Revisiting the role of correlation coefficient to distinguish chaos from noise

2000 ◽  
Vol 13 (2) ◽  
pp. 399-403 ◽  
Author(s):  
J. Bhattacharya ◽  
P.P. Kanjilal
1987 ◽  
Vol 58 (02) ◽  
pp. 744-748 ◽  
Author(s):  
A R Saniabadi ◽  
G D O Lowe ◽  
J C Barbenel ◽  
C D Forbes

SummarySpontaneous platelet aggregation (SPA) was studied in human whole blood at 3, 5, 10, 20, 30, 40 and 60 minutes after venepuncture. Using a whole blood platelet counter, SPA was quantified by measuring the fall in single platelet count upon rollermixing aliquots of citrated blood at 37° C. The extent of SPA increased with the time after venepuncture, with a correlation coefficient of 0.819. The inhibitory effect of dipyridamole (Dipy) on SPA was studied: (a) 10 μM at each time interval; (b) 0.5-100 μM at 3 and 30 minutes and (c) 15 μM in combination with 100 μM adenosine, 8 μM 2-chloroadenosine (2ClAd, an ADP receptor blocker) and 50 μM aspirin. There was a rapid decrease in the inhibitory effect of Dipy with the time after venepuncture; the correlation coefficient was -0.533. At all the concentrations studied, Dipy was more effective at 3 minutes than at 30 minutes after venepuncture. A combination of Dipy with adenosine, 2ClAd or aspirin was a more effective inhibitor of SPA than either drug alone. However, when 15 μM Dipy and 10 μM Ad were added together, the inhibitory effect of Dipy was not increased significantly, suggesting that Dipy inhibits platelet aggregation independent of Ad. The increase in SPA with the time after venepuncture was abolished when blood was taken directly into the anticoagulant containing 5 μM 2ClAd. It is suggested that ADP released from the red blood cells is responsible for the increased platelet aggregability with the time after venepuncture and makes a serious contribution to the artifacts of in vitro platelet function studies.


2012 ◽  
Vol 2 (4) ◽  
pp. 187
Author(s):  
Hossein Safarzadeh ◽  
Alireza Soloukdar ◽  
Ali Alipour ◽  
Seyedeh Akram Parpanchi

Emotion and power have been studied very deeply especially during the last decade; however, the common effects of these two factors on individuals' optional behaviors (organizational citizenship, anti-productivity, unethical behaviors) have been less focused. In the present paper, the role of individuals' emotionality, their interest in power, and their tendency to unethical behaviors will be discussed according to the model of Levine. Three questionnaires were distributed and the collected data were analyzed using Pearson’s Correlation Coefficient, Multiple Regression, and T- test. Findings indicated that there is a significant relationship between the two independent variables of emotionality and power and tendency to unethical behaviors. Moreover, according to the results of the tests, men are more emotion-oriented and power seekers than women. Keywords: Power, Emotion, Ethical Behaviors


2010 ◽  
Vol 14 (1) ◽  
pp. 303-314
Author(s):  
Katarzyna Podhorodecka

Abstract The author seeks an answer to the question whether a higher intensity of tourism movement is connected with a higher share of tourism in the economy in selected tropical island territories. With the use of the Spearman correlation coefficient, the existence of the average positive correlation between the intensity of tourism movement and the share of tourism in the economy has been determined. In the second part of paper, the author looks at the conditions which affect the role of tourism in the economy in proportion to the intensity of tourism movement. For this purpose, the Chi-square test and detailed case studies of chosen tropical islands are discussed.


