Correlation Component Analysis Research Articles

Effect of changing climatic variables on abundance of Anopheles mosquitoes (Diptera: Culicidae) in urbanizing Ghaziabad district, Uttar Pradesh, India

Climatic variables like temperature, rainfall and humidity play an important role in dynamics of mosquitoes. But the effect of climate change during urbanization on Anopheles mosquitoes has not been studied. The objective of present study was to explore the effects through the changes in climate variables of urbanizing Ghaziabad District, India on malaria vector Anopheles sp., particularly Anopheles stephensi (Liston) and An. culicifacies sensu lato (Diptera: Culicidae). The study was conducted in urban, rural and peri-urban parts seasonally from April 2014 to October 2016. Association between climate variables, malaria and Anopheles abundance was studied through Pearson’s correlation and Principal Component Analysis (PCA). Results showed that pollution in water bodies and low rainfall has decreased the abundance of An. culicifacies s.l in rural and peri-urban whereas An. stephensi L has increased in rural areas. In urban and peri-urban areas rainfall has lesser influence on An. stephensi hence species breeds throughout the year easily whereas the humidity supports both the vectors. The role of temperature was found to be uncertain, although minimum temperature found to influence vector density as indicated by cluster analysis in the present study.

Distributions, contamination level and ecological risk of heavy metals in surface sediments from intertidal zone of the Sanmen Bay, East China

The concentrations of heavy metals, total organic carbon and total phosphorus were analyzed to assess the environmental pollution characteristics, ecological risk levels, and possible sources of heavy metals in the surface sediments from the intertidal zone of Sanmen Bay. The mean concentrations of As, Cd, Cr, Cu, Hg, Pb and Zn were 14.3 ± 1.4, 0.112 ± 0.018, 84.8 ± 6.0, 40.7 ± 4.4, 0.067 ± 0.008, 30.5 ± 3.3, and 116 ± 1.6 mg/kg dry weight, respectively. The contamination factors and ecological risk assessment indicated that the intertidal zone of Sanmen Bay is not currently facing ecological risk of studied heavy metals. The results of Pearson's correlation and principal component analysis showed that Cd, Cr, Hg, and Pb may be mainly derived from natural inputs, and hydrodynamic condition and organic matter content have major effects on the distribution of heavy metals. However, As, Cu and Zn could come from both natural and anthropogenic sources.

Utilization of Grain Physical and Biochemical Traits to Predict Malting Quality of Barley (Hordeum vulgare L.) under Sub-Tropical Climate.

Barley is the most popular raw material for malting, and recently, the demand for malt-based products has increased several folds in India and other South Asian countries. The barley growing season is peculiar in the sub-tropical plains region compared to European or Northern American conditions, characterized by a total crop duration of 130-145 days with a maximum grain filling duration of around only 35-40 days. A total of 19 barley genotypes were grown for three years to assess the comparative performance in relation to different quality traits, including grain physical traits and biochemical and malt quality parameters. Analysis of variance, Pearson correlation, and principal component analysis were performed to determine the correlation among different traits. The results showed significant genotypic variation among genotypes for individual grain and malt traits. Despite the shorter window for grain filling, several good malting genotypes have been developed for the sub-tropical climates. The genotypes DWRUB52, DWRB101, RD2849, DWRUB64, and DWRB91 were found suitable for malting. Based on correlation studies, a few grain parameters have been identified which can be used to predict the malting potential of a barley genotype. The hot water extract was found to be positively correlated with the grain test weight, thousand-grain weight, and malt friability but was negatively correlated with the husk content. Beta-glucan content varied from 3.4 to 6.1% (dwb); reducing the grain beta-glucan content and increasing the amylase could be priorities to address in future malt barley improvement programs under sub-tropical climatic conditions.

