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"Statistical correlation"
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Mapping of soil erosion-prone sub-watersheds through drainage morphometric analysis and weighted sum approach: a case study of the Kulfo River basin, Rift valley, Arba Minch, Southern Ethiopia
by
Dawit, Zerihun
,
Abebe, Abel
,
Jothimani, Muralitharan
in
Agricultural management
,
Bifurcations
,
Chemistry and Earth Sciences
2020
In the present study, soil erosion prioritization of sub-watersheds of the Kulfo River basin was conducted by adopting a drainage morphometric analysis along with a statistical correlation matrix-based weighted sum approach. The drainage network extracted and sub-watershed boundaries were demarcated through GIS techniques using advanced space-borne thermal emission and reflection–digital elevation model (ASTER–DEM). The Kulfo River basin was separated into six sub-watersheds (SW-1 to SW-6), and different morphometric criteria were calculated using the standard formula. And, morphometric parameters like drainage frequency, bifurcation ratio, drainage density, form factor, circulatory ratio, drainage texture, elongation ratio, compact coefficient, and length of overland flow have been considered for sub-watershed prioritization. Based on the results, the Kulfo River basin’s sub-watersheds were categorized into five priority classes: very low, low, medium, high, and very high. The results illustrate the sub-watersheds (SW-1, SW-2, SW-3, and SW-6) that approximately 65% of the Kulfo River basin’s total area fall under the very high, high, and medium soil erosion-prone areas, respectively. Therefore, the above-mentioned four sub-watersheds can be a value for the consideration of the soil protection plan. The outcomes derived from this study will be valuable information for several partners like agriculturists, surface and groundwater wealth administrators, and decision-makers for improving the soil management process. The current research shows that ASTER–DEM data, GIS approach, and a statistical correlation matrix-based weighted sum approach are vibrant tools for watershed prioritization in data-scarce regions.
Journal Article
Hydrochemical evaluation of groundwater quality: a case study from parts of North-Central, Nigeria
by
Adewoye, Folashade Omolola
,
Obasaju, Daniel Opemipo
,
Ige, Olusegun Omoniyi
in
Boreholes
,
Calcium chloride
,
Calcium ions
2021
Hydrochemical character of groundwater samples from a part of North-Central Nigeria has been investigated to decipher the physicochemical properties, sources of dissolved ions, hydrochemical facies, factors influencing the groundwater chemistry as well as the suitability of the waters for drinking and irrigation purposes. Sixty-seven (67) groundwater samples from hand-dug wells and boreholes were subjected to major ions and heavy metal analyses. The results were further analysed and studied using Pearson’s statistical correlation, ionic ratios and variation plots. The Pearson’s statistical correlation shows that there exists a very strong correlation between water hardness (TH) with Ca
2+
(0.99) and Mg
2+
(0.91), this indicates that both ions originate from similar sources. The ionic ratio plots of HCO
3
and Mg/Na versus Ca/Na; Ca
2+
+ Mg
2+
/HCO
3
−
+ SO
4
2−
; (Ca
2+
+ Mg
2+
) vs total cations (TZ); (Na + K) vs total cations (TZ) revealed that both carbonate dissolution and silicate weathering serve as major contributor of ions to groundwater chemistry in the study area. Piper and Schoeller’s plots revealed that majority of the water samples are of CaHCO
3
type, and few NaHCO
3
and CaCl
2
types. Gibbs plot suggested that chemical weathering of rocks, ionic exchange and secondary carbonates dissolution and precipitation influenced the groundwater chemistry. Comparison of the concentrations of the ions to World Health Organization (WHO) and Standard Organization of Nigeria (SON) showed that they are generally within permissible limits and therefore suitable for drinking purpose. Irrigation parameters such as, electrical conductivity, sodium adsorption ratio, Wilcox ratio, residual sodium carbonate (RSC), sodium solubility percentage (SSP), magnesium ratio/hazard (MR), permeability index (PI), Kelly ratio/index (KI), all revealed that > 90% of water samples fell into suitable, good and excellent water class and are thus generally suitable for irrigation purposes.
