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Search Results: 1 - 10 of 4475 matches for " correlation "
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Critical analysis of correlation and heritability phenomenon in the silkworm, Bombyx mori (Lepidoptera: Bombycidae)  [PDF]
Tribhuwan Singh, Madan Mohan Bhat, Mohammad Ashraf Khan
Advances in Bioscience and Biotechnology (ABB) , 2011, DOI: 10.4236/abb.2011.25051
Abstract: Correlation and heritability studies of quantitative traits are a pre-requisite for judicious selection for genetic improvement of complex characters of economic importance. The success of selection is governed by the degree to which the desired trait is transmitted to the succeeding generation. The nature of selection is to be given due consideration at appropriate developmental stages for pursuing selection in desired direction while improving or evolving high productive breeds or hybrids of the silkworm. Characters showing high heritability as well as high genetic advance respond better to simple phenotypic selection while those having low heritability and low genetic advance may respond better to mass selection. Characters showing high heritability and low genetic advance may yield good response to hybridization and recurrent selection. An attempt has been made in this review article to briefly discuss the magnitude of correlation and heritability in selection strategies for the improvement of quantitative traits in desired direction in the silkworm, Bombyx mori (L.).
No Demonstrable Relationship Was Found between Alcohol Dependence and Concomitant Drug Abuse amongst Detainees in Police Custody in West Yorkshire, England  [PDF]
Remy Bahl, William P. Tormey
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.55057
Abstract:

The behavioural effects of alcohol and drug abuse may lead to arrest by the police. Individuals who abuse one substance may be at risk of developing multiple drug dependencies. Using the forensic records, data were collected on 50 successive subjects detained in police custodies across West Yorkshire, England who had gave history of alcohol addiction to a single practitioner. The degree of correlation between alcohol dependency and illicit drug usage was assessed by calculating the Spearman’s Rank coefficient. Thirty three subjects in this study did not use any illicit drugs. There was no correlation between alcohol dependency and concomitant drug abuse in this group. Spearman’s coefficient was statistically insignificant (p = 0.230). Kruskal’s Gamma, which is used for comparing ordinal data, also failed to show a significant link between the alcohol and drug group (p = 0.185). As the degree of alcohol dependency increased, co-use of other drugs decreased. Conversely as the use of stronger drugs increased, co-use with alcohol and other drugs increased. Alcohol dependency is a distinct disorder. Once alcoholism had set in, the use of other drugs falls. The forensic behavioural patterns linked alcohol with “violent disorder” and Class A drug abuse with “organised crime”. This study does not support the contention that most alcohol dependent individuals will also abuse illicit drugs.

Environmental and Occupational Risk Factors Effect to Arterial Hypertension: Correlation between Arterial Hypertension and Lead  [PDF]
D. Оyunbileg, I. Bolormаа, U. Tsolmon, О. Chimedsuren
Journal of Geoscience and Environment Protection (GEP) , 2015, DOI: 10.4236/gep.2015.32010
Abstract:

The main risk factors for hypertension include smoking, the consumption of alcohol, poor dietary habits, lack of exercise, and stress. Scientists have also linked exposure to lead as a risk factor for hypertension. Chemicals are fundamental negative factors for occupational health as they penetrate an organism through the respiratory tract in the state of vapors, gases, dust, and others. There is high correlation between the concentration of chemicals in the environment and time spent of exposure to the chemicals. Some chemicals compounds penetrate through the respiratory tract and irritate the upper respiratory track and lung lobes. They have different influences depending on their solubility. Lead has a harmful effect on organism when it is in higher doses than normal. It exerts an especially harmful effect upon the nervous and circulatory systems. Sources of environmental lead pollution are benzene, coal, paints containing lead, and some working conditions. A population based case controlling model of an analytic study was used. For the study data analysis SPSS 20.0 program were applied single and combined risk factors were accounted by regressive investigation method and results gained were expressed by odds ratio and 95% confidence interval (95% CI) p value. The goal is to assess the correlation of lead to arterial hypertension among miners of the Gobi region provinces. In the sampling we employed a random collection method with collection ratio of 1:2. One hundred miners with hypertension took part in the study. In the control group people without hypertension were assigned and they were of the same age and sex with the experimental group. Among the participants, those of working age had a high prevalence of hypertension and the disease is beginning to affect those of a younger age as well. 82% of those in the experimental group work in hard working conditions and 86% of them work for an average of 11.3 hours in noisy and dusty conditions. The increase of blood-lead content greatly depends on service length. Miners with arterial hypertension who worked for many years had a high content of lead in their blood. Lead content in the air outside of working places has a weak correlation (r = 0.3) with hypertension among those in the experimental group and was statistically significant (p = 0.007). With an increased blood-lead content, a risk for arterial hypertension (AH) increased two times (OR = 2.11 [95% CL; 1.52 - 2.94], p = 0.0001). But lead content in drinking water has an inversely associated with

