scholarly journals Genetic consequences of climatic oscillations in the Quaternary

2004 ◽  
Vol 359 (1442) ◽  
pp. 183-195 ◽  
Author(s):  
G. M. Hewitt
Keyword(s):  
North America ◽  
Geographical Area ◽  
The Arctic ◽  
Temperate Species ◽  
Genetic Constitution ◽  
Spatial Effects ◽  
Tropical Regions ◽  
Climatic Oscillations ◽  
North East ◽  
The North

An appreciation of the scale and frequency of climatic oscillations in the past few million years is modifying our views on how evolution proceeds. Such major events caused extinction and repeated changes in the ranges of those taxa that survived. Their spatial effects depend on latitude and topography, with extensive extinction and recolonization in higher latitudes and altitudinal shifts and complex refugia nearer the tropics. The associated population dynamics varied with life history and geography, and the present genetic constitution of the populations and species carry attenuated signals of these past dynamics. Phylogeographic studies with DNA have burgeoned recently and studies are reviewed from the arctic, temperate and tropical regions, seeking commonalities of cause in the resulting genetic patterns. Arctic species show distinct shallow genetic clades with common geographical boundaries. Thus Beringia is distinct phylogeographically, but its role as a refugial source is complex. Arctic taxa do not show the common genetic pattern of southern richness and northern purity in north-temperate species. Temperate refugial regions in Europe and North America show relatively deep DNA divergence for many taxa, indicating their presence over several Ice Ages, and suggesting a mode of speciation by repeated allopatry. DNA evidence indicates temperate species in Europe had different patterns of postglacial colonization across the same area and different ones in previous oscillations, whereas the northwest region of North America was colonized from the north, east and south. Tropical montane regions contain deeply diverged lineages, often in a relatively small geographical area, suggesting their survival there from the Pliocene. Our poor understanding of refugial biodiversity would benefit from further combined fossil and genetic studies.

The origins and development of the English diaspora in North America

2017 ◽  
Author(s):  
Tanja Bueltmann ◽  
Donald M. MacRaild
Keyword(s):  
North America ◽  
English Language ◽  
Republican Period ◽  
North East ◽  
The North ◽  
The Social ◽  
Early Republican ◽  
Ethnic Associations ◽  
Migrant Groups

Chapter 1 frames the following discussion of English associations and ethnic activities by charting English migration to North America from the mid-1700s. The earlier emigrants carried with them cultural characteristics, habits and customs that were critical in shaping the social and civic life that marked the English as foundational and invisible within America society. We problematize existing scholarship and challenge the assumption that the hegemony of the English language and the early immigrants’ foundational context provided all subsequent English migrants with a permanent and unchanging advantage over other migrant groups by default. Ordinary English migrants faced the same challenges and hardships as any other group; working-class immigrants in particular dealt with many common economic pressures regardless of their origins. Ultimately, the English had much in common with those of other backgrounds. The English settled in all colonies, counties and states; they were loaded towards the urban and industrial areas, but the focus upon the north-east—in both the colonial and early Republican period, as well as north of the border in what was to become Canada—gradually gave way to greater diffusion: a diffusion in line with the spread of ethnic associations. In the nineteenth century, English-born immigrants—the mainstay of English ethnic associations—came to be hugely out-numbered by several immigrant groups, most notably the Irish, with whom innate tensions were reprised in the new country. Chapter 1 explores such factors as a frame for the study that follows.

Lower Jurassic Amaltheidae (Ammonitina) in North America: paleobiogeography and tectonic implications

2001 ◽  
Vol 38 (10) ◽  
pp. 1439-1449 ◽  
Author(s):  
Paul L Smith ◽  
Howard W Tipper ◽  
David M Ham
Keyword(s):  
North America ◽  
North Atlantic ◽  
Lower Jurassic ◽  
The Arctic ◽  
Longitudinal Displacement ◽  
The North ◽  
East Pacific ◽  
Northwest Europe ◽  
Dispersal Route ◽  
North American Craton

