scholarly journals Numerical taxonomic study of the genus Crotalaria L. (Crotalarieae, Fabaceae) in Nigeria

2018 ◽  
Vol 50 (1) ◽  
pp. 25-32
Author(s):  
Samaila Samaila Yaradua ◽  
Dhafer Ahmed Alzahrani ◽  
Abubakar Bello
Keyword(s):  
Cluster Analysis ◽  
Multivariate Analysis ◽  
Numerical Taxonomy ◽  
Field Work ◽  
Taxonomic Study ◽  
Cophenetic Correlation ◽  
Euclidian Distance ◽  
Ordination Analysis ◽  
Qualitative Characters ◽  
Numerical Taxonomic Study

Abstract Numerical taxonomic study of the genus Crotalaria L. in Nigeria was conducted to identify and differentiate some of the species of the genus Crotalaria using numerical taxonomy based on quantitative and qualitative characters. Field work was conducted, where different species were collected and analyzed using multivariate analysis. The results showed that all the collected species are distinct at Euclidian distance of 0.41 in the cluster analysis with Cophenetic correlation (r)=0.964. The ordination analysis based on the results of the PCA, separated the specimens into 7 groups corresponding to the result of cluster analysis. The first two components of the PCA account for 81.5%. The length of petiole, width of leaflet and length of fruit contributed more to showing delimitation among the species.

A numerical taxonomic study of the British Phaeophyta

1975 ◽  
Vol 55 (4) ◽  
pp. 763-784 ◽  
Author(s):  
G. Russell ◽  
R. L. Fletcher
Keyword(s):  
Numerical Taxonomy ◽  
Taxonomic Study ◽  
Numerical Techniques ◽  
Marine Algal ◽  
Numerical Taxonomic Study

The principles and aims of numerical taxonomy were clearly stated by Sokal & Sneath (1963) and their procedures have since been adopted by many botanists working with numerous different groups of plants. Marine algal taxonomists, however, seem largely to have ignored these developments although Whitton (1969) has recommended that numerical techniques should be employed to help solve outstanding problems in the taxonomy of the Cyanophyta.

Numerical taxonomy of psychrotrophic bacteria isolated from raw ewes' milk

1993 ◽  
Vol 60 (3) ◽  
pp. 371-383 ◽  
Author(s):  
María-Rosario García-Armesto ◽  
Miguel Prieto ◽  
Carlos Alonso ◽  
María-Luisa GarcíLópez ◽  
María-Camino García-Fernández ◽  
...  
Keyword(s):  
Low Temperature ◽  
Aeromonas Hydrophila ◽  
Numerical Taxonomy ◽  
Taxonomic Study ◽  
Coagulase Negative Staphylococci ◽  
Gram Negative ◽  
Identification Schemes ◽  
Psychrotrophic Bacteria ◽  
Numerical Taxonomic Study ◽  
Reference Strains

SummaryA total of 204 psychrotrophic isolates from raw ewes' milk (hand and machine milked) were identified by conventional methods. In addition, a numerical taxonomic study was conducted on 180 of these isolates and 19 reference strains. Three of the isolates were yeasts. Using identification schemes, 54 isolates were assigned to genera of Gram-negative aerobic rods (Pseudomonas, Acinetobacter, Flavobacterium, MoraxellaandPsychrobacter), 48 were Enterobacteriaceae (Entero-bacter, Hafnia, Klebsiella, CitrobacterandSerratia) and one was identified asAeromonas hydrophila. The 98 Gram-positive isolates were identified asEnterococcus, Streptococcus, Leuconostoc, Lactococcus, Bacillus, Staphylococcus, Micrococcus, Aureobacterium, KurthiaandMicrobacterium. At the 82% similarity level (SSM), 18 clusters were formed. Cluster I included 34 strainsof Lactococcus, StreptococcusandLeuconostoc. Most of the 35 strains in cluster II wereEnterococcus. Clusters III and IV were identified asKurthiaandMicrobacteriumrespectively. Cluster V was identified asAureobacteriumand cluster VI consisted of coagulase-negative staphylococci. Gram-negative isolates formed 12 clusters:Aeromonas(one cluster), Enterobacteriaceae (two clusters),Flavobacterium(two clusters),PseudomonasandPsychrobacter immobilis(three clusters) andAcinetobacter(four clusters). Non-motile variants ofPs. fragiwere found.Enterococcusand Enterobacteriaceae did not have significant spoilage properties. As expected, Gram-negative aerobic rods were proteolytic and/or lipolytic even at low temperature. Contamination with certain types of psychrotrophs (Gram-negative aerobic rods and enterococci) seemed to be associated with the milking method. The isolate ofAes. hydrophilahad properties associated with virulence.

