The Relationship Between Surface Curvature and Abdominal Aortic Aneurysm Wall Stress

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Sergio Ruiz de Galarreta ◽  
Aitor Cazón ◽  
Raúl Antón ◽  
Ender A. Finol
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Mean Curvature ◽  
Linear Regression Analysis ◽  
Wall Stress ◽  
Outer Wall ◽  
Maximum Diameter ◽  
Patient Specific ◽  
Abdominal Aortic ◽  
The Relationship

The maximum diameter (MD) criterion is the most important factor when predicting risk of rupture of abdominal aortic aneurysms (AAAs). An elevated wall stress has also been linked to a high risk of aneurysm rupture, yet is an uncommon clinical practice to compute AAA wall stress. The purpose of this study is to assess whether other characteristics of the AAA geometry are statistically correlated with wall stress. Using in-house segmentation and meshing algorithms, 30 patient-specific AAA models were generated for finite element analysis (FEA). These models were subsequently used to estimate wall stress and maximum diameter and to evaluate the spatial distributions of wall thickness, cross-sectional diameter, mean curvature, and Gaussian curvature. Data analysis consisted of statistical correlations of the aforementioned geometry metrics with wall stress for the 30 AAA inner and outer wall surfaces. In addition, a linear regression analysis was performed with all the AAA wall surfaces to quantify the relationship of the geometric indices with wall stress. These analyses indicated that while all the geometry metrics have statistically significant correlations with wall stress, the local mean curvature (LMC) exhibits the highest average Pearson's correlation coefficient for both inner and outer wall surfaces. The linear regression analysis revealed coefficients of determination for the outer and inner wall surfaces of 0.712 and 0.516, respectively, with LMC having the largest effect on the linear regression equation with wall stress. This work underscores the importance of evaluating AAA mean wall curvature as a potential surrogate for wall stress.

The Relationship Between Wall Stress and 3D Asymmetry in Repaired and Ruptured Abdominal Aortic Aneurysms

2010 ◽  
Author(s):  
Barry J. Doyle ◽  
Tim M. McGloughlin
Keyword(s):  
Risk Factors ◽  
Wall Stress ◽  
Posterior Wall ◽  
Aortic Aneurysms ◽  
Three Dimensions ◽  
Maximum Diameter ◽  
Patient Specific ◽  
Infrarenal Aorta ◽  
Abdominal Aortic ◽  
The Relationship

Abdominal aortic aneurysm (AAA) is a permanent dilation of the infrarenal aorta and is defined as having a diameter 50% greater than the original diameter. If left untreated, an AAA will continue to expand until rupture. The maximum diameter is currently the primary indicator of rupture-risk with AAAs > 5.5 cm deemed a likely to rupture. There have, however, been many reports identifying the inadequacies of the maximum diameter criterion to accurately determine the threat of rupture. It is believed by many researchers that there is a need to review the decision of surgical intervention based solely on aneurysm diameter, and rather include other relevant risk factors. These additional risk factors could, for example, include, AAA wall stress, AAA expansion rate, degree of asymmetry, presence of intraluminal thrombus (ILT), and hypertension. The addition of these parameters may aid the surgical decision-making process. A previous report by our group identified the relationship between asymmetry and posterior wall stress in patient-specific cases [1,2] and as over 80% of ruptures occur on the posterior wall [3] this finding may have significant clinical relevance. In this previous report, the study group was limited to 15 cases and asymmetry was only measured in the anterior-posterior plane. This current paper furthers this previous work by increasing the cohort to 40 cases of electively repaired AAAs and also examines 8 cases of ruptured AAAs. The methodology has been improved to now measure asymmetry in all three dimensions (3D).