The amaltheids are restricted temporally to the late Pliensbachian and geographically to the northern part of the northern hemisphere. Amaltheus stokesi is the only species that occurs in all areas of North America where amaltheids are found. The craton north of the Canada–U.S.A. border yields the most diverse amaltheid fauna, including six of the seven taxa known in North America. On Quesnellia and Stikinia, there are no endemic amaltheids, and diversity is low; A. stokesi increases in abundance northwards where, in Stikinia, A. margaritatus makes rare appearances. Wrangellia, with its rich Pliensbachian Tethyan and east Pacific faunas, is almost devoid of amaltheids, but its amaltheid fauna does include two specimens of A. viligaensis, an eastern Russian species that is unknown elsewhere in North America. Cratonal amaltheid faunas have more in common with those of northwest Europe than eastern Eurasia, suggesting that the Arctic and northern North Atlantic constituted the main dispersal route. Paleobiogeographic patterns on the major allochthonous terranes argue against terrane rotation and in support of post-Pliensbachian northward displacement relative to the North American craton. In addition, the presence of western Pacific faunal elements on Wrangellia suggests a more significant longitudinal displacement relative to the craton for this terrane compared to that for Quesnellia and Stikinia. The Chilliwack terrane of southwestern British Columbia is a Pliensbachian paleobiogeographic anomaly.

Hydrogenetic Fe-Mn crusts from European seas: source of potentially economic cobalt mining.

2020 ◽  
Author(s):  
Egidio Marino ◽  
Javier González ◽  
Teresa Medialdea ◽  
Luis Somoza ◽  
Rosario Lunar ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Essential Elements ◽  
Raw Material ◽  
The Arctic ◽  
World Production ◽  
Critical Metals ◽  
North West ◽  
North East ◽  
The North ◽  
The World

<p>The world increasing demand of electric vehicles (EVs) that use lithium-ion batteries (LIB), in which cobalt is one of the essential elements, focused the attention on its demand that is calculated will increase of 7-13% annually until 2030. The actual production of cobalt, usually extract as by-product of nickel and copper mine, is reduced to almost 20 countries between which the Democratic Republic of the Congo is the bigger producer with 55% of the world production. In Europe cobalt is produced only in Finland that actually provides 2.300 tonnes, the 2% of the world production. In this way several projects have been promoted by European Union, with the Raw Material Initiative, in order to find and evaluate the sustainable production of important materials in Europe.</p><p>MINDeSEA[1] project is part of the GeoERA and represent the collaboration of 12 national geological institution partners, to characterize marine deposits and their contents in Critical Raw Materials (CRM) and to generate a comprehensive cartography and metallogenic models of them. The first preliminary map produced in 2019 represents the localization and evaluation of cobalt rich deposits in the oceans within the EEZ and ECS of the European countries.  Cobalt deposits are represented essentially by hydrogenetic Fe-Mn crusts located essentially in the Macaronesian area of the north east Atlantic Ocean (in the Portugal and Spain), submarine plateaus, as the Galicia Bank (in the north west Spanish) and in the Arctic Ocean ridges (Norway and Iceland). The report differentiates between occurrences (<0.05 wt. %) and deposits (>0.05 wt. %), with the possibility of more than 200 Mt resources per potential deposit.</p><p>Detailed mineralogical, geochemical and metallogenic studies are being developed in crusts from the Macaronesia. Fe-Mn crusts absorb dissolved elements in seawaters on the surface of the fresh precipitated oxy-hydroxides during their slow growth through millions of years. Several elements are concentrated in Fe-Mn crusts and between them cobalt is one of the most enriched trace metals (average 0.6 wt. %) accompanied by other strategic and critical metals such as nickel, copper, tellurium, molybdenum and rare earth elements plus yttrium (REY) (respectively 3000, 500, 150, 500 and 3500 µg/g). Micro Raman and micro X-Ray diffraction can be used to differentiate the mineralogy in laminae of less than 20 microns. On the other hand, electron probe micro-analyzer (EPMA) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), are useful in order to quantify contents of CRM in the different mineral phases. These are innovative techniques in order to identify critical-elements bearing minerals and thus choose the metallurgic method for a more efficient and sustainable extraction of the interesting elements.</p><p>The evaluation of a seamount as a future mine site has to take into account all these mineralogical and chemical features as well as a proper knowledge of the seamount (morpho-structure, geology, oceanography, ecosystems) and the Fe-Mn crust thickness and extension</p><div><br><div> <p>[1] This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 731166</p> </div> </div>

