluated in an internal test dataset and an external validation dataset. Results: In total, 3828 images were collected from 1339 patients. The mean accuracies of ResNet-152 model for the seven-category and four-category classification were 60.2% and 67.3% in the internal test dataset, and 74.7% and 79.2% in the external validation dataset, respectively, including 240 images. In the external validation, ResNet-152 outperformed two endoscopists for four-category classification, and showed a higher mean area under the curve (AUC) for detecting TA+ lesions (0.818) compared to the worst-performing endoscopist. The mean AUC for detecting HGD+ lesions reached 0.876 by Inception-ResNet-v2. Conclusions: A deep learning model presented promising performance in classifying colorectal lesions on white-light colonoscopy images; this model could help endoscopists build optimal treatment strategies.

scholarly journals Validity of a Non-Proprietary Algorithm for Identifying Lying Down Using Raw Data from Thigh-Worn Triaxial Accelerometers

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 904
Author(s):  
Pasan Hettiarachchi ◽  
Katarina Aili ◽  
Andreas Holtermann ◽  
Emmanuel Stamatakis ◽  
Magnus Svartengren ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Sedentary Time ◽  
Daily Life ◽  
Validation Dataset ◽  
Time Duration ◽  
Raw Data ◽  
The Mean ◽  
Sedentary Bouts ◽  
Lying Down ◽  
Duration Criterion

Body postural allocation during daily life is important for health, and can be assessed with thigh-worn accelerometers. An algorithm based on sedentary bouts from the proprietary ActivePAL software can detect lying down from a single thigh-worn accelerometer using rotations of the thigh. However, it is not usable across brands of accelerometers. This algorithm has the potential to be refined. Aim: To refine and assess the validity of an algorithm to detect lying down from raw data of thigh-worn accelerometers. Axivity-AX3 accelerometers were placed on the thigh and upper back (reference) on adults in a development dataset (n = 50) and a validation dataset (n = 47) for 7 days. Sedentary time from the open Acti4-algorithm was used as input to the algorithm. In addition to the thigh-rotation criterion in the existing algorithm, two criteria based on standard deviation of acceleration and a time duration criterion of sedentary bouts were added. The mean difference (95% agreement-limits) between the total identified lying time/day, between the refined algorithm and the reference was +2.9 (−135,141) min in the development dataset and +6.5 (−145,159) min in the validation dataset. The refined algorithm can be used to estimate lying time in studies using different accelerometer brands.

Use of a screening tool for detection of sleep-disordered breathing

2009 ◽  
Vol 123 (7) ◽  
pp. 746-749 ◽  
Author(s):  
A L Clark ◽  
S Crabbe ◽  
A Aziz ◽  
P Reddy ◽  
M Greenstone
Keyword(s):  
Body Mass Index ◽  
Standard Deviation ◽  
Sleep Disordered Breathing ◽  
Screening Tool ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
Sleep Apnoea ◽  
High Risk Populations ◽  
The Mean ◽  
Nasal Pressure

AbstractBackground:Sleep apnoea, whether obstructive or central, is usually diagnosed by polysomnography. A simpler tool for screening high risk populations may be of value.Methods:We compared a portable device using nasal pressure cannulae and a high-sensitivity pressure sensor (the ApneaLink®) with our standard polysomnography technique for diagnosing sleep apnoea (using the Embletta® device), in 67 patients being investigated for possible sleep apnoea. The patients' average age was 52.6, 79 per cent were male, the mean body mass index was 32.3, and the mean Epworth sleepiness score was 13.0.Results:Twenty-five patients (45 per cent) were identified as having an apnoea–hypopnoea index of >15, as measured by the Embletta. The mean (standard deviation) apnoea–hypopnoea index was 21.5 ± 23.0 as measured by the Embletta and 24.3 ± 26.2 as measured by the ApneaLink. The sensitivity of the ApneaLink for an apnoea–hypopnoea index cut-off point of 15 was 92 per cent and the specificity was 96.7 per cent. The negative predictive value of the ApneaLink for an apnoea–hypopnoea index of ≤15 was 94 per cent.Conclusions:The ApneaLink is a useful tool for screening patients thought to have possible sleep apnoea, and for selecting patients for definitive diagnostic testing.

At Least One Standard Deviation Above the Mean

1969 ◽  
Vol 14 (9) ◽  
pp. 470-471
Author(s):  
M. DAVID MERRILL
Keyword(s):  
Standard Deviation ◽  
The Mean

The Estimation of Blood Platelet Survival

1972 ◽  
Vol 28 (03) ◽  
pp. 447-456 ◽  
Author(s):  
E. A Murphy ◽  
M. E Francis ◽  
J. F Mustard
Keyword(s):  
Standard Deviation ◽  
Least Squares ◽  
Experimental Error ◽  
Blood Platelet ◽  
Least Squares Estimation ◽  
Systematic Relationship ◽  
Platelet Survival ◽  
The Mean ◽  
Normally Distributed

SummaryThe characteristics of experimental error in measurement of platelet radioactivity have been explored by blind replicate determinations on specimens taken on several days on each of three Walker hounds.Analysis suggests that it is not unreasonable to suppose that error for each sample is normally distributed ; and while there is evidence that the variance is heterogeneous, no systematic relationship has been discovered between the mean and the standard deviation of the determinations on individual samples. Thus, since it would be impracticable for investigators to do replicate determinations as a routine, no improvement over simple unweighted least squares estimation on untransformed data suggests itself.