Effect of Parboiling on the Physicochemical and Phytochemicals Characteristics of Traditional Rice Cultivars

Background: The indigenous rice varieties of India are cultivated and utilized by tribal peoples as well as people in the distant regions with traditional culture. The main aim of the research work was to explore the inherit beneficial characteristics of traditional rice cultivars over hybrid varieties. Methods: The research work was aimed to investiagate the physicochemical and phytochemicals characteristics in traditional red rice cultivars (Mapillai Samba and Karungkuruvai) and traditional white rice cultivars (IR 20 and Improved White Ponni). The different treatments used in the study were raw rice (unpolished, polished) and parboiled rice (unpolished, polished). The interaction between physicochemical characteristics and phytochemicals were evaluated using Pearson correlation and Principal component analysis. Result: The physicochemical characteristics were analyzed for all the rice cultivars. It was observed that parboiled-unpolished mapillai samba showed highest length, breadth, 1000 grain weight. The raw rice cultivars showed highest phytochemicals than parboiled rice. The total phenolic, total flavonoids and total anthocyanin contents were highest for the mapillai samba (raw rice-unpolished). Among different traditional rice cultivars, mapillai samba showed significantly higher antioxidant levels. The results of the study suggested that these traditional rice cultivars can be incorporated in value added products.

Application of selection index for rice mutant screening under a drought stress condition imposed at reproductive growth phase

Abstract. Sarwendah M, Lubis I, Junaedi A, Purwoko BS, Sopandie D, Dewi AK. 2022. Application of selection index for rice mutant screening under a drought stress condition imposed at reproductive growth phase. Biodiversitas 23: 5446-5452. Drought is a condition of limited availability of water that can reduce rice growth and productivity, and may threaten food security. Therefore, efforts are needed to produce drought-tolerant rice genotypes. This study aimed to select drought tolerant of the M3 mutant upland rice population at the reproductive growth phase. This research was carried out in dryland at BATAN, Indonesia, from September 2020 to February 2021, using an augmented design. The study employed 360 ??genotypes of mutant upland rice and 5 check varieties, namely Salumpikit, IR20, IR64, Limboto, and Situgintung. The selection index was constructed based on multivariate analyses such as correlation, path, and Principal Component Analysis (PCA). The coefficient of the selected main component can be used as a selection index. Before selecting the character values of each genotype, the values were standardized to obtain the same degree of value. The results showed that grain weight per hill (W.G.), panicle density (P.D.), panicle length (P.L.), and the number of filled grains per panicle (NFG) could be used as selection criteria for mutant upland rice tolerant to drought at reproductive growth phase. The selection index formula was I = (5*0.44*WG) + (2*0.41*PD) + (0.23*PL) + (0.42*NFG). Selection of genotypes of mutant upland rice based on weighted index selection resulted in 89 genotypes with high yields and good agronomic characteristics so that they could be tested in further research.

Variations of Nutrient and Antinutrient Components of Bambara Groundnut (Vigna subterranea (L.) Verdc.) Seeds

Bambara groundnut (BGN) fits the bill when it comes to an acceptable level of nutrient and mineral composition. BGN is a balanced food that can help eradicate food and nutritional insecurity if it is incorporated into the major food system. However, there is a large degree of variation in nutrient composition and antinutritional factors among BGN accessions. Here, we show the degree of variability of nutrient and antinutrient components such as percentage ash, moisture, protein, fat, tryptophan, tannin, and phytate contents in seeds of 95 accessions of BGN. Data were subjected to analysis of variance (ANOVA), followed by correlation and principal component analysis. Clustering was done to show the relatedness between the accessions in response to the various traits. A high level of heterogeneity was observed among the accessions for the various traits studied. PC1 and PC2 show 41.2% of the total observed variations. Cluster analysis grouped accessions into four main clusters. This study was able to confirm the high level of diversity in the components of nutrients and antinutrients previously reported in BGN. The results of this study are expected to aid in identifying parent lines for improved breeding programs.

