Morphological and genetic variation in Centrolepis paludicola and C. monogyna (Centrolepidaceae)

1999 ◽  
Vol 12 (5) ◽  
pp. 679 ◽  
Author(s):  
J. Cambecèdes ◽  
R. E. Vaillancourt ◽  
B. M. Potts
Keyword(s):  
Multivariate Analysis ◽  
Genetic Variation ◽  
Molecular Markers ◽  
Morphological Data ◽  
Species Status ◽  
Variable Species ◽  
The Common ◽  
Local Differentiation ◽  
Vegetative Characters ◽  
High Level

Centrolepis paludicola is a small cushion-forming herb which is listed as an endangered species. However, some taxonomists have questioned its species status and treat it as a subspecies of the common C. monogyna. Morphological measurements were taken on plants from 50 cushions collected from 31 sites throughout Tasmania, and included C. paludicola, C. monogyna and C. fascicularis as an outgroup to resolve this taxonomic issue. While C. fascicularis was distinct in all morphological analyses, the sympatric C. paludicola and C. monogyna could not be clearly distinguished on the basis of the reproductive and vegetative characters that are supposed to separate them. Centrolepis monogyna is henceforth interpreted as a morphologically variable species which includes C. paludicola. Once it was shown that these are best treated as one species, RAPD molecular markers were used to analyse genetic variation between populations. This analysis revealed a high level of polymorphism between cushions. As in the multivariate analysis of morphological data, C. monogyna and C. paludicola containing cushions were indistinguishable. However, there was a strong geographical structure to the genetic variation in the C. monogyna/C. paludicola group, consistent with a model in which gene flow between populations is limited and local differentiation has occurred.

High Levels of Genetic Variability in an Isolated Colony of Rock-wallabies (Petrogale assimilis): Evidence from Three Classes of Molecular Markers

1997 ◽  
Vol 45 (2) ◽  
pp. 199 ◽  
Author(s):  
Peter B. S. Spencer ◽  
Mark Adams ◽  
Helene Marsh ◽  
David J. Miller ◽  
Mark D. B. Eldridge
Keyword(s):  
Genetic Variation ◽  
Molecular Markers ◽  
Genetic Variability ◽  
Mating Systems ◽  
Selective Pressure ◽  
Multiple Mating ◽  
Dna Fingerprints ◽  
Average Heterozygosity ◽  
Low Levels ◽  
High Level

Estimates of genetic variation for a small (Ne = 39) colony of allied rock-wallabies (Petrogale assimilis) were calculated with three different categories of molecular marker. Average heterozygosity was estimated at 3·8% for allozymes, 47·3% for multilocus ‘DNA fingerprints’ and 85·5% for microsatellite markers. Overall these values indicate that this small isolated colony of rock-wallabies maintains a high level of genetic variation despite its relative isolation and the apparently low levels of migration between colonies. It is likely that mechanisms exist (such as kin avoidance, multiple mating systems, high and variable selective pressure in extreme and fluctuating environmental conditions) that promote the maintenance of high levels of genetic variation in isolated colonies of P. assimilis. These mechanisms are discussed in the context of the results obtained from the molecular markers.

scholarly journals Are Palmer’s Elm-Leaf Goldenrod and the Smooth Elm-Leaf Goldenrod Real? The Angiosperms353 Kit Provides Within-Species Signal in Solidago ulmifolia s. l.

