scholarly journals A Highly Prevalent and Pervasive Densovirus Discovered among Sea Stars from the North American Atlantic Coast

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Elliot W. Jackson ◽  
Charles Pepe-Ranney ◽  
Mitchell R. Johnson ◽  
Daniel L. Distel ◽  
Ian Hewson
Keyword(s):  
North American ◽  
Atlantic Coast ◽  
Sea Star ◽  
Sea Stars ◽  
Content Type ◽  
Pyloric Caeca ◽  
The North ◽  
Wasting Syndrome ◽  
The Pacific ◽  
Asterias Forbesi

ABSTRACT The etiology of sea star wasting syndrome is hypothesized to be caused by a densovirus, sea star-associated densovirus (SSaDV), that has previously been reported on the Pacific and Atlantic Coasts of the United States. In this study, we reevaluated the presence of SSaDV among sea stars from the North American Atlantic Coast and in doing so discovered a novel densovirus that we have named Asterias forbesi-associated densovirus (AfaDV), which shares 78% nucleotide pairwise identity with SSaDV. In contrast to previous studies, SSaDV was not detected in sea stars from the North American Atlantic Coast. Using a variety of PCR-based techniques, we investigated the tissue tropism, host specificity, and prevalence of AfaDV among populations of sea stars at five locations along the Atlantic Coast. AfaDV was detected in three sea star species (Asterias forbesi, Asterias rubens, and Henricia sp.) found in this region and was highly prevalent (>80% of individuals tested; n = 134), among sampled populations. AfaDV was detected in the body wall, gonads, and pyloric caeca (digestive gland) of specimens but was not detected in their coelomic fluid. A significant difference in viral load (copies mg−1) was found between tissue types, with the pyloric caeca having the highest viral loads. Further investigation of Asterias forbesi gonad tissue found germ line cells (oocytes) to be virus positive, suggesting a potential route of vertical transmission. Taken together, these observations show that the presence of AfaDV is not an indicator of sea star wasting syndrome because AfaDV is a common constituent of these animals’ microbiome, regardless of health. IMPORTANCE Sea star wasting syndrome is a disease primarily observed on the Pacific and Atlantic Coasts of North America that has significantly impacted sea star populations. The etiology of this disease is unknown, although it is hypothesized to be caused by a densovirus, SSaDV. However, previous studies have not found a correlation between SSaDV and sea star wasting syndrome on the North American Atlantic Coast. This study suggests that this observation may be explained by the presence of a genetically similar densovirus, AfaDV, that may have confounded previous studies. SSaDV was not present in sea stars screened in this study, and instead, AfaDV was commonly found in sea star populations across the New England region, with no apparent signs of disease. These results suggest that sea star densoviruses may be common constituents of the animals’ microbiome, and the diversity and extent of these viruses among wild populations may be greater than previously recognized.

scholarly journals A highly prevalent and pervasive densovirus discovered among sea stars from the North American Atlantic Coast

2019 ◽  
Author(s):  
Elliot W. Jackson ◽  
Charles Pepe-Ranney ◽  
Mitchell R. Johnson ◽  
Daniel L. Distel ◽  
Ian Hewson
Keyword(s):  
Viral Load ◽  
North American ◽  
Atlantic Coast ◽  
Northwest Pacific ◽  
Sea Star ◽  
Sea Stars ◽  
Pyloric Caeca ◽  
The North ◽  
Wasting Syndrome ◽  
Asterias Forbesi

AbstractViral metagenomes prepared from tissues from Forbes’ sea star (Asterias forbesi) led to the discovery of a complete genome of a novel sea star densovirus (AfaDV). The genome organization of AfaDV and phylogenetic analysis place this virus among the Ambidensovirus genus in the subfamily Densoviridae, family Parvoviridae. AfaDV shares 78% nucleotide pairwise identity to the sea star associated densovirus (SSaDV), previously described as the putative causative agent of Sea Star Wasting Syndrome among sea stars from the Northwest Pacific. SSaDV was not found in specimens collected in this study, and the discovery of AfaDV might explain previous reports of SSaDV among sea stars from the Atlantic Coast. A qPCR assay was designed to assess tissue tropism, host specificity, and prevalence of AfaDV among wild populations of sea stars at five locations on the North American Atlantic Coast. AfaDV was detected in all three common sea star species (Asterias forbesi, Asterias rubens, and Henricia sp.) found in the region and was highly prevalent (80-100% of individuals tested, n=134), among populations collected at disparate sites 7 years apart. AfaDV was detected in the body wall, gonads, and pyloric caeca (digestive gland) of specimens but was not detected in their coelomic fluid. A significant difference in viral load was found between tissue types with the pyloric caeca having the highest viral load suggesting it is the primary site of viral replication in the animal. Further investigation of Asterias forbesi gonad tissue found germline cells (oocytes) to be virus positive suggesting a potential route of vertical transmission. Taken together, these observations show that the presence AfaDV is not an indicator of Sea Star Wasting Syndrome because AfaDV is a common constituent of these animals’ microbiome, regardless of health. These results broaden the understanding of echinoderm densoviruses outside the context of disease that suggest these viruses might form commensal or mutualistic relationships with their hosts.