A numerical taxonomic study of variation in populations of Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae)

1978 ◽  
Vol 56 (1) ◽  
pp. 55-65 ◽  
Author(s):  
D. A. Chant ◽  
R. I. C. Hansell ◽  
H. Rowell
Keyword(s):  
Host Plants ◽  
Numerical Taxonomy ◽  
Morphological Characters ◽  
The Other ◽  
Climatic Variables ◽  
Taxonomic Study ◽  
Multivariate Tests ◽  
Morphological Variations ◽  
Numerical Taxonomic Study ◽  
Typhlodromus Caudiglans

Variation in morphological characters between Canadian populations of Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae) was examined by the methods of numerical taxonomy. Western populations are separated from the other populations when multivariate tests are used. Two subspecies are proposed, and Typhlodromella nodosus De Leon is synonymized with Typhlodromus caudiglans. Morphological variations between northern and eastern populations are correlated with climatic variables and with host plants.

Dendrobium speciosum (Dendrocoryne: Orchidaceae) complex in north Queensland

2006 ◽  
Vol 19 (3) ◽  
pp. 259 ◽  
Author(s):  
Peter B. Adams ◽  
Jacinta M. Burke ◽  
Sheryl D. Lawson
Keyword(s):  
Cluster Analysis ◽  
Multivariate Analysis ◽  
Morphological Variation ◽  
Taxonomic Study ◽  
Principal Coordinates Analysis ◽  
New Variety ◽  
Southern Group ◽  
Medium Length ◽  
Principal Coordinates ◽  
Small Overlap

Dendrobium speciosum Sm. has received insufficient taxonomic study north of St Lawrence, Queensland, where plants display much morphological variation in diverse habitats. Two varieties have been described previously, variety pedunculatum, occurring north of Townsville, and variety curvicaule for plants between the Connors Range south of Mackay and Annan River, south of Cooktown. In this multivariate analysis of 107 representative plants sampled from areas between St Lawrence and Cooktown, cluster analysis and principal coordinates analysis, were used to categorise the variation. Three overlapping varieties are revealed. North of Townsville variety pedunculatum intergrades with a medium-to-tall rainforest form, which separates with a small overlap in analyses from variety curvicaule plants south of Townsville. We formally describe these rainforest forms, previously referred to as variety curvicaule, as a new variety, Dendrobium speciosum variety boreale, which occurs between Cooktown and Mt Elliot, south of Townsville. Variety boreale is characterised by the presence of a collum in most individuals, medium to long pseudobulbs, large, wide leaves, long pedicels, and fairly uniform off-white to cream flowers. Dendrobium speciosum variety curvicaule Bailey is shown to be a name of uncertain application, and is neotypified to apply to the southern group of north Queensland plants, which occur between St Lawrence and Mt Dryander and on the Whitsunday Islands. Variety curvicaule is characterised by pseudobulbs that are of medium length, wide base and have an inconspicuous collum. The flowers have relatively wide segments in relation to all other varieties, long wide petals and incurving lateral sepals.

Multivariate consumption profiling (MCP) for intelligent meter systems: a methodology to define categories and levels

2010 ◽  
Vol 10 (5) ◽  
pp. 710-720 ◽  
Author(s):  
J. L. Solanas ◽  
M. R. Cussó
Keyword(s):  
Cluster Analysis ◽  
Factor Analysis ◽  
Multivariate Analysis ◽  
Discriminant Analysis ◽  
Reference Population ◽  
Statistical Analyses ◽  
Conceptual Schema ◽  
Data Variability ◽  
Water Companies ◽  
Analyse Data

Multivariate Consumption Profiling (MCP) is a methodology to analyse the readings made by Intelligent Meter (IM) systems. Even in advanced water companies with well supported IM, full statistical analyses are not performed, since no efficient methods are available to deal with all the data items. Multivariate Analysis has been proposed as a convenient way to synthesise all IM information. MCP uses Factor Analysis, Cluster Analysis and Discriminant Analysis to analyse data variability by categories and levels, in a cyclical improvement process. MCP obtains a conceptual schema of a reference population on a set of classifying tables, one for each category. These tables are quantitative concepts to evaluate consumption, meter sizing, leakage and undermetering for populations and groupings and individual cases. They give structuring items to enhance “traditional” statistics. All the relevant data from each new meter reading can be matched to the classifying tables. A set of indexes is computed and thresholds are used to select those cases with the desired profiles. The paper gives an example of a MCP conceptual schema for five categories, three variables, and five levels, and obtains its classifying tables. It shows the use of case profiles to implement actions in accordance with the operative objectives.