The Influences of Palindromes in mRNA on Protein Folding Rates

2020 ◽  
Vol 27 (4) ◽  
pp. 303-312 ◽  
Author(s):  
Ruifang Li ◽  
Hong Li ◽  
Sarula Yang ◽  
Xue Feng
Keyword(s):  
Protein Folding ◽  
Regression Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Folding Rate ◽  
Folding Rates ◽  
Negative Linear Correlation ◽  
Protein Folding Rate ◽  
The Relationship ◽  
Structure Environment

Background: It is currently believed that protein folding rates are influenced by protein structure, environment and temperature, amino acid sequence and so on. We have been working for long to determine whether and in what ways mRNA affects the protein folding rate. A large number of palindromes aroused our attention in our previous research. Whether these palindromes do have important influences on protein folding rates and what’s the mechanism? Very few related studies are focused on these problems. Objective: In this article, our motivation is to find out if palindromes have important influences on protein folding rates and what’s the mechanism. Method: In this article, the parameters of the palindromes were defined and calculated, the linear regression analysis between the values of each parameter and the experimental protein folding rates were done. Furthermore, to compare the results of different kinds of proteins, proteins were classified into the two-state proteins and the multi-state proteins. For the two kinds of proteins, the above linear regression analysis were performed respectively. Results : Protein folding rates were negatively correlated to the palindrome frequencies for all proteins. An extremely significant negative linear correlation appeared in the relationship between palindrome densities and protein folding rates. And the repeatedly used bases by different palindromes simultaneously have an important effect on the relationship between palindrome density and protein folding rate. Conclusion: The palindromes have important influences on protein folding rates, and the repeatedly used bases in different palindromes simultaneously play a key role in influencing the protein folding rates.

scholarly journals HUBUNGAN PERSEPSI TENTANG PROFESI FISIOTERAPI DENGAN MOTIVASI BELAJAR MAHASISWA AKADEMI FISIOTERAPI UKI

2018 ◽  
Vol 10 (3) ◽  
pp. 226
Author(s):  
Maksimus Bisa
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Correlation Analysis ◽  
Correlation Coefficient ◽  
Linear Regression Analysis ◽  
Motivation To Learn ◽  
Simple Linear Regression ◽  
Level 1 ◽  
Relationship Of ◽  
The Relationship

ABSTRACTThis study is descriptive analitik, aims to describe the relationship of perceptions about the physiotherapy profession with the motivation to learn students of the Academy of Physiotherapy UKI. Data collection through questionnaires to students of Physiotherapy Academy UKI level 1, 2, and 3 with a sample of 53 students, then give a score of each statement of questionnaire.The result of correlation analysis shows that p = 0,584> α (0,05) ho is accepted, so there is no significant relationship between the two variables. To measure the closeness and intensity of the relationship between the two variables, test of correlation coefficient and simple linear regression. The result of correlation coefficient test (r) obtained by -0,077, lies below the value of -0.30 (very weak) thus can be said there is no relation between perception about physiotherapy profession with motivation learn student Akfis UKI. Result of linear regression analysis obtained equation: Y = 73,52 + (-0,088) X. This means that every 1 point decrease of perception value will influence motivation value equal to 0,088 times.Keywords: Perception, motivation, physiotherapy profession, and learning achievement. ABSTRAKPenelitian ini bersifat deskriptif analitik, bertujuan untuk mendeskripsikan hubungan persepsi tentang profesi fisioterapi dengan motivasi belajar siswa Akademi Fisioterapi UKI. Pengumpulan data melalui kuesioner kepada siswa Fisioterapi Academy UKI tingkat 1, 2, dan 3 dengan sampel sebanyak 53 siswa, kemudian memberikan skor masing-masing kuesioner pernyataan. Hasil analisis korelasi menunjukkan bahwa p = 0,584> α (0,05) ho diterima, sehingga tidak ada hubungan yang signifikan antara kedua variabel tersebut. Untuk mengukur kedekatan dan intensitas hubungan antara kedua variabel tersebut, uji koefisien korelasi dan regresi linier sederhana. Hasil uji koefisien korelasi (r) diperoleh sebesar -0,077, berada di bawah nilai -0,30 (sangat lemah) sehingga dapat dikatakan tidak ada hubungan antara persepsi tentang profesi fisioterapi dengan motivasi belajar siswa Akfis UKI. Hasil analisis regresi linier diperoleh persamaan: Y = 73,52 + (-0,088) X. Artinya setiap 1 titik penurunan nilai persepsi akan mempengaruhi nilai motivasi sebesar 0,088 kali.Kata kunci: Persepsi, motivasi, profesi fisioterapi, dan prestasi belajar.