Distribution Characteristics and Ecological Risk Assessment of Nitrogen, Phosphorus, and Some Heavy Metals in the Sediments of Yueliang Lake in Western Jilin Province, Northeast China

This study seeks to clarify the content characteristics, spatial distribution, potential sources and ecological risks of nitrogen, phosphorus and some heavy metals (As, Hg, Cd, Cr, Cu, Pb, Zn and Ni) in the sediments of Yueliang Lake. Nitrogen, phosphorus and heavy metals were analyzed in the surface and core sediments of Yueliang Lake. The present situation of heavy metal pollution and the degree of potential ecological risk in sediments was evaluated by the geo-accumulation index (Igeo) and potential ecological risk index (RI). The correlation (CA) and principal component analysis (PCA) methods were used to analyze the potential sources of the main pollutants among the heavy metals. The results show that the total nitrogen (TN = 2305 mg/kg) and total phosphorus (TP = 530 mg/kg) in the surface sediments of Yueliang Lake are at medium and low levels, respectively. The average content of organic matter was 2.17%, and the nutrient ratio was 6.90–11.92, which was significantly higher in the northwest than in the middle and east of Yueliang Lake, indicating that the organic matter was a mixture of endogenous aquatic plants and exogenous terrestrial plants in the sediments. From two evaluation indices (RI and Igeo) calculated using element contents, the heavy metals in the surface sediments were at a moderate ecological risk level. The level of Hg was moderately polluted, Pb and Cd were at the mildly polluted level, and Cu, Zn, As, Cr and Ni were at pollution-free levels. Except for Hg, the other elements in the core sediment are basically not polluting, and the whole is at the level of slight ecological risk. The sources of heavy metals in the sediments are roughly divided into three categories. The first category is natural sources, including Cr, Ni, As, Zn and Cu. The second category includes Cd and Hg and the main sources are highly related to energy development and agricultural activities. The third category is light Pb pollution caused by vehicular traffic and coal-related industrial activities. Therefore, the pollution problems caused by tourism development and agricultural activities should be considered in the future development of the Yueliang Lake area.

Study on Droplet Impact and Spreading and Deposition Behavior of Harvest Aids on Cotton Leaves.

The deposition and spreading of pesticide droplets on the surface of plants is a severe challenge to precise pesticide application, which directly affects the pesticide utilization rate and efficacy. Cotton harvest aids are widely used in machine-picked cotton but the effect of formulation and concentration on the droplet behavior and defoliation effect of cotton defoliants is not clear. To clarify the influence of formulation and concentration on the droplet behavior of cotton defoliants, four formulations (suspension concentrate (SC), water dispersible granule (WG), oil dispersion (OD), and wettable powder (WP)) of cotton defoliants were used to prepare different concentrations of harvest aid solutions, according to the spraying volume. The physicochemical properties, droplet impact, and spreading and deposition behavior were studied. The results indicated that the four kinds of harvest aids have good physicochemical properties and can be wet and spread on cotton leaves. The surface tension of the high-concentration harvest aid solution (the spraying volume was less than 1.2 L/667 m2) was increased, which increased the contact angle and reduced the adhesion tension, adhesion work, and the spreading area. Once the harvest aid solution systems impacted the cotton leaves, it could spread to the maximum in a short time (10 ms). The field experiment showed that the droplet spectrum of harvest aids changed slightly, the coefficient of variation (CV) did not exceed 50%, and the defoliation rate was better when the spraying volume was 1.5 L/667 m2. The correlation and principal component analysis showed that the spraying volume (concentration) and coverage were negatively correlated with the defoliation rate, while the viscosity, diffusion factor, and spreading rate were positively correlated with the defoliation rate. Overall, the use of appropriate spraying volume application in cotton fields can improve the performance of spray, increase the effective deposition and wetting spread of defoliants on cotton leaves, further reduce the dosage of defoliants, and improve pesticide utilization. These results can provide a theoretical basis for the scientific preparation and spraying of cotton harvest aid solutions.

Screening of some sweet potato (Ipomoea batatas (L.) Lam) genotypes for yield and damage by Cylas puncticollis under rainfed conditions in Umudike, Southeastern Nigeria