PENGARUH PENDIDIKAN KESEHATAN REPRODUKSI PADA PEER GROUP (TEMAN SEBAYA) TERHADAP PENGETAHUAN DAN PERSEPSI REMAJA TENTANG PENDEWASAAN USIA PERKAWINAN DI SMA NEGERI 1 KECAMATAN NAMORAMBE KAB. DELI SERDANG 2018

2020 ◽  
Vol 1 (2) ◽  
pp. 56-66
Author(s):  
Irma Linda
Keyword(s):  
Standard Deviation ◽  
Health Education ◽  
Reproductive Health ◽  
Peer Group ◽  
Peer Groups ◽  
A Value ◽  
Significant Difference ◽  
Reproductive Health Education ◽  
The Mean ◽  
Adolescent Perceptions

Background: Early marriages are at high risk of marital failure, poor family quality, young pregnancies at risk of maternal death, and the risk of being mentally ill to foster marriage and be responsible parents. Objective: To determine the effect of reproductive health education on peer groups (peers) on the knowledge and perceptions of adolescents about marriage age maturity. Method: This research uses the Quasi experimental method with One group pre and post test design, conducted from May to September 2018. The statistical analysis used in this study is a paired T test with a confidence level of 95% (α = 0, 05). Results: There is an average difference in the mean value of adolescent knowledge between the first and second measurements is 0.50 with a standard deviation of 1.922. The mean difference in mean scores of adolescent perceptions between the first and second measurements was 4.42 with a standard deviation of 9.611. Conclusion: There is a significant difference between adolescent knowledge on the pretest and posttest measurements with a value of P = 0.002, and there is a significant difference between adolescent perceptions on the pretest and posttest measurements with a value of p = 0.001. Increasing the number of facilities and facilities related to reproductive health education by peer groups (peers) in adolescents is carried out on an ongoing basis at school, in collaboration with local health workers as prevention of risky pregnancy.

Regularity and latency of units in ventral cochlear nucleus: implications for unit classification and generation of response properties

1988 ◽  
Vol 60 (1) ◽  
pp. 1-29 ◽  
Author(s):  
E. D. Young ◽  
J. M. Robert ◽  
W. P. Shofner
Keyword(s):  
Standard Deviation ◽  
Cochlear Nucleus ◽  
Interspike Interval ◽  
Rate Adaptation ◽  
Stellate Cells ◽  
Instantaneous Rate ◽  
Ventral Cochlear Nucleus ◽  
Bushy Cell ◽  
Low Pass ◽  
The Mean

1. The responses of neurons in the ventral cochlear nucleus (VCN) of decerebrate cats are described with regard to their regularity of discharge and latency. Regularity is measured by estimating the mean and standard deviation of interspike intervals as a function of time during responses to short tone bursts (25 ms). This method extends the usual interspike-interval analysis based on interval histograms by allowing the study of temporal changes in regularity during transient responses. The coefficient of variation (CV), equal to the ratio of standard deviation to mean interspike interval, is used as a measure of irregularity. Latency is measured as the mean and standard deviation of the latency of the first spike in response to short tone bursts, with 1.6-ms rise times. 2. The regularity and latency properties of the usual PST histogram response types are shown. Five major PST response type classes are used: chopper, primary-like, onset, onset-C, and unusual. The presence of a prepotential in a unit's action potentials is also noted; a prepotential implies that the unit is recorded from a bushy cell. 3. Units with chopper PST histograms give the most regular discharge. Three varieties of choppers are found. Chop-S units (regular choppers) have CVs less than 0.35 that are approximately constant during the response; chop-S units show no adaptation of instantaneous rate, as measured by the inverse of the mean interspike interval. Chop-T units have CVs greater than 0.35, show an increase in irregularity during the response and show substantial rate adaptation. Chop-U units have CVs greater than 0.35, show a decrease in irregularity during the response, and show a variety of rate adaptation behaviors, including negative adaptation (an increase in rate during a short-tone response). Irregular choppers (chop-T and chop-U units) rarely have CVs greater than 0.5. Choppers have the longest latencies of VCN units; all three groups have mean latencies at least 1 ms longer than the shortest auditory nerve (AN) fiber mean latencies. 4. Chopper units are recorded from stellate cells in VCN (35, 42). Our results for chopper units suggest a model for stellate cells in which a regularly firing action potential generator is driven by the summation of the AN inputs to the cell, where the summation is low-pass filtered by the membrane capacitance of the cell.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Blood Oxygenation Level Dependent Magnetic Resonance Imaging (MRI), Dynamic Contrast Enhanced MRI and Diffusion Weighted MRI for Benign and Malignant Breast Cancer Discrimination: A Preliminary Experience

