Principal Component Analysis Biplot Research Articles

Discriminability and uncertainty in principal component analysis (PCA) of temporal check-all-that-apply (TCATA) data

Temporal check-all-that-apply (TCATA) data can be summarized and explored using principal component analysis (PCA). Here we analyze TCATA data on Syrah wines obtained from a trained sensory panel. We evaluate new and existing methods to explore the uncertainty in the PCA scores. To do so, we use the bootstrap procedure to obtain many virtual panels from the real panel’s data. Virtual-panel PCA scores are obtained using two methods. The first method, called the partial bootstrap (PB), obtains virtual-panel scores from regression. The second method, called the truncated total bootstrap (TTB), applies PCA to the virtual-panel results to obtain scores, which are truncated and superimposed on the real-panel scores by Procrustes rotation. We use the virtual scores from each method to investigate uncertainty in the real-panel PCA scores visually and numerically. To understand the uncertainty of the scores, we obtain confidence ellipses (CEs) and their areas, as well as confidence intervals (CIs) and their widths. Next, to determine whether PCA scores for different samples are well separated, we propose a procedure for approximating the standard errors of sample differences and correcting for multiple comparisons. We propose a discriminability index, and show that it can enhance the interpretability of PCA results. We incorporate graphical features into our PCA biplots to visualize discriminability. We did not find a large difference between the PB and TTB methods for understanding the uncertainty and discriminability in PCA scores. Although the TCATA data that we analyzed have a special structure, the methodological approaches presented here can be readily adapted to other applications of PCA.

BIPLOT ANALYSIS ON PRINCIPAL COMPONENTS OF HUMAN DEVELOPMENT IN ASEAN COUNTRIES

The Human Development Index (HDI) has been the key indicator for assessing the development of a country throughout the years. It is conducted from four indicators that represent the health dimension, the education dimension, and the standard of living dimension. In ASEAN countries, the HDI tends to rise from year to year, with some countries can achieve the very high and high level of human development, while the others are still in the medium level. The aim of this study is to find the information about relative positions, characteristic similarities between ASEAN countries and the diversity of the components that construct the human development index. The Principal Component Analysis Biplot used divides the ten countries into four groups. Group 1 are the countries with the high scores especially in GNI per capita, group 2 are the ones with high scores especially in the mean years of schooling, group 3 have low scores especially in GNI per capita, and group 4 have low scores especially in the mean years of schooling

English

Salinity stress is one of the leading abiotic stresses seriously affecting the crop productivity across the world. Early growth stages are more affected by salinity stress than terminal growth stages. Therefore, maize genotypes were evaluated for their performance in three different studies (Experiment-1: irrigation of seeds with salt solutions (distilled water, 4 dS/m, 6 dS/m and 10 dS/m) for 5 days, Experiment-2: application of different salinity treatments (distilled water, 4 dS/m, 6 dS/m and 10 dS/m) for 20 days from sowing to seedling emergence stage, Experiment-3: application of salinity stresses in hydroponic culture under four above mentioned different salinity treatments. Time to start germination (TSG), time to 50% germination (TFG) and final germination percentage (FGP) of the maize genotypes was reduced by salinity stress. Radicle length, plumule length, root and shoot length and fresh weight and chlorophyll contents were also linearly reduced in maize genotypes by increasing salinity levels. Moreover, sodium (Na+) concentration was increased in seeds and seedlings of maize genotypes whereas; potassium (K+) concentration was reduced with gradual rise in salinity levels. Principal Component Analysis (PCA) biplots facilitated the efficient assortment of susceptible, moderately susceptible, moderately tolerant and tolerant maize genotypes for each of the three studies separately. Genotype „YS-2008‟ was susceptible for seed treatment and hydroponic studies whereas, genotype „T267-5‟ was susceptible for early seedling and hydroponic studies. Genotype „C864-284‟ was tolerant in early seedling and hydroponic studies. The GGE biplot analysis indicated that „YS-2008‟ genotype was susceptible for salinity stress. Under hydroponic conditions, genotypes could effectively be discriminated by the imposition of severe salt stress (10 dS/m); however, under seed treatments and early seedling growth stages, mild stress treatments (4 dS/m) were sufficient enough to discriminate the maize genotypes. Hydroponic evaluation of genotypes is suitable and preferable under high stress conditions at early growth stages. Identified tolerant and susceptible genotypes could be effectively used in different breeding programs to develop salt tolerant new cultivars for commercial purposes. © 2021 Friends Science Publishers

Effect of capsaicinoids in hot pepper powder on microbial community and free sugar during kimchi fermentation.