2008 ◽  
Author(s):  
Georgios Aim. Skianis ◽  
Konstantinos G. Nikolakopoulos ◽  
Dimitrios A. Vaiopoulos

2020 ◽  
Vol 44 (2) ◽  
pp. 74-78
Author(s):  
Charlotte Taylor ◽  
Lukasz P. Zielinski ◽  
Mohammed M. Chowdhury ◽  
Patrick A. Coughlin

Lower limb arterial calcification associates with poor cardiovascular outcomes. The gold standard method of assessment is via computed tomography, yet duplex is our primary imaging modality. Currently, there is no standardized objective assessment of lower limb arterial calcification using duplex. We aimed to define the role of duplex in the assessment of lower limb arterial calcification. Initial consensus was achieved between a cohort of vascular scientists on objective imaging specific markers of lower limb arterial calcification severity using duplex. This resulted in objective descriptions to grade calcification from 0 to 3 (no calcification through to severe calcification) which formed the duplex lower limb arterial calcification score. Reproducibility of the duplex lower limb arterial calcification score was assessed and further validation was undertaken by comparing the duplex lower limb arterial calcification with computed tomography–based assessment in a separate cohort of 44 patients investigated with both modalities. The intra- and inter-class correlation coefficient were > 0.87 . The Spearman rank correlation coefficient between the duplex and CT based arterial calcium measurements was (ρ = 0.644, P < .001). The duplex lower limb arterial calcification score provides a standardized and reproducible modality for assessment of lower limb arterial calcification and may aid with risk stratification in patients with peripheral arterial disease.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
M Gavazzoni ◽  
M Z Zuber ◽  
A P Pozzoli ◽  
M T Taramasso ◽  
F M Maisano

Abstract Background/Introduction. Recently the central role of hemodynamic invasive monitoring during MitraClip (Abbott Vascular, Santa Clara, CA, USA) procedure has been raised. After removal of Steerable Guide Catheter (SGC) at the end of procedure, iatrogenic interatrial septum defect determines acute sub-clinical hemodynamic changes depending on right atrial (RA) and left atrial (LA) pressures. The possibility to assess LAP non-invasively by Doppler -echocardiography at the end of the procedure allows to quantify real hemodynamic impact of reduction of MR and leaves the door open to further therapeutic decisions (such as closure of iatrogenic IASd). Purpose This prospective study aimed to assess the role of evaluation of post-procedural mean trans-atrial gradient with continuous-wave (CW) Doppler (DPmean-IAS) in estimating final m-LAP after removal of SGC. Methods We prospectively performed the computation of trans-atrial CW- Doppler tracing for estimation of mean-transatrial gradient (meanGp-LA-RA) in patients treated with MitraClip; we added the estimation of central venous pressure (CVP) according to: i) dilatation of superior vena cava (IVC, mm); ii) presence or not of systolic excursion of IVC (end-inspiratory excursion was not evaluable in patients under sedation); iii) hepatic vein dilatation. The sum of CVP estimated and meanGp-LA-RA (mmHg) represents the m-LAP-Echo-measured at the end of procedure. This value has been compared with m-LAP measured invasively before removal of SGC. We tested the inter-rater reliability with the Intra-class Correlation Coefficient for comparing this method with the gold standard (invasive assessment of LAP). Results we included 19 patients; aetiology of MR was degenerative in 89% of cases. Basal m-LAP was 15 ± 13,3 mmHg and decreased by 32% by the end of procedure (mean-LAP at the end: 10,1 ± 3,3 mmHg, p &lt; 0.001). At the end of the procedure mean Gp-LA-RA was 2.5 ± 1.2 mmHg and CVP 7.5 ± 3.5; the m-LAP-Echo-measured was 9.6 ± 2.4. The delay in time of computation of m-LAP by echocardiography with respect to last invasive assessment available was computed and settled around 5 minutes (IQR 3-9 min). The inter-rater reliability with the Intra-class Correlation Coefficient was high: 0.8, (CI95% 0.647-0.948, p &lt; 0.01); with Bland-Altman test we could assess that bias of measures was acceptable for this clinical context with upper concordance limit of 2,7 mmHg and lower of 4,7 mmHg, with a bias of 0,9 mmHg, not relevant for this clinical purpose. Conclusions The present study represents the first validation of a Doppler-based method for non invasively assessing post-procedural LAP in percutaneous mitral valve interventions requiring transeptal approach. Follow up is needed for correlate this value with clinical outcomes.


