Slavic Sociolinguistics in North America: Lineage and Leading Edge

2009 ◽  
Vol 17 (1) ◽  
pp. 3-59
Author(s):  
Mark Richard Lauersdorf
Keyword(s):  
North America ◽  
Leading Edge

scholarly journals Ten-year projection of white-nose syndrome disease dynamics at the southern leading-edge of infection in North America

2020 ◽  
Author(s):  
Melissa B. Meierhofer ◽  
Thomas M. Lilley ◽  
Lasse Ruokolainen ◽  
Joseph S. Johnson ◽  
Steven Parratt ◽  
...  
Keyword(s):  
Infectious Disease ◽  
North America ◽  
Environmental Conditions ◽  
Leading Edge ◽  
Environmental Data ◽  
Disease Spread ◽  
Disease Dynamics ◽  
Pseudogymnoascus Destructans ◽  
White Nose Syndrome ◽  
Management Actions

AbstractPredicting the emergence and spread of infectious diseases is critical for effective conservation of biodiversity. White-nose syndrome (WNS), an emerging infectious disease of bats, has resulted in high mortality in eastern North America. Because the fungal causative agent Pseudogymnoascus destructans is constrained by temperature and humidity, spread dynamics may vary greatly by geography. Environmental conditions in the southern part of the continent, where disease dynamics are typically studied, making it difficult to predict how the disease will manifest. Herein, we modeled the spread of WNS in Texas based on available cave densities and average dispersal distances of species occupying these sites, and projected these results out to 10 years. We parameterized a predictive model of WNS epidemiology and its effects on hibernatory bat populations with observed environmental data from bat hibernation sites in Texas. Our model suggests that bat populations in northern Texas will be more affected by WNS mortality than southern Texas. As such, we recommend prioritizing the preservation of large overwintering colonies of bats in north Texas through management actions. Our model further illustrates that infectious disease spread and infectious disease severity can become uncoupled over a gradient of environmental variation. Finally, our results highlight the importance of understanding host, pathogen and environmental conditions in various settings to elucidate what may happen across a breadth of environments.

scholarly journals Mid-Cenozoic succession on the northeast limb of the Mount Diablo anticline, California—A stratigraphic record of tectonic events in the forearc basin

2021 ◽  
Author(s):  
Raymond Sullivan ◽  
Morgan D. Sullivan ◽  
Stephen W. Edwards ◽  
Andrei M. Sarna-Wojcicki ◽  
Rebecca A. Hackworth ◽  
...  
Keyword(s):  
North America ◽  
Late Miocene ◽  
Plate Boundary ◽  
Leading Edge ◽  
Late Eocene ◽  
Late Cenozoic ◽  
Forearc Basin ◽  
Late Mesozoic ◽  
The North ◽  
Silicic Volcanic

ABSTRACT The mid-Cenozoic succession in the northeast limb of the Mount Diablo anticline records the evolution of plate interactions at the leading edge of the North America plate. Subduction of the Kula plate and later Farallon plate beneath the North America plate created a marine forearc basin that existed from late Mesozoic to mid-Cenozoic times. In the early Cenozoic, extension on north-south faults formed a graben depocenter on the west side of the basin. Deposition of the Markley Formation of middle to late? Eocene age took place in the late stages of the marine forearc basin. In the Oligocene, the marine forearc basin changed to a primarily nonmarine basin, and the depocenter of the basin shifted eastward of the Midland fault to a south-central location for the remainder of the Cenozoic. The causes of these changes may have included slowing in the rate of subduction, resulting in slowing subsidence, and they might also have been related to the initiation of transform motion far to the south. Two unconformities in the mid-Cenozoic succession record the changing events on the plate boundary. The first hiatus is between the Markley Formation and the overlying Kirker Formation of Oligocene age. The succession above the unconformity records the widespread appearance of nonmarine rocks and the first abundant appearance of silicic volcanic detritus due to slab rollback, which reversed the northeastward migration of the volcanic arc to a more proximal location. A second regional unconformity separates the Kirker/Valley Springs formations from the overlying Cierbo/Mehrten formations of late Miocene age. This late Miocene unconformity may reflect readjustment of stresses in the North America plate that occurred when subduction was replaced by transform motion at the plate boundary. The Cierbo and Neroly formations above the unconformity contain abundant andesitic detritus due to proto-Cascade volcanism. In the late Cenozoic, the northward-migrating triple junction produced volcanic eruptive centers in the Coast Ranges. Tephra from these local sources produced time markers in the late Cenozoic succession.

scholarly journals A Conceptual Model for Development of Intense Pyrocumulonimbus in Western North America

2017 ◽  
Vol 145 (6) ◽  
pp. 2235-2255 ◽  
Author(s):  
David A. Peterson ◽  
Edward J. Hyer ◽  
James R. Campbell ◽  
Jeremy E. Solbrig ◽  
Michael D. Fromm
Keyword(s):  
North America ◽  
Conceptual Model ◽  
Leading Edge ◽  
Western North America ◽  
Major Step ◽  
Meteorological Model ◽  
Thermal Buoyancy ◽  
Fire Activity ◽  
Potential Trigger ◽  
Triggering Mechanisms

