Articles de revues : « Indians of North America – Plateau region »

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Nickens, Paul R. « Imagining the Multilayered Cultural Landscape : A Template from the Columbia Plateau of North America ». Land 11, n^o 10 (21 septembre 2022) : 1613. http://dx.doi.org/10.3390/land11101613.

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Cultural landscapes encompass a diversity of manifestations of the interaction between humankind and the natural environment occurring in both space and time. In some instances where the human occupation of a specific area or region encompass a continuous and extended timeframe, successive cultural layers yield contrasting and disparate landscapes and heritage values. This “layering” of past cultural landscapes often leads to conflicting modern-day land, cultural resource management, and heritage value issues. A case study is presented from the Hanford Site in south-central Washington state, USA, where the natural landscape comprises prehistoric Native American, historic ethnographic, and historic period non-Indian evidence from over 10,000 years of occupation and use that clearly separate into several culturally and chronologically defined and overlapping cultural landscapes, which can be visualized as layered entities occurring on the same physical space.

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Kumar Pokharia, Anil, B. Sekar, Jagannath Pal et Alka Srivastava. « Possible Evidence of Pre-Columbian Transoceanic Voyages Based on Conventional LSC and AMS 14C Dating of Associated Charcoal and a Carbonized Seed of Custard Apple (Annona squamosa L.) ». Radiocarbon 51, n^o 3 (2009) : 923–30. http://dx.doi.org/10.1017/s0033822200033993.

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An attempt was made to trace the antiquity of custard apple in India on the basis of accelerator mass spectrometry (AMS) and liquid scintillation counting (LSC) radiocarbon dates. Recently, seed remains of custard apple (Annona squamosa L.) in association with wood charcoals were encountered from the Neolithic archaeological site of Tokwa at the confluence of the Belan and Adwa rivers, Mirzapur District, in the Vidhyan Plateau region of north-central India. The wood charcoal sample was dated at the 14C laboratory of the Birbal Sahni Institute of Palaeobotany (BSIP), Lucknow, by conventional LSC 14C dating. The sample dated to 1740 cal BC (BS-2054). A seed sample of custard apple was dated by AMS at the Institute of Physics 14C laboratory, Bhubaneswar, India (3MV tandem Pelletron accelerator). Interestingly, the AMS date was given as 1520 cal BC (IOPAMS-10), showing a reasonable agreement with the LSC date carried out at BSIP. On botanical grounds, the custard apple is native to South America and the West Indies and was supposed to have been introduced in India by the Portuguese in the 16th century. The present 14C dates of the samples pushes back the antiquity of custard apple on Indian soil to the 2nd millennium BC, favoring a group of specialists proposing diverse arguments for Asian-American transoceanic contacts before the discovery of America by Columbus in AD 1492.

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Wang, Zhibiao, Renguang Wu, Anmin Duan et Xia Qu. « Influence of Eastern Tibetan Plateau Spring Snow Cover on North American Air Temperature and Its Interdecadal Change ». Journal of Climate 33, n^o 12 (15 juin 2020) : 5123–39. http://dx.doi.org/10.1175/jcli-d-19-0455.1.

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AbstractPrevious studies revealed the influence of the autumn–winter Tibetan Plateau snow cover on atmospheric circulation and climate in the North American region. The present study documents the relationship between the eastern Tibetan Plateau snow cover and the North American air temperature in spring and the associated physical processes using satellite-based snow cover, reanalysis atmospheric and surface variables, observation-based surface air temperature (SAT), and sea surface temperature (SST). A stable relationship is identified between the eastern Tibetan Plateau snow cover and the North American SAT in spring before the mid-2000s. Positive snow-cover anomalies over the eastern Tibetan Plateau induce cooling in the local atmospheric column. The atmospheric cooling stimulates a large-scale atmospheric wave pattern at the upper level that extends northeastward from the eastern Tibetan Plateau via northeast Asia and the North Pacific to North America. An anomalous high forms over North America, accompanied by anomalous descent. In the northwestern part, the horizontal advection by anomalous southerly winds along the west flank of anomalous anticyclone induces SAT increase. In the central part, the enhanced surface sensible heat flux following anomalous descent-induced downward shortwave radiation increase leads to SAT increase. The relationship between the eastern Tibetan Plateau snow cover and the North American SAT is weakened after the mid-2000s. The weakened relationship is attributed to an intensified impact of tropical central Pacific SST anomalies on the North American SAT variations through a Pacific–North America-like atmospheric circulation pattern, which overcomes the influence of the Tibetan Plateau snow-cover anomalies.