Pengaruh Promosi terhadap Penjualan Polis Asuransi Syariah

2020 ◽  
Vol 3 (2) ◽  
pp. 144-152
Author(s):  
Ermayanis Ermayanis ◽  
Nurse Fatimah MZ
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Quantitative Methods ◽  
Linear Regression Analysis ◽  
Insurance Companies ◽  
Simple Linear Regression ◽  
Insurance Policy ◽  
Insurance Policies ◽  
Islamic Insurance ◽  
The Relationship

This study aimed to determine the effect of promotion on the sales of Islamic insurance policies at PT. Asuransi Takaful Keluarga RO Riau Agency Pekanbaru. This research was motivated by the development of Islamic insurance companies both in terms of assets and in terms of company contributions that have an impact on insurance policy sales. The formulation of the problem in this study was to determine the effect of the relationship promotion on insurance policy sales. This research used quantitative methods with simple linear regression analysis. The sample in this study was 49 respondents. Based on the results of the partial test (t-test), the tcount was 1.391 <t-table 2.016, so the promotion had no significant effect on the variable sales of the insurance policy of PT. Asuransi Takaful Keluarga RO Riau Pekanbaru. The regression results showed that the promotion variable does not affect sales.

The relationship between transformational leadership and job satisfaction in selected colleges at King Khalid University, Abha, Saudi Arabia

2019 ◽  
Author(s):  
Esther Iriagbonse Eroje ◽  
Erasmus Kofi Appiah ◽  
Alezi Braimoh Ifindon Eroje ◽  
MEER ZAKIRULLA ◽  
Jimly James Kunjappu ◽  
...  
Keyword(s):  
Job Satisfaction ◽  
Transformational Leadership ◽  
Saudi Arabia ◽  
Regression Analysis ◽  
Linear Regression ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Leadership Behaviour ◽  
R Value ◽  
The Relationship

Abstract Background Leadership has become the key issues in managing the organization, the emerging business and economic environments have forced organizations to be flexible, adaptive, entrepreneurial and innovative to meet changing demand of the present-day business environment. The purpose of the present study is to examine the relationship between the various dimensions of transformational leadership (predictor variable) and their effects on employees’ job satisfaction (criterion variable) in three selected Colleges (Medicine, Dentistry and Science) in King Khalid University. Methods The methodology employed in this study was a quantitative and cross-sectional correlational survey type of design Data collection was done using a questionnaire design that was directly administered to the participants. 250 questionnaires were sent to the participating three colleges (Medicine, Dentistry and Sciences). Results The findings of the multiple linear regression analysis indicated a weak positive association between transformational leadership behaviour and employees’ job satisfaction (R-value 0.386). The multiple linear regression analysis signifies a weak positive correlation between transformational leadership behaviour and job satisfaction (R-value 0.386). A p-value in Spearman’s rho that is less than the 0.05 level of significance indicated that there is a significant level of relationship which exists between transformational leadership behaviour and job satisfaction. Conclusions This study concluded that transformational leadership behaviour and its four dimensions showed a weak positive correlation with a statistically significant level of relationship between transformational leadership behaviour and employees’ job satisfaction among three selected colleges (Medicine, Dentistry and Sciences) in King Khalid University, Abha, Saudi Arabia.

scholarly journals Strategic Management in the Relationship between Competitiveness and Organizational Performance in MSMES of the Service Sector in Mexico

2017 ◽  
Vol 12 (4) ◽  
pp. 55
Author(s):  
Marisol Sanchez Guerrero ◽  
Alejandro Arellano Gonzalez ◽  
Nidia J. Rios Vazquez
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Strategic Management ◽  
Organizational Performance ◽  
Service Sector ◽  
Linear Regression Analysis ◽  
Food And Beverage ◽  
Positive Direct ◽  
The Relationship

The objective of this research is to analyze the influence of strategic management on competitiveness and organizational performance, an issue that is present in micro, small and medium-sized enterprises in the food and beverage preparation industry of the service sector. The study sample was of 200 Mexican organizations from Ciudad Obregón, Sonora. The results indicated that strategic management has a positive, direct and significant effect on competitiveness. The results that were obtained by means of linear regression analysis make it possible to assert that the interaction between both variables (strategic management and competitiveness) establishes significant differences in the levels of organizational performance. It was concluded that the enhancement of strategic management contributes to the increase in organizational performance. Therefore, a joint intervention must take place on strategic management and competitiveness.