scholarly journals Intraseasonal and Interannual Variability in North American Storm Tracks and Its Relationship to Equatorial Pacific Variability

2013 ◽  
Vol 141 (10) ◽  
pp. 3610-3625 ◽  
Author(s):  
Kevin M. Grise ◽  
Seok-Woo Son ◽  
John R. Gyakum
Keyword(s):  
North America ◽  
Interannual Variability ◽  
North American ◽  
Southern Oscillation ◽  
Extratropical Cyclones ◽  
The North ◽  
The Pacific ◽  
Cyclone Tracks ◽  
Lagrangian Tracking ◽  
The North Atlantic Oscillation

Abstract Extratropical cyclones play a principal role in wintertime precipitation and severe weather over North America. On average, the greatest number of cyclones track 1) from the lee of the Rocky Mountains eastward across the Great Lakes and 2) over the Gulf Stream along the eastern coastline of North America. However, the cyclone tracks are highly variable within individual winters and between winter seasons. In this study, the authors apply a Lagrangian tracking algorithm to examine variability in extratropical cyclone tracks over North America during winter. A series of methodological criteria is used to isolate cyclone development and decay regions and to account for the elevated topography over western North America. The results confirm the signatures of four climate phenomena in the intraseasonal and interannual variability in North American cyclone tracks: the North Atlantic Oscillation (NAO), the El Niño–Southern Oscillation (ENSO), the Pacific–North American pattern (PNA), and the Madden–Julian oscillation (MJO). Similar signatures are found using Eulerian bandpass-filtered eddy variances. Variability in the number of extratropical cyclones at most locations in North America is linked to fluctuations in Rossby wave trains extending from the central tropical Pacific Ocean. Only over the far northeastern United States and northeastern Canada is cyclone variability strongly linked to the NAO. The results suggest that Pacific sector variability (ENSO, PNA, and MJO) is a key contributor to intraseasonal and interannual variability in the frequency of extratropical cyclones at most locations across North America.

scholarly journals Toward Identifying Subseasonal Forecasts of Opportunity Using North American Weather Regimes

2020 ◽  
Vol 148 (5) ◽  
pp. 1861-1875
Author(s):  
Andrew W. Robertson ◽  
Nicolas Vigaud ◽  
Jing Yuan ◽  
Michael K. Tippett
Keyword(s):  
North American ◽  
El Niño ◽  
Geopotential Height ◽  
Large Scale ◽  
El Nino ◽  
Lead Times ◽  
Seasonal Forecasts ◽  
The North ◽  
The Pacific ◽  
Graphical Tool

Abstract Large-scale atmospheric circulation regime structures are used to diagnose subseasonal forecasts of wintertime geopotential height fields over the North American sector, from the NCEP CFSv2 model. Four large-scale daily circulation regimes derived from reanalysis 500-hPa geopotential height data using K-means clustering are used as a low-dimensional basis for diagnosing the model’s forecasts up to 45 days ahead. On average, hindcast skill in regime space is found to be limited to 10–15 days ahead, in terms of anomaly correlation of 5-day averages of regime counts, over the 1999–2010 period. However, skill up to 30 days ahead is identified in individual winters, and intraseasonal episodes of high skill are identified using a forecast-evolution graphical tool. A striking vacillation between the West Coast and Pacific ridge patterns during December–January 2008/09 is shown to be predicted 20–25 days in advance, illustrating the possibility to identify “forecasts of opportunity” when subseasonal forecast skill is much higher than the average. The forecast-evolution tool also provides insight into the poor seasonal forecasts of California precipitation by operational centers during the 2015/16 El Niño winter. The Pacific trough regime is shown to be greatly overpredicted beyond 1–2 weeks in advance during the 2015/16 winter, with weather-scale features dominating the forecast evolution at shorter lead times. A similar though less extreme situation took place during the weaker El Niño of 2009/10, with the Pacific trough overforecast at S2S lead times.