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ZHAO, XIN, DANDAN FENG, YUNTAO LI et HAOYU LIU. « Diversity and distribution of the superfamily Grylloidea (Orthoptera : Ensifera : Gryllidea) in the Nearctic region ». Zootaxa 5040, n^o 2 (21 septembre 2021) : 283–88. http://dx.doi.org/10.11646/zootaxa.5040.2.7.

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Based on the geographic distribution database of the Orthoptera Species File, the diversity and distribution of the superfamily Grylloidea in the Nearctic region was studied using the statistics and Sorensen dissimilarity coefficient. A total of 164 species or subspecies belonging to 4 families, 9 subfamilies and 27 genera were recorded from this region; among which Gryllidae (93, 56.70%), followed by Trigonidiidae (44, 26.83%), Mogoplistidae (25, 15.24%), and Phalangopsidae (2, 1.22%). The diversity exhibits an asymmetric distribution pattern, with the southeastern coastal plain, the Interior Plateau and Piedmont of the United States was the most abundant. At the same time, the regional similarity of species distribution was analyzed, and the Nearctic was divided into four subregions: Boreal & Arctic zone of North America, Eastern temperate North America, Northeast temperate North America, and Southern North America & western temperate North America.

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Ames, Kenneth M., Kristen A. Fuld et Sara Davis. « Dart and Arrow Points on the Columbia Plateau of Western North America ». American Antiquity 75, n^o 2 (avril 2010) : 287–325. http://dx.doi.org/10.7183/0002-7316.75.2.287.

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The timing of the bow and arrow's introduction, spread, and replacement of the atlatl is an important research question in North American prehistory. Although regional archaeologists have not focused on the issue, it is generally thought that the bow and arrow were introduced on the Columbia Plateau ca. 2,300 years ago and completely replaced the atlatl by 1000 B.P. We apply two sets of discriminate functions and four threshold values to three large projectile point samples from the Columbia Plateau and a control sample from the Western Great Basin. Our results indicate that the atlatl was used on the Plateau by ca. 10,800 B.P. While the bow and arrow may have been present by 8500 B.P., they were ubiquitous in the region by 4400 B.P. Atlatl use appears to have increased for a while after 3000 B.P. At the same time, metric differences between dart and arrow points strengthened. Darts became rare after 1500 B.P. but seem to have been in use in small numbers at least until contact.

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Foster II, H. Thomas, et Arthur D. Cohen. « Palynological Evidence of the Effects of the Deerskin Trade on Forest Fires during the Eighteenth Century in Southeastern North America ». American Antiquity 72, n^o 1 (janvier 2007) : 35–51. http://dx.doi.org/10.2307/40035297.

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Three palynological cores from the coastal plain of Georgia and Alabama were analyzed for paleobotanical remains. Results show that the Indians of southeastern North America increased forest fires used in hunting as a response to the demand for deer hides during the early eighteenth century. Palynological data are consistent with known anthropogenic changes in the region. Charcoal abundance increased significantly between A.D. 1715 and 1770, which is the period of the most intensive hunting by the Indians. This study shows that forest fires from hunting had a significant and measurable effect on the evolution of the biophysical environment.

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Gamble, Lynn H. « Archaeological Evidence for the Origin of the Plank Canoe in North America ». American Antiquity 67, n^o 2 (avril 2002) : 301–15. http://dx.doi.org/10.2307/2694568.

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Advanced maritime technology associated with long-distance exchange and intensified resource acquisition has been linked to the development of stratification and greater sociopolitical complexity in the Pacific Rim region. One such example is the emergence of hereditary chiefs among the Chumash Indians of southern California. Plank boats owned by an elite group of wealthy individuals and chiefs were an integral part of an elaborate economic system that was based on maritime exchange. An artifact assemblage associated with the construction, maintenance, and use of this watercraft was identified and analyzed. It included wooden planks, asphaltum plugs, asphaltum caulking, and chipped stone drills. Radiocarbon dates and other relative-dating techniques provide strong evidence that the plank canoe originated at least 1,300 years ago in southern California. This represents the earliest use of this type of watercraft in North America and probably in the New World. The timing of this innovation provides evidence that sociopolitical complexity developed in the region at least 500 years earlier than previously proposed.