Effect of capsaicinoids in hot pepper powder (HP) contains various chemical compounds, including capsaicin and dihydrocapsaicin, which are the main ingredients of the spicy taste. To evaluate the effect of HP on the microbial community in kimchi fermentation, kimchi [kimchi-HP, kimchi-HPE and kimchi-HPER made by adding HP, HP alcohol extract (HPE) and HPE residues (HPER)] was fermented at 4°C for 28 days. The pH and titratable acidity of the samples and the number of bacteria changed with fermentation time. Kimchi-HPER had significantly higher total viable and lactic acid bacteria (LAB) than other samples after 28 days of fermentation. The capsaicinoids content did not differ before and after fermentation, whereas the major free sugar content decreased, and the mannitol content increased. The principal component analysis (PCA) biplots showed similar patterns between kimchi-HP and -HPE. It was confirmed that Leuconostoc and Weissella were related to the initial fermentation, and Lactobacillus was involved in late fermentation. Kimchi-HP and kimchi-HPE increased the ratio of Lactobacillus sakei and decreased that of Leuconostoc mesenteroides compared to kimchi-HPER. Overall, these results revealed that capsaicinoids contained in HP affected Lactobacillus proliferation and mannitol increase during kimchi fermentation.

Categorical CVA biplots

Techniques to visualise and understand large amounts of data are of paramount importance. In most settings, this data is usually multivariate, which further stresses the need for effective visualisation techniques. Multivariate visualisation techniques such as canonical variate analysis (CVA) biplots allow for simultaneous lower-dimensional visualisation and data classification by incorporating class-specific data. CVA biplots, however, are currently restricted to numerical data. Through combining concepts from both CVA and non-linear principal component analysis (PCA) biplots, a new biplot construction methodology that improves on the traditional CVA biplot by allowing for categorical variables is proposed. This technique, named CVA(Hr), is showcased using the established mushroom data set, which contains a mix of categorical and ordinal variables. This novel method improves upon existing biplot construction in terms of classification accuracy and class separation.

Identification of high-yielding wheat genotypes resistant to Pyrenophora tritici-repentis (tan spot)

Tan spot, caused by Pyrenophora tritici-repentis, is a major foliar disease of wheat in Kazakhstan. This study evaluated 103 winter wheat genotypes for tan spot resistance and high-productivity traits in the field in two years. Entries were also characterized using the molecular marker Xfcp623, indicative of Tsn1 gene conferring sensitivity to Ptr ToxA. The proportion of entries insensitive to Ptr ToxA was relatively high (71%). Forty-eight entries with the lowest tan spot severity in the field were confirmed to be insensitivity to Ptr ToxA in the molecular screening. Entries which were resistant under field conditions had similar level of seedling resistance. Principal component analysis biplots showed, that all spike productivity traits were highly correlated. Days to heading (DH) and tan spot severity, as well as the normalized difference vegetation index and DH were strongly correlated. Thousand kernels weight (TKW) and plant height were highly correlated and both were negatively correlated with DH and tan spot severity, indicating that taller cultivars tended to be more resistant. The Xfcp623 negative entries had lower disease severity (by about 40%), flowered up to 2 days later than entries with Tsn1 and had significantly more spikelets per spike, number of grains per spike, TKW and grain weight/spike. The results of the study will be important for increasing the efficiency of breeding based on the elimination of the genotypes with dominant allele Tsn1. Of the 103 entries evaluated, 28 can be directly used in breeding programs to improve tan spot resistance and productivity of winter wheat.