?Tethyaster albertensis, a Late Cretaceous (Turonian) sea star from the Cardium Formation, Alberta, Canada

1990 ◽  
Vol 64 (6) ◽  
pp. 1045-1049 ◽  
Author(s):  
Russell L. Hall ◽  
Suzan Moore
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Sea Star ◽  
Sea Stars ◽  
Peace River ◽  
The North ◽  
The Family ◽  
Cardium Formation ◽  
Northern Alberta ◽  
Limited Change

Although many of the surviving lineages of sea stars appeared during an early Mesozoic radiation of the class and have undergone limited change since then, they have left a very poor fossil record, particularly in the Mesozoic of North America (Blake, 1981). This record from the Late Cretaceous of Alberta is made more significant by the fact that it is apparently only the second occurrence of a member of the family Astropectinidae in the Cretaceous of North America; Lophidiaster silentiensis was described by McLearn (1944) from the Lower Cretaceous (Albian) Hasler Formation, from a now-submerged locality on the Peace River in northern Alberta. All previously recorded fossil sea stars from the North American Cretaceous are representatives of the family Goniasteridae.

“An Outlet to the Western Sea”: Puget Sound, Terraqueous Mobility, and Northern Pacific Railroad’s Pursuit of Trade with Asia, 1864–1892

2020 ◽  
Vol 51 (4) ◽  
pp. 439-458
Author(s):  
Sean Fraga
Keyword(s):  
North American ◽  
American West ◽  
Puget Sound ◽  
North American West ◽  
The North ◽  
The Pacific ◽  
Aqueous Environments ◽  
Physical Infrastructure ◽  
The Pacific Ocean ◽  
Northern Pacific

Abstract The Northern Pacific Railroad saw Puget Sound harbors as environments uniquely suited to connect the North American interior with the Pacific Ocean and enable U.S. trade with East Asia. But in building the physical infrastructure to link transcontinental trains with transpacific ships, Northern Pacific significantly altered Commencement Bay’s shoreline and displaced Puyallups from their traditional territory. The articles uses a terraqueous perspective, emphasizing movement between terrestrial and aqueous environments, to demonstrate how U.S. pursuit of transpacific trade shaped the North American West.

Speedy Mexico-EU trade deal promises risks and rewards

2017 ◽  
Keyword(s):  
North America ◽  
Free Trade ◽  
North American ◽  
Free Trade Agreement ◽  
Trade Agreement ◽  
Transportation Costs ◽  
Donald Trump ◽  
Content Type ◽  
The North

Subject Mexico-EU trade talks Significance Talks on modernising the Mexico-EU Free Trade Agreement (FTA) have gained urgency since the election of US President Donald Trump as the prospect of an end to free trade within North America forces Mexican officials to get serious about diversifying relations. While negotiators hope to seal a new EU deal by the end of the year, many issues are yet to be addressed and renegotiation of the North American Free Trade Agreement (NAFTA) is absorbing bureaucratic capacity. Impacts Anti-American sentiment stemming from Washington’s hostility could favour European firms and investors in Mexico. The rush to conclude agreements risks bad deals and political blowback from Mexico’s opposition. Transportation costs and connectivity will ultimately matter more for Mexican diversification than already low tariffs.

A dream deferred: interdisciplinary accounting in the US

2014 ◽  
Vol 27 (8) ◽  
pp. 1265-1270 ◽  
Author(s):  
Timothy J. Fogarty
Keyword(s):  
North American ◽  
Design Methodology ◽  
Content Type ◽  
Research Perspective ◽  
Accounting Research ◽  
Policy Practice ◽  
The North ◽  
Current State ◽  
The Us ◽  
The Usa

Purpose – The purpose of this paper is to set out to examine and critique the current state and future trajectory of interdisciplinary accounting research in the USA. Design/methodology/approach – The analysis is based on the author's involvement in and research into accounting research and publication contexts, drivers and patterns in the accounting discipline. Findings – In all likelihood, research will continue established traditions that prevent the explorations of economics and finance from material broadening. This paper identifies how that which everyone believes to be such a good idea cannot bear fruit. Research limitations/implications – Conventional economics-based accounting research has proliferated in volume but has largely exhausted its potential for significant contributions to knowledge. Failure to embrace broadened interdisciplinary perspectives risks a crisis of accounting research contribution to policy, practice, and society. Originality/value – This critique reveals the serious weaknesses and serious risks to international accounting scholarship of the continuance and global mimicking of the North American pursuit of an exclusively economic accounting research perspective.

scholarly journals Possibility of recovery of slip deficit rate between the North American plate and the Pacific plate off Sanriku, northeast Japan

2007 ◽  
Vol 34 (20) ◽  
Author(s):  
Shinzaburo Ozawa ◽  
Hisashi Suito ◽  
Takuya Nishimura ◽  
Mikio Tobita ◽  
Hiroshi Munekane
Keyword(s):  
North American ◽  
Pacific Plate ◽  
North American Plate ◽  
The North ◽  
Slip Deficit ◽  
The Pacific ◽  
Off Sanriku
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