A field experiment was conducted at the National Root Crops Research Institute, Umudike, Southeastern Nigeria during the 2015 and 2016 cropping seasons to evaluate diversity among F1 population of sweet potato, namely: Sauti × 442162 (6), Ligri × Faara (17), Sauti × Bohye (17), including two checks (Umuspo 3 and TIS 87/0087). This experiment was laid out in a randomized complete block design with three replicates under rainfed condition. Data on fresh storage root yield were recorded at 120 days after planting. Analysis of variance, correlation and principal component analysis were utilized for data analysis. The study revealed that yield of fresh storage root showed significant differences (P< 0.05) among the sweet potato genotypes. Sauti X Bohye produced the highest storage root yield (19.33 t/ha) in 2015 and performed better than the national check TIS 87/0087 that recorded a storage root yield of 10.84 t/ha. The result from the study showed that out of the forty genotypes evaluated, twenty-six (26) genotypes recorded attack of C. puncticollis. The extent of the damge recorded among the genotypes attacked by C. puncticollis ranged from severe damage to little damage among the genotypes that recorded fresh storage root damage. SautiXBohye/11, SautiXBohye/13, SautiXBohye/17 recorded severe damage caused by C. puncticollis while LigriXFaara/15 recorded moderate damaged caused by C. puncticollis. Fifteen (15) genotypes did not record any infestation by Cylas puncticollis. All characters except unmarketable storage root weight at harvest exhibited positive and significant (P< 0.01) correlation with total roots weight (yield). Principal component analysis had three main principal components explaining 84.25% of the total variation with number of marketable roots, weight of marketable roots, storage root yield and Cylas incidence contributing the most to the first PCA. These genotypes could possess resistance genes to Cylas puncticollis and these genotypes could be incorporated in breeding programs for further trail.

Fingerprinting of Volatile Organic Compounds as an Advance Technology to Assess the Seed Quality of Groundnut Through Correlation and Principal Component Analysis Method

Background: Groundnut seeds are highly sensitive to deterioration mainly due to their chemical composition and moisture content. The high oil content and fatty acids of groundnut seeds reduces the seed viability well in advance due to lipid peroxidation process, which is the most frequent cause of seed ageing. As a result, not only lipid peroxidation, but also a series of reactions that produce toxic products occur. Stored seeds produce increased level of volatile organic compounds that leads to seed deterioration. Methods: The experiment was conducted to profile volatile organic compounds emitted from groundnut seeds during storage and also to analysis the volatile organic compounds through correlation and principal component analysis method. Volatile organic compounds profiling of stored groundnut seeds was done through Gas Chromatography Mass Spectrometry (GC-MS). The air sample was taken at monthly intervals from the glass bottle using solid-phase micro extraction (SPME) method. Result: The results of the study clearly demonstrated that, totally 52 volatile compounds comprising of 10 alcohols, 5 aldehydes, 15 acids, 9 esters, 7 alkanes, 3 alkenes, 2 ketones and 1 ether were trapped in stored groundnut seeds. Finally the study concluded that ethanol, 1-butanol, 1-hexanol, acetaldehyde, hexanal, Nonenal, 9,12,15-octadecatrionic acid, acetic acid and 3-methyl acetate were found to be highly negatively correlated with seed germination.

Evolution of the morphological, structural, and molecular properties of gluten protein in dough with different hydration levels during mixing.

To understand the formation process of dough with different hydration levels upon mixing and the response of dough rheology, the dynamic evolution of gluten protein was tracked and quantified at morphological, structural, and molecular levels. Both macroscopical and microscopic distribution images showed that partial and full hydration induced quick formation of a more compact gluten network compared with limited hydration. Gluten network in highly hydrated samples was more susceptible to the formation and collapse induced by mechanical force. SE-HPLC results indicated significant depolymerization of glutenin macropolymer (GMP) in fully and partially hydrated samples. Sufficient mixing was accompanied by the increase of ionic and hydrogen bonds, while excessive mixing increased exposure of free -SH. Higher hydration level induced more ordered secondary structure. Correlation and principal component analysis revealed the patterns and dynamics of gluten evolution during dough formation with different hydration levels, and their contribution to the changes in dough modulus.