Response of the invasive Alliaria petiolata to extreme temperatures and drought

AbstractAlliaria petiolata, a strict biennial in North America, can have an annual alternating high abundance of rosettes and flowering plants. We monitored changes in abundance of rosettes and flowering plants in permanent plots (2004–2014). Three times during our study, the alternating yearly cycle was not observed (2007–2008, 2008–2009, and 2013–2014). We concluded stochastic extreme climate events (ECEs), deviating from long‐term climatic data norms (10th or 90th percentile), likely caused negative organism responses. Long‐term data from a local NOAA station located 25 km from our study site included monthly data (1) total precipitation, (2) number of days with >0.13 cm precipitation, and (3) mean and minimum temperatures. September 2007 met the criteria for ECEs for all monthly variables. We first observed A. petiolata on our study site in 1988, and by the early 1990s, it was abundant. To determine whether September 2007 significantly differed from other September (1984–2014), we used six variables related to drought: (1) total precipitation, (2) number of days with precipitation, (3) number of contiguous days without precipitation, (4) mean monthly temperature, (5) mean maximum daily temperature, and (6) the number of days with temperatures >30°C. The first two variables likely increase plant stress as they decrease, whereas stress declines as the remaining variables decrease. We used the six variables to generate a principal component analysis (PCA) biplot. Axes 1 and 2 accounted for 74.3% of the variance. Record‐breaking minimum temperatures (ECEs) for January (2009) and February–March (2014) likely reduced rosette abundance and disrupted reestablishment of alternating high abundance of rosettes and flowering plants. Our data suggest that a single ECE variable, minimum temperature, and multiple ECE variables related to drought likely had negative effects on A. petiolata.

Analysis of Geomagnetic Ap Index on Worldwide Earthquake Occurrence using the Principal Component Analysis and Hierarchical Cluster Analysis

Geoeffective solar events, especially the coronal mass ejection (CME) and the high-speed solar wind (HSSW) will induce geomagnetic storm upon its arrival to Earth. The solar events could trigger an earthquake occurred during the arrival. In this study, the focus is on the proxy of the geoeffective solar events, which is the geomagnetic Ap index and the data of shallow worldwide earthquakes. The main objective was to investigate the impact of geomagnetic storms on the occurrences of earthquakes from 1994 to 2017 from a statistical perspective. The geomagnetic Ap index data was obtained from the Helmholtz-Centre Postdam - GFZ German Research Centre for Geosciences and the shallow worldwide earthquake data were from the United States Geological Survey (USGS) earthquake catalogue. The Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were used to analyse the data. Two groups were obtained from the PCA biplot: Group 1 - before the event (Day-4 to Day-1) and Group 2 - after the event group (Day 0 to Day+4). A two-cluster solution was obtained from the HCA, which shows that days before and after geostorm are divided into two main clusters. The statistical results show that earthquakes activity might have different behaviour before and after the geostorm occurred. In conclusion, the results emphasize that there are differences between days before and after the geostorm occurrence, hence, the solar influence upon earthquake occurrences cannot be neglected entirely.

Welfare Assessment of 30 Dairy Goat Farms in the Midwestern United States.

Dairy goat animal welfare assessment protocols have been developed and conducted in Europe and the United Kingdom for dairy goats; however, there are no published reports of large-scale welfare assessment for dairy goats on farms in the Midwestern United States (US). Therefore, the objective of this study was to perform welfare assessment of lactating dairy goats and identify the most prevalent welfare issues on 30 farms across the Midwestern US. Thirty dairy goat farms (self-selected) were enrolled in the study if they shipped milk for human consumption (regardless of herd size). The number of lactating does on each farm ranged from 34 to 6,500 goats, with a median number of 158 lactating does (mean ± SD: 602 ± 1,708 lactating does). The protocol used was developed from available literature on goat welfare assessment but modified for use in the Midwestern US. Observations were made without handling the animals and included 22 animal-based indicators evaluated at the group- and individual-level. The observations were conducted during ~3–5 h during a milking session (either morning or afternoon) and time in the home pen. Principal components analysis (PCA) was carried out on the welfare assessment data from each farm. The first two dimensions of the PCA explained 34.8% of the variation. The PCA biplot indicated correlations between indicators. The most prevalent conditions observed across the 30 farms included any knee calluses (80.9%), any claw overgrowth (51.4%), poor hygiene (14.9%), skin lesions (8.9%), poor hair coat condition (8.3%) and any ear pathology (8.0%). These results are the first to provide the Midwestern US dairy goat industry with information to improve commercial dairy goat welfare.

