Branching characteristics of coronary arteries in rats

1984 ◽  
Vol 62 (12) ◽  
pp. 1453-1459 ◽  
Author(s):  
M. Zamir ◽  
S. Phipps ◽  
B. L. Langille ◽  
T. H. Wonnacott
Keyword(s):  
Cardiovascular System ◽  
Coronary Arteries ◽  
P Values ◽  
High Significance ◽  
Significance Levels ◽  
Very High

The purpose of this study is to examine quantitatively the branching characteristics of the coronary arteries. Branching angles and vessel diameters were measured in a total of 175 arterial bifurcations in the coronary beds of rats, and the results are compared with those of 350 bifurcations in other parts of the cardiovascular system of the same species. Significant differences are found in the values of branch diameters and branching angles, both being found generally lower in the coronary bed than in other parts of the system. On statistical grounds these differences are found to have very high significance levels, with P values less than 0.02 in the case of branching angles and much less than 0.001 in the ease of branch diameters. On physiological grounds, the differences are such as to place the coronary arteries further away from the "theoretical optimum" than are vessels in other parts of the cardiovascular system. The theoretical optimum represents branching angles and branch diameters which make arterial bifurcations more efficient physiologically.

scholarly journals DLPFC Transcriptome Defines Two Molecular Subtypes of Schizophrenia

2017 ◽  
Author(s):  
C. Harker Rhodes ◽  
Elijah F. W. Bowen ◽  
Jack L. Burgess ◽  
Richard Granger
Keyword(s):  
Independent Set ◽  
Differentially Expressed ◽  
Expression Array ◽  
High Significance ◽  
Rnaseq Data ◽  
Dorsolateral Prefrontal ◽  
Significance Levels ◽  
And Control ◽  
Very High

AbstractLittle is known about the molecular pathogenesis of schizophrenia, possibly because of unrecognized heterogeneity in diagnosed patient populations. We analyzed gene expression data collected from the dorsolateral prefrontal cortex (DLPFC) of post-mortem frozen brains of 189 adult diagnosed schizophrenics and 206 matched controls. Transcripts from 633 genes are differentially expressed in the DLPFC of schizophrenics as compared to controls at Bonferroni-corrected significance levels. Seventeen of those genes are differentially expressed at very high significance levels (< 10−8 after Bonferroni correction).Weighted Gene Co-expression Network Analysis (WGCNA) of the schizophrenic subjects, based on the transcripts differentially expressed in the schizophrenics as compared to controls, divides them into two groups: "Type 1" schizophrenics, have a DLPFC transcriptome similar to that of controls with no expressed genes identified in this subcohort while the "type 2" schizophrenics have a DLPFC transcriptome dramatically different from that of controls, with 3,652 expression array probes to 3,200 genes detecting transcripts that are differentially expressed at very high significance levels. These findings were re-tested and replicated in a separate independent cohort, using the RNAseq data from the DLPFC of an independent set of schizophrenics and control subjects.We suggest the hypothesis that these striking differences in DLPFC transcriptomes, identified and replicated in two populations, imply a fundamental biologic difference between these two groups of patients who have been diagnosed as schizophrenic.

scholarly journals Immunoglobulin G4-related masses surrounding coronary arteries: a case report

2021 ◽  
Vol 5 (3) ◽  
Author(s):  
Takuya Nakamura ◽  
Yutaka Goryo ◽  
Takuya Isojima ◽  
Hiroyuki Kawata
Keyword(s):  
Coronary Artery ◽  
Coronary Angiography ◽  
Cardiovascular System ◽  
Coronary Arteries ◽  
Elevated Serum ◽  
High Serum ◽  
Immunoglobulin G4 ◽  
Coronary Arteritis ◽  
Serum Igg4 ◽  
Mass Formation