Implications of phenotypic plasticity for numerical taxonomy of Ornithogalum montanum (Liliaceae)

1991 ◽  
Vol 69 (1) ◽  
pp. 34-38 ◽  
Author(s):  
M. Pigliucci ◽  
M. G. Politi ◽  
D. Bellincampi
Keyword(s):  
Principal Component Analysis ◽  
Phenotypic Plasticity ◽  
Numerical Taxonomy ◽  
Natural Populations ◽  
Principal Component ◽  
Reaction Norm ◽  
Component Analysis ◽  
Morphological Response ◽  
Numerical Taxonomic Study ◽  
High Degree

Implications of phenotypic plasticity in a subspecific numerical taxonomic study of Ornithogalum montanum Cyr. (Liliaceae) are discussed. Clones belonging to six natural populations were grown in a glasshouse, and their morphological response to three water dosages was analyzed by means of principal component analysis. PC-1 ranks the three groups of replicated populations, suggesting a high degree of phenotypic plasticity; on the other hand, PC-3 is almost environmentally independent. Proximities in the phenetic space are shown to be at least partially environmentally dependent, suggesting a reaction norm for the character correlation matrix. The results do not corroborate a previous recognition of six subspecies of O. montanum. Key words: phenotypic plasticity, numerical taxonomy, Ornithogalum, reaction norm, principal component analysis.

scholarly journals Use of Highly Discriminating Morphological Characters and Isozymes in the Study of Spanish Chestnut Cultivars

2006 ◽  
Vol 131 (6) ◽  
pp. 770-779 ◽  
Author(s):  
Santiago Pereira-Lorenzo ◽  
María Belén Díaz-Hernández ◽  
Ana María Ramos-Cabrer
Keyword(s):  
Principal Component Analysis ◽  
Cluster Analysis ◽  
Multivariate Analysis ◽  
Castanea Sativa ◽  
Principal Component ◽  
Market Value ◽  
Morphological Characters ◽  
Minor Importance ◽  
Breeding Programs ◽  
And Cluster Analysis

Morphological characters (six traits) and isozymes (four systems, five loci) were used to discriminate between Spanish chestnut cultivars (Castanea sativa Mill.) from the Iberian Peninsula. A total of 701 accessions (representing 168 local cultivars) were analyzed from collections made between 1989 and 2003 in the main chestnut growing areas: 31 were from Andalucía (12 cultivars), 293 from Asturias (65 cultivars), 25 from Castilla-León (nine cultivars), four from Extremadura (two cultivars) and 348 from Galicia (80 cultivars). Data were synthesized using multivariate analysis, principal component analysis, and cluster analysis. A total of 152 Spanish cultivars were verified: 58 cultivars of major importance and 94 of minor importance, of which 18 had high intracultivar variation. Thirty-seven cultivars were clustered into 14 synonymous groups. Six of these were from Galicia, one from Castilla-León (El Bierzo), four from Asturias, one from Asturias and Castilla-León (El Bierzo), and two from Asturias, Castilla-León (El Bierzo), and Galicia. The chestnut cultivars from Galicia and Asturias were undifferentiated in genetic terms, indicating that they are not genetically isolated. Overall, chestnut cultivars from southern Spain showed the least variation. Many (58%) of Spanish cultivars produced more than 100 nuts/kg; removing this low market-value character will be a high priority. The data obtained will be of use in chestnut breeding programs in Spain and elsewhere.

Tightening the Life-Cycle Construct: A Taxonomic Study of Growth Stage Configurations in High-Technology Organizations

1994 ◽  
Vol 18 (2) ◽  
pp. 5-29 ◽  
Author(s):  
Steven H. Hanks ◽  
Collin J. Watson ◽  
Erik Jansen ◽  
Gaylen N. Chandler
Keyword(s):  
Cluster Analysis ◽  
Life Cycle ◽  
Growth Stage ◽  
High Technology ◽  
Life Cycle Stage ◽  
Growth Stages ◽  
Taxonomic Study ◽  
Organization Context ◽  
Organization Life Cycle

Over the years much has been written about the organization life cycle, yet there has been remarkably little attention given to the underlying construct of a life-cycle stage. It is proposed in this study that each life-cycle stage consists of a unique configuration of variables related to organization context and structure. Cluster analysis is used to derive a taxonomy of growth stage configurations in a sample of 126 high-technology organizations. The derived configurations suggest a sequence of four growth stages.

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