Morphometric analysis of western North American Antennaria (Asteraceae: Inuleae). I. Sexual species of sections Alpinae, Dioicae, and Plantaginifoliae

1987 ◽  
Vol 65 (11) ◽  
pp. 2389-2395 ◽  
Author(s):  
Randall J. Bayer
Keyword(s):  
Morphometric Analysis ◽  
Principal Components ◽  
North American ◽  
Cluster Analyses ◽  
Sexual Species ◽  
Morphometric Analyses

Eight sexual species of Antennaria Gaertner from sections Alpinae, Dioicae, and Plantaginifoliae have been recognized based on morphometric analyses such as principal components and cluster analyses. These taxa include A. aromatica Evert (Alpinae), A. corymbosa Nelson (Dioicae), A. marginata Greene (Dioicae), A. media Greene (Alpinae), A. microphylla Rydb. (Dioicae), A. racemosa Hook. (Plantaginifoliae), A. rosulata Rydb. (Dioicae), and A. umbrinella Rydb. (Dioicae). Taxa having both diploid and polyploid cytotypes are A. aromatica, A. marginata, A. media, A. microphylla, and A. umbrinella, whereas A. corymbosa, A. racemosa, and A. rosulata are strictly sexually reproducing diploids.

Systematics of North American Petasites (Asteraceae: Senecioneae). I. Morphometric analyses

1998 ◽  
Vol 76 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Donna M Cherniawsky ◽  
Randall J Bayer
Keyword(s):  
North America ◽  
Principal Components ◽  
North American ◽  
Complex Form ◽  
Morphological Differentiation ◽  
Classification Systems ◽  
Morphological Data ◽  
Morphometric Analyses ◽  
Cohesive Group ◽  
Reproductive Characters

Petasites Mill. (Asteraceae: Senecioneae) is a taxonomically difficult genus of polygamodioecious, perennial clonal herbs distributed across Canada, Alaska, and the northern contiguous United States. The taxonomic confusion surrounding the genus is reflected in the ambiguity of the various classification systems currently used. As many as ten species and as few as two species have been recognized (Petasites sagittatus (Banks ex Pursh) Gray and Petasites frigidus (L.) Fries with three varieties), in addition to one hybrid taxon. To determine if discrete groups could be recognized according to a combination of vegetative and (or) reproductive characters and thereby clarify the phenetic relationships among the taxa of Petasites, morphological data were subjected to principal components and discriminant analyses. Particular emphasis was placed on P. frigidus var. frigidus, P. frigidus var. nivalis sensu Bogle, and the purported hybrid between these taxa, which exhibits an intermediate morphology (the frigidus complex). Additionally, the specific status of P. sagittatus was investigated. Evidence obtained from multivariate morphometric analyses indicates that North American Petasites is comprised of four closely related polymorphic entities. While morphological variation among different taxa of Petasites is continuous for most reproductive characters, leaf characters were determined to be the most taxonomically discriminating. The entities of the frigidus complex form a cohesive group somewhat distinct from the other taxa. The morphological differentiation between P. sagittatus and other taxa of Petasites is not considered sufficient to warrant recognition of specific status. Therefore, we recommend that only one polymorphic species of Petasites in North America be recognized (P. frigidus with three varieties) in addition to one hybrid taxon originating from a cross between two of the varieties. Key words: Petasites, Asteraceae, North America, systematics, principal components analysis, discriminant analysis.

scholarly journals Comparison of histometric and morphometric analyses of bone height in ligature-induced periodontitis in rats

2007 ◽  
Vol 21 (3) ◽  
pp. 216-221 ◽  
Author(s):  
Marilene Issa Fernandes ◽  
Eduardo José Gaio ◽  
Rui Vicente Oppermann ◽  
Pantelis Varvaki Rados ◽  
Cassiano Kuchenbecker Rosing
Keyword(s):  
Periodontal Disease ◽  
Morphometric Analysis ◽  
Wistar Rats ◽  
T Test ◽  
The Other ◽  
Limited Capacity ◽  
Height Measurement ◽  
Morphometric Analyses ◽  
Left And Right ◽  
Bone Height

The purpose of this study was to compare histologic and morphometric procedures of bone height measurement. Microscopic measurements are the most frequent methods in periodontal studies with animals, but have limited capacity to identify bone levels associated with both healthy tissues and periodontal disease. Ligatures were placed in the maxillary left second molars of 10 male 60-day-old Wistar rats for 30 days. Left and right maxillary sides of 5 rats were processed for histologic analysis (H), sectioned buccolingually, and stained with HE. The maxillae of the other 5 rats were defleshed and used for morphometric analysis (M). Histometric measurements from the cementoenamel junction to the bone crest were performed. Standardized photographs were used for morphometric analysis. The t test was used for dependent or independent samples (alpha = 0.05%). Distances from cementoenamel junction to bone crest were 0.95 ± 0.25 and 1.07 ± 0.30 mm for H and M, respectively. Buccal measurements were 0.92 ± 0.16 and 1.08 ± 0.35 mm for H and M. The values obtained using H and M for areas without ligatures were 0.44 ± 0.15 and 0.47 ± 0.11 mm for lingual measurements and 0.23 ± 0.08 and 0.41 ± 0.10 mm for buccal measurements. No significant differences were found between the two methods in the detection of bone height associated with the placement of ligatures in rats.

