scholarly journals Age of Pre-Neoglacial Cirque Moraines in the Central North American Cordillera

2007 ◽  
Vol 41 (3) ◽  
pp. 365-375 ◽  
Author(s):  
P. Thompson Davis ◽  
Gerald Osborn

ABSTRACT In the western mountains of the United States and Canada are pre-Neoglacial cirque moraines that lie up to about 3 km outside Neoglacial moraines. There is considerable uncertainty as to the ages of the outer moraines and whether or not they are age-equivalent from range to range. The variety of assigned radiocarbon ages found in the literature may be partly due to some authors' use of minimum-limiting dates as near-absolute dates, and use of dates that cannot be definitely related to the deposits in question. With one possible exception, all the dated moraines described in the literature could be as old as the type Temple Lake moraine of Wyoming which has a minimum age of about 11,400 yrs BP based on a recently obtained radiocarbon date. Nearly all paleoecological proxy data from the North American Cordillera, generally derived from continuous sedimentary records, suggest that early Holocene climate was warmer than at present. Global circulation models also suggest an early Holocene thermal maximum in the Cordillera, probably due to Milankovitch forcing. For these reasons a proposal gaining popularity in the literature that widespread "Mesoglaciation" occurred in early Holocene time is premature. We hypothesize that most, if not all, of the moraines in question are correlative and date from Late Pleistocene time.

2019 ◽  
Author(s):  
William A. Matthews ◽  
◽  
Marie-Pier Boivin ◽  
Kirsten Sauer ◽  
Daniel S. Coutts

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1278
Author(s):  
Michael Glenn O’Connor ◽  
Amjad Horani ◽  
Adam J. Shapiro

Primary Ciliary Dyskinesia (PCD) is a rare, under-recognized disease that affects respiratory ciliary function, resulting in chronic oto-sino-pulmonary disease. The PCD clinical phenotype overlaps with other common respiratory conditions and no single diagnostic test detects all forms of PCD. In 2018, PCD experts collaborated with the American Thoracic Society (ATS) to create a clinical diagnostic guideline for patients across North America, specifically considering the local resources and limitations for PCD diagnosis in the United States and Canada. Nasal nitric oxide (nNO) testing is recommended for first-line testing in patients ≥5 years old with a compatible clinical phenotype; however, all low nNO values require confirmation with genetic testing or ciliary electron micrograph (EM) analysis. Furthermore, these guidelines recognize that not all North American patients have access to nNO testing and isolated genetic testing is appropriate in cases with strong clinical PCD phenotypes. For unresolved diagnostic cases, referral to a PCD Foundation accredited center is recommended. The purpose of this narrative review is to provide insight on the North American PCD diagnostic process, to enhance the understanding of and adherence to current guidelines, and to promote collaboration with diagnostic pathways used outside of North America.


2021 ◽  
pp. 1-20
Author(s):  
Ayana Omilade Flewellen ◽  
Justin P. Dunnavant ◽  
Alicia Odewale ◽  
Alexandra Jones ◽  
Tsione Wolde-Michael ◽  
...  

This forum builds on the discussion stimulated during an online salon in which the authors participated on June 25, 2020, entitled “Archaeology in the Time of Black Lives Matter,” and which was cosponsored by the Society of Black Archaeologists (SBA), the North American Theoretical Archaeology Group (TAG), and the Columbia Center for Archaeology. The online salon reflected on the social unrest that gripped the United States in the spring of 2020, gauged the history and conditions leading up to it, and considered its rippling throughout the disciplines of archaeology and heritage preservation. Within the forum, the authors go beyond reporting the generative conversation that took place in June by presenting a road map for an antiracist archaeology in which antiblackness is dismantled.


1940 ◽  
Vol 72 (7) ◽  
pp. 135-145 ◽  
Author(s):  
G. Stuart Walley

As noted below the two North American species described in Syndipnus by workers appear to belong in other genrra. In Europe the gunus is represented by nearly a score of species and has been reviewed in recent years by two writers (1, 2). North American collections contain very few representatives of the genus; after combining the material in the National Collection with that from the United States National Museum, the latter kindly loaned to me by Mr. R. A. Cushman, only thirty-seven specimens are available for study.


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