Journal Article
Causal discovery-based post mining method for operation anomaly detection of building energy systems
2025
Association rule mining has shown outstanding capacity in extracting operation patterns from extensive building operational data. However, it typically generates a large number of association rules, most of which fail to reveal useful patterns. It is still unclear about how to develop effective methods to extract useful association rules. Additionally, it is challenging to extract clear insights from fragmented association rules, as a single rule can represent multiple meanings. To address these issues, advanced post mining methods are necessary for automatically eliminating most of worthless association rules. Therefore, this study proposes a causal discovery-based post mining method that uses Granger causality tests, based on the time series characteristics of building operational data, to replace traditional strong correlation tests in association rule mining. This method effectively integrates causality with statistical correlation to assess the value of association rules. The average causal effect is introduced to clarify the causal relationships between variables in association rules. By grouping rules with similar variables, it clarifies the expression of these relationships, enhancing interpretation efficiency and clarity. Causal strength is introduced to evaluate the intensity of each association rule, which can improve the robustness of rule assessment. The proposed method is evaluated using 20,564 association rules extracted from the historical operational data of an actual chiller plant in summer. Three common indexes (support, confidence, lift) are selected as benchmarks for comparison with the proposed method. The traditional method identifies 15,245 knowledge items as valuable, with an actual value density of 9.73%, while the proposed method identifies 625 knowledge Items with a value density of 95.52%. It proves that the proposed method has excellent performance in extracting valuable association rules, with significant advantages in clarity of meaning, precision, and user-friendliness.
Journal Article
Key indicators of Arctic climate change: 1971-2017
by
Christensen, Torben Røjle
,
Pawlak, Janet
,
Overland, James E
in
Air temperature
,
AMAP
,
Aquatic animals
2019
Key observational indicators of climate change in the Arctic, most spanning a 47 year period (1971-2017) demonstrate fundamental changes among nine key elements of the Arctic system. We find that, coherent with increasing air temperature, there is an intensification of the hydrological cycle, evident from increases in humidity, precipitation, river discharge, glacier equilibrium line altitude and land ice wastage. Downward trends continue in sea ice thickness (and extent) and spring snow cover extent and duration, while near-surface permafrost continues to warm. Several of the climate indicators exhibit a significant statistical correlation with air temperature or precipitation, reinforcing the notion that increasing air temperatures and precipitation are drivers of major changes in various components of the Arctic system. To progress beyond a presentation of the Arctic physical climate changes, we find a correspondence between air temperature and biophysical indicators such as tundra biomass and identify numerous biophysical disruptions with cascading effects throughout the trophic levels. These include: increased delivery of organic matter and nutrients to Arctic near-coastal zones; condensed flowering and pollination plant species periods; timing mismatch between plant flowering and pollinators; increased plant vulnerability to insect disturbance; increased shrub biomass; increased ignition of wildfires; increased growing season CO2 uptake, with counterbalancing increases in shoulder season and winter CO2 emissions; increased carbon cycling, regulated by local hydrology and permafrost thaw; conversion between terrestrial and aquatic ecosystems; and shifting animal distribution and demographics. The Arctic biophysical system is now clearly trending away from its 20th Century state and into an unprecedented state, with implications not only within but beyond the Arctic. The indicator time series of this study are freely downloadable at AMAP.no.
Journal Article
MultiPhen: Joint Model of Multiple Phenotypes Can Increase Discovery in GWAS
by
Calboli, Federico C. F.
,
Elliott, Paul
,
Hoggart, Clive J.