2011 ◽  
Vol 26 (S2) ◽  
pp. 444-444
Author(s):  
R. Allahyarahmadi

AimThe study investigated the role of social and economic factors on religion beliefs in university students.MethodParticipants were 150 students from Babol Payame Noor University that were randomly selected and Religious Beliefs Inventory (RBI) administered on them. The data were analyzed with correlation coefficient formula.ResultsFindings showed significant relationship between student and their father's level of income and literacy, culture, gender, resident place, social category, mass media with religion believes.


2017 ◽  
Vol 2 (1) ◽  
pp. 159
Author(s):  
I Gusti Ayu Oka Suryawardani ◽  
Agung Suryawan Wiranatha

Digital marketing intends to influence consumers’ desire, cognition, feelings, belief, attitude and image concerning products and brands which has the ultimate goal to influence consumers’ purchase behaviour.  Digital marketing has been widely used to promote tourism around the world, including Sanur Village Festival in Bali.  Sanur Village Festival is one of the famous events in Bali which has been held annually since year 2005 in order to recover image and reputation of Bali as a peaceful destination after terrorism attacks.  Research was designed to examine the role of digital marketing in visitors’ behavioural intention in visiting Sanur Village Festival 2015.  Research was undertaken in the area of Sanur Village Festival (SVF) on 26 - 30 August 2015.  The number of respondents was 207 visitors. Data was analysed by using SmartPLS program.The results show that among four indicators, only indicator of event advertisement significantly influences visitors’ intention in visiting SVF with Alpha Cronbach coefficient is 0.59 (≥ 0.6) and  correlation coefficient is 0.369 (≥ 0.3).  Meanwhile, three other indicators, namely source of event’s information, accompany to visit, and event’s arrangement is not significant to influence visitors’ intention to visit SVF.  Among types of advertisement, the results show that the highest percentage of advertisement’s type which affected the visitors’ intention to visit SVF is the use of digital advertisement, namely television (41.2%), internet (32.7%), and broadcast (13.4%).  However, non-digital advertisement has less influence, namely printed media (4.8%), banner (4.5%) and brochure (3.4%).  Understanding development of preferred weblogs and portals by internet users is very important to be able to get more success in gaining specific target market, as people are getting more internets oriented.  The results indicate that successful promotional strategy in the information and technological era should be focused on digital marketing with a clear focus on efficiency, sustainability and experiences enrichment.  However, it cannot be denied that other factors such as attitudes toward behaviour and perceived behaviour control are also defining factors in influencing consumers’ purchase behaviour which is also need to be focused on.


Jurnal Ecopsy ◽  
2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Maya Irka Anggriani ◽  
Hemy Heryati Anward ◽  
Rooswita Santia Dewi