Patency and Clinico-Haematological Pathologies Sequel to Trypanosoma brucei and Trypanosoma evansi Induced Infections in Yankasa Sheep I

Trypanosomosis remains one of the most deadly protozoan diseases that pose a significant impact on livestock health in the tropics. Sixteen (16) rams aged between 24 to 30 months and weighed between 22-25kg were acclimatized under standard animal housing conditions. Twelve (12) of the sheep deemed fit and healthy were randomly divided into four groups (I, II, III, and IV) of three sheep each. Each sheep in groups I and II was inoculated intravenously with 2 mL containing 2 X 106 trypomastigote forms of Trypanosoma brucei and Trypanosoma evansi, respectively. While group III, each sheep received 2 mL containing 2 X 106 mixed inoculums of T. brucei and T. evansi (50% each by volume of the infective inoculums). Sheep in group IV served as the non-infected control. Post-infection animals were monitored for 14 weeks for parasitaemia, clinical signs, and haematological pathologies. The patent infection became evident in groups I, II, and III between 5-21 days post-infection with average patency of 7, 20, and 8.5 days respectively. The infection was characterized by intermittent pyrexia with a significant decrease (p< 0.001) in mean weekly packed cell volume (PCV), haemoglobin concentration (Hb), live weight gain, plasma protein, which significantly decreased (p< 0.001) in all the infected groups. Pearson’s correlation (r) indicates a strong positive correlation (r= 0.991) between parasitaemia and pyrexia, and principal component analysis (PCA) biplot increased the predictabilities of these two indices as the major precursors in the progression of the trypanosomes pathogenesis in sheep.
 Keywords: Trypanosomosis; Patency; Clinico-haematological pathologies; Trypanosoma brucei; Trypanosoma evansi; Yankasa sheep

Concentration and Spatial Distribution of Potentially Toxic Elements in Surface Soil of a Peak-Cluster Depression, Babao Town, Yunnan Province, China.

Potentially toxic elements (PTEs) in Chinese agricultural soils, including those in some heritage protection zones, are serious and threaten food safety. Many scientists think that these PTEs may come from parent rock. Hence, at a karst rice-growing agricultural heritage area, Babao town, Guangnan County, Yunnan Province, China, the concentrations of eight PTEs (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined in 148 surface soil, 25 rock, and 52 rice grain samples. A principal component analysis (PCA) and hierarchical cluster analysis were used to divide the surface soil into groups, and inverse distance weighting (IDW) was used to analyze the spatial distribution of PTEs. Soil pollution was assessed with the geoaccumulation index (Igeo). The results show that Cd, Hg, Zn, and Cr were polluting the soil (average Igeo > 0). The highest concentration of PTEs was distributed in the southwest of Babao town in the carbonate rock area, which had the highest pH and soil total organic carbon (Corg), Mn, and TFe2O3 contents. PCA biplots of soil samples showed that the carbonate rock area was associated with the most species of PTEs in the study area including Pb, Cd, Hg, As, and Zn. The clastic rock area was associated with Cu and Ni, and the lime and cement plants were associated with CaO, pH, Corg, TC, and aggravated PTE pollution around factories. In high-level PTE areas, rice was planted. Two out of 52 rice grain samples contained Cd and 4 out of 52 rice grain samples had Cr concentrations above the Chinese food safety standard pollutant limit (Cd 0.2 mg/kg; Cr 1 mg/kg). Therefore, the PTEs from parent rocks are already threatening rice safety. The government should therefore plan rice cultivation areas accordingly.

Another insight into the contamination levels at Ogoniland in Niger Delta, Nigeria, with focus on Goi Creek.