Phenolic Composition of Bud Exudates of Populus deltoides

1990 ◽  
Vol 45 (6) ◽  
pp. 587-593 ◽  
Author(s):  
W. Greenaway ◽  
S. English ◽  
F. R. Whatley
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Methyl Ether ◽  
Principal Components ◽  
North American ◽  
Populus Deltoides ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenolic Composition ◽  
American States ◽  
Related Compounds

Abstract Bud exudate of Populus deltoides clones originating from six central and eastern American states was examined by gas chromatography/mass spectrometry and the components were identified. The principal components of the bud exudate were the flavone galangin, the flavanone pinocembrin and the flavanonol pinobanksin, together with the related compounds pinocembrin chalcone, pinobanksin methyl ether and pinobanksin-3-acetate. The bud exudate composition was very different from that seen in a North American poplar of the section Tacamahaca, P. balsamifera. The bud exudates from all P. deltoides specimens were similar excepting that from Vermont.

A morphometric analysis of hybrid salamanders (genus Ambystoma) and their progenitors on Kelleys Island in Lake Erie

1989 ◽  
Vol 67 (10) ◽  
pp. 2376-2383 ◽  
Author(s):  
Clifford W. Zeyl ◽  
Leslie A. Lowcock
Keyword(s):  
Morphometric Analysis ◽  
Principal Components ◽  
Lake Erie ◽  
Meristic Character ◽  
Discriminant Functions ◽  
Morphometric Characters ◽  
Size And Shape ◽  
Canonical Variates

Six morphometric characters and one meristic character were measured on 96 adult and 88 juvenile Ambystoma from Kelleys Island, where extensive hybridization involves three species. Canonical variates, discriminant functions, and size-constrained principal components analyses showed that A. laterale (represented only in hybrids on Kelleys Island), A. texanum, A. tigrinum, and A. laterale–texanum–tigrinum are distinguishable from each other and from a complex of hybrids involving A. texanum and A. laterale. Within the latter complex, different ploidies are not distinct morphologically. Introgression may explain isolated atypical individuals. Adults differ from juveniles in both size and shape, demonstrating allometry.

The Dimensions of Peer Evaluation in Israel: A Cross-Cultural Perspective

1992 ◽  
Vol 15 (3) ◽  
pp. 299-314 ◽  
Author(s):  
Orit Krispin ◽  
Kathleen J. Sternberg ◽  
Michael E. Lamb
Keyword(s):  
Principal Components ◽  
North American ◽  
Cross Cultural ◽  
Three Dimensions ◽  
Peer Evaluation ◽  
Cultural Perspective ◽  
Seventh Grade ◽  
Cultural Convergence ◽  
Convergence And Divergence ◽  
Class Play

The Revised Class Play (RCP), a procedure designed to assess peer evaluations, was administered to 1445 second-through seventh-grade children in Israel. Recent studies, using North American samples, revealed three reliable dimensions: Sociability-Leadership; Aggressive-Disruptive; and Sensitive-Isolated. The goal of the present study was to see whether the same three dimensions were evident when the RCP was used in Israel. The principal-components analyses revealed interesting degrees of cross-cultural convergence and divergence. The results are discussed in the context of other research on Israeli values.

A re-evaluation of species limits in Canadian Arctic Island Puccinellia (Poaceae): resolving key characters

2001 ◽  
Vol 79 (8) ◽  
pp. 927-956 ◽  
Author(s):  
L L Consaul ◽  
L J Gillespie
Keyword(s):  
Principal Components ◽  
Canadian Arctic ◽  
Small Degree ◽  
Species Boundaries ◽  
Key To Species ◽  
Species Complexes ◽  
Morphometric Analyses ◽  
Species Groups ◽  
Components Analysis ◽  
Variation Explained