in
Analysis
,
Autoimmune diseases
,
Biology
2012
The genome-wide association study (GWAS) approach has discovered hundreds of genetic variants associated with diseases and quantitative traits. However, despite clinical overlap and statistical correlation between many phenotypes, GWAS are generally performed one-phenotype-at-a-time. Here we compare the performance of modelling multiple phenotypes jointly with that of the standard univariate approach. We introduce a new method and software, MultiPhen, that models multiple phenotypes simultaneously in a fast and interpretable way. By performing ordinal regression, MultiPhen tests the linear combination of phenotypes most associated with the genotypes at each SNP, and thus potentially captures effects hidden to single phenotype GWAS. We demonstrate via simulation that this approach provides a dramatic increase in power in many scenarios. There is a boost in power for variants that affect multiple phenotypes and for those that affect only one phenotype. While other multivariate methods have similar power gains, we describe several benefits of MultiPhen over these. In particular, we demonstrate that other multivariate methods that assume the genotypes are normally distributed, such as canonical correlation analysis (CCA) and MANOVA, can have highly inflated type-1 error rates when testing case-control or non-normal continuous phenotypes, while MultiPhen produces no such inflation. To test the performance of MultiPhen on real data we applied it to lipid traits in the Northern Finland Birth Cohort 1966 (NFBC1966). In these data MultiPhen discovers 21% more independent SNPs with known associations than the standard univariate GWAS approach, while applying MultiPhen in addition to the standard approach provides 37% increased discovery. The most associated linear combinations of the lipids estimated by MultiPhen at the leading SNPs accurately reflect the Friedewald Formula, suggesting that MultiPhen could be used to refine the definition of existing phenotypes or uncover novel heritable phenotypes.
Journal Article
Diverse Cretaceous larvae reveal the evolutionary and behavioural history of antlions and lacewings
2018
Myrmeleontiformia are an ancient group of lacewing insects characterized by predatory larvae with unusual morphologies and behaviours. Mostly soil dwellers with a soft cuticle, their larvae fossilize only as amber inclusions, and thus their fossil record is remarkably sparse. Here, we document a disparate assemblage of myrmeleontiform larvae from the mid-Cretaceous amber (99 Ma) of Myanmar, evidence of a considerable diversification. Our cladistic analysis integrating extant and extinct taxa resolves the fossils as both stem- and crown-groups. Similarities between extinct and extant species permit inferences of larval ethology of the fossil species through statistical correlation analyses with high support, implying that morphological disparity matched behavioural diversity. An improved understanding of the evolutionary history of antlions and relatives supports the conclusion that hunting strategies, such as camouflage and fossoriality, were acquired early within the lineage.
Larvae of the Myrmeleontiformia, which include antlions, are not well preserved in much of the fossil record. Here, Badano et al. describe a collection of predatory myrmeleontiform larvae from Cretaceous amber, resolving their evolutionary relationships and inferring their ecology.
Journal Article
Evaluating the quality of life among melasma patients using the MELASQoL scale: A systematic review and meta-analysis
by
Zhu, Yuan
,
Ying, Jieya
,
Zeng, Xiaofang
in
Biology and Life Sciences
,
Complications and side effects
,
Correlation
2022
According to the literature, pigmentary disorders have a significantly negative impact on a person's health-related quality of life. Moreover, among pigmentary disorders, incidence of melasma ranks high. The Melasma Area and Severity Index (MASI) is the scale that is generally used to evaluate a melasma-affected area and its severity. However, the relationship between the MASI and Melasma Quality of Life (MELASQoL) scores, as well as the impact of melasma on patients' quality of life, remain unclear.
To explore the influence of melasma on patients' lives, analyze the relationship between the MASI and MELASQoL scores, and identify the factors that may be influencing the quality of life of patients with melasma.
Two reviewers independently searched four databases (PubMed, Embase, the Cochrane Library, and Web of Science) for literature on quality of life of patients with melasma. In addition to an epidemiological study, a cross-sectional study, and validation studies, gray literature was also included. StataSE version 16 software was used for the meta-analysis. The score of each item on the MELASQoL scale was determined using a random-effects model.
Fourteen studies with a total of 1398 melasma patients were included in the systematic review, four of which were eligible for meta-analysis. The relationship between the MELASQoL and MASI scores was found to be mixed. Five studies concluded that the MASI and MELASQoL scores were statistically correlated, while seven studies found no statistical correlation between the two. It is obvious that melasma causes emotional distress and has a negative impact on patients' social lives. Patients were most bothered by the appearance of their skin condition. However, the MELASQoL score had no definite correlation with patient characteristics such as age, education levels, and history.
Melasma has a significant negative impact on patients' quality of life. Thus, evaluating the quality of life of patients with melasma should not be ignored. Additionally, utilization of the MELASQoL scale should be considered in the care plan. Further studies with larger sample sizes are needed to confirm the relationship between melasma and quality of life.
