Cytogenetics of Elymus magellanicus and its intra- and inter-generic hybrids with Pseudoroegneria spicata, Hordeum violaceum, E. trachycaulus, E. lanceolatus, and E. glaucus (Poaceae: Triticeae)

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Kevin B. Jensen
Keyword(s):  
Chromosome Pairing ◽  
North American ◽  
South American ◽  
The South ◽  
Pseudoroegneria Spicata ◽  
Bivalent Formation ◽  
North And South

This paper describes the cytogenetics of the South American grass Elymus magellanicus (2n = 4x = 28) and its inter- and intra-generic hybrids with North American Pseudoroegneria spicata (2n = 2x = 14; SS), Iranian Hordeum violaceum (2n = 2x = 14; HH), and North American E. trachycaulus (2n = 4x = 28; SSHH), E. lanceolatus (2n = 4x = 28; SSHH), and E. glaucus (2n = 4x = 28; SSHH). Chromosome pairing in the F1 hybrid of E. magellanicus × P. spicata (2n = 3x = 21) averaged 4.09 bivalents per cell. Bivalent frequencies in the E. magellanicus × H. violaceum (2n = 3x = 21) averaged 4.86 bivalents per cell. Bivalent formation (frequencies) in hybrids between North and South American tetraploids averaged 11.42 in E. magellanicus × E. trachycaulus, 13.02 in E. magellanicus × E. lanceolatus, and 10.91 in E. magellanicus × E. glaucus. Meiotic data demonstrated that E. magellanicus is an allotetraploid having the same basic genomes (SSHH) as North American E. trachycaulus, E. lanceolatus, and E. glaucus.Key words: chromosome pairing, meiosis.

scholarly journals Balance Differences between North and South American Older Adults: A Cross-Sectional, Age and Sex Matched Study

2021 ◽  
Author(s):  
Matheus Almeida Souza ◽  
Daniel Goble ◽  
Paige Arney ◽  
Edgar Ramos Vieira ◽  
Gabriela Silveira-Nunes ◽  
...  
Keyword(s):  
Older Adults ◽  
High Risk ◽  
North American ◽  
Force Plate ◽  
South American ◽  
Risk Of Falling ◽  
Men And Women ◽  
Falls Risk ◽  
South Americans ◽  
North And South

This study aimed to characterize the risk of falling in low, moderate and high risk participants from two different geographical locations using a portable force-plate. A sample of 390 older adults from South and North America were matched for age, sex, height and weight. All participants performed a standardized balance assessment using a force plate. Participants were classified in low, moderate and high risk of falling. No differences were observed between South and North American men, nor comparing North American men and women. South American women showed the significantly shorter center of pressure path length compared to other groups. The majority of the sample was categorized as having low risk of falling (male: 65.69 % and female: 61.87 %), with no differences between men and women. Also, no differences were found between North vs. South Americans, nor for falls risk levels when male and female groups were compared separately. In conclusion, South American women had better balance compatible with the status of the 50-59 years’ normative age-range. The prevalence of low falls risk was ~ 61-65 % and the prevalence of moderate to high risk was ~ 16-19 %. The frequency of fall risk did not differ significantly between North and South Americans, nor between males and females.

ON THE GEOGRAPHICAL DISTRIBUTION OF NORTH AMERICAN LEPIDOPTERA

1886 ◽  
Vol 18 (11) ◽  
pp. 213-220
Author(s):  
Aug. R. Grote
Keyword(s):  
Geographical Distribution ◽  
North American ◽  
North American Species ◽  
South American ◽  
Seasonal Temperature ◽  
The South ◽  
Old World ◽  
The North

Again, the genera Citheronia and Eacles are a South American element in our fauna, while the typical Attacinæ, such as Actias, probably belong to the Old World element in our fauna, together with all our Platypteryginœ. Among the Hawk Moths the genera Philampelus and Phlegethontius are of probable South American extraction, though represented now by certain strictly North American species. Mr. Robert Bunker, writing from Rochester, N. Y., records the fact that Philampelus Pandorus, going into chrysaiis Augnst 1, came out Sept. 10 as a moth, showing that in a warmer climate the species would become doublebrooded. And this is undoubtedly the case with many species the farther we go South, where insect activities are not interrupted so long and so strictly by the cold of winter. Since the continuance of the pupal condition is influenced by cold, a diminishing seasonal temperature for ages may have originally affected, if not induced, the transformations of insects as a whole. Butterflies and Moths which are single brooded in the North become double brooded in the South.

