scholarly journals Phylogenetics of a Rapid, Continental Radiation: Diversification, Biogeography, and Circumscription of the Beardtongues (Penstemon; Plantaginaceae)

2021 ◽  
Author(s):  
Andrea D Wolfe ◽  
Paul D Blischak ◽  
Laura Kubatko
Keyword(s):  
North America ◽  
Bootstrap Method ◽  
Nuclear Gene ◽  
American Continent ◽  
Broad Distribution ◽  
North American Continent ◽  
The Past ◽  
The North ◽  
Evolutionary Radiation ◽  
Founder Event

Abstract. Penstemon (Plantaginaceae), the largest genus of plants native to North America, represents a recent continental evolutionary radiation. We investigated patterns of diversification, phylogenetic relationships, and biogeography, and determined the age of the lineage using 43 nuclear gene loci. We also assessed the current taxonomic circumscription of the ca. 285 species by developing a phylogenetic taxonomic bootstrap method. Penstemon originated during the Pliocene/Pleistocene transition. Patterns of diversification and biogeography are associated with glaciation cycles during the Pleistocene, with the bulk of diversification occurring from 1.0-0.5 mya. The radiation across the North American continent tracks the advance and retreat of major and minor glaciation cycles during the past 2.5 million years with founder-event speciation contributing the most to diversification of Penstemon. Our taxonomic bootstrap analyses suggest the current circumscription of the genus is in need of revision. We propose rearrangement of subgenera, sections, and subsections based on our phylogenetic results. Given the young age and broad distribution of Penstemon across North America, it offers an excellent system for studying a rapid evolutionary radiation in a continental setting.

scholarly journals Q fever in South Australia: an outbreak in a meat-works

1962 ◽  
Vol 60 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Margaret D. Beech ◽  
A. E. Duxbury ◽  
Peter Warner
Keyword(s):  
Q Fever ◽  
South Australia ◽  
Meteorological Conditions ◽  
American Continent ◽  
North American Continent ◽  
The Past ◽  
The North ◽  
Epidemiological Features ◽  
Very High ◽  
Abattoir Workers

This paper consists of an epidemiological study of 52 cases of Q fever occurring in metropolitan Adelaide in 1957 and also a description of the results of a survey of 516 sera obtained from abattoir workers.The only case occurring outside the abattoirs was a dairy farmer who probably became infected while visiting the abattoirs. If this were so the incubation period (35 days) of his disease would have been exceptionally long.The general features of the outbreak, which lasted several months, differed from those on the North American continent in that the latter occurred explosively within a few days with very high attack rates. The situation in the Adelaide abattoirs is similar to that in Brisbane, where the disease appears to be endemic. However, unlike in Adelaide, cases are commonly recognized outside the abattoirs in Brisbane.In the abattoirs the disease affected mainly inspectors, those working on killing beef, and those working on offal. Mutton workers were not so severely affected. However, all these groups had similar incidences of low titre antibodies suggesting that in the past Q fever spread equally in all killing departments. In departments not directly associated with slaughtering the incidence both of cases in 1957 and low titre antibodies was relatively small.It was suggested that the epidemiological features of Q fever in Adelaide could be explained by the irregular appearance of animals from infected herds situated perhaps in Queensland—a known endemic area. Perhaps the appearance of such animals in the Adelaide abattoirs might be governed by meteorological conditions such that they were prevented from going to the ordinarily most convenient slaughterhouse.

Disaster and Response in an Experiment Called New Orleans, 1700s–2000s

2016 ◽  
Author(s):  
Richard Campanella
Keyword(s):  
New Orleans ◽  
Mississippi River ◽  
Natural Environment ◽  
American Continent ◽  
North American Continent ◽  
Hazard Exposure ◽  
The Past ◽  
The North ◽  
History Of ◽  
Urban Risk

As an urbanized river-dominated delta, New Orleans, Louisiana, ranks among the most experimental of cities, a test of whether the needs of a stable human settlement can coexist with the fluidity of a deltaic environment—and what happens when they do not. That natural environment bestowed upon New Orleans numerous advantages, among them abundant fresh water, fertile soils, productive wetlands and, above all, expedient passage between maritime and continental realms. But with those advantages came exposure to potential hazards—an overflowing Mississippi River, a tempestuous Gulf of Mexico, sinking soils, eroding coasts, rising seas, biotic invasion, pestilence, political and racial discord, conflagration—made all the worse by the high levels of social vulnerability borne by all too many members of New Orleans’ population. More so than any other major metropolis on the North American continent, this history of disaster and response is about the future of New Orleans as much as it is about the past. This article examines two dozen disasters of various types and scales, with origins oftentimes traceable to anthropogenic manipulation of the natural environment, and assesses the nature of New Orleans’ responses. It frames these assessments in the “risk triangle” framework offered by David Crichton and other researchers, which views urban risk as a function of hazard, exposure, and vulnerability. “Hazard” implies the disastrous event or trauma itself; “exposure” means human proximity to the hazard, usually in the form of settlement patterns, and “vulnerability” indicates individuals’ and communities’ ability to respond resiliently and adaptively—which itself is a function of education, income, age, race, language, social capital, and other factors—after having been exposed to a hazard.