Analysis and potential ecological risk assessment of heavy metals in surface sediments of the freshwater ecosystem in Zhenjiang City, China

Heavy metals contamination in freshwater ecosystems has drawn attention worldwide. It is necessary to investigate heavy metals content and assess their ecological risk in order to protect the aquatic ecosystems. In this study, we collected surface sediment samples from the freshwater ecosystem of the city of Zhenjiang, in China, in both winter and summer. Then, we analyzed the seasonal and spatial distribution patterns of lead (Pb), chromium (Cr), cadmium (Cd), zinc (Zn), and copper (Cu). The contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), and potential ecological risk (Eri) were jointly used to assess the pollution degree and the ecological risk posed to the freshwater ecosystem by the aforementioned elements. Multivariate statistical analysis, including Pearson’s correlation and principal component analysis and cluster analysis, were used to identify potential sources of the investigated metals in this research area. Study results showed that: (1) the average concentrations values were 1.81 mg/kg and 1.15 mg/kg for Cd, 55.3 mg/kg and 62.2 mg/kg for Cu, 88.0 mg/kg and 52.5 mg/kg for Cr, 27.3 mg/kg and 22.8 mg/kg for Pb, 87.0 mg/kg and 271 mg/kg for Zn, in winter and summer, respectively. Amongst the investigated elements, the average concentrations of Cd, Cu, Cr, and Pb, were above the local background values in winter, whereas, Cd, Cu and Zn concentrations were higher than the background values in Zhenjiang; (2) The CF and EF indicated that Cd had a high contamination degree and a significant enrichment compare to others investigated metals in the surface sediment of in this research area. (3) Cd posed moderate, considerable, or very high ecological risks in different sites, while the other elements (i.e., Cu, Cr, Pb, and Zn) presented a low degree of ecological risk. (4) Multivariate statistical analyses results indicated Pb, Cu, and Zn had similar geochemical characteristics, while, Cd and Cr had significant differences with the above elements. Therefore, Pb, Cu, and Zn probably originate from the same sources, while Cd and Cr might have mixed sources, including both natural sources and human activities. Overall, more attention should be paid to Cd for risk assessment in the current study area. The findings of this study provide fundamental information for the evaluation and management of the heavy metals investigated in the freshwater ecosystem of Zhenjiang.

Contamination and source of metals in surface sediments from the Nandu River of Hainan Island, China.

Concentrations of eight metals, organic carbon (Corg), and eight oxides were measured in 33 river sediment samples from the Nandu River. Sediment quality guidelines (SQGs) showed no severe pollution at all stations. However, according to the geo-accumulation index (Igeo), enrichment factor (EF), and potential ecological risk index (EI and RI), As and Cd were the primary pollutants in the survey area and caused low to moderate potential ecological risk. The positive correlations between Al2O3, TFe2O3, Mn, Corg, and metals indicated that clay, FeMn oxides, and organic carbon content were the main factors for metal accumulation in the study area. From the results of correlation (CA) and principal component analysis (PCA), we inferred that Cr, Ni, Cu, and Zn were mainly from natural sources, while As, Cd, Hg, and Pb were from anthropogenic activities in the Nandu River basin. This was the first study of metal pollution in the surface sediments of the Nandu River, which will serve as a reference for future research.

Morphometrics Diversity and Phenotypic Relationship of the Red Snapper (Lutjanus gibbus) in Northern Papua Waters

Morphometric and meristic studies can be used to identify stocks and relationships between populations of fish resources. Lutjanus gibbus is a fish species commonly found in the waters of northern Papua and is one of the fishery commodities targeted by fishermen other than groupers. In this study, the morphometric and meristic characteristics of L. gibbus snapper from several locations in the northern Papua Seas were addressed. The study was conducted in June and July 2022. One hundred and six fish individuals of the L. gibbus species were examined using the cluster, Pearson correlation, and Principal Component Analysis (PCA). The findings demonstrated a substantial correlation between these species’ morphometric traits, particularly regarding the relationship between the total length and standard length (0.960) of the fish’s bodies. According to PCA analysis, total length, standard length, and distance between the ventral fin and the end of fin origin are the three most important morphometric features. Meristic traits like anal-fin spine and anal-fin soft ray exhibit stable numbers across all populations, but other morphometric traits show significant individual variation. According to the results of Pearson Correlation analysis and dendrogram reconstruction, the populations of L. gibbus in the waters of northern Papua had a strong correlation and a high degree of morphometric similarity. Character relationships and a high degree of similarity indicate that there is no morphometric structure formed between populations.