A NEW WATER-BUG FROM CANADA

1897 ◽  
Vol 29 (3) ◽  
pp. 56-56
Author(s):  
William H. Ashmead
Keyword(s):  
New Species ◽  
Fresh Water ◽  
North American ◽  
South American ◽  
The South ◽  
Water Stream ◽  
The North ◽  
Water Species

The interesting new species of water-bug described below was received some time ago from Abbé P. A. Bégin, of Sherbrooke, Canada. It was captured swimming on a fresh-water stream some little distance above Sherbrooke, and is of more than ordinary interest, from the fact that it belongs to the genus Halobatopsis, Bianchi, a genus not yet recognized in the North American fauna, and only recently characterized, being based upon the South American Halobates platensis, Berg., also a fresh-water species.

SUSCEPTIBILITY OF ARGENTINE MELANOPLINES (ORTHOPTERA: ACRIDIDAE) TO ENTOMOPOXVIRUSES (ENTOMOPOXVIRINAE) FROM NORTH AMERICAN AND AFRICAN GRASSHOPPERS

1993 ◽  
Vol 125 (6) ◽  
pp. 1127-1129 ◽  
Author(s):  
C.E. Lange ◽  
D.A. Streett
Keyword(s):  
North American ◽  
South American ◽  
Pest Species ◽  
The South ◽  
Land Bridge ◽  
Important Species ◽  
Different Parts

Grasshoppers are responsible for considerable agricultural losses in different parts of Argentina (C.O.P.R. 1982). Most of the pest species in Argentina belong to the subfamily Melanoplinae. It is generally accepted that South American melanoplines are derived from a nearctic stock that crossed the Panamanian land bridge (Carbonell 1977). The genus Dichroplus Stål is one of the largest genera within the South American Melanoplinae (Ronderos and Cigliano 1990). Dichroplus contains several economically important species and is believed to be closely related to the nearctic genus Melanoplus Stål (Vickery 1989).

The North American Species of Diathrausta Lederer (Lepidoptera: Pyralidae)

1956 ◽  
Vol 88 (10) ◽  
pp. 579-583
Author(s):  
Eugene Munroe
Keyword(s):  
North American ◽  
North American Species ◽  
South American ◽  
The South ◽  
The North ◽  
Geographical Race ◽  
Geographic Race ◽  
Lepidoptera Pyralidae

Dyar (1913) listed Diathrausta reconditalis (Walker) as a “form” of the South American D. nerinalis (Walker) and described as new the “form” harlequinalis from Arizona. From the context it is evident that in that paper Dyar used “form” as equivalent to geographic race, and the form names he proposed there can accordingly be treated as valid trinomina. Haimbach (1915), apparently in ignorance of Dyar's paper, described Diathrausta montana from Colorado. This was sunk by Barnes and McDunnough (1917) as a synonym of harlequinalis. Barnes and McDunnough listed harlequinalis as a geographical race of reconditalis, but did not follow Dyar in uniting these with nerinalis.

RAPD analysis of the relationship of North and South American subspecies of Fragaria chiloensis

1998 ◽  
Vol 76 (10) ◽  
pp. 1812-1817 ◽  
Author(s):  
Sue Porebski ◽  
Paul M Catling
Keyword(s):  
North American ◽  
Random Amplified Polymorphic Dna ◽  
Molecular Evidence ◽  
South American ◽  
Cophenetic Correlation ◽  
The North ◽  
Fragaria Chiloensis ◽  
Protection And Utilization ◽  
Relationship Of ◽  
North And South

To improve the intraspecific classification of Fragaria chiloensis (L.) Duchesne, 35 plants including 5 North American ssp. lucida, 15 North American ssp. pacifica, and 15 South American ssp. chiloensis were analysed using random amplified polymorphic DNA (RAPDs). From 100 primers screened, 12 were selected providing 62 scorable polymorphic bands. The phenogram (cophenetic correlation, r = 0.99) based on UPGMA clustering of Jaccard's coefficients revealed a clear division between North American and South American plants, but only partial separation was shown between the two North American subspecies. This is the first comprehensive molecular evidence for major genetic divergence between the North American and South American subspecies of F. chiloensis and suggests greater genetic variation within the Canadian material of the North American ssp. pacifica than within the South American ssp.chiloensis. These findings strongly support protection and utilization of wild Canadian Fragaria germplasm for crop improvement.Key words: strawberry, Fragaria chiloensis, ssp. chiloensis, ssp. pacifica, ssp. lucida, RAPD, variation, germplasm, Canada, United States, Chile.