2021 ◽  
Vol 46 (4) ◽  
pp. 1107-1113
Author(s):  
James B. Beck ◽  
Morgan L. Markley ◽  
Mackenzie G. Zielke ◽  
Justin R. Thomas ◽  
Haley J. Hale ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Clustering Analysis ◽  
Phylogenetic Analyses ◽  
Morphological Data ◽  
Herbarium Specimens ◽  
Species Status ◽  
Genetic Groups ◽  
The Status ◽  
Distinct Taxon ◽  
Sheer Number

Abstract— The genus Solidago represents a taxonomically challenging group due to its sheer number of species, putative hybridization, polyploidy, and shallow genetic divergence among species. Here we use a dataset obtained exclusively from herbarium specimens to evaluate the status of Solidago ulmifolia var. palmeri, a morphologically subtle taxon potentially confined to Alabama, Arkansas, Mississippi, and Missouri. A multivariate analysis of both discrete and continuous morphological data revealed no clear distinction between S. ulmifolia var. palmeri and Solidago ulmifolia var. ulmifolia. Solidago ulmifolia var. palmeri’s status was also assessed with a phylogenomic and SNP clustering analysis of data generated with the “Angiosperms353” probe kit. Neither analysis supported Solidago ulmifolia var. palmeri as a distinct taxon, and we suggest that this name should be discarded. The status of Solidago delicatula (formerly known as Solidago ulmifolia var. microphylla) was also assessed. Both morphological and phylogenetic analyses supported the species status of S. delicatula and we suggest maintaining this species at its current rank. These results highlight the utility of the Angiosperms353 probe kit, both with herbarium tissue and at lower taxonomic levels. Indeed, this is the first study to utilize this kit to identify genetic groups within a species.

scholarly journals Is Palmer's elm leaf goldenrod real? The Angiosperms353 kit provides within-species signal in Solidago ulmifolia s.l.

2021 ◽  
Author(s):  
James B Beck ◽  
Morgan L Markley ◽  
Mackenzie G Zielke ◽  
Justin R Thomas ◽  
Haley J Hale ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Genetic Divergence ◽  
Clustering Analysis ◽  
Morphological Data ◽  
Herbarium Specimens ◽  
Species Status ◽  
Genetic Groups ◽  
The Status ◽  
Distinct Taxon ◽  
Sheer Number

The genus Solidago represents a taxonomically challenging group due to its sheer number of species, putative hybridization, polyploidy, and shallow genetic divergence among species. Here we use a dataset obtained exclusively from herbarium specimens to evaluate the status of Solidago ulmifolia var. palmeri, a morphologically subtle taxon potentially confined to Alabama, Arkansas, Mississippi, and Missouri. A multivariate analysis of both discrete and continuous morphological data revealed no clear distinction between S. ulmifolia var. palmeri and Solidago ulmifolia var. ulmifolia. Solidago ulmifolia var. palmeri status was also assessed with a phylogenomic and SNP clustering analysis of data generated with the Angiosperms353 probe kit. Neither analysis supported Solidago ulmifolia var. palmeri as a distinct taxon, and we suggest that this name should be discarded. The status of Solidago delicatula (formerly known as Solidago ulmifolia var. microphylla) was also assessed. Both morphological and phylogenic analyses supported the species status of S. delicatula and we suggest maintaining this species at its current rank. These results highlight the utility of the Angiosperms353 probe kit, both with herbarium tissue and at lower taxonomic levels. Indeed, this is the first study to utilize this kit to identify genetic groups within a species.

Negotiations over Accounting Issues: The Congruency of Audit Partner and Chief Financial Officer Recalls

2005 ◽  
Vol 24 (s-1) ◽  
pp. 171-193 ◽  
Author(s):  
Michael Gibbins ◽  
Susan A. McCracken ◽  
Steven E. Salterio
Keyword(s):  
Negotiation Process ◽  
Chief Financial Officers ◽  
Chief Financial Officer ◽  
Relative Importance ◽  
Common Elements ◽  
Contextual Features ◽  
Large Numbers ◽  
The Common ◽  
High Level ◽  
Two Sides

