scholarly journals Interspecific Variation in Resistance of Asian, European, and North American Birches (Betulaspp.) to Bronze Birch Borer (Coleoptera: Buprestidae)

2011 ◽  
Vol 40 (3) ◽  
pp. 648-653 ◽  
Author(s):  
David G. Nielsen ◽  
Vanessa L. Muilenburg ◽  
Daniel A. Herms
Keyword(s):  
North American ◽  
Interspecific Variation ◽  
Bronze Birch Borer

Growth and Physiology Vary Little Among North American, an Asian, and a North American x Asian Hybrid Ash in a Common Garden in Ohio, U.S.A

2019 ◽  
Vol 45 (3) ◽  
Author(s):  
Laurel Haavik ◽  
Daniel Herms
Keyword(s):  
Photosystem Ii ◽  
North American ◽  
Intercellular Co2 Concentration ◽  
Emerald Ash Borer ◽  
Common Garden ◽  
Co2 Concentration ◽  
Interspecific Variation ◽  
Co2 Assimilation ◽  
Agrilus Planipennis ◽  
White Ash

The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) invasion of North America has increased interest in ash (Fraxinus, Oleaceae) phylogeny, ecology, and physiology. In a common garden in central Ohio, we compared the performance of three North American ash cultivars that are highly susceptible to EAB (F. pennsylvanica ‘Patmore,’ F. americana ‘Autumn Purple,’ and F. nigra ‘Fall Gold’), one North American species that is less susceptible to EAB (F. quadrangulata), and two taxa that are resistant to EAB (F. mandshurica and F. mandshurica × F. nigra ‘Northern Treasure’). During the 2015 growing season, we measured diameter growth, foliar N concentration, specific leaf area, and on four dates (two with adequate and two with low precipitation) we measured CO2 assimilation rate (A), stomatal conductance (gs), intercellular CO2 concentration (Ci), photosynthetic nitrogen use efficiency (PNUE), variable fluorescence (Fv’/Fm’: efficiency of energy harvested by open photosystem II reaction centers), and the fraction of photons absorbed by photosystem II that were used for photosynthesis (ɸPSII). F. pennsylvanica grew fastest and on most sampling dates was superior in physiological performance (A, gs, and ɸPSII). Generally, however, there was little interspecific variation in growth and physiology among the different ash taxa tested, as all performed well. This suggests that the EAB-resistant F. mandshurica and F. mandshurica × F. nigra hybrid, as well as the moderately resistant blue ash, are as physiologically well-suited to growing conditions in the Midwestern United States as green and white ash cultivars that had been widely planted prior to the EAB invasion.

scholarly journals Review of the North American fauna of Drymeia Meigen (Diptera, Muscidae) and evaluation of DNA barcodes for species-level identification in the genus

ZooKeys ◽  
2021 ◽  
Vol 1024 ◽  
pp. 31-89
Author(s):  
Jade Savage ◽  
Vera S. Sorokina
Keyword(s):  
New Species ◽  
Prior Knowledge ◽  
North American ◽  
Interspecific Variation ◽  
Species Level ◽  
Dna Barcodes ◽  
The North ◽  
Species Groups ◽  
Annotated Checklist ◽  
Level Identification

The North American fauna of Drymeia Meigen was studied. Four new species are described (Drymeia huckettisp. nov., Drymeia pontisp. nov., Drymeia vockerothisp. nov., Drymeia woodorumsp. nov.), and three new synonymies are proposed: Drymeia amnicola (Huckett, 1966) (= Drymeia rivalis (Huckett, 1966), syn. nov.); Drymeia glacialis (Rondani, 1866) (= Drymeia alpicola (Rondani, 1871), syn. nov.); and Drymeia spinitarsis (Aldrich, 1918) (= Drymeia longiseta Sorokina & Pont, 2015, syn. nov.). An annotated checklist, DNA barcodes (when available), and keys for each sex of the 24 named species of North American Drymeia are provided. The utility of DNA barcodes for the identification of Drymeia species across a wide geographical range was explored using sequences from five countries. A match between morphology and DNA barcodes was found for 71% (22/31) of species studied (including three unnamed taxa). The remaining nine species clustered into two groups of taxa with very little interspecific variation within clusters (groups of two and seven species). Caution is advised against using DNA barcoding as the only determination tool for Drymeia material without prior knowledge of its limitations for certain species groups.

