Perturbing sound speed field estimates to study quality of acoustic ranging

2020 ◽  
Vol 148 (4) ◽  
pp. 2546-2546
Author(s):  
Ashwin Sarma ◽  
Rex Andrew ◽  
Geoffrey Edelson ◽  
John Waterston
Akustika ◽  
2020 ◽  
pp. 45-50
Author(s):  
Alena Rohanová

This paper explores the analysis of sound speeds in the longitudinal direction and their reduction to the reference moisture content w = 12 %. The sound speed cw was determined with Sylvatest Duo device. Moisture content of beech sawmill assortments (round timber: N = 16, logs: N = 2 × 16, structural boards: N = 54) in the range of 12 – 72 % was measured. For the analysis purposes, the sound speed was converted to reference conditions (c12, uref = 12%). A second-degree polynomial (parabola) with a regression equation of the form: c// = 5649 - 27,371 × w + 0.0735 × w2 was used to convert cw to c12, and correction of measured and calculated values was used as well. The sound speeds c12 in sawmill assortments (c12,round, c12,log, c12,board) were evaluated by linear dependences. Dependence was not confirmed for c12,round and c12,board1 (r = 0.168), in contrast for c12,round and c12,log2 the dependence is statistically very significant (r = 0.634). The results of testing showed that the most suitable procedure for predicting quality of structural timber is the first step round timber – log2, the second step: log2 - board2. More exact results of the construction boards were obtained from log2 than from log1. The sound speed is used in the calculation of dynamic modulus of elasticity (Edyn). EN 408 mentions the possibility of using dynamic modulus of elasticity as an alternative method in predicting the quality of structural timber.


Author(s):  
Beatrice Heim ◽  
Florian Krismer ◽  
Klaus Seppi

AbstractDifferential diagnosis of parkinsonian syndromes is considered one of the most challenging in neurology. Quantitative MR planimetric measurements were reported to discriminate between progressive supranuclear palsy (PSP) and non-PSP-parkinsonism. Several studies have used midbrain to pons ratio (M/P) and the Magnetic Resonance Parkinsonism Index (MRPI) in distinguishing PSP patients from those with Parkinson's disease. The current meta-analysis aimed to compare the performance of these measures in discriminating PSP from multiple system atrophy (MSA). A systematic MEDLINE review identified 59 out of 2984 studies allowing a calculation of sensitivity and specificity using the MRPI or M/P. Meta-analyses of results were carried out using random effects modelling. To assess study quality and risk of bias, the QUADAS-2 tool was used. Eight studies were suitable for analysis. The meta‐analysis showed a pooled sensitivity and specificity for the MRPI of PSP versus MSA of 79.2% (95% CI 72.7–84.4%) and 91.2% (95% CI 79.5–96.5%), and 84.1% (95% CI 77.2–89.2%) and 89.2% (95% CI 81.8–93.8%), respectively, for the M/P. The QUADAS-2 toolbox revealed a high risk of bias regarding the methodological quality of patient selection and index test, as all patients were seen in a specialized outpatient department without avoiding case control design and no predefined threshold was given regarding MRPI or M/P cut-offs. Planimetric brainstem measurements, in special the MRPI and M/P, yield high diagnostic accuracy for the discrimination of PSP from MSA. However, there is an urgent need for well-designed, prospective validation studies to ameliorate the concerns regarding the risk of bias.


Vascular ◽  
2020 ◽  
pp. 170853812098020
Author(s):  
Ertan Yetkin ◽  
Makbule Kutlu Karadag ◽  
Mehmet Ileri ◽  
Ramazan Atak ◽  
Nevzat Erdil ◽  
...  

Objectives We aimed to evaluate peripheral varicose vein symptoms including ecchymosis and coldness by using the Venous Insufficiency Epidemiological and Economic Study-Quality of Life/Symptoms (VEINES-QoL/Sym) questionnaire. Methods A total of 1120 patients were enrolled to the analysis after the exclusion of 199 patients who did not match the inclusion criteria. Patients were asked to answer the VEINES-Sym questionnaire and questions about ecchymosis and coldness. Scores of ecchymosis and coldness were calculated similar to VEINES-Sym questionnaire. Classifications of peripheral varicose vein were made according to the clinical part of clinical, etiological, anatomical, and pathophysiological classification system and patients with grade 2 or higher were considered as positive for peripheral varicose vein. Results Frequency of symptoms present in the VEINES-Sym instrument, ecchymosis and coldness were significantly higher in patients with peripheral varicose vein. Mean score of each symptom was significantly lower in peripheral varicose vein patients including scores of ecchymosis and coldness. Logistic regression analysis revealed that presence of hemorrhoids and all symptoms in VEINES-Sym questionnaire except restless leg were significantly and independently associated with peripheral varicose vein. Besides, ecchymosis (odds ratio: 2.04, 95% confidence interval: 1.34–3.08, p = 0.008) but not coldness was significantly and independently associated with peripheral varicose vein. There was also significant correlation of VEINES-Sym score with ecchymosis ( r = 0.43, p < 0.001) and coldness ( r = 0.47, p < 0.001). Conclusions Venous leg symptoms present in VEINES-Sym questionnaire except restless legs, presence of hemorrhoids and ecchymosis are significantly and independently associated with peripheral varicose vein. Not only ecchymosis but also coldness has shown an independent association with total VEINES-Sym score.


