ÉTUDE BIOMÉTRIQUE DU CARYOTYPE DE LA BRUCHE DU HARICOT (ACANTHOSCELIDES OBTECTUS, COLÉOPTÈRES, BRUCHIDAE)

1982 ◽  
Vol 24 (6) ◽  
pp. 687-692 ◽  
Author(s):  
P. Garaud ◽  
P. Lecher
Keyword(s):  
Comparative Analysis ◽  
Diploid Number ◽  
Relative Length ◽  
Graphic Representation ◽  
Acanthoscelides Obtectus ◽  
European Strain ◽  
Bean Beetle ◽  
Two Parameters

The karyotype of a European strain of the bean beetle, Acanthoscelides obtectus, has been made using biometrical methods with two parameters: arm ratio and relative length; each chromosome is defined by two values. Graphic representation of all chromosomes gave well scattered points. This method allowed us to determine the diploid number (2n = 20), sex mechanism (XY/XX) and the establishment of a definite karyotype. This study is part of an ongoing comparative analysis of strains from various geographical origins.[Translated by the journal]

Associated evolution of bipedality and cursoriality among Triassic archosaurs: a phylogenetically controlled evaluation

Paleobiology ◽  
2012 ◽  
Vol 38 (3) ◽  
pp. 474-485 ◽  
Author(s):  
Tai Kubo ◽  
Mugino O. Kubo
Keyword(s):  
Comparative Analysis ◽  
Relative Length ◽  
Independent Contrasts ◽  
Avian Flight ◽  
Phylogenetically Independent Contrasts ◽  
Controlled Evaluation

Bipedalism evolved more than twice among archosaurs, and it is a characteristic of basal dinosaurs and a prerequisite for avian flight. Nevertheless, the reasons for the evolution of bipedalism among archosaurs have barely been investigated. Comparative analysis using phylogenetically independent contrasts showed a significant correlation between bipedality (relative length of forelimb) and cursoriality (relative length of metatarsal III) among Triassic archosaurs. This result indicates that, among Triassic archosaurs, bipeds could run faster than quadrupeds. Bipedalism is probably an adaptation for cursoriality among archosaurs, which may explain why bipedalism evolved convergently in the crocodilian and bird lineages. This result also indicates that the means of acquiring cursoriality may differ between archosaurs and mammals.

Anaximander’s Model and the Measures of the Sun and Moon

2017 ◽  
Vol 137 ◽  
pp. 92-111 ◽  
Author(s):  
Philip Thibodeau
Keyword(s):  
Observational Data ◽  
Graphic Representation ◽  
The Sun ◽  
The Earth ◽  
New Interpretation ◽  
Two Parameters ◽  
Cosmic Model

AbstractThis paper proposes a new interpretation of the dimensions of the sun and moon wheels in Anaximander's cosmology. While the traditional reconstruction proposed by Tannery and Diels posits six measures for three different wheels (sun, moon and stars), it will be argued here that Anaximander gave only two basic measurements, one for the moon's wheel (19 times bigger than the earth) and one for the sun's (28 times bigger). These two values can be accounted for by their connection to the lunar month – a graphic representation of the wheels which includes motion accurately reproduces the relative positions of the sun and moon; in fact they are the smallest pair of figures from which a twowheel model can be made that represents the month correctly. Anaximander derived his two parameters by attempting to incorporate basic observational data into a cosmic model.

A chromosomal investigation of five European species of Anacaena Thomson (Coleoptera: Hydrophilidae)

1990 ◽  
Vol 21 (4) ◽  
pp. 415-426 ◽  
Author(s):  
Fatma A. Shaarawi ◽  
Robert B. Angus
Keyword(s):  
Diploid Number ◽  
Relative Length ◽  
Distinct Species ◽  
Deletion Polymorphism ◽  
European Species ◽  
Single Origin ◽  
Multiple Origins ◽  
Chromosomal Data ◽  
And Bisexual ◽  
Two Populations

AbstractChromosomal data are given for five European species of Anacaena. A. bipustulata, A. limbata and A. lutescens have the diploid number 16 + XY (male), 16 + XX (female). A. globulus has the number 14 + XY/XX, while in A. rufipes the number is 10 + neo-XY (male). Chromosomal data from various Hydrobiinae suggest that a diploid number of 16 + XY or XX is normal in this subfamily, and that the karyotypes of A. globulus and A. rufipes result from reductions in number. In A. globulus the sizes and shapes of the chromosomes suggest that there may have been loss of the centromere from one of the smaller chromosome pairs, with the two arms fusing with two different autosomes. In A. rufipes the process appears to have gone further, with the original sex chromosomes fusing with a pair of autosomes to give a neo-XY. The karyotypes of all five species are distinctive, confirming the recognition of A. lutescens as a distinct species. In populations of A. lutescens comprising only females, all specimens were heterozygous for a deletion polymorphism in one pair of autosomes. This deletion was not found in bisexual populations. Two of the females-only populations included a proportion of triploid individuals, and this, in conjunction with the deletion polymorphism, is taken as evidence that these populations are parthenogenetic. Present evidence is not considered sufficient to show whether the parthenogenesis has a single origin in A. lutescens or whether it is polyphyletic, though the discovery of consistent small differences in the relative length of two autosomes, between parthenogenetic and bisexual populations, suggests a single origin. The triploid karyotypes show small differences between the two populations in which they are known, and this suggests that triploidy has arisen after the establishment of parthenogenesis, and is of multiple origins. In most cases the only tissue available for chromosome preparations was mid-gut of adult beetles, and the methods used are described.