Abstract Background Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition with high serum IgG4 levels affecting various organs, such as the pancreas, lacrimal and salivary glands, thyroid, kidney, and lung. Typical cardiovascular manifestations of IgG4-RD include periaortitis, coronary arteritis, and pericarditis. However, reports of IgG4-RD associated with coronary arteritis are rare. Here, we report a case of IgG4-related masses surrounding the coronary arteries. Case summary A 59-year-old man was referred to our hospital because of mediastinal masses detected by computed tomography (CT). Coronary CT angiography revealed masses surrounding the right coronary artery and the left anterior descending coronary artery. An elevated serum level of IgG4 and histological findings led to the diagnosis of IgG4-related coronary arteritis with mass formation. Coronary angiography showed numerous feeding arteries to the masses, which were demonstrated as multiple microchannels in the intravascular ultrasound (IVUS) images. Discussion IgG4-RD involving the cardiovascular system has been reported. However, coronary artery disease associated with IgG4-RD is very rare, and the mechanism of mass formation in IgG4-related coronary arteritis is unclear. In our case, within the cardiovascular system, IgG4-RD was limited to the coronary arteries, suggesting that the affected coronary arteries may provide the necessary blood supply to the mass, thus, aiding its growth. These findings were supported by the images from coronary angiography and IVUS.

scholarly journals Cavalier Use of Inferential Statistics Is a Major Source of False and Irreproducible Scientific Findings

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 603
Author(s):  
Leonid Hanin
Keyword(s):  
Sample Size ◽  
Gaussian Approximation ◽  
Statistical Significance ◽  
Statistical Analyses ◽  
Random Sample Size ◽  
P Values ◽  
The Central Limit Theorem ◽  
Fixed Sample ◽  
Large Numbers ◽  
Significance Levels

I uncover previously underappreciated systematic sources of false and irreproducible results in natural, biomedical and social sciences that are rooted in statistical methodology. They include the inevitably occurring deviations from basic assumptions behind statistical analyses and the use of various approximations. I show through a number of examples that (a) arbitrarily small deviations from distributional homogeneity can lead to arbitrarily large deviations in the outcomes of statistical analyses; (b) samples of random size may violate the Law of Large Numbers and thus are generally unsuitable for conventional statistical inference; (c) the same is true, in particular, when random sample size and observations are stochastically dependent; and (d) the use of the Gaussian approximation based on the Central Limit Theorem has dramatic implications for p-values and statistical significance essentially making pursuit of small significance levels and p-values for a fixed sample size meaningless. The latter is proven rigorously in the case of one-sided Z test. This article could serve as a cautionary guidance to scientists and practitioners employing statistical methods in their work.

scholarly journals SAFETY OF USE OF HIGH ALTITUDE PROTECTION SUITS FOR KINESITHERAPY – PRELIMINARY REPORT

2020 ◽  
Vol 25 (1) ◽  
pp. 50-54
Author(s):  
Maciej Abakumow ◽  
◽  
Krzysztof Kowalczuk ◽  
Keyword(s):  
Blood Pressure ◽  
Healthy Volunteers ◽  
High Altitude ◽  
Cardiovascular System ◽  
Preliminary Report ◽  
Pressure Increase ◽  
Blood Pressure Increase ◽  
Safety Considerations ◽  
Very High

Abstract: Apart from protection from very high altitude or influence of increased gravitational accelerations protective suits sometimes are used for another applications like supporting kinesitherapy. Because of some safety considerations connected with possible cardiovascular system overload and dangerous blood pressure increase we tested if these concerns are valid. Main aim ot presented research performed with participation of healthy volunteers was to confirm that use of High Altitude Protection (HAP) suit is safe in terms of increased cardiovascular.

Study of some parameters of electrocardiography of skiers-riders

2021 ◽  
pp. 68-75
Author(s):  
Sergey V. Saykin ◽  
Valery N. Yakovlev
Keyword(s):  
Physical Activity ◽  
Cardiovascular System ◽  
Motor Skills ◽  
The Body ◽  
Young Athletes ◽  
Functional Diagnosis ◽  
Electrocardiographic Examination ◽  
One Year ◽  
The One ◽  
Very High

Very high results, the achievement of which is possible only with long systematic train-ing with the use of large and sometimes excessive physical activity characterizes modern sports. The preparation process from beginner to master of sports takes an average of 5–10 years. During this time, the athlete must develop and improve special physical and mental qualities, as well as master certain motor skills specific to this sport. Therefore, children's and youth's organisms of athletes are subject to increased loads, especially in classes that develop endurance. But not always physical activity contributes to the strengthening of the body, sometimes excessive loads, especially with the wrong approach, lead to complications from the cardiovascular system, in particular, to changes in heart rate. Therefore, the issue of adapting the functions of the heart of young athletes to muscle loads becomes increasingly important. The purpose of the work was to study the activities of the cardiovascular system of skiers-riders in the preparatory period of the one-year cycle. Currently, various methods of functional diagnosis of the cardiovascular system are used. We considered the results obtained during electrocardiographic examination of skiers-riders. We investigated electrical activity of the heart and presented model characteristics according to the considered indicators.