Journal Article
The mechanisms and meteorological drivers of the summertime ozone–temperature relationship
2019
Surface ozone (O3) pollution levels are strongly correlated with daytime surface temperatures, especially in highly polluted regions. This correlation is nonlinear and occurs through a variety of temperature-dependent mechanisms related to O3 precursor emissions, lifetimes, and reaction rates, making the reproduction of temperature sensitivities – and the projection of associated human health risks – a complex problem. Here we explore the summertime O3–temperature relationship in the United States and Europe using the chemical transport model GEOS-Chem. We remove the temperature dependence of several mechanisms most frequently cited as causes of the O3–temperature “climate penalty”, including PAN decomposition, soil NOx emissions, biogenic volatile organic compound (VOC) emissions, and dry deposition. We quantify the contribution of each mechanism to the overall correlation between O3 and temperature both individually and collectively. Through this analysis we find that the thermal decomposition of PAN can explain, on average, 20 % of the overall O3–temperature correlation in the United States. The effect is weaker in Europe, explaining 9 % of the overall O3–temperature relationship. The temperature dependence of biogenic emissions contributes 3 % and 9 % of the total O3–temperature correlation in the United States and Europe on average, while temperature-dependent deposition (6 % and 1 %) and soil NOx emissions (10 % and 7 %) also contribute. Even considered collectively these mechanisms explain less than 46 % of the modeled O3–temperature correlation in the United States and 36 % in Europe. We use commonality analysis to demonstrate that covariance with other meteorological phenomena such as stagnancy and humidity can explain the bulk of the remainder of the O3–temperature correlation. Thus, we demonstrate that the statistical correlation between O3 and temperature alone may greatly overestimate the direct impacts of temperature on O3, with implications for the interpretation of policy-relevant metrics such as climate penalty.
Journal Article
Healthy lifestyle during pregnancy: Uncovering the role of online health information seeking experience
by
Rezaee, Rita
,
Ravangard, Ramin
,
Dehghani Tafti, Arefeh
in
Biology and Life Sciences
,
Computer and Information Sciences
,
Correlation
2022
In the new era, many people seek their health-related information through the Internet due to the increasing access to this technology. Searching online health information can affect the health behavior. This study aimed to investigate the correlation between online health information-seeking behavior and a healthy lifestyle during pregnancy in a sample of Iranian pregnant women. This cross-sectional study was conducted among pregnant women admitted to health centers of Eghlid city, Fars province, Iran in 2019. A total of 193 women participated in the study. The required data were gathered using two validated questionnaires to measure the online health information-seeking behavior and the healthy lifestyle practices of the participants. The collected data were analyzed through descriptive statistics and Pearson correlation coefficient using SPSS version 22. Online health information experience and its subscales showed no statistical correlation with a healthy lifestyle. Age and education did not correlate with online health information-seeking behavior. Age had a statistical correlation with a healthy lifestyle, but education had the same correlation only with some subscales of a healthy lifestyle. The findings were surprising, suggesting that online health information-seeking behavior does not affect the lifestyle of pregnant women. These finding and probable explanations are discussed, but due to the limited literature on the subject, further studies are recommended to be conducted.
Journal Article
Experimental and Statistical Study on Mechanical Characteristics of Geopolymer Concrete
2020
This paper studies the statistical correlation in mechanical characteristics of class F fly ash based geopolymer concrete (CFGPC). Experimentally measured values of the compressive strength, elastic modulus and indirect tensile strength of CFGPC specimens made from class F fly ash (CFA) were presented and analyzed. The results were compared with those of corresponding ordinary Portland cement concrete (OPCC) using statistical hypothesis tests. Results illustrated that when possessing similar compressive and tensile strength, the elastic modulus for CFGPC is significantly lower than that of OPCC. The corresponding expressions recommended by standards for the case of OPCC is proved to be inaccurate when applied in the case of CFGPC. Statistical regression was used to identify tendencies and correlations within the mechanical characteristics of CFGPC, as well as the empirical equations for predicting tensile strength and elastic modulus of CFGPC from its compressive strength values. In conclusion, CFGPC and OPCC has significant differences in terms of the correlations between mechanical properties. The empirical equations obtained in this study could provide relatively accurate predictions on the mechanical behavior of CFGPC.
Journal Article