Environmental pollution arising from crude oil exploratory activities has adversely impacted both the living and non-living components of the ecosystem. An insight into the impact of such activities with focus on Goi Creek in Ogoniland was provided in this study. We generated reliable data for physicochemical, heavy metal, and total hydrocarbon levels in the creek via a total of 40 samples collected across 4 stations designated within the creek in a duration of 10 months. With the exception of temperature, total dissolve solid, dissolved oxygen, chloride, sulfate, nitrate, zinc, and vanadium, the levels of other regulated parameters in the samples were not compatible with the national and international guidelines and standards for surface water quality including Federal Ministry of Environment Guidelines and standards for water quality in Nigeria and Environmental Protection Agency National recommended water quality criteria, respectively. The principal components (PCs) 1 and 2 of principal component analysis biplot revealed that the concentrations of the physicochemical parameters showed a mixed distribution among the stations; however, the heavy metals were more localized to station 4. Moreover, the dataset was subjected to water quality index (WQI), contamination index (Cd), heavy metal evaluation index (HEI), trace element toxicity index (TETI), and environmental water quality index (EWQI) to determine the extent of contamination. The result showed poor WQI, high contamination for Cd, and low-to-medium contamination for HEI. Although, there were variations among the stations on the contamination level, uniform remediation method should be adopted due to the similarity of the contaminants in all the stations.

PRINCIPAL COMPONENT ANALYSIS BIPLOT GLOBAL COMPETITIVENESS INDEX ASEAN COUNTRIES

ASEAN's global competitiveness requires institutional and ASEAN countries appear to be a formidable economic actors in protecting the economic interests and at the same time having an open economic system that indicates the readiness of ASEAN to compete with the economic strength of the entire region in the world. In this case the measurement of global competitiveness factors become important aspects of state enterprises in the face of global competition. This study was conducted to determine how competitive the ASEAN countries with Biplot method of Principal Component Analysis. Results obtained from this study is the ASEAN countries have different advantages in each of the variables related to the global competitiveness index. In addition, the diversity of which can be explained more than 70% which is 90.69% which means that Principal Component Analysis Biplot describes well the overall total

Variation in frequency of CQA-tested municipal solid waste compost can alter metabolites in vegetables

The use of compost to enhance plant growth and mineral nutrients composition are extensively studied but not much literature information exists on its influence on plant metabolic profiles. A study was performed to assess a 5-year variable frequency of application of Compost Quality Alliance tested municipal solid waste (MSW) compost effect on metabolic profiles of the edible portions of four different vegetable plants. The plants were lettuce (Latuca sativa cv. Grand Rapids), beets (Beta vulgaris cv. Detroit Supreme), carrot (Daucus carota cv. Nantes) and green beans (Phaseolus vulgaris cv. Golden Wax) grown under a sub-humid continental climate. The treatments were annual, biennial and no (control) applications of the MSW compost. Typically, soil fertility highly increased with the annual application of the MSW compost followed by the biennial application but declined in the control plot. The annually applied MSW compost increased total amino acids in the lettuce, carrot, beets, and green beans by ca. 323%, 109%, 94% and 18% respectively, compared to the control. Overall, total phospholipids were enhanced by the biennially applied MSW compost. Total organic acids in the lettuce, beets, and green beans were altered by the annual and biennial MSW compost applications by ca. 35% and 23%; 6% and 6.4%; and 22% and 65%, respectively compared to the control. A 2-dimension principal component analysis biplot confirmed positive association between the different frequencies of MSW compost application and soil fertility enhancement of plant metabolites. In conclusion, the annual application of MSW compost enhanced amino acids, phospholipids, acylcarnitines, amines and choline but reduced glucose in the lettuce, beets, carrot, and green beans. Further studies to elucidate the mechanisms underpinning such biofortification will be required.