Much of what takes place in auditor-client management negotiations occurs in unobservable settings and normally does not result in publicly available archival records. Recent research has increasingly attempted to probe issues relating to accounting negotiations in part due to recent events in the financial world. In this paper, we compare recalls from the two sides of such negotiations, audit partners, and chief financial officers (CFOs), collected in two field questionnaires. We examine the congruency of the auditors' and the CFOs' negotiation recalls for all negotiation elements and features that were common across the two questionnaires (detailed analyses of the questionnaires are reported elsewhere). The results show largely congruent recall: only limited divergences in recall of common elements and features. Specifically, we show a high level of congruency across CFOs and audit partners in the type of issues negotiated, parties involved in resolving the issue, and the elements making up the negotiation process, including agreement on the relative importance of various common accounting contextual features. The analysis of the common accounting contextual features suggests that certain contextual features are consistently important across large numbers of negotiations, whether viewed from the audit partner's or the CFO's perspective, and hence may warrant future study. Finally, the comparative analysis allows us to identify certain common elements and contextual features that may influence both audit partners and CFOs to consider the accounting negotiation setting as mainly distributive (win-lose).

scholarly journals POPULATION GENETICS OF ALLOZYME VARIATION IN NEUROSPORA INTERMEDIA

Genetics ◽  
1975 ◽  
Vol 80 (4) ◽  
pp. 785-805
Author(s):  
P T Spieth
Keyword(s):  
Genetic Variation ◽  
Vegetative Reproduction ◽  
Vascular Plant ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Regular Feature ◽  
Local Populations ◽  
Neurospora Intermedia ◽  
Pattern Of Variation ◽  
High Level

ABSTRACT Electrophoretically detectable variation in the fungus Neurospora intermedia has been surveyed among isolates from natural populations in Malaya, Papua, Australia and Florida. The principal result is a pattern of genetic variation within and between populations that is qualitatively no different than the well documented patterns for Drosophila and humans. In particular, there is a high level of genetic variation, the majority of which occurs at the level of local populations. Evidence is presented which argues that N. intermedia has a population structure analogous to that of an annual vascular plant with a high level of vegetative reproduction. Sexual reproduction appears to be a regular feature in the biology of the species. Substantial heterokaryon function seems unlikely in natural populations of N. intermedia. Theoretical considerations concerning the mechanisms underlying the observed pattern of variation most likely should be consistent with haploid selection theory. The implications of this constraint upon the theory are discussed in detail, leading to the presentation of a model based upon the concept of environmental heterogeneity. The essence of the model, which is equally applicable to haploid and diploid situations, is a shifting distribution of multiple adaptive niches among local populations such that a given population has a small net selective pressure in favor of one allele or another, depending upon its particular distribution of niches. Gene flow among neighboring populations with differing net selective pressures is postulated as the principal factor underlying intrapopulational allozyme variation.

Caged-electron States and Split-electron States in Endohedral Alkali C60

2021 ◽  
Author(s):  
yifan yang ◽  
Lorenz S Cederbaum
Keyword(s):  
State Of The Art ◽  
Electronic States ◽  
Electron States ◽  
The Common ◽  
High Level

The low-lying electronic states of neutral X@C60(X=Li, Na, K, Rb) have been computed and analyzed by employing state-of-the-art high level many-electron methods. Apart from the common charge-separated states, well known...

Inheritance and development of molecular markers linked to angular leaf spot resistance genes in the common bean accession G10909

2010 ◽  
Vol 28 (1) ◽  
pp. 57-71 ◽  
Author(s):  
George S. Mahuku ◽  
María Antonia Henríquez ◽  
Carmenza Montoya ◽  
Carlos Jara ◽  
Henry Teran ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Common Bean ◽  
Resistance Genes ◽  
Leaf Spot ◽  
Angular Leaf Spot ◽  
The Common

Ba-, Si- and vacancy-rich phlogopites from the talc-bearing sulfide ore deposit of La Creuse, Beaujolais, France