Inference for econometric modeling in antidumping, countervailing duty and safeguard investigations

2009 ◽  
Vol 8 (4) ◽  
pp. 545-557 ◽  
Author(s):  
JAMES J. FETZER
Keyword(s):  
Confidence Intervals ◽  
Econometric Models ◽  
Econometric Modeling ◽  
P Values ◽  
Flexible Approach ◽  
Fixed Level ◽  
Point Estimates ◽  
Level Of Confidence ◽  
Significance Levels

AbstractThis paper examines how to make inferences from econometric models prepared for antidumping, countervailing duty, and safeguard investigations. Analysis of these models has typically entailed drawing inferences from point estimates that are significantly different from zero at a fixed level of confidence. This paper suggests a more flexible approach of drawing inferences using confidence intervals at various significance levels and reporting p-values for the relevant test of injury. Use of confidence intervals and p-values to identify insights and data patterns would have more impact on USITC trade remedy determinations than definitive conclusions about injury based on whether estimates are statistically significant.

Potential pitfalls in the use of p-values and in interpretation of significance levels

1994 ◽  
Vol 33 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Hans-Peter Beck-Bornholdt ◽  
Hans-Hermann Dubben
Keyword(s):  
P Values ◽  
Significance Levels

The Effect of Feature Displacement on Face Recognition

Perception ◽  
1984 ◽  
Vol 13 (5) ◽  
pp. 505-512 ◽  
Author(s):  
Nigel D Haig
Keyword(s):  
Image Processing ◽  
Face Recognition ◽  
Visual Recognition ◽  
High Sensitivity ◽  
Human Beings ◽  
Monitor Screen ◽  
High Significance ◽  
Facial Images ◽  
Vertical Positioning ◽  
Very High

Human beings possess a remarkable ability to recognise familiar faces quickly and without apparent effort. In spite of this facility, the mechanisms of visual recognition remain tantalisingly obscure. An experiment is reported in which image processing equipment was used to displace slightly the features of a set of original facial images to form groups of modified images. Observers were then required to indicate whether they were being shown the “original” or a “modified” face, when shown one face at a time on a TV monitor screen. Memory reinforcement was provided by displaying the original face at another screen position, between presentations. The data show, inter alia, the very high significance of the vertical positioning of the mouth, followed by eyes, and then the nose, as well as high sensitivity to close-set eyes, coupled with marked insensitivity to wide-set eyes. Implications of the results for the use of recognition aids such as Identikit and Photofit are briefly discussed.

scholarly journals Visualization Strategies for Regression Estimates with Randomization Inference

2019 ◽  
Author(s):  
Marshall A. Taylor
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Regression Models ◽  
Statistical Significance ◽  
Permutation Tests ◽  
P Value ◽  
P Values ◽  
Alpha Level ◽  
Significance Levels ◽  
Nonprobability Sample

Coefficient plots are a popular tool for visualizing regression estimates. The appeal of these plots is that they visualize confidence intervals around the estimates and generally center the plot around zero, meaning that any estimate that crosses zero is statistically non-significant at at least the alpha-level around which the confidence intervals are constructed. For models with statistical significance levels determined via randomization models of inference and for which there is no standard error or confidence intervals for the estimate itself, these plots appear less useful. In this paper, I illustrate a variant of the coefficient plot for regression models with p-values constructed using permutation tests. These visualizations plot each estimate's p-value and its associated confidence interval in relation to a specified alpha-level. These plots can help the analyst interpret and report both the statistical and substantive significance of their models. Illustrations are provided using a nonprobability sample of activists and participants at a 1962 anti-Communism school.

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