The species of Thecaphora on Compositae in North America

1982 ◽  
Vol 60 (8) ◽  
pp. 1512-1522 ◽  
Author(s):  
Rubén Durán
Keyword(s):  
New Species ◽  
North America ◽  
North American ◽  
Morphological Characteristics ◽  
American Continent ◽  
Bright Field ◽  
New Host ◽  
North American Continent ◽  
The North ◽  
Scanning Electron

Five new species of Thecaphora collected in Mexico are described, some of which are parasitic on genera of Compositae not previously reported as hosts. Species of Thecaphora on Compositae for the North American continent now total 11. New species include Thecaphora denticulata, T. heliopsidis, T. hennenea, T. melampodii, and T. neo-mexicana. New host genera for North America include Bidens, Heliopsis, and Melampodium. Morphological characteristics of Thecaphora species and taxonomic criteria to delimit them are discussed. Keys to the species, interpretations of spore ball morphology and spore sculpturing, and scanning electron and bright-field micrographs are presented.

‘Homesick for the North American Continent’: Elizabeth Bowen's Postwar Transatlantic Crossings

2021 ◽  
Vol 51 (1) ◽  
pp. 114-130
Author(s):  
Heather Corbally Bryant
Keyword(s):  
United States ◽  
North America ◽  
The United States ◽  
Eudora Welty ◽  
Central Question ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Mother And Child ◽  
The Relationship

This article investigates the influence of North America on Bowen's later work. After the war, Bowen traveled to America, at least once a year, until her last illness. Yet her time in the United States has often been overlooked. In the States, she lectured at colleges and universities across the country, and taught at several prestigious schools. She also wrote articles and essays for the more lucrative American journals and periodicals. In addition to touring the country, she was able to see her many American friends, such as Eudora Welty, and her publishers, the Knopfs, as well as her lover, Charles Ritchie. This new continent allowed Bowen to confront old traumas on new grounds, especially in the American element of Eva Trout, in which she displaces the central question of the relationship between mother and child onto American soil to interrogate the (literally, in Jeremy's case) unspeakable nature of trauma.

Hazards of the Caribbean

2005 ◽  
Author(s):  
Susan Elizabeth Hough ◽  
Roger G. Bilham
Keyword(s):  
United States ◽  
Puerto Rico ◽  
North America ◽  
Plate Tectonics ◽  
Plate Boundary ◽  
The United States ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
The Caribbean

The Caribbean is a place of romance. Idyllic beaches, buoyant cultures, lush tropical flora; even the Caribbean pirates of yore often find themselves romanticized in modern eyes, and on modern movie screens. Yet it requires barely a moment’s reflection to appreciate the enormous resilience that must exist in a place that is so routinely battered by storms of enormous ferocity. News stories tend to focus on large storms that reach the United States, but many large hurricanes arrive in the United States by way of the Caribbean. Before it slammed into South Carolina in 1989, Hurricane Hugo brushed the Caribbean islands, skimming Puerto Rico and devastating many small islands to its east. Other hurricanes have hit the islands more directly. These include Inez, which claimed some 1,500 lives in 1966, and the powerful Luis, which caused $2.5 billion in property damage and 17 deaths when it pummeled the Leeward Islands and parts of Puerto Rico and the Virgin Islands in 1995. Hurricanes also figure prominently in the pre-20th-century history of the Caribbean—storms that had no names, the sometimes lethal fury of which arrived unheralded by modern forecasts. Most people know that the Caribbean is hurricane country; probably few realize that it is earthquake country as well. After all, the western edge of North America is the active plate boundary; earthquakes occur in the more staid midcontinent and Atlantic seaboard, but far less commonly. What can be overlooked, however, is North America’s other active plate boundary. To understand the general framework of this other boundary, it is useful to return briefly to basic tenets of plate tectonics theory. As discussed in earlier chapters, the eastern edge of North America is known as a passive margin. Because the North American continent is not moving relative to the adjacent Atlantic oceanic crust, in plate tectonics terms, scientists do not differentiate between the North American continent and the western half of the Atlantic ocean.

A new Early Cretaceous articulate brachiopod from the Northwest Territories, Canada, and its paleobiogeographic significance

1990 ◽  
Vol 64 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Michael R. Sandy
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Early Cretaceous ◽  
New Record ◽  
High Latitudes ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Northwest Europe ◽  
Central Atlantic

A new terebratellid brachiopod species, Modestella jeletzkyi n. sp., is described from the Early Cretaceous of Prince Patrick Island, Northwest Territories, Canada. The occurrence extends the paleobiogeographic range of Modestella from northwest Europe into the northern high-latitudes of the North American continent. This new record of Modestella suggests brachiopod dispersal between northwest Europe and North America via the East Greenland Seaway, probably during the Albian. The occurrences of two other Cretaceous terebratellid genera, Advenina and Psilothyris, are updated. They are both homeomorphic with Modestella. Advenina, from the Tethyan and Jura regions of Europe, is now recorded from the Early Cretaceous of Sardinia. The occurrence of Psilothyris in North America and Europe is best explained by dispersal through the opening central Atlantic Ocean, indicating the continuation of Hispanic Corridor-type faunal links established during the Jurassic.

scholarly journals THE EFFECT OF THE GLACIAL EPOCH UPON THE DISTRIBUTION OF INSECTS IN NORTH AMERICA

1875 ◽  
Vol 7 (9) ◽  
pp. 164-167
Author(s):  
Aug. R. Grote
Keyword(s):  
United States ◽  
North America ◽  
North American ◽  
The United States ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Glacial Epoch

From the condition of an hypothesis the glacial epoch has been elevated into that of a theory by the explanations it has afforded to a certain class of geological phenomena. The present paper endeavors to show that certain zoological facts are consistent with the presence, during past times, of a vast progressive field of ice, which, in its movement from north to south, gradually extended over large portions of the North American continent. These facts, in the present instance, are furnished by a study of our Lepidoptera, or certain kinds of butterflies and moths now inhabiting the United States and adjacent territories.

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