Pheromone Bouquet of the Dried Bean Beetle,Acanthoscelides obtectus(Col.: Chrysomelidae), Now Complete

2015 ◽  
Vol 2015 (22) ◽  
pp. 4843-4846 ◽  
Author(s):  
József Vuts ◽  
Wittko Francke ◽  
Kenji Mori ◽  
Paulo H. G. Zarbin ◽  
Antony M. Hooper ◽  
...  
Keyword(s):  
Acanthoscelides Obtectus ◽  
Bean Beetle

scholarly journals Comparative Analysis of Karyotypes of Two Cryptic Species of Pelobatid Frogs (Amphibia, Anura) of Ukraine

2014 ◽  
Vol 48 (6) ◽  
pp. 511-520 ◽  
Author(s):  
N. N Suryadnaya
Keyword(s):  
Comparative Analysis ◽  
Cryptic Species ◽  
Chromosome Pair ◽  
Morphological Analysis ◽  
Relative Length ◽  
Diagnostic Features ◽  
Pelobates Fuscus ◽  
Comparative Morphological Analysis ◽  
Absolute Length ◽  
Secondary Constrictions

Abstract The paper first describes in detail the karyotype of Pelobates vespertinus (Pallas, 1771) in comparison with the karyotype of Pelobates fuscus (Laurenti, 1768). Comparative morphological analysis of chromosomes has shown that these two cryptic species have a symmetrical karyotype consisting of two-armed chromosomes. It has been established that their chromosome sets consist of 7 pairs of large chromosomes and 6 pairs of small ones. The species diff er by the position of the centromere in the chromosomes of the 10th and 11th pairs. The 10th pair of P. fuscus is metacentrics, the 11th pair is submetacentric; the 10th pair of P. vespertinus is submetacentric, and the 11th one is metacentrics. Secondary constrictions are on the short arms of the 7th chromosome pair. The chromosomal formula for both species is 4 meta-(m) + 7 submeta-(sm) + 2 subtelocentrics (st), 2n = 26, N.F. = 52. Absolute length of all the chromosomes in the karyotype of P. fuscus is somewhat larger than that one in the karyotype of P. vespertinus. The parameters of relative length are equivalent on average, but they diff er in individual chromosomes. On the background of established chromosomal differences between the cryptic species, reliable diagnostic features have not been identified.

scholarly journals Morphometry of the eyes in regenerant of genus Dugesia (Platyhelminthes, Turbellaria, Dugesiidae)

2004 ◽  
Vol 64 (1) ◽  
pp. 1-9 ◽  
Author(s):  
N. M. R. de Campos-Velho ◽  
K. A. R. Lopes ◽  
J. Hauser
Keyword(s):  
Comparative Analysis ◽  
Regenerative Process ◽  
Graphic Representation ◽  
Morphometric Data ◽  
Statistical Parameters ◽  
Morphometric Characters ◽  
Pigment Spot ◽  
Dugesia Tigrina

The photodocumentation technique was used weekly to observe until the end of the regenerative process of eyes in three species of Dugesia. Morphometric data based on the measurement of 96 samples of the species: Dugesia tigrina, D. schubarti, and D. anderlani were analyzed A comparative analysis was made through graphic representation of statistical parameters of the following morphometric characters: the length of the transversal and longitudinal axes of the macula alba, pigment spot, and ocular opening. An interesting feature appeared in D. schubarti: the average of ocular opening during the regenerative process is bigger than in the original samples.

Effects of hydraulic and medium characteristics on solute transfer to surface runoff

1994 ◽  
Vol 30 (7) ◽  
pp. 145-155 ◽  
Author(s):  
J. L. Lai ◽  
S. L. Lo ◽  
C. F. Lin
Keyword(s):  
Mass Loss ◽  
Potassium Chloride ◽  
Surface Runoff ◽  
Relative Length ◽  
Packed Bed ◽  
Rate Of Change ◽  
Solute Transfer ◽  
Factors Affecting ◽  
The Media ◽  
Two Parameters

A two-stage scouring-based model including two parameters for each stage, the ultimate scoured depth and rate of change of scoured depth, was developed to describe solute transfer to surface runoff. While the first stage is a quick decrease of mass loss of solute to surface runoff, the second stage is a slow one. An experimental flume with a medium packed bed was designed. Four different sizes of glass beads were chosen to be the media and saturated with uniform concentration (20000 ppm) of potassium chloride solution before runoff occurred. In a series of experiments, runoff was passed at varied flow rate, velocities, and depths over the medium bed. Runoff samples were taken at the end of flume and the concentration of potassium chloride analysed. By use of this model, the dimensionless ultimate scoured depth and the dimensionless rate of change of each stage were investigated. The results showed that the Reynolds number within media and the relative length were two important factors affecting mass loss of chemicals.

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