scholarly journals Resolving spatial complexities of hybridization in the context of the gray zone of speciation in North American ratsnakes ( Pantherophis obsoletus complex)

Evolution ◽  
2021 ◽  
Author(s):  
Frank T. Burbrink ◽  
Marcelo Gehara ◽  
Alexander D. McKelvy ◽  
Edward A. Myers
Keyword(s):  
North American ◽  
Gray Zone ◽  
Obsoletus Complex

Additional comments on the types and nomina of several North American ratsnakes (Pantherophis obsoletus complex, Colubridae, Serpentes)

Bionomina ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
R. ALEXANDER PYRON ◽  
STEVE GOTTE ◽  
FRANK T. BURBRINK
Keyword(s):  
North American ◽  
Poor Condition ◽  
Catalog Number ◽  
Senior Synonym ◽  
Obsoletus Complex ◽  
Subjective Synonym

Here, we provide updates to our recent paper reviewing the taxonomy and nomenclature of the Eastern ratsnakes (Pantherophis obsoletus complex, Colubridae, Serpentes). Specifically, we clarify that Coluber alleghaniensis Holbrook, 1836 is a subjective, rather than objective, senior synonym of Elaphis holbrookii Duméril, Bibron & Duméril, 1854. Contrary to our statement that USNM 1733–4 were syntypes of Scotophis lindheimerii Baird & Girard, 1853, the former is the holotype and the latter is the paratype. The holotype is lost and the paratype is in poor condition, but no neotype designation is warranted at present. We note that USNM 248870, which we designated as the lectotype of Coluber obsoletus lemniscatus Cope, 1888, was originally cataloged as USNM 4710. This catalog number was shared with the type of the salamander Amblystoma tenebrosum Baird & Girard, 1852, and the snake was re-cataloged as USNM 248870 in 1985. Finally, we originally treated C. reticulatus La Cépède, 1789 and C. reticularis Daudin, 1803 as senior subjective synonyms of C. corais Boie, 1827, but here corroborate recent authors in designating it a senior subjective synonym of C. obsoletus Say in James, 1823. As the Commission suppressed C. reticulatus La Cépède, 1789 (an exoplonym), this subsequently rendered C. reticularis Daudin, 1803 (an exoploneonym) unavailable as well.

scholarly journals Resolving spatial complexities of hybridization in the context of the gray zone of speciation in North American ratsnakes (Pantherophis obsoletus complex)

2020 ◽  
Author(s):  
Frank T. Burbrink ◽  
Marcelo Gehara ◽  
Edward A. Myers
Keyword(s):  
Gene Flow ◽  
Spatial Information ◽  
Hybrid Zones ◽  
Gray Zone ◽  
Population Genomic ◽  
Species Pairs ◽  
History Of ◽  
Flow Changes ◽  
Network Approaches ◽  
Obsoletus Complex

AbstractInferring the history of divergence between species in a framework that permits the presence of gene flow has been crucial for characterizing the gray zone of speciation, which is the period of time where lineages have diverged but have not yet achieved strict reproductive isolation. However, estimates of both divergence times and rates gene flow often ignore spatial information, for example the formation and shape of hybrid zones. Using population genomic data from the eastern ratsnake complex (Pantherophis obsoletus), we infer phylogeographic groups, gene flow, changes in demography, the timing of divergence, and hybrid zone widths. We examine the spatial context of diversification by linking migration and timing of divergence to the location and widths of hybrid zones. Artificial neural network approaches are applied to understand how landscape features and past climate have influenced population genetic structure among these lineages prior to hybridization. Rates of migration between lineages are associated with the width and shape of hybrid zones. Timing of divergence is not related to migration rate across species pairs and is therefore a poor proxy for inferring position in the gray zone. However, timing of divergence is related to the number of loci weakly introgressing through hybrid zones.

Unusual Microstructure in Shock-Compacted Graphite

1970 ◽  
Vol 28 ◽  
pp. 474-475
Author(s):  
Lucien F. Trueb
Keyword(s):  
Mechanical Characteristic ◽  
Compression Wave ◽  
Gray Zone ◽  
Flyer Plate ◽  
Compacted Graphite ◽  
The Impact

Crushed and statically compressed Madagascar graphite that was explosively shocked at 425 kb by means of a planar flyer-plate is characterized by a black zone extending for 2 to 3 nun below the impact plane of the driver. Beyond this point, the material assumes the normal gray color of graphite. The thickness of the black zone is identical with the distance taken by the relaxation wave to overtake the compression wave.The main mechanical characteristic of the black material is its great hardness; steel scalpels and razor blades are readily blunted during attempts to cut it. An average microhardness value of 95-3 DPHN was obtained with a 10 kg load. This figure is a minimum because the indentations were usually cracked; 14.8 DPHN was measured in the gray zone.

Adaptation of the Connected Speech Test: Rerecording and Passage Equivalency

2020 ◽  
Vol 29 (2) ◽  
pp. 259-264 ◽  
Author(s):  
Hasan K. Saleh ◽  
Paula Folkeard ◽  
Ewan Macpherson ◽  
Susan Scollie
Keyword(s):  
Speech Perception ◽  
North American ◽  
First Language ◽  
Intraclass Correlation ◽  
Normal Hearing ◽  
Connected Speech ◽  
Internal Reliability ◽  
Speech Test ◽  
The Mean ◽  
Unit Standard

Purpose The original Connected Speech Test (CST; Cox et al., 1987) is a well-regarded and often utilized speech perception test. The aim of this study was to develop a new version of the CST using a neutral North American accent and to assess the use of this updated CST on participants with normal hearing. Method A female English speaker was recruited to read the original CST passages, which were recorded as the new CST stimuli. A study was designed to assess the newly recorded CST passages' equivalence and conduct normalization. The study included 19 Western University students (11 females and eight males) with normal hearing and with English as a first language. Results Raw scores for the 48 tested passages were converted to rationalized arcsine units, and average passage scores more than 1 rationalized arcsine unit standard deviation from the mean were excluded. The internal reliability of the 32 remaining passages was assessed, and the two-way random effects intraclass correlation was .944. Conclusion The aim of our study was to create new CST stimuli with a more general North American accent in order to minimize accent effects on the speech perception scores. The study resulted in 32 passages of equivalent difficulty for listeners with normal hearing.

1588: The Bicalutamide Early Prostate Cancer Program: Findings of the North American Trial at 7.7 Years' Median Follow-Up

2006 ◽  
Vol 175 (4S) ◽  
pp. 511-512
Author(s):  
David G. McLeod ◽  
Ira Klimberg ◽  
Donald Gleason ◽  
Gerald Chodak ◽  
Thomas Morris ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
North American ◽  
Early Prostate Cancer ◽  
The North ◽  
Cancer Program
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