Scavenging by Alloperla (Plecoptera: Chloroperlidae) nymphs on dead pink (Oncorhynchus gorbuscha) and chum (O. keta) salmon embryos

1968 ◽  
Vol 46 (4) ◽  
pp. 787-796 ◽  
Author(s):  
Stephen J. Nicola
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Chum Salmon ◽  
Linear Regression Analysis ◽  
Oncorhynchus Gorbuscha ◽  
Beneficial Effects ◽  
Salmon Eggs ◽  
The Relationship

The relationship between stonefly nymphs of the genus Alloperla and developing pink and chum salmon embryos was studied in Harris River, Alaska, from August, 1965, to April, 1966. Polyethylene containers with alternating layers of salmon eggs and washed gravel and containers with washed gravel only were buried in sections of an upstream spawning riffle and were removed and examined in three sampling periods. Correlation and linear regression analysis of numbers of missing embryos, dead embryos, and stonefly nymphs in the containers supported the hypothesis that the nymphs were scavengers but failed to support the hypothesis that they were predators.Some of the beneficial effects to living embryos of scavenging by nymphs is discussed, as well as the likelihood of occurrence of predation by stonefly nymphs in general.

Use of the Photoelastic Method to Determine the Wall Stress in Realistic Abdominal Aortic Aneurysm Models

2011 ◽  
Author(s):  
Barry J. Doyle ◽  
Anthony Callanan ◽  
John Killion ◽  
Timothy M. McGloughlin
Keyword(s):  
Wall Stress ◽  
Aortic Aneurysms ◽  
Maximum Diameter ◽  
Patient Specific ◽  
Western World ◽  
Photoelastic Method ◽  
Element Analysis ◽  
Abdominal Aortic ◽  
The Us ◽  
Numerical Tools

Abdominal aortic aneurysms (AAAs) remain a significant cause of death in the Western world with over 15,000 deaths per year in the US linked to AAA rupture. Recent research [1] has questioned the use of maximum diameter as a definitive risk parameter as it is now believed that alternative factors may be important in rupture-prediction. Wall stress was shown to be a better predictor than diameter of rupture [1], with biomechanics-based rupture indices [2,3] and asymmetry also reported to have potential clinical applicability [4]. However, the majority of numerical methods used to form these alternative rupture parameters are without rigorous experimental validation, and therefore may not be as accurate as believed. Validated experiments are required in order to convince the clinical community of the worth of numerical tools such as finite element analysis (FEA) in AAA risk-prediction. Strain gauges have been used in the past to determine the strain on an AAA [5], however, the photoelastic method has also proved to be a useful tool in AAA biomechanics [6]. This paper examines the approach using three medium-sized patient-specific AAA cases at realistic pressure loadings.

Influence of Tempertature on Corrosion Behavior of DH36 Steel in Seawater Full Immersion Zone

2015 ◽  
Vol 1120-1121 ◽  
pp. 1115-1118
Author(s):  
Peng Cheng ◽  
Xian Qiu Huang
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Linear Regression Analysis ◽  
Artificial Seawater ◽  
Corrosion Behaviors ◽  
Corrosion Problem ◽  
Full Immersion ◽  
The Relationship

Aimed at the corrosion problem of DH36 steel in the seawater full immersion zone, corrosion environment of full immersion zone has been simulated with artificial seawater in laboratory. The corrosion behaviors of DH36 steel in the full immersion zone were investigated by using full immersion tests. The morphology of corrosion products was observed by SEM. Using linear regression analysis to establish the relationship between temperature and the corrosion of DH36 steel. The results showed that the corrosion of DH36 steel immersed in full immersion zone corroded seriously, and the corrosion rate of DH36 steel increased with temperature increasing.

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