Abstract The first observationally based conceptual model for intense pyrocumulonimbus (pyroCb) development is described by applying reanalyzed meteorological model output to an inventory of 26 intense pyroCb events from June to August 2013 and a control inventory of intense fire activity without pyroCb. Results are based on 88 intense wildfires observed within the western United States and Canada. While surface-based fire weather indices are a useful indicator of intense fire activity, they are not a skillful predictor of intense pyroCb. Development occurs when a layer of increased moisture content and instability is advected over a dry, deep, and unstable mixed layer, typically along the leading edge of an approaching disturbance or under the influence of a monsoonal anticyclone. Upper-tropospheric dynamics are conducive to rising motion and vertical convective development. Mid- and upper-tropospheric conditions therefore resemble those that produce traditional dry thunderstorms. The specific quantity of midlevel moisture and instability required is shown to be strongly dependent on the surface elevation of the contributing fire. Increased thermal buoyancy from large and intense wildfires can serve as a potential trigger, implying that pyroCb occasionally develop in the absence of traditional meteorological triggering mechanisms. This conceptual model suggests that meteorological conditions favorable for pyroCb are observed regularly in western North America. PyroCb and ensuing stratospheric smoke injection are therefore likely to be significant and endemic features of summer climate. Results from this study provide a major step toward improved detection, monitoring, and prediction of pyroCb, which will ultimately enable improved understanding of the role of this phenomenon in the climate system.

scholarly journals Ten-year projection of white-nose syndrome disease dynamics at the southern leading-edge of infection in North America

2021 ◽  
Vol 288 (1952) ◽  
pp. 20210719
Author(s):  
Melissa B. Meierhofer ◽  
Thomas M. Lilley ◽  
Lasse Ruokolainen ◽  
Joseph S. Johnson ◽  
Steven R. Parratt ◽  
...  
Keyword(s):  
Infectious Disease ◽  
North America ◽  
Environmental Conditions ◽  
Leading Edge ◽  
Environmental Data ◽  
Disease Spread ◽  
Disease Dynamics ◽  
Pseudogymnoascus Destructans ◽  
White Nose Syndrome ◽  
Management Actions

Predicting the emergence and spread of infectious diseases is critical for the effective conservation of biodiversity. White-nose syndrome (WNS), an emerging infectious disease of bats, has resulted in high mortality in eastern North America. Because the fungal causative agent Pseudogymnoascus destructans is constrained by temperature and humidity, spread dynamics may vary by geography. Environmental conditions in the southern part of the continent are different than the northeast, where disease dynamics are typically studied, making it difficult to predict how the disease will manifest. Herein, we modelled WNS pathogen spread in Texas based on cave densities and average dispersal distances of hosts, projecting these results out to 10 years. We parameterized a predictive model of WNS epidemiology and its effects on bat populations with observed cave environmental data. Our model suggests that bat populations in northern Texas will be more affected by WNS mortality than southern Texas. As such, we recommend prioritizing the preservation of large overwintering colonies of bats in north Texas through management actions. Our model illustrates that infectious disease spread and infectious disease severity can become uncoupled over a gradient of environmental variation and highlight the importance of understanding host, pathogen and environmental conditions across a breadth of environments.

scholarly journals Orogenic link ∼41°N–46°N: Collisional mountain building and basin closure in the Cordillera of western North America

Geosphere ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 136-181
Author(s):  
Keith D. Gray ◽  
V. Isakson ◽  
D. Schwartz ◽  
Jeffrey D. Vervoort
Keyword(s):  
North America ◽  
Leading Edge ◽  
Mass Conservation ◽  
Age Dating ◽  
Thrust Belt ◽  
Late Mesozoic ◽  
Salmon River ◽  
Blue Mountains ◽  
Blue Mountains Province ◽  
Terrane Accretion

Abstract Polyphase structural mapping and mineral age dating across the Salmon River suture zone in west-central Idaho (Riggins region; ∼45°30′N, ∼117°W–116°W) support a late Mesozoic history of penetrative deformation, dynamothermal metamorphism, and intermittent magmatism in response to right-oblique oceanic-continental plate convergence (Farallon–North America). High-strain linear-planar tectonite fabrics are recorded along an unbroken ∼48 km west-to-east transect extending from the Snake River (Wallowa intra-oceanic arc terrane; eastern Blue Mountains Province) over the northern Seven Devils Mountains into the lower Salmon River Canyon (ancestral North America; western Laurentia). Given the temporally overlapping nature (ca. 145–90 Ma) of east-west contraction in the Sevier fold-and-thrust belt (northern Utah–southeast Idaho–southwest Montana segment), we propose that long-term terrane accretion and margin-parallel northward translation in the Cordilleran hinterland (∼41°N–46°N latitude; modern coordinates) drove mid- to upper-crustal shortening >250 km eastward into the foreland region (∼115°W–113°W). During accretion and translation, the progressive transfer of arc assemblages from subducting (Farallon) to structurally overriding (North American) plates was accommodated by displacement along a shallow westward-dipping basal décollement system underlying the Cordilleran orogen. In this context, large-magnitude horizontal shortening of passive continental margin strata was balanced by the addition of buoyant oceanic crust—late Paleozoic to Mesozoic Blue Mountains Province—to the leading edge of western Laurentia. Consistent with orogenic float modeling (mass conservation, balance, and displacement compatibility), diffuse dextral-transpressional deformation across the accretionary boundary (Salmon River suture: Cordilleran hinterland) was kinematically linked to eastward-propagating structures on the continental interior (Sevier thrust belt; Cordilleran foreland). As an alternative to noncollisional convergent margin orogenesis, we propose a collision-related tectonic origin and contractional evolution for central portions of the Sevier belt. Our timing of terrane accretion supports correlation of the Wallowa terrane with Wrangellia (composite arc/plateau assemblage) and implies diachronous south-to-north suturing and basin closure between Idaho and Alaska.

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