The study on contamination of bottom sediments from the Odra River estuary (SW Baltic Sea) by tributyltin using environmetric methods

We present the first comprehensive study on the occurrence of tributyltin (TBT) in the Odra River estuary (SW Baltic Sea) that encompasses both densely populated and urbanized agglomeration Szczecin city, and sparsely populated biosphere reserves “Natura 2000”. Relationship between TBT and physicochemical parameters of bottom sediments such as granulometry total organic carbon (TOC), total nitrogen (TN), acid volatile sulfide (AVS), As, and metals: Ba, Cd, Co, Cr, Cu, Fe, Hg, Ni, Mn, Mo, Pb, Sn, and Zn was investigated in 120 samples collected in 2017 and 2018. The highest TBT concentrations were over 3000 ng g−1 (dry weight). They were observed in samples collected in the vicinity of the ship maintenance zones of the Szczecin city. Despite the EU ban on its use since 2003, TBT is still present in the environment. Environmetrics analyses such as correlation, cluster, and principal component analysis of obtained results revealed that the main source of sediments contamination by TBT, metalloids, and metals is likely related to the maritime industry: shipyards, ship maintenance as well as ports and marines. TBT is still present in the bottom sediments because of its emission to the environment with dust and paint chips formed during sandblasting cleaning of ship surfaces. The pollutant is further transported with water current to remote localization in the Szczecin Lagoon. Slow water exchange between the Szczecin Lagoon and the Baltic Sea favors accumulation of pollutants in the lagoon sediments. Therefore, it is necessary to implement environmentally friendly methods into ship maintenance and management of the materials from dredged waterways, harbors, and marinas.

Mapping and understanding of correlated electroencephalogram (EEG) responses to the newsvendor problem

Decision-making is one of the most critical activities of human beings. To better understand the underlying neurocognitive mechanism while making decisions under an economic context, we designed a decision-making paradigm based on the newsvendor problem (NP) with two scenarios: low-profit margins as the more challenging scenario and high-profit margins as the less difficult one. The EEG signals were acquired from healthy humans while subjects were performing the task. We adopted the Correlated Component Analysis (CorrCA) method to identify linear combinations of EEG channels that maximize the correlation across subjects (n=23) or trials (n=40). The inter-subject or inter-trial correlation values (ISC or ITC) of the first three components were estimated to investigate the modulation of the task difficulty on subjects’ EEG signals and respective correlations. We also calculated the alpha- and beta-band power of the projection components obtained by the CorrCA to assess the brain responses across multiple task periods. Finally, the CorrCA forward models, which represent the scalp projections of the brain activities by the maximally correlated components, were further translated into source distributions of underlying cortical activity using the exact Low Resolution Electromagnetic Tomography Algorithm (eLORETA). Our results revealed strong and significant correlations in EEG signals among multiple subjects and trials during the more difficult decision-making task than the easier one. We also observed that the NP decision-making and feedback tasks desynchronized the normalized alpha and beta powers of the CorrCA components, reflecting the engagement state of subjects. Source localization results furthermore suggested several sources of neural activities during the NP decision-making process, including the dorsolateral prefrontal cortex, anterior PFC, orbitofrontal cortex, posterior cingulate cortex, and somatosensory association cortex.

Analysis of Landscape Pattern Evolution and Driving Forces Based on Land-Use Changes: A Case Study of Yilong Lake Watershed on Yunnan-Guizhou Plateau

In order to explore the landscape pattern evolution and driving forces of the Yilong Lake watershed, the combined method of supervised classification with manual visual interpretation based on the landsat5TM/8OLI remote sensing image data sources was used to establish a high-precision spatial distribution information database of the Yilong Lake watershed. Landscape index was used to analyze the distribution and spatial pattern change characteristics of various land-use types. Based on correlation and principal component analysis, we discuss the relationship between the change characteristics of land-use type, distribution and spatial pattern, and the interference of local socio-economic development and natural factors. The results show that: (1) In the past 30 years, the land-use types of the Yilong Lake watershed are mainly forest, garden plot and cultivated land. The forest area decreased significantly by 30.45 km2, of which the fastest reduction stage was from 2000 to 2005, with a total reduction of 20.56 km2. The garden plot conversion is relatively large, with a total of 181.69 km2 transferred out, of which 28.84 km2 has become unused land, respectively. (2) In the past 30 years, the maximum patch index decreased by 9.94% and the patch density index increased by 14.25%, indicating that the landscape fragmentation in the whole basin increased. The Shannon diversity index showed an increasing process; the aggregation index showed a decreasing process. (3) The change in landscape pattern in the watershedwas closely related to economic growth, population growth, social affluence and agricultural development. Natural factors, social factors and economic indicators are significantly positively correlated with patch density, edge density, landscape shape index and Shannon diversity index, and significantly negatively correlated with the largest patch index and the contagion index. On the whole, the wetlands in the basin are shrinking and the landscape diversity is changing. Reducing the excessive impact of human activities on the watershed ecosystem is a key factor for the local protection of wetland resources and the maintenance of wetland ecological functions.