scholarly journals Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America

2016 ◽  
Vol 12 (4) ◽  
pp. 20160062 ◽  
Author(s):  
Kieren J. Mitchell ◽  
Sarah C. Bray ◽  
Pere Bover ◽  
Leopoldo Soibelzon ◽  
Blaine W. Schubert ◽  
...  
Keyword(s):  
South America ◽  
North American ◽  
Convergent Evolution ◽  
Phylogenetic Analyses ◽  
Early Pleistocene ◽  
South American ◽  
The North ◽  
Molecular Phylogenetic ◽  
North And South America ◽  
North And South

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear ( Tremarctos ornatus ), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears ( Tremarctos ), South American short-faced bears ( Arctotherium ) and North American short-faced bears ( Arctodus ) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears ( Arctodus and Arctotherium ), potentially as an adaptation to dominate competition for megafaunal carcasses.

Differences in bleaching responses from fungal- versus bacterial-derived enzymes

TAPPI Journal ◽  
2012 ◽  
Vol 11 (3) ◽  
pp. 21-27 ◽  
Author(s):  
PETER W. HART
Keyword(s):  
North American ◽  
Cost Savings ◽  
Operating Conditions ◽  
South American ◽  
Oxygen Delignification ◽  
The North ◽  
Eucalyptus Pulp ◽  
The One ◽  
Enzyme Bleaching ◽  
North And South

Several mills in North America have been successful in using xylanase enzymes expressed from Trichoderma reesei (a fungus) as part of their bleaching sequence for many years. These mills process hardwood and softwood species, with and without oxygen delignification. These mills also use three-, four-, and five-stage bleaching sequences. North American mills tend to report increased pulp brightness ceilings and decreased bleaching costs as benefits associated with the application of enzymes in the bleaching process. Laboratory testing suggests that eucalyptus pulp is highly susceptible to fungal- and bacterial-derived enzyme bleaching and should result in significant cost savings in South American mills. At least four different mills in South America have attempted to perform enzyme bleaching trials using bacterial-derived enzymes. Each of these mill trials resulted in significantly increased operating costs and/or unsustainable operating conditions. More recently, one of these South American mills performed a short trial using a commercially available, fungal-derived enzyme. This trial was technically successful. This report attempts to determine why the South American mill experiences with bacterial-derived enzymes have been poor, while North American mills and the one South American mill trial have had good results with fungal-derived enzymes. Operating conditions and trial goals for the North and South American mills also were examined.

CYTOTAXONOMIC STUDIES ON NEW WORLD SPECIES OF ANEMONE (SECTION ERIOCEPHALUS) WITH TUBEROUS ROOTSTOCKS

1966 ◽  
Vol 44 (7) ◽  
pp. 899-928 ◽  
Author(s):  
Cecily Joseph ◽  
Margaret Heimburger
Keyword(s):  
North American ◽  
New World ◽  
Diploid Species ◽  
Pollen Grain ◽  
South American ◽  
New Taxon ◽  
South American Species ◽  
The North ◽  
Additional Support ◽  
North And South

The American species of Anemone L. (section Eriocephalus Hook. f. & Thoms.) with tuberous rootstocks were studied by biosystematic methods. Anemone caroliniana Walt., A. heterophylla Nutt. ex Torr. & Gray, A. tuberosa Rydb., and A. edwardsiana Tharp (tentatively) are recognized from North America and A. decapetala Ard., A. triternata Vahl, and A. cicutifolia Johnst. from South America. Karyotypes of the diploid species (2n = 16), A. heterophylla, A. tuberosa, A. decapetala, and A. triternata are described. They resemble the karyotype of A. caroliniana published earlier. Anemone edwardsiana and A. cicutifolia are also presumed diploid from stomatal and pollen grain studies. A new taxon (2n = 32), of undecided status, was obtained from Chile. North American plants included by authors in A. decapetala are here referred to A. heterophylla. The North and South American species appear to form two separate groups, the species of each continent being more closely related among themselves than to those of the other continent. Fewer stomata, larger chromosome size, and higher DNA content are characteristic of the North American species. Additional support for the separation of the two groups derives from limited meiotic studies which indicate a larger number of inversion differences in inter- than in intra-continental hybrids.

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