Author(s):  
Kun Sha ◽  
Ping Qian ◽  
Li-Jun Wang ◽  
Zhan-hui Lu ◽  
Li-Te Li

In this study, quality of Man-tou, the Chinese traditional steamed bread during storage was studied. Values for water retention capacity, total water solubles, soluble starch, and soluble amylose and amylopectin of Man-tou decreased with storage time. Results showed that hardness, chewiness and gumminess of Man-tou increased, while, springiness cohesiveness and resilience decreased along with prolonged storage time (p<0.05). Sensory evaluation results showed that all sensory rating of Man-tou, including softness, stickiness, cohesiveness, elasticity, taste and total score, dropped drastically within 24 h of storage time (p<0.05). Differential Scanning Calorimeter (DSC) was used to determine crystalline structure of amylopectin in Man-tou, and the value for enthalpy of crystallization was found increased with storage time. Amylopectin crystallization was significantly associated to Man-tou firming (p<0.01).


2021 ◽  
pp. 1-17
Author(s):  
Christine W. St. Laurent ◽  
Katrina Rodheim ◽  
Rebecca M.C. Spencer

The aim of this systematic review was to examine the associations between physical activity and sleep in children aged less than 6 years. Articles were included if participants were primarily aged less than 6 years and study designs were observational or experimental. Study characteristics were extracted, and the Grading Recommendations Assessment, Development and Evaluation framework was used to assess study quality. Thirty-six studies (16 sleep, 16 physical activity, and three fitness outcomes) from 18 countries reported in 29 articles were included. The majority of sleep and physical activity outcome studies reported mixed effects with very low to low quality of evidence. Fitness outcome studies were limited, and therefore, evidence was insufficient. The high prevalence of mixed and null results could be related to study limitations. Importantly, this review points to the critical need for higher quality studies of sleep and physical activity in young children, which would support health recommendations and intervention strategies for healthier child development.


Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Ruth E Taylor-Piliae ◽  
Brooke A Finley

Background: Regular exercise is beneficial for adults with chronic heart failure (CHF). Tai Chi is popular among older adults and may offer additional exercise options for those with CHF. Objectives: A systematic review and meta-analysis was conducted to examine the benefits of Tai Chi exercise among adults with CHF. Methods: An electronic literature search of ten databases (AMED, CINAHL, Embase, OpenGrey, PsycARTICLES, PsycINFO, PubMed, Scopus, SPORTDiscus, and Web of Science) was conducted from January 1, 2004 to August 1, 2019. Clinical trials that examined Tai Chi exercise, were published in English or German languages, among participants with CHF were included. Study quality was assessed independently by two reviewers, using the modified Downs and Black Quality Index checklist (low quality = score ≤14, moderate quality = score 15-23, high quality = score ≥ 24). Comprehensive Meta-Analysis version 2.0 software (Biostat, Inc.) was used to calculate the effect sizes (i.e., Hedges’ g) and the 95% confidence intervals using random effects models. Results: A total of six studies met the inclusion criteria (five RCTs and one quasi-experimental study with a comparison group), enrolling 229 participants (mean age=68 years old, 28% women, mean ejection fraction=37%). The Yang style of Tai Chi was most commonly practiced in these studies (n=5, 83%), with usual care the most common control condition. Study quality was moderate (mean score=23). At least three studies reported outcomes for exercise capacity, quality of life (QOL), depression, and b-type natriuretic peptide (BNP), allowing for meta-analysis. Compared to controls, Tai Chi participants had significantly better exercise capacity (Hedge’s g=0.353; p=0.026, I 2 =32.72%), improved QOL (Hedge’s g=0.617; p=0.000, I 2 =0%), with less depression (Hedge’s g=0.627; p=0.000, I 2 =0%), and decreased BNP expression (Hedge’s g=0.333; p=0.016, I 2 =0%). Conclusion: Among adults with CHF, Tai Chi was effective in improving exercise capacity and quality of life, with less depression and BNP levels observed, when compared to controls. Tai Chi is popular and safe form of exercise among older adults, yet few studies have been conducted during the past 15 years examining the benefits of Tai Chi among adults with CHF. Tai Chi can be easily integrated into existing cardiac rehabilitation programs. Further research is needed with more rigorous study designs and larger samples, before widespread recommendations can be made.


Angiology ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 329-337 ◽  
Author(s):  
Adalet Kutlu ◽  
Emel Yılmaz ◽  
Dilek Çeçen ◽  
Erhan Eser ◽  
Alper Özbakkaloğlu

Sign in / Sign up

Export Citation Format

Share Document