Multivariate Volatility Regulated Kelly Strategy: A Superior Choice in Low Correlated Portfolios  [PDF]
Ruanmin Cao, Zhenya Liu, Shixuan Wang, Weifeng Zhou
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.75098
Abstract: We propose a Multivariate Volatility Regulated Kelly strategy, which has extra penalization on variance compared to the Kelly criterion. The objective function is constructed and solved. We show the superiority of our method in relatively low correlated portfolios, relative to the fractional Kelly and full Kelly strategies. Our strategy reduces the short-term risk without sacrificing the growth rate to invest more in risk-free assets. Simulation results and Chinese commodity future empirical results strongly support our method.
Document Analysis of Correlation between Climate and Stroke  [PDF]
Hongwei Li, Yonggang Qian, Shubi Wang, Hairong Zhang, Wenfang Gou, Mingzhu Niu, Di Yu, Ruijie Wu, Liqun Gao, Baofeng Chi, Qingxia Wang, Wenli Hao, Wuyuntana Li, Tao Yan, Liwei Niu, Yan Liu, Jing Zhao, Yuan Jin, Maolin Du, Juan Sun
Open Journal of Epidemiology (OJEpi) , 2019, DOI: 10.4236/ojepi.2019.91008
Abstract: Aim: The aim of the research is to determine characteristic of the correlation between climate and stroke through the analysis of relevant documents. Methods: We found 115 researches of temperature and season on stroke mortality/incidence and these were categorized according to location, meteorology, date span, data source and research sites’ latitudes. We divided the globe into 5 temperature zones based on latitude ranges: 0 - 10, 10 - 23.5, 23.5 - 40, 40 - 50, and >50 degrees, and allotted a zone to each country. Stroke mortality by five temperature zones was calculated per 100,000 people. Results: 70% of the researches came from latitudes greater than 40 degrees with 92% of researches located in Europe, USA, and Asia. The mortality range was 42 - 63 per 105 individuals within latitudes 0 - 40 degrees. In latitudes 40 - 66.5 degrees, a linear upward trend (y = 69.82x 22.823, R2 = 0.99) was noticed. More than 75% of the research reports indicated a negative correlation between climate and stroke, and the proportion was almost 6 and 7 times greater than that of the fluctuation and non-correlation, respectively. The most frequently used research methods were regression analysis and time series analysis. Conclusion: All of the research results confirmed that lower temperature is associated with higher mortality and incidence of stroke, while higher latitude is correlated with higher stroke mortality, consistent with the temperature zones.
Extended Correlations in Finance  [PDF]
Mark Burgin, Gunter Meissner
Journal of Mathematical Finance (JMF) , 2016, DOI: 10.4236/jmf.2016.61017
Abstract:

Extended correlations, i.e. correlations that can take values less than − 1?and/or larger than 1, occur naturally in mathematical models of financial processes. Extended correlations also occur in financial practice, especially in dispersion trading, implying arbitrage opportunities. Based on theoretical and practical emergence of extended correlations, we derive a mathematical framework for extended correlations explaining interpretations and applications. We develop a broader mathematical approach, which can model conventional as well as extended correlations.