This study examined morphological variation for species of Puccinellia that have traditionally posed problems of identification in the Canadian Arctic Archipelago. The first part of the study involved a re-examination of several characters that were difficult to define or describe. Microscopic examination of lemma and glume apices revealed that the characters "erose-ciliolate" lemma and glume apex margins are more accurately divided into two characters: degree to which they are erose, and presence of trichomes. These trichomes consist of acute or acuminate cells that protrude 15–35 µm from the margin, sometimes with a spinulose tip up to 10 µm long. The term "thickened pedicel" is clarified to mean thickened below the apex in relation to the apex. The second part of the study involved preliminary morphometric analyses on the above-mentioned revised characters, plus other characters previously shown to have low plasticity in this genus, for 10 recognized species that are difficult to distinguish. Many species or species complexes resolved to a small degree, but no taxa formed distinct groups. Correlations among many characters were low, accounting for a low percentage of variation explained by the first few principal components. Hypotheses of species boundaries and a preliminary revised key to species and species groups, incorporating findings from this study, are presented.Key words: Puccinellia, Canadian Arctic, morphology, trichomes, principal components analysis, cluster analysis.

scholarly journals Phegopteris excelsior (Thelypteridaceae): A New Species of North American Tetraploid Beech Fern

2019 ◽  
Vol 27 (4) ◽  
pp. 211-218 ◽  
Author(s):  
Nikisha R. Patel ◽  
Susan Fawcett ◽  
Arthur V. Gilman
Keyword(s):  
New Species ◽  
North America ◽  
Principal Components Analysis ◽  
Principal Components ◽  
North American ◽  
Northeastern North America ◽  
Specific Rank ◽  
Components Analysis ◽  
Morphological Differences ◽  
A New Species

Since the 1970s, an apomictic tetraploid beech fern (genus Phegopteris (C. Presl) Fée) has been known in northeastern North America. Previously published isozyme data suggest that this lineage is of allopolyploid origin involving long beech fern (P. connectilis (Michx.) Watt.) but not broad beech fern (P. hexagonoptera (Michx.) Fée), as originally hypothesized. Its second progenitor remains unknown. We performed a principal components analysis of the apomict and its North American congeners to elucidate morphological differences between them. We recognize the apomictic tetraploid at specific rank as P. excelsior N. R. Patel & A. V. Gilman and provide an illustration, a range map, a list of exsiccatae, and a key to Phegopteris species of North America.

scholarly journals Taxonomic and systematic revisions to the North American Nimravidae (Mammalia, Carnivora)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1658 ◽  
Author(s):  
Paul Z. Barrett
Keyword(s):  
North American ◽  
Valid Species ◽  
Phylogenetic Species ◽  
Phylogenetic Species Concept ◽  
The North ◽  
Morphometric Analyses ◽  
Cladistic Analyses ◽  
Initial Discovery ◽  
Taxonomic Assignments ◽  
Answering Questions

The Nimravidae is a family of extinct carnivores commonly referred to as “false saber-tooth cats.” Since their initial discovery, they have prompted difficulty in taxonomic assignments and number of valid species. Past revisions have only examined a handful of genera, while recent advances in cladistic and morphometric analyses have granted us additional avenues to answering questions regarding our understanding of valid nimravid taxa and their phylogenetic relationships. To resolve issues of specific validity, the phylogenetic species concept (PSC) was utilized to maintain consistency in diagnosing valid species, while simultaneously employing character and linear morphometric analyses for confirming the validity of taxa. Determined valid species and taxonomically informative characters were then employed in two differential cladistic analyses to create competing hypotheses of interspecific relationships. The results suggest the validity of twelve species and six monophyletic genera. The first in depth reviews ofPogonodonandDinictisreturned two valid species (P. platycopis,P. davisi) for the former, while only one for the latter (D. felina). The taxonomic validity ofNanosmilusis upheld. Two main clades with substantial support were returned for all cladistic analyses, the Hoplophoneini and Nimravini, with ambiguous positions relative to these main clades for the European taxa:Eofelis,Dinailurictis bonali, andQuercylurus major; and the North American taxaDinictisandPogonodon.Eusmilusis determined to represent a non-valid genus for North American taxa, suggesting non-validity for Old World nimravid species as well. Finally,Hoplophoneus mentalisis found to be a junior synonym ofHoplophoneus primaevus, while the validity ofHoplophoneus oharraiis reinstated.

scholarly journals Sexual dimorphism and morphometric analysis of Filopaludina martensi martensi (Gastropoda: Viviparidae)

2021 ◽  
Vol 31 (2) ◽  
pp. 87-92
Author(s):  
Weerachon Sawangproh ◽  
Chetsada Phaenark ◽  
Supatra Chunchob ◽  
Paiphan Paejaroen
Keyword(s):  
Sexual Dimorphism ◽  
Morphometric Analysis ◽  
Sexual Differences ◽  
Morphometric Analyses ◽  
Different Characteristics

Sexual dimorphism is the condition where individuals of different sex in the same species exhibit different characteristics beyond the differences in their sexual organs. In this study, individuals of a viviparid species Filopaludina martensi from the Kwai Yai River in Kanchanaburi Province (Thailand) were examined for eight shell and operculum characteristics. Sexual differences were observed in size of shell and operculum, with females being larger than males. The results indicated that morphometric analyses are useful to detect subtle differences between sexes in this species.

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