Entity

Time filter

Source Type

Rutherford College, NC, United States

Lamb T.,East Carolina University | Beamer D.A.,East Carolina University | Beamer D.A.,Nash Community College
PLoS ONE | Year: 2012

Change in digit number, particularly digit loss, has occurred repeatedly over the evolutionary history of tetrapods. Although digit loss has been documented among distantly related species of salamanders, it is relatively uncommon in this amphibian order. For example, reduction from five to four toes appears to have evolved just three times in the morphologically and ecologically diverse family Plethodontidae. Here we report a molecular phylogenetic analysis for one of these four-toed lineages - the Eurycea quadridigitata complex (dwarf salamanders) - emphasizing relationships to other species in the genus. A multilocus phylogeny reveals that dwarf salamanders are paraphyletic with respect to a complex of five-toed, paedomorphic Eurycea from the Edwards Plateau in Texas. We use this phylogeny to examine evolution of digit number within the dwarf-Edwards Plateau clade, testing contrasting hypotheses of digit loss (parallelism among dwarf salamanders) versus digit gain (re-evolution in the Edwards Plateau complex). Bayes factors analysis provides statistical support for a five-toed common ancestor at the dwarf-Edwards node, favoring, slightly, the parallelism hypothesis for digit loss. More importantly, our phylogenetic results pinpoint a rare event in the pedal evolution of plethodontid salamanders. © 2012 Lamb, Beamer. Source


Graham S.P.,Pennsylvania State University | Beamer D.,Nash Community College | Lamb T.,East Carolina University
Herpetological Conservation and Biology | Year: 2012

The Seepage Salamander (Desmognathus aeneus) is a tiny, terrestrial plethodontid with a patchy distribution across the Blue Ridge, Coastal Plain, and Piedmont physiographic provinces of the Southeastern United States. The species is of conservation concern or protected in most states within its limited geographic range, and anecdotal reports of population declines or extirpation have prompted a recent petition for federal listing under the Endangered Species Act. To assess the current status of the Seepage Salamander, we conducted 136 surveys at 101 sites, including 46 historical collection localities. Our survey results provide rare good news in this era of declining amphibian populations: we confirmed the presence of Seepage Salamanders at 78% of the historical locations surveyed and discovered new populations at 35 additional localities. Several of these new sites were within 5 km of historical collection sites where the species was not found. Encounter rates (salamanders/person hour searching) were comparable to encounter rates reported by a previous researcher in 1971. Although this species appears to be common and secure over the majority of its range (i.e., the Blue Ridge physiographic province of Georgia and North Carolina), encounter rates were lower and they occupied fewer sites across the Piedmont and Coastal Plain of Alabama and western Georgia, suggesting conservation may be warranted within these regions. © 2012. Sean Graham. All Rights Reserved. Source


Neuls P.D.,HealthSouth Rehabilitation Hospital | Clark T.L.,Nash Community College | Van Heuklon N.C.,UW Hospital and Clinics | Proctor J.E.,Susquehanna Health Neuroscience Center | And 5 more authors.
Journal of Geriatric Physical Therapy | Year: 2011

Objective: The purpose of this systematic review was to complete a comprehensive search and review of the literature to determine the ability of the Berg Balance Scale (BBS) to predict falls in the elderly with and without pathology. Specifically, the cutoff score that is most predictive of falls in the older adults and the sensitivity and specificity of the BBS in predicting falls. Methods: A search of English-language-based literature with relevant search terms using the OVID, CINAHL, PubMed, and MEDLINE search engines from 1985 to March 2009. Results: Nine studies warranted inclusion in this systematic review after evaluation for article objectives, inclusion criteria, and scoring 5 or more out of 10 on the Physiotherapy Evidence Database scale. Five studies addressed the elderly population (x - = 65 years) without pathology. The remaining 4 studies addressed elderly participants with neurological disorders. All 9 studies reported sensitivity and specificity of the BBS in predicting falls. Sensitivity and specificity results varied greatly depending on the cutoff score and the author's objectives. Eight of the 9 studies recommended specific cutoff scores. Discussion and Conclusion: The BBS alone is not useful for predicting falls in the older adults with and without pathological conditions. Given the varied recommended cutoff scores and psychometric values, clinicians should use the BBS in conjunction with other tests/measures considering unique patient factors toquantify the chances of falls in the older adults. This study recommends research to formulate a scoring algorithm that can further enhance the clinician's ability to predict falls in the older adults. Copyright © 2011 The Section on Geriatrics, American Physical Therapy Association. Source


Grundel R.,U.S. Geological Survey | Grundel R.,Nash Community College | Beamer D.A.,U.S. Geological Survey | Beamer D.A.,Nash Community College | And 6 more authors.
Biodiversity and Conservation | Year: 2015

Temperate savannas are threatened across the globe. If we prioritize savanna restoration, we should ask how savanna animal communities differ from communities in related open habitats and forests. We documented distribution of amphibian and reptile species across an open-savanna–forest gradient in the Midwest U.S. to determine how fire history and habitat structure affected herpetofaunal community composition. The transition from open habitats to forests was a transition from higher reptile abundance to higher amphibian abundance and the intermediate savanna landscape supported the most species overall. These differences warn against assuming that amphibian and reptile communities will have similar ecological responses to habitat structure. Richness and abundance also often responded in opposite directions to some habitat characteristics, such as cover of bare ground or litter. Herpetofaunal community species composition changed along a fire gradient from infrequent and recent fires to frequent but less recent fires. Nearby (200-m) wetland cover was relatively unimportant in predicting overall herpetofaunal community composition while fire history and fire-related canopy and ground cover were more important predictors of composition, diversity, and abundance. Increased developed cover was negatively related to richness and abundance. This indicates the importance of fire history and fire related landscape characteristics, and the negative effects of development, in shaping the upland herpetofaunal community along the native grassland–forest continuum. © 2014, Springer Science+Business Media Dordrecht (out side the USA). Source

Discover hidden collaborations