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2421
Author(s):  
Roberta Fusco ◽  
Vincenza Granata ◽  
Mauro Mattace Raso ◽  
Paolo Vallone ◽  
Alessandro Pasquale De Rosa ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Univariate Analysis ◽  
Mean Value ◽  
Blood Oxygenation ◽  
Breast Lesions ◽  
Dce Mri ◽  
Malignant Lesions ◽  
The Mean ◽  
And Diffusion ◽  
Skewness And Kurtosis

Purpose. To combine blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), dynamic contrast enhanced MRI (DCE-MRI), and diffusion weighted MRI (DW-MRI) in differentiation of benign and malignant breast lesions. Methods. Thirty-seven breast lesions (11 benign and 21 malignant lesions) pathologically proven were included in this retrospective preliminary study. Pharmaco-kinetic parameters including Ktrans, kep, ve, and vp were extracted by DCE-MRI; BOLD parameters were estimated by basal signal S0 and the relaxation rate R2*; and diffusion and perfusion parameters were derived by DW-MRI (pseudo-diffusion coefficient (Dp), perfusion fraction (fp), and tissue diffusivity (Dt)). The correlation coefficient, Wilcoxon-Mann-Whitney U-test, and receiver operating characteristic (ROC) analysis were calculated and area under the ROC curve (AUC) was obtained. Moreover, pattern recognition approaches (linear discrimination analysis and decision tree) with balancing technique and leave one out cross validation approach were considered. Results. R2* and D had a significant negative correlation (−0.57). The mean value, standard deviation, Skewness and Kurtosis values of R2* did not show a statistical significance between benign and malignant lesions (p > 0.05) confirmed by the ‘poor’ diagnostic value of ROC analysis. For DW-MRI derived parameters, the univariate analysis, standard deviation of D, Skewness and Kurtosis values of D* had a significant result to discriminate benign and malignant lesions and the best result at the univariate analysis in the discrimination of benign and malignant lesions was obtained by the Skewness of D* with an AUC of 82.9% (p-value = 0.02). Significant results for the mean value of Ktrans, mean value, standard deviation value and Skewness of kep, mean value, Skewness and Kurtosis of ve were obtained and the best AUC among DCE-MRI extracted parameters was reached by the mean value of kep and was equal to 80.0%. The best diagnostic performance in the discrimination of benign and malignant lesions was obtained at the multivariate analysis considering the DCE-MRI parameters alone with an AUC = 0.91 when the balancing technique was considered. Conclusions. Our results suggest that the combined use of DCE-MRI, DW-MRI and/or BOLD-MRI does not provide a dramatic improvement compared to the use of DCE-MRI features alone, in the classification of breast lesions. However, an interesting result was the negative correlation between R2* and D.

Elevation of pulse pressure in middle age is associated with the risk of dementia: data from a population-based cohort

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Kim ◽  
H Jung ◽  
P.S Yang ◽  
H.T Yu ◽  
T.H Kim ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Pulse Pressure ◽  
Middle Age ◽  
Population Based ◽  
Entire Cohort ◽  
Incident Dementia ◽  
Increased Risk ◽  
Diagnosis Of Dementia ◽  
History Of ◽  
The Mean

Abstract Aims Pulse pressure (PP) is a well-known risk factor for cardiovascular disease. However, the association between the PP and dementia is not well identified. This study aimed to determine the effect of PP on the risk of dementia development in different age subgroups using a longitudinal, population-based, and stroke-free cohort from the general population. Methods The association of PP with the development of incident dementia was assessed from January 1, 2005, to December 31, 2013, in 433,154 participants without a history of dementia or stroke from the Korea National Health Insurance Service-Health Screening cohort. The diagnosis of dementia was defined using the 10th revision of the International Classification of Disease codes. Results The mean age of the cohort was 55.7±9.2 years, 45.7% were women. Hypertension was 23.6%. The mean systolic and diastolic blood pressure of the entire cohort were 125.9±16.6 and 78.4±10.7 mmHg, respectively. Mean PP was 47.5±10.9 mmHg. In the middle-age group (40 to 50 year-old), increasing of 10 mmHg of PP was associated with incident dementia after adjusting mean blood pressure and clinical variables with a hazard ratio (HR) of 1.21 (95% confidence interval [CI]: 1.19–1.23, p<0.001). The association was still significant even after censoring for stroke (HR: 1.16, 95% CI: 1.08–1.22, p<0.001). In the older population, elevation of PP was not associated with dementia development (HR: 0.98, 95% CI: 0.95–1.01, p=0.247) Conclusion PP was associated with increased risk of dementia only in middle-aged population beyond that of mean arterial pressure. Funding Acknowledgement Type of funding source: None

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