scholarly journals Microanatomy and paleohistology of the intercentra of North American metoposaurids from the Upper Triassic of Petrified Forest National Park (Arizona, USA) with implications for the taxonomy and ontogeny of the group

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3183 ◽  
Author(s):  
Bryan M. Gee ◽  
William G. Parker ◽  
Adam D. Marsh
Keyword(s):  
North American ◽  
National Park ◽  
Interspecific Variation ◽  
Species Discrimination ◽  
Diagnostic Feature ◽  
Chinle Formation ◽  
Poor Understanding ◽  
Petrified Forest National Park ◽  
Petrified Forest

Metoposaurids are temnospondyl amphibians that are commonly recovered from the Chinle Formation deposits of North America. Two species, Koskinonodon perfectus and Apachesaurus gregorii, are known from Petrified Forest National Park (PEFO), AZ. Small, elongate intercentra are the single diagnostic postcranial characteristic of the smaller A. gregorii. However, a poor understanding of the earliest life stages of Koskinonodon perfectus and other large metoposaurids makes it unclear whether the proportions of the intercentra are a diagnostic feature for species discrimination or whether they are influenced by ontogeny. Previous work on metoposaurid intercentra has shown that ontogenetic information can be extrapolated from histological analyses. Here, we perform an analysis of the microanatomy and the histology of metoposaurid intercentra from PEFO to determine their ontogenetic maturity and in turn whether elongate intercentra are a reliable taxonomic feature for distinguishing North American metoposaurids. Our findings suggest that the elongate intercentra are the result of ontogenetic variation within a single large-bodied metoposaurid taxon rather than interspecific variation between two metoposaurids of vastly different adult sizes. These findings have significant implications for the taxonomy of North American metoposaurids and subsequently for interpretations of the Chinle Basin paleoenvironment. Furthermore, this study provides the first histological characterization of North American metoposaurid intercentra, thereby improving the understanding of vertebral ontogeny within Metoposauridae and offering new insights into the ecology of large metoposaurids.

Genome size variation in North American minnows (Cyprinidae). II. Variation among 20 species

Genome ◽  
1987 ◽  
Vol 29 (3) ◽  
pp. 481-489 ◽  
Author(s):  
J. R. Gold ◽  
C. T. Amemiya
Keyword(s):  
Genome Size ◽  
North American ◽  
Nuclear Dna ◽  
Interspecific Variation ◽  
Size Difference ◽  
Significant Heterogeneity ◽  
Genome Size Variation ◽  
Size Change ◽  
Dna Values ◽  
Cyprinid Fishes

Genome sizes (nuclear DNA contents) from 200 individuals representing 20 species of North American cyprinid fishes (minnows) were examined spectrophotometrically. The distributions of DNA values of individuals within populations of the 20 species were essentially continuous and normal; the distribution of DNA values among species was continuous and overlapping. These observations suggest that changes in DNA quantity in cyprinids are small in amount, involve both gains and losses of DNA, and are cumulative and independent in effect. Significant heterogeneity in mean genome size occurs both between individuals within populations of species and among species. The former averages maximally around 6% of the cyprinid genome and is nearly the same as the amount of DNA theoretically needed for the entire cyprinid structural gene component. The majority of the DNA content variation among the 20 species is distributed above the level of individuals within populations. Comparisons of average genome size difference or distance between individuals drawn from different levels of taxonomic organization indicate that considerably greater divergence in genome size has occurred in the extremely speciose cyprinid genus Notropis as compared with other North American cyprinid genera. This may suggest that genome size change is concentrated in speciation episodes. Finally, no associations were found between interspecific variation in genome size and five life-history characters. This suggests that much of the variation in genome size within and among the 20 species may be phenotypically inconsequential. Key words: genome size, North American cyprinid fishes, evolution.

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.

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