Penelitian ini bertujuan untuk mengetahui ada tidaknya peranan suasana kerja terhadap keinginan pindah kerja karyawan. Populasi pada penelitian ini yaitu seluruh karyawan PT. Hasnur Jaya Utama. Jenis pengambilan sampel yang dilakukan pada penelitian ini adalah Purposive Random Sampling yaitu pemilihan sampel secara acak sesuai dengan karakteristik yang ditentukan berdasarkan tujuan penelitian yang berjumlah 60 orang.  Sedangkan metode pengumpulan data dengan menggunakan skala suasana kerja, skala kepuasan kerja dan kuesioner keinginan pindah kerja. Dalam penelitian ini analisis data menggunakan analisis regresi linear sederhana. Hasil analisis peranan suasana kerja terhadap kepuasan kerja, diperoleh koefisien korelasi R sebesar 0,759 artinya hubungan suasana kerja dan kepuasan kerja erat. Ditemukan juga koefisien determinasi (R2) yang menunjukkan peranan suasana kerja terhadap kepuasan kerja sebesar 57,5% dan untuk analisis t observasi (8,882) > t tabel (1,672) menunjukkan  ada peranan suasana kerja terhadap kepuasan kerja. Kemudian, hasil analisis peranan kepuasan kerja terhadap keinginan pindah kerja ditemukan koefisien regresi R (0,680) artinya kepuasan kerja dan keinginan pindah kerja memiliki hubungan yang cukup erat. Selanjutnya, diperoleh juga (R2) yang menunjukkan peranan kepuasan kerja terhadap keinginan pindah kerja sebesar 46,3%  dan   untuk  analisis   t   observasi (-7,069) t tabel (1,672) menunjukkan ada peranan kepuasan kerja terhadap keinginan pindah kerja dengan signifikan negatif. Berdasarkan hasil penelitian tersebut maka dapat ditarik kesimpulan bahwa suasana kerja dan kepuasan kerja pada karyawan perlu diperhatikan oleh perusahaan agar dapat meminimalkan keinginan pindah kerja karyawan. Kata Kunci: Suasana kerja, kepuasan kerja, keinginan pindah kerjaThis study purposed to determine whether there is the influence of the working atmosphere to intention turnover on employees. The population in this study are all employees of PT. Hasnur Jaya Utama. Type of sampling conducted in this study is Purposive Random Sampling is the selection of a random sample according to the characteristics that are determined based on the research goals of 60 people. The methods of data collection by using the scale of the working atmosphere, the scale of job satisfaction and intention turnover questionnaire. In this study analyzes the data using simple linear regression analysis. The results of the analysis of the influence of working atmosphere to job satisfaction, the correlation coefficient R of 0.759 means that the relationship working atmosphere and job satisfaction is quite close. Also found the coefficient of determination (R2) which indicates the role of working conditions on job satisfaction at 57.5% and for the analysis of observation (8.882) > t table (1.672) which indicates means that the influence of the atmosphere to job satisfaction. Then, the results of the analysis of the influence of job satisfaction to intention turnover a correlation coefficient R (0.680) means that job satisfaction and intention turnover to have a close relationship. Furthermore, also obtained (R2 ) which indicates the role of job satisfaction to intention turnover of 46,3% and for the analysis of t observation (-7.069) > t table (1.672) which indicates means that the influence of job satisfaction to intention turnover with a significant negative . Based on these results it can be concluded that the working atmosphere and job satisfaction in employees need to be considered by the company in order to minimize intention turnover ob the employees. Keywords: The working atmosphere, job satisfaction, intention turnover.


1987 ◽  
Author(s):  
A R Saniabadi ◽  
G D O Lowe ◽  
C D Forbes

Spontaneous platelet aggregation (SPA) was studied in human whole blood at 3,5, 10, 20, 30, 40 and 60 minutes after venepuncture. Using a whole blood platelet counter (Ultra Flo 100), SPA was quantified by measuring the fall in single platelet count upon rollermixing aliquots of blood at 37°C. The extent of SPA increased with the time after venepuncture, with a correlation coefficient of 0.819. The inhibitory effect of dipyridamole (Dipy) on SPA was studied: (a) 10-5M at each time interval; (b) 0.5-100 x 10-6M at 3 and 30 minutes, and (c) 15 x 10-6M in combination with 2 x 10-4M adenosine (Ad), 8 x 10-6M 2-chloradenosine (2ClAd, a specific ADP receptor blocker) and 5 x 10-5M aspirin. There was a rapid decrease in the inhibitory effect of Dipy with the time after venepuncture; the correlation coefficient was -0.533. At all the concentrations studied, Dipy was more effective at 3 minutes than at 30 minutes after venepuncture. A combination of Dipy withAd, 2ClAd or aspirin was a more effective inhibitor of SPA than either drug alone. However, when an effective concentration of Dipy and an ineffective concentration of Ad (10-4M) were addedtogether, the inhibitory effect of Dipy was not increased, suggesting that Dipy inhibits platelet aggregation independent of Ad.The increase in SPA with the time after venepuncture was abolished when bloodwas taken directly into the anticoagulant containing 2ClAd (5 x 10-6M). We conclude that ADP released from the red blood cells is responsible for the increased platelet aggregability with the time after venepuncture, and makes a serious contribution to the artifacts ofin vitro platelet function studies. Furthermore, the decrease in the inhibitory action of Dipy with the time after venepuncture may explain why previously, it has not been possible to observe inhibition of platelet aggregation by Dipy in platelet rich plasma which requires time to prepare.


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