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Liu, Shizuo, Qigang Wu, Steven R. Schroeder, Yonghong Yao, Yang Zhang, Tongwen Wu, Lei Wang et Haibo Hu. « Near-Global Atmospheric Responses to Observed Springtime Tibetan Plateau Snow Anomalies ». Journal of Climate 33, n^o 5 (1 mars 2020) : 1691–706. http://dx.doi.org/10.1175/jcli-d-19-0229.1.

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AbstractPrevious studies show that there are substantial influences of winter–spring Tibetan Plateau (TP) snow anomalies on the Asian summer monsoon and that autumn–winter TP heavy snow can lead to persisting hemispheric Pacific–North America-like responses. This study further investigates global atmospheric responses to realistic extensive spring TP snow anomalies using observations and ensemble transient model integrations. Model ensemble simulations are forced by satellite-derived observed March–May TP snow cover extent and snow water equivalent in years with heavy or light TP snow. Heavy spring TP snow causes simultaneous significant local surface cooling and precipitation decreases over and near the TP snow anomaly. Distant responses include weaker surface cooling over most Asian areas surrounding the TP, a weaker drying band extending east and northeast into the North Pacific Ocean, and increased precipitation in a region surrounding this drying band. Also, there is tropospheric cooling from the TP into the North Pacific and over most of North America and the North Atlantic Ocean. The TP snow anomaly induces a negative North Pacific Oscillation/western Pacific–like teleconnection response throughout the troposphere and stratosphere. Atmospheric responses also include significantly increased Pacific trade winds, a strengthened intertropical convergence zone over the equatorial Pacific Ocean, and an enhanced local Hadley circulation. This result suggests a near-global impact of the TP snow anomaly in nearly all seasons.

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Jin, L., Y. Peng, F. Chen et A. Ganopolski. « Modeling sensitivity study of the possible impact of snow and glaciers developing over Tibetan Plateau on Holocene African-Asian summer monsoon climate ». Climate of the Past Discussions 4, n^o 6 (11 décembre 2008) : 1265–87. http://dx.doi.org/10.5194/cpd-4-1265-2008.

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Abstract. The impacts of various scenarios of snow and glaciers developing over the Tibetan Plateau on climate change in Afro-Asian monsoon region and other regions during the Holocene (9 kyr BP–0 kyr BP) are studied by using the coupled climate model of intermediate complexity, CLIMBER-2. The simulations show that the imposed snow and glaciers over the Tibetan Plateau in the mid-Holocene induce global summer temperature decreases, especially in the northern parts of Europe, Asia, and North America. At the same time, with the imposed snow and glaciers, summer precipitation decreases strongly in North Africa and South Asia as well as northeastern China, while it increases in Southeast Asia and the Mediterranean. For the whole period of Holocene (9 kyr BP–0 kyr BP), the response of vegetation cover to the imposed snow and glaciers cover over the Tibetan Plateau is not synchronous in South Asia and in North Africa, showing an earlier and a more rapid decrease in vegetation cover in North Africa from 9 to 6 kyr BP while it has only minor influence on that in South Asia until 5 kyr BP. Imposed gradually increased snow and glacier cover over the Tibetan Plateau causes temperature increases in South Asia and it decreases in North Africa and Southeast Asia during 6 kyr BP to 0 kyr BP. The precipitation decreases rapidly in North Africa and South Asia while it decreases slowly or unchanged during 6 kyr BP to 0 kyr BP with imposed snow and glacier cover over the Tibetan Plateau. The different scenarios of snow and glacier developing over the Tibetan Plateau would result in differences in variation of temperature, precipitation and vegetation cover in North Africa, South Asia and Southeast Asia. The model results show that the response of climate change in African-Asian monsoon region to snow and glacier cover over the Tibetan Plateau is in the way that the snow and glaciers amplify the effect of vegetation feedback and, hence, further amplify orbital forcing.

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Shagapova, G. R. « Ethno-cultural contacts of ancestors of the Khanty and Mansi peoples based on the materials of game culture ». Bulletin of Ugric studies 10, n^o 4 (2020) : 748–58. http://dx.doi.org/10.30624/2220-4156-2020-10-4-748-758.