2018 ◽  
Vol 82 (5) ◽  
pp. 1187-1210
Author(s):  
Marie-Lola Pascal ◽  
Michel Fonteilles ◽  
Véronique Tournis ◽  
Benoît Baptiste ◽  
Jean-Louis Robert ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Monoclinic Space Group ◽  
Excess Charge ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Ore Deposit ◽  
Sulfide Ore ◽  
The Common ◽  
The Stability ◽  
High Level

ABSTRACTBa-rich and Si-rich phlogopites occur in the talc-bearing rocks of the La Creuse sulfide ore deposit in Beaujolais, France. They form a group of compositions completely separated from the common Al-rich phlogopites that occur in the surrounding talc-free metasiltites and metarhyolites, with higher Ba and Mg and lower Al contents. The Ba-rich phlogopites have a relatively narrow compositional range (0.24 to 0.80 Ba per formula unit, for 44 valencies) with high and constant Si (5.8 atoms per formula unit, apfu) and Mg + Fe (5.6 apfu), probably buffered by the presence of talc. Compared to low-Al phlogopites from talc-free rocks, the excess charge introduced by the BaK–1 substitution is compensated by interlayer vacancies. Such a high level of interlayer vacancy (0.56 pfu), related to the talc-producing metasomatic conditions, is essential for the stability of this special group of Ba-rich and Si-rich phlogopites.Single crystal X-ray diffraction analyses were performed. Ba-rich and Si-rich phlogopite is monoclinic, space group C2/m, (R = 5.31%) with a = 5.3185(5), b = 9.2136(9), c = 10.1349(11) Å and β = 100.131(11)°. The occupancies of Mg/Fe and K/Ba were refined exploring different vacancies. The solutions giving the best R factor (4.77%) and goodness-of-fit (1.06) are obtained with 15% < vacancy < 40% at the interlayer site.

scholarly journals A MULTIVARIATE ANALYSIS OF GENETIC VARIATION IN THE ADVERTISEMENT CALL OF THE GRAY TREEFROG,HYLA VERSICOLOR

Evolution ◽  
2014 ◽  
Vol 68 (6) ◽  
pp. 1629-1639 ◽  
Author(s):  
Allison M. Welch ◽  
Michael J. Smith ◽  
H. Carl Gerhardt
Keyword(s):  
Multivariate Analysis ◽  
Genetic Variation ◽  
Advertisement Call ◽  
Hyla Versicolor ◽  
Gray Treefrog

scholarly journals From Driverless Dilemmas to More Practical Common-Sense Tests for Automated Vehicles

2020 ◽  
Author(s):  
Julian De Freitas ◽  
Bryant Walker Smith ◽  
Andrea Censi ◽  
Luigi Di Lillo ◽  
Sam E. Anthony ◽  
...  
Keyword(s):  
Common Sense ◽  
Autonomous Systems ◽  
Driving Behavior ◽  
Automated Vehicles ◽  
Everyday Lives ◽  
The Common ◽  
High Level ◽  
First Time ◽  
Trolley Dilemmas ◽  
Relevant Component

For the first time in history, automated vehicles (AVs) are being deployed in populated environments. This unprecedented transformation of our everyday lives demands a significant undertaking: endowing complex autonomous systems with ethically acceptable behavior. We outline how one prominent, ethically-relevant component of AVs—driving behavior—is inextricably linked to stakeholders in the technical, regulatory, and social spheres of the field. Whereas humans are presumed (rightly or wrongly) to have the ‘common sense’ to behave ethically in new driving situations beyond a standard driving test, AVs do not (and probably should not) enjoy this presumption. We examine, at a high level, how to test the common sense of an AV. We start by reviewing discussions of ‘driverless dilemmas’, adaptions of the traditional ‘trolley dilemmas’ of philosophy that have sparked discussion on AV ethics but have limited use to the technical and legal spheres. Then, we explain how to substantially change the premises and features of these dilemmas (while preserving their behavioral diagnostic spirit) in order to lay the foundations for a more practical and relevant framework that tests driving common sense as an integral part of road rules testing.

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