The Possibility of Studying the Processes of Interconversion of Volatile Compounds of Needles on the Basis of Static Data

The results of a study of the population structure of biochemical features (a large number of volatile needle terpenoids) on large samples of Scots pine trees are presented. Data were analyzed using correlation, cluster, and principal component analysis. Significant conjugation of the content of all isolated needle compounds was shown. Features of the correlation structure of terpenoids indicate that the processes of their group synthesis can be simultaneously triggered in plants. It is concluded that it is possible to use static data obtained on large samples of trees for a preliminary study of the processes of interconversions of terpenoid compounds in coniferous plants, which are characterized by high reactivity and the complexity of their study by chemical methods.

Covariance-based vs. correlation-based functional connectivity dissociates healthy aging from Alzheimer disease

Prior studies of aging and Alzheimer disease have evaluated resting state functional connectivity (FC) using either seed-based correlation (SBC) or independent component analysis (ICA), with a focus on particular functional systems. SBC and ICA both are insensitive to differences in signal amplitude. At the same time, accumulating evidence indicates that the amplitude of spontaneous BOLD signal fluctuations is physiologically meaningful. We systematically compared covariance-based FC, which is sensitive to amplitude, vs. correlation-based FC, which is not, in affected individuals and controls drawn from two cohorts of participants including autosomal dominant Alzheimer disease (ADAD), late onset Alzheimer disease (LOAD), and age-matched controls. Functional connectivity was computed over 222 regions of interest and group differences were evaluated in terms of components projected onto a space of lower dimension. Our principal observations are: (1) Aging is associated with global loss of resting state fMRI signal amplitude that is approximately uniform across resting state networks. (2) Thus, covariance FC measures decrease with age whereas correlation FC is relatively preserved in healthy aging. (3) In contrast, symptomatic ADAD and LOAD both lead to loss of spontaneous activity amplitude as well as severely degraded correlation structure. These results demonstrate a double dissociation between age vs. Alzheimer disease and the amplitude vs. correlation structure of resting state BOLD signals. Modeling results suggest that the AD-associated loss of correlation structure is attributable to a relative increase in the fraction of locally restricted as opposed to widely shared variance.

Soil texture influences on soil health scoring functions in Ontario agricultural soils: a possible framework towards a provincial soil health test

Since soil health is impacted by inherent soil properties, it is, therefore, challenging to apply the same soil health frameworks across multiple regions and soil types. Here, we examined the effect of soil textural group (coarse, medium, and fine) on four soil health indicators of soils sampled from diverse agricultural systems across Ontario. Scoring functions were developed by calculating cumulative normal distributions, using the mean and standard deviation of each soil health indicator, for three or five soil textural groups. For each soil health indicator, soil health scoring values were provided using the “more is better” approach, where greater soil health scores implied better soil health. Soil health indicators were significantly affected by three but not all five soil textural groups. Evolved NH3 and CO2, and potentially mineralizable N had stronger associations with each other as revealed by correlation and principal component analysis. Our results also suggested that mean separation of the tested soil health indicators was more consistent with three soil textural groups (coarse, medium, and fine) than five soil textural groups (clays, clay loams, loams, sandy loams, and sand); therefore, we recommend using three soil textural groups to develop soil health scoring functions. The findings of this study lay a groundwork for future soil health assessment involving a larger number of samples across Ontario and more soil indicators, which will facilitate the regional interpretation of soil health.