Vegetation classification for the management of large mammalian herbivores: a case study at Mushingashi Conservancy, Central Province, Zambia

The vegetation of Mushingashi Conservancy in central Zambia was classified and mapped to provide a template for wildlife management. Putative vegetation types were delineated using Landsat 8 imagery, then sampled with 73 plots for vegetation composition and structure, and topo-edaphic properties. Classification followed a four-stage process. Valley dambo and floodplain grasslands were first separated as landscape units from wooded plots. Hierarchical cluster analysis was then used to identify 13 vegetation types based on woody composition and structure. Convex hull plots on a principal component analysis biplot successfully delineated the topo-edaphic environment and woody structure of each type. Linear discriminant analysis confirmed differences in topo-edaphic environment among types. The main environmental gradient was from vertic clays, supporting open Acacia woodland, to sandy soils, supporting miombo woodland, but other gradients were also important. Of a total of 193 woody species recorded, 25 occurred only on large termitaria. An influence of environmental gradients independent of plant-available moisture and nutrients is emphasised. Total woody cover decreased conspicuously on clay-rich soils with increased water availability. A functional vegetation classification of this nature is considered an essential first step towards the informed management of rangeland for large herbivores. Potential applications for management are discussed.

Morphological characterization and genotypic identity of African yam bean (Sphenostylis stenocarpaHochst ex. A. Rich. Harms) germplasm from diverse ecological zones

AbstractAfrican yam bean (AYB) is an affordable protein source capable of diversifying the food base in sub-Saharan Africa. However, research efforts made towards the crop's improvement and in expanding production are limited. This study characterized 169 AYB accessions at Jimma, Ethiopia, using 31 phenotypic characters. The analysis of variance revealed highly significant (P< 0.01) differences for days to 50% flowering, days to first flowering, leaf area, number of seeds per pod, pod length, seed thickness, total seed weight, petiole length and significant (P< 0.05) difference for terminal leaf length. Accession TSs62B produced the highest number of seeds per pod (17.65) and recorded the highest 100 seed weight (25.30 g), while 3A was the earliest to flower at an average of 84.50 d. Principal component analysis (PCA) of qualitative traits attributed 77.6% of observed variations to the first five principal components, of which the first two PC axes accounted for 53.6% of total variations. Cluster analysis and PCA biplot distinctly grouped the accessions into two major groups, cluster I had the highest number of accessions (108). The analytical approaches used confirmed considerable diversity across the germplasm with a distance matrix ranging from 0.37 to 0.85. The extent of diversity reflected in the current study provides breeders the baseline information to design breeding strategies, which might help identify materials for release as variety or parental lines for hybridization programmes.

Variations in life-history traits and statolith shape for Sepioteuthis spp. in the waters off southwestern Japan

Sepioteuthis lessoniana is a crucial squid species in fisheries and plays a critical role in marine ecosystems. At least two taxa of the squid species have been identified in the waters around Japan; however, the basic biological information of these taxa is limited. In this study, the taxa composition of Sepioteuthis was examined using molecular evidence, and the life-history traits and statolith shape of these taxa were analyzed to elucidate the potential population structure. A total of 142 squid samples were collected from six locations around Nagasaki (southwestern Japan) where high taxonomic diversity has been found previously. Three taxa (Sepioteuthis sp. 1, sp. 2, and sp. 2A) were identified based on the mitochondrial cytochrome oxidase c subunit I (COI) gene, among which Sepioteuthis sp. 2A was defined for the first time. Sepioteuthis sp. 2 was predominant in the region (average occurrence rate 84%), whereas Sepioteuthis sp. 1 was rare, with only two individuals found near Goto Islands. The mantle length composition, mantle length–body weight relationship, age structure, and average growth rates were similar between Sepioteuthis sp. 2 and sp. 2A. However, Sepioteuthis sp. 2 mainly hatched during summer (June–July), whereas Sepioteuthis sp. 2A hatched during winter (December–February). The statolith shapes of the squids were similar between the taxa, although slight differences were noted in the wing regions. The three taxa largely overlapped in a principal component analysis bi-plot based on variations extracted from five life-history traits. These results suggest that at least three taxa of Sepioteuthis inhabited the region, although few differences were found between them in life-history traits or statolith shapes that might be substantially influenced by regional oceanographic conditions. This study provides essential information on the population structure and connectivity of the squid, which is crucial in the context of conservation and management measures for fisheries.