Emerging Scenario of Trade Potentialities of North-East India: Challenges and Opportunities

2009 ◽  
Vol 5 (1) ◽  
pp. 68-86
Author(s):  
Ram Krishna Mandal
Keyword(s):  
Geographical Area ◽  
North East India ◽  
Advantages And Disadvantages ◽  
North East ◽  
The North ◽  
East Region ◽  
Foreign Countries ◽  
Challenges And Opportunities ◽  
Late Start ◽  
Poor Infrastructure

The North-East Region (NER) of India which comprises of eight states, namely Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura shares most of its boundary with China, Bangladesh, Bhutan and Myanmar. The NER accounts for about eight per cent of the country's geographical area and about four per cent of population. Tribals account for more than 30 per cent of the total population of NER. Inadequate and poor infrastructure, inhospitable terrain and a com¬paratively late start in the development process are some of the reasons for economic back¬wardness of the region. However, the NER has certain strengths in different angles to achieve economic development in easy way. From the geo-political angle, the NER is located in a strategic location as it is bounded by these several foreign countries. Naturally it has got both advantages and disadvantages due to its location. So far advantages are concerned it is connected with the South-East Asian countries mainly China, Myanmar, Bhutan, Bangladesh, Malaysia, Thailand, Philippines, Cambodia and Indonesia etc where almost half of the world’s population live. There is no doubt that this vast population could have great advantage for establishing any kind of trade and commerce. But the vary geographical condition basically the rivers and mountains of the country stand as a barrier and create geo–political tensions which ultimately act as most disadvantages factors in creating a conducive atmosphere in the path of developing trade relation among those countries.

The Arctic Institute of North America

Polar Record ◽  
1956 ◽  
Vol 8 (52) ◽  
pp. 22-23 ◽  
Author(s):  
P. D. Baird
Keyword(s):  
North America ◽  
North American ◽  
Scientific Research ◽  
The Arctic ◽  
The North ◽  
Reference Information ◽  
North American Arctic ◽  
Mcgill University

The Arctic Institute of North America was established in 1945 in two small rooms in McGill University, with a staff consisting of Dr Lincoln Washburn and a secretary, who made up for the lack of equipment and facilities by abundant energy and enthusiasm. Since then the Institute's growth has been considerable, always in the direction of its three main objectives—to form a centre for reference information and study on the North American Arctic, to encourage arctic scientific research in any field, and to disseminate arctic information by means of a journal, other publications, and lectures.

scholarly journals Effect of climatic oscillations on small pelagic fisheries and its economic profit in the Gulf of Cadiz

2021 ◽  
Author(s):  
Jairo Castro-Gutiérrez ◽  
Remedios Cabrera-Castro ◽  
Ivone Alejandra Czerwinski ◽  
José Carlos Báez
Keyword(s):  
Linear Models ◽  
Supply And Demand ◽  
The Arctic ◽  
Gulf Of Cadiz ◽  
East Atlantic ◽  
European Anchovy ◽  
Climatic Oscillations ◽  
North East ◽  
Gulf Of Cádiz ◽  
First Sale

AbstractSeveral studies have shown the effect of climatic oscillations on fisheries. Small pelagic fish are of special global economic importance and very sensitive to fluctuations in the physical environment in which they live. The main goal of this study was to explore the relationship between the North Atlantic Oscillation (NAO), the East Atlantic pattern (EA), and the Arctic Oscillation (AO) on the landings and first sale prices of the most representative small pelagic commercial species of the purse-seine fisheries in the Gulf of Cadiz (North East Atlantic), the European anchovy Engraulis encrasicolus and the European sardine Sardine pilchardus. Generalised linear models (GLMs) with different data transformations and distribution errors were generated to analyse these relationships. The best results of the models were obtained by applying a moving average of order 3 to the dataset with a double weighted median. Our results demonstrate relationships between NAO, AO, and EA and European anchovy and sardine landings. These cause an indirect effect on the first sale price in markets through catch variations, which affect the price according to the law of supply and demand. The limitations of this study and management implications are discussed.

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