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Introduction: game culture of the Khanty end Mansi peoples has been developed over a long period of time, and it reveals different game plots, analogies of which we can find only in the Far East, Amur region, North-East of Russia and in North America. This allows us to determine the directions of the oldest contacts of migrations and cultural borrowings. Objective: to reveal common game plots in the culture of the Ob Ugrians and the peoples of the Far East and the North- East of Russia with following determination of the time and place of their emergence. Research materials: game plots published in works on the game culture of the Ob Ugrians, the peoples of the Far East, the Amur region, the North-East of Russia, and the Indians of North America. Results and novelty of the research: two games «The Snow Snake» and «Get Into the Ring With A Spear» were revealed, which linked the game cultures of Western Siberia, the Far East, the Amur region and North America, as well as at least three original stories: games with a large number of stones, various types of jumping, and jumping over sledges (narty) of the Khanty and Mansi peoples, which found analogies with the games of the peoples of the Far East and the North-East of Russia. The same type of rules, similar game equipment, and the male character of the games are observed. The author comes to the conclusion that the considered games originate from the oldest male rituals that came to America with Paleolithic migrants and have been preserved in the format of games. The games of the Eskimos, Chukchi, Koryaks and peoples of the Amur region, as well as the Ob Ugrians, indicate the existence of a common cultural space at a later time, but not earlier than the Paleolithic. Subsequently, the unity was destroyed: tribes and cultures migrated to the North-West (the ancestors of the Khanty and Mansi), to the North-East (the ancestors of the Chukchi, Koryaks, Evenks, etc.), and to the East (the ancestors of the peoples of the Amur region and the Far East). The novelty of the work lies in the fact that the game culture of the mentioned ethnic groups in a comparative aspect has not previously been the subject of scientific research.

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Gorman, Andrew R., Ron M. Clowes, Robert M. Ellis, Timothy J. Henstock, George D. Spence, G. Randy Keller, Alan Levander et al. « Deep Probe : imaging the roots of western North America ». Canadian Journal of Earth Sciences 39, n^o 3 (1 mars 2002) : 375–98. http://dx.doi.org/10.1139/e01-064.

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Analysis of the Lithoprobe Deep Probe and Southern Alberta Refraction Experiment data sets, focusing on the region between Deep Probe shots 43 and 55, has resulted in a continental-scale velocity structural model of the lithosphere of platformal western Laurentia reaching depths of ~150 km. Three major lithospheric blocks were investigated: (i) the Hearne Province, a typical continental Archean cratonic province lying beneath the Western Canada Sedimentary Basin; (ii) the Wyoming Province, an even older block of Phanerozoic-modified Archean crust with an enigmatic lower lithosphere; and (iii) the YavapaiMazatzal Province, Proterozoic terranes underlying the Colorado Plateau and Southern Rocky Mountains. In this study, the northern two of these regions are investigated with a modified ray-theoretical traveltime inversion routine that respects the spherical geometry of the Earth. The resulting crustal velocity structure, combined with supporting geological and geophysical data, reveals that the Medicine Hat block (MHB), lying between the Hearne and Wyoming provinces, is a third independent Archean crustal block. The subcrustal lithosphere along the profile is homogeneous in velocity structure, but two significant northward-dipping reflectors are apparent and interpreted as relic subduction zones associated with sutures between the three Archean blocks. The Hearne crust is typical of an Archean shield or platform both in its thickness of 3450 km and its seismic velocity structure. The crust of the Archean MHB and Wyoming Province, which ranges in thickness from 49 to 60 km, includes a 1030 km thick high-velocity layer, interpreted to be Proterozoic in age. Such a feature is unexpected beneath Archean crustal provinces, but if the region is considered to be the remanent marginal portion of a larger Archean continent, then the interpreted Proterozoic underplating and lack of an Archean lithospheric root can be explained. The variable topography along the reflective upper and lower boundaries of this layer, especially within the MHB, suggests considerable variability in its emplacement and subsequent tectonic history.

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Oyague, Eduardo. « Peatlands of the Central Andes Puna, South America ». Wetland Science & ; Practice 37, n^o 4 (octobre 2020) : 255–60. http://dx.doi.org/10.1672/ucrt083-204.

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The Andean puna is the highest elevation mountain and plateau region in the western hemisphere, extending from northern Peru to central Chile and Argentina, with vast areas above 4,250 m elevation. The Atacama Desert on the western side of the Andes is the world’s most arid region, and this aridity extends across the mountains. The upland vegetation is mostly continuous in the more humid north but becomes more and more patchy and barren composed only of bunch grasses in the central and southern region. Extensive upland talus, moraines, and colluvial deposits of the mountains produces perennial ground water flow systems that support thousands of peatlands and other wetlands that are regionally termed “bofedales” or “vegas”. The peatlands are dominated by several species in the family Juncaceae, most famously Distichia muscoides, that forms dense clonal cushions that characterize the alpine peatlands and landscapes. Being close to the equator, the growing season extends across the entire year, and continuous growth of the cushion plants have produced high carbon accumulation rates and peat bodies 7-10 m thick in many areas. The region supports unique plants and animals, and ecosystems, and the wetlands are threatened by overuse for livestock grazing, and climate changes that could reduce water provision may lead to some bofedales completely drying.

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Tushingham, Shannon, Charles M. Snyder, Korey J. Brownstein, William J. Damitio et David R. Gang. « Biomolecular archaeology reveals ancient origins of indigenous tobacco smoking in North American Plateau ». Proceedings of the National Academy of Sciences 115, n^o 46 (29 octobre 2018) : 11742–47. http://dx.doi.org/10.1073/pnas.1813796115.

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Chemical analysis of residues contained in the matrix of stone smoking pipes reveal a substantial direct biomolecular record of ancient tobacco (Nicotiana) smoking practices in the North American interior northwest (Plateau), in an area where tobacco was often portrayed as a Euro-American–introduced postcontact trade commodity. Nicotine, a stimulant alkaloid and biomarker for tobacco, was identified via ultra-performance liquid chromatography-mass spectrometry in 8 of 12 analyzed pipes and pipe fragments from five sites in the Columbia River Basin, southeastern Washington State. The specimens date from 1200 cal BP to historic times, confirming the deep time continuity of intoxicant use and indigenous smoking practices in northwestern North America. The results indicate that hunting and gathering communities in the region, including ancestral Nez Perce peoples, established a tobacco smoking complex of wild (indigenous) tobacco well before the main domesticated tobacco (Nicotiana tabacum) was introduced by contact-era fur traders and settlers after the 1790s. This is the longest continuous biomolecular record of ancient tobacco smoking from a single region anywhere in the world—initially during an era of pithouse development, through the late precontact equestrian era, and into the historic period. This contradicts some ethnohistorical data indicating that kinnikinnick, or bearberry (Arctostaphylos uva-ursi) was the primary precontact smoke plant in the study area. Early use likely involved the management and cultivation of indigenous tobaccos (Nicotiana quadrivalvis or Nicotiana attenuata), species that are today exceedingly rare in the region and seem to have been abandoned as smoke plants after the entry of trade tobacco.

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Botiková, Marta. « Folk and Literary Reflections on the Culture of Northwest Coast Indians of the Puget Sound Area of North America ». Ethnologia Actualis 19, n^o 1 (1 juin 2019) : 117–26. http://dx.doi.org/10.2478/eas-2019-0013.

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Abstract Vi Hilbert, collector, performer and activist who worked with the folklore material of the northwestern region, has found somebody to follow in her footsteps in the promotion of the local culture and literature. This somebody is Sherman Alexie, a writer, publicist, poet and scriptwriter who has published around 30 books to date. Like Vi Hilbert, Sherman Alexie, who is three generations younger, proclaims his Native American heritage. He represents it and helps other readers and interested people understand, or join the path towards building this identity. His texts are characterised by a humorous distance as well as an excellent gift of observation. Alexie is one of the most significant figures of the literature of the indigenous Americans and is a textbook example of a new type of narration, which has deep roots in this region and is nurtured. His early works were a great surprise at the time of their publication, both for readers from the Native American community and other Americans. From an ethnological point of view, they are not only a factual source of knowledge, but also provide a perspective for evaluating the culture emically.

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Marr, Kendrick L., Richard J. Hebda et William H. MacKenzie. « New alpine plant records for British Columbia and a previously unrecognized biogeographical element in western North America ». Botany 90, n^o 6 (juin 2012) : 445–55. http://dx.doi.org/10.1139/b2012-009.

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The distribution of northern British Columbia alpine plants is poorly documented. To improve our understanding of the flora of this vast, remote region, we collected more than 11 000 specimens from 65 mountains during 2002–2011. Most of these locations had not been visited by botanists. Of the more than 400 species we have collected, two are new to the province, others represent significant range extensions. Twelve species share elements of a disjunct distribution that has apparently not been previously recognized and consists of three regions: (1) northwestern North America; (2) Beartooth Plateau; and (3) northern Colorado. These 12 species appear to be absent from the extensive areas of suitable habitat that occur in the intervening areas. The most reasonable explanation for this pattern is that these species, adapted to arctic–alpine tundra conditions, migrated throughout western North America during the Pleistocene, a time when suitable habitat was much more widespread than now, and subsequently went extinct in many areas as the climate warmed during the Holocene.

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Sui, Yijie, Min Feng, Chunling Wang et Xin Li. « A high-resolution inland surface water body dataset for the tundra and boreal forests of North America ». Earth System Science Data 14, n^o 7 (19 juillet 2022) : 3349–63. http://dx.doi.org/10.5194/essd-14-3349-2022.

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Abstract. Inland surface waters are abundant in the tundra and boreal forests of North America, essential to environments and human societies but vulnerable to climate changes. These high-latitude water bodies differ greatly in their morphological and topological characteristics related to the formation, type, and vulnerability. In this paper, we present a water body dataset for the North American high latitudes (WBD-NAHL). Nearly 6.5 million water bodies were identified, with approximately 6 million (∼90 %) of them smaller than 0.1 km2. The dataset provides area and morphological attributes for every water body. During this study, we developed an automated approach for detecting surface water extent and identifying water bodies in the 10 m resolution Sentinel-2 multispectral satellite data to enhance the capability of delineating small water bodies and their morphological attributes. The approach was applied to the Sentinel-2 data acquired in 2019 to produce the water body dataset for the entire tundra and boreal forests in North America. The dataset provided a more complete representation of the region than existing regional datasets for North America, e.g., Permafrost Region Pond and Lake (PeRL). The total accuracy of the detected water extent by the WBD-NAHL dataset was 96.36 % through comparison to interpreted data for locations randomly sampled across the region. Compared to the 30 m or coarser-resolution water datasets, e.g., JRC GSW yearly water history, HydroLakes, and Global Lakes and Wetlands Database (GLWD), the WBD-NAHL provided an improved ability on delineating water bodies and reported higher accuracies in the size, number, and perimeter attributes of water body by comparing to PeRL and interpreted regional dataset. This dataset is available from the National Tibetan Plateau/Third Pole Environment Data Center (TPDC; http://data.tpdc.ac.cn, last access: 6 June 2022): https://doi.org/10.11888/Hydro.tpdc.271021 (Feng and Sui, 2020).

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Riggs, N. R., T. B. Sanchez et S. J. Reynolds. « Evolution of the early Mesozoic Cordilleran arc : The detrital zircon record of back-arc basin deposits, Triassic Buckskin Formation, western Arizona and southeastern California, USA ». Geosphere 16, n^o 4 (30 juin 2020) : 1042–57. http://dx.doi.org/10.1130/ges02193.1.

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Abstract A shift in the depositional systems and tectonic regime along the western margin of Laurentia marked the end of the Paleozoic Era. The record of this transition and the inception and tectonic development of the Permo-Triassic Cordilleran magmatic arc is preserved in plutonic rocks in southwestern North America, in successions in the distal back-arc region on the Colorado Plateau, and in the more proximal back-arc region in the rocks of the Buckskin Formation of southeastern California and west-central Arizona (southwestern North America). The Buckskin Formation is correlated to the Lower–Middle Triassic Moenkopi and Upper Triassic Chinle Formations of the Colorado Plateau based on stratigraphic facies and position and new detrital zircon data. Calcareous, fine- to medium-grained and locally gypsiferous quartzites (quartz siltstone) of the lower and quartzite members of the Buckskin Formation were deposited in a marginal-marine environment between ca. 250 and 245 Ma, based on detrital zircon U-Pb data analysis, matching a detrital-zircon maximum depositional age of 250 Ma from the Holbrook Member of the Moenkopi Formation. An unconformity that separates the quartzite and phyllite members is inferred to be the Tr-3 unconformity that is documented across the Colorado Plateau, and marks a transition in depositional environments. Rocks of the phyllite and upper members were deposited in wholly continental depositional environments beginning at ca. 220 Ma. Lenticular bodies of pebble to cobble (meta) conglomerate and medium- to coarse-grained phyllite (subfeldspathic or quartz wacke) in the phyllite member indicate deposition in fluvial systems, whereas the fine- to medium-grained beds of quartzite (quartz arenite) in the upper member indicate deposition in fluvial and shallow-lacustrine environments. The lower and phyllite members show very strong age and Th/U overlap with grains derived from Cordilleran arc plutons. A normalized-distribution plot of Triassic ages across southwestern North America shows peak magmatism at ca. 260–250 Ma and 230–210 Ma, with relatively less activity at ca. 240 Ma, when a land bridge between the arc and the continent was established. Ages and facies of the Buckskin Formation provide insight into the tectono-magmatic evolution of early Mesozoic southwestern North America. During deposition of the lower and quartzite members, the Cordilleran arc was offshore and likely dominantly marine. Sedimentation patterns were most strongly influenced by the Sonoma orogeny in northern Nevada and Utah (USA). The Tr-3 unconformity corresponds to both a lull in magmatism and the “shoaling” of the arc. The phyllite and upper members were deposited in a sedimentary system that was still influenced by a strong contribution of detritus from headwaters far to the southeast, but more locally by a developing arc that had a far stronger effect on sedimentation than the initial phases of magmatism during deposition of the basal members.

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Casey, Christine L., Stephen L. Rathbun, David E. Stallknecht et Mark G. Ruder. « Spatial Analysis of the 2017 Outbreak of Hemorrhagic Disease and Physiographic Region in the Eastern United States ». Viruses 13, n^o 4 (25 mars 2021) : 550. http://dx.doi.org/10.3390/v13040550.

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Hemorrhagic disease (HD) is considered one of the most significant infectious diseases of white-tailed deer in North America. Investigations into environmental conditions associated with outbreaks suggest drought conditions are strongly correlated with outbreaks in some regions of the United States. However, during 2017, an HD outbreak occurred in the Eastern United States which appeared to be associated with a specific physiographic region, the Appalachian Plateau, and not drought conditions. The objective of this study was to determine if reported HD in white-tailed deer in 2017 was correlated with physiographic region. There were 456 reports of HD from 1605 counties across 26 states and 12 physiographic regions. Of the 93 HD reports confirmed by virus isolation, 76.3% (71/93) were identified as EHDV-2 and 66.2% (47/71) were from the Appalachian Plateau. A report of HD was 4.4 times more likely to occur in the Appalachian Plateau than not in 2017. Autologistic regression models suggested a statistically significant spatial dependence. The underlying factors explaining this correlation are unknown, but may be related to a variety of host, vector, or environmental factors. This unique outbreak and its implications for HD epidemiology highlight the importance for increased surveillance and reporting efforts in the future.

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Hugh-Jones, Stephen. « The Pleiades and Scorpius in Barasana Cosmology ». Journal of Skyscape Archaeology 1, n^o 1 (10 juillet 2015) : 113–26. http://dx.doi.org/10.1558/jsa.v1i1.26957.

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In 1905, the German ethnographer Koch-Grünberg published a report of an Indian astronomical system from the Northwest Amazon region.1 His account, based on drawings by two Indian informants, has remained one of the most comprehensive descriptions of ethnoastronomy from lowland South America. Scattered references to star lore in the works of other writers,2 together with Koch-Grünberg’s own word lists of the many different languages spoken in the area,3 suggest that the basic elements of the system he described are probably common to all the Tukanoan speaking Indians of the Vaupés and to their Arawakan speaking neighbors to the north. In his account, Koch-Grünberg identifies some seventeen named stars and constellations and states that knowledge of astronomy is used in time reckoning, orientation, and the regulation of agricultural activities. But little information is given, either by him or by other writers, as to how this knowledge is used and how it relates to the cosmology and worldview of the Indians involved. In this paper, I shall try to answer some of these questions with reference to the Barasana.

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Zhao, C., X. Liu et L. R. Leung. « The impact of Great Basin Desert dust on the summer monsoon system over southwestern North America ». Atmospheric Chemistry and Physics Discussions 11, n^o 12 (2 décembre 