Extension of Cut Carnation Vase Life Using Compost Tea, Putrescine and Plant Extracts

Cut flower vase life can be extended by various natural products, but their efficacy when mixed with compost tea is not reported. A study was performed to determine cut carnation (Dianthus caryophyllus cv. White Sim) vase life in 1 L of formulations (1) C3.5: 3.5% compost tea + 15 mg putrescine; (2) R5L10: C3.5 + 5 mL rosemary (Salvia rosmarinus) + 10 mL lemon (Citrus limon) extracts; (3) R10L10: C3.5 + 10 mL rosemary + 10 mL lemon extracts; (4) R5L20: C3.5 + 5 mL rosemary + 20 mL lemon extracts; (5) R10L20: C3.5 + 10 mL rosemary + 20 mL lemon extracts; (6) Chrysal: Floral Chrysal Clear (positive control); and (7) Dw: distilled water alone (negative control). The 15 mg putrescine significantly (P=0.002) reduced compost tea turbidity by 34%. The neutral pH of C3.5 and Dw did not change. However, pH increased by 24% in Chrysal and reduced by 39% in R5L10, R10L10 and R5L20 and by 54% in R10L20 on day 11. TDS and EC were highest in Chrysal from days 1 to 11. Petal discoloration, wilt, shrinkage and neck bend were delayed by C3.5 followed by Chrysal and then R5L10, but were accelerated by the other treatments. In conclusion, the cut carnation cv. White Sim longevity as influenced by variations in the vase solutions was Chrysal (14 days) > C3.5 (12.6 days) > R5L10 (10.7 days) but ≤ 9 days in the other treatments. These results were confirmed by a 2-D principal component analysis biplot. Future study will investigate microbial interaction.

Biplots for compositional data derived from generalized joint diagonalization methods

Biplots constructed from principal components of a compositional data set are an established means to explore its features. Principal Component Analysis (PCA) is also used to transform a set of spatial variables into spatially decorrelated factors. However, because no spatial structures are accounted for in the transformation the application of PCA is limited. In geostatistics and blind source separation a variety of different matrix diagonalization methods have been developed with the aim to provide spatially or temporally decorrelated factors. Just as PCA, many of these transformations are linear and so lend themselves to the construction of biplots. In this contribution we consider such biplots for a number of methods (MAF, UWEDGE and RJD transformations) and discuss how and if they can contribute to our understanding of relationships between the components of regionalized compositions. A comparison of the biplots with the PCA biplot commonly used in compositional data analysis for the case of data from the Northern Irish geochemical survey shows that the biplots from MAF and UWEDGE are comparable as are those from PCA and RJD. The biplots emphasize different aspects of the regionalized composition: for MAF and UWEDGE the focus is the spatial continuity, while for PCA and RJD it is variance explained. The results indicate that PCA and MAF combined provide adequate and complementary means for exploratory statistical analysis.

Effect of ultraviolet radiation on the metabolomic profiles of potentially toxic cyanobacteria.

Interactions between climate change and ultraviolet radiation (UVR) have a substantial impact on aquatic ecosystems, especially on photosynthetic organisms. To counteract the damaging effects of UVR, cyanobacteria developed adaptive strategies such as the biosynthesis of secondary metabolites. This study aimed to evaluate the effects of UVR on the metabolomic profiles of potentially toxic cyanobacteria. Twelve strains were irradiated with ultraviolet A and ultraviolet B radiation and parabolic aluminized reflector lamps for 3 days, followed by liquid chromatography-tandem mass spectometry (LC-MS/MS) analysis to assess changes in metabolomic profiles. Matrices were used to generate principal component analysis biplots, and molecular networks were obtained using the Global Natural Products platform. Most strains showed significant changes in their metabolomic profiles after UVR exposure. On average, 7% of MS features were shown to be exclusive to metabolomic profiles before UVR exposure, while 9% were unique to metabolomic profiles after UVR exposure. The identified compounds included aeruginosins, spumigins, cyanopeptolins, microginins, namalides, pseudospumigins, anabaenopeptins, mycosporine-like amino acids, nodularins and microcystins. Data showed that cyanobacteria display broad metabolic plasticity upon UVR exposure, including the synthesis and differential expression of a variety of secondary metabolites. This could result in a competitive advantage, supporting cyanobacterial blooms under various UVR light exposures.