EEGcorco: a computer program to simultaneously calculate and statistically analyze EEG coherence and correlation  [PDF]
Miguel Angel Guevara, Marisela Hernández-González, Araceli Sanz-Martin, Claudia Amezcua
Journal of Biomedical Science and Engineering (JBiSE) , 2011, DOI: 10.4236/jbise.2011.412096
Abstract: EEGcorco is a computer program designed to analyze the degree of synchronization between two electroencephalographic signals (EEG) by mean the analysis of correlation and coherence index. The correlation and coherence values permit the quantitative determination of the similarity among EEG signals from homologous areas of the cerebral hemispheres (interhemispheric), and among localized areas within one cerebral hemisphere (intrahemispheric). EEG coherence is a function of frequency; thus it is commonly presented in a spectral manner (coherence values in every frequency of the spectrum), in contrast, the correlation function has been employed mainly to search periodic components of bioelectrical signals, and normally appears as punctual values defined in time, hence it is not common calculate correlation spectra. EEGcorco offers an easy and novel way to calculate correlation spectra by mean the application of the Fast Fourier Transformation (FFT) to digitized EEG signals. Both, correlation and coherence spectra are obtained in both independent frequencies and frequencies grouped in wide bands. Moreover, the program applies parametric statistical analyses to those coherence and correlation spectra also, for each individual frequency and for the frequencies grouped in bands. The program functions on any PC-compatible computer equipped with a Pentium or superior processor and a minimum of 512 Mb of RAM memory (though the higher the capacity the better). The space required on the hard disk depends on the signals to be analyzed, as the output takes the form of files in text format that occupy very little space. The program has been elaborated completely in the Delphi environment for the Windows operating system. The efficacy and versatility of EEGcorco allow it to be easily adapted to different experimental and clinical needs.
The Risk of Impaired Coagulation in Surgical Jaundice: An Analysis of Routine Parameters  [PDF]
David O. Irabor
Surgical Science (SS) , 2012, DOI: 10.4236/ss.2012.33023
Abstract: The study is a retrospective study of 30 patients who had operations for obstructive jaundice at the University College Hospital Ibadan, Nigeria between 1998 and 2003. The aim was to see if one could predict the patients at risk of bleeding by analysing the routine investigations like the Packed Cell Volume (PCV), Serum bilirubin levels, Alkaline phosphatase and the International Normalised Ratio (INR). These parameters were analysed against the age and pathology of the condition i.e. the respective diagnoses. The male/female ratio was 1:1.4 and the mean age was 52.8 years. The mean total bilirubin was 14.2 mg% (241.4 micromol/L) and the mean PCV was 31.6%. The condition of the pathology was split between carcinoma of the head of pancreas, carcinoma of the gall bladder, common bile duct stone and peri-ampullary carcinoma. The results suggest that the risk of haemorrhage increases with age and the levels of bilirubin beyond 15 mg% (255 micromol/L) in persons with carcinoma of the gall bladder.
Limit of the Principal’s Information  [PDF]
Kazumi Hori
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.72018
Abstract: This note characterizes the optimal contract when a principal has unverifiable subjective information that is correlated with an agent’s private information. We find that the principal’s subjective information cannot alleviate the information asymmetry and, moreover, the second best contract is independent from it if the correlation is low.
Estimation of Tree Height and Forest Biomass Using Airborne LiDAR Data: A Case Study of Londiani Forest Block in the Mau Complex, Kenya  [PDF]
Faith Kagwiria Mutwiri, Patroba Achola Odera, Mwangi James Kinyanjui
Open Journal of Forestry (OJF) , 2017, DOI: 10.4236/ojf.2017.72016
Abstract: Tactical decisions on natural resource management require accurate and up to date spatial information for sustainable forest management. Remote sensing devices by the use of multispectral data obtained from satellites or airborne sensors, allow substantial data acquisition that reduce cost of data collection and satisfy demands for continuous precise data. Forest height and Diameter at Breast Height (DBH) are crucial variables to predict volume and biomass. Traditional methods for estimation of tree heights and biomass are time consuming and labour intensive making it difficult for countries to carry out periodic National forest inventories to support forest management and REDD+ activities. This study assessed the applicability of LiDAR data in estimating tree height and biomass in a variety of forest conditions in Londiani Forest Block. The target forests were natural forest, plantation forests and other scattered forests analysed in a variety of topographic conditions. LiDAR data were collected by an aircraft flying at an elevation of 1550 m. The LIDAR pulses hitting the forest were used to estimate the forest height and the density of the vegetation, which implied biomass. LiDAR data were collected in 78 sampling plots of 15 m radius. The LiDAR data were ground truthed to compare its accuracy for above ground biomass (AGB) and height estimation. The correlation coefficients for heights between LiDAR and field data were 0.92 for the pooled data, 0.79 in natural forest, 0.95 in plantation forest and 0.92 in other scattered forest. AGB estimated from LiDAR and ground truthed data had a correlation coefficient of 0.86 for the pooled data, 0.78 in natural forest, 0.84 in plantation forest and 0.51 in other scattered forests. This implied 62%, 84% and 89% accuracy of AGB estimation in natural forests, other scattered forests and plantation forests respectively. The even aged conditions of plantation forests might have resulted to better estimates of height and AGB as compared to uneven aged natural forests and scattered forests. The results imply the reliability of using Airborne LIDAR scanning in forest biomass estimates in Kenya and are an option for supporting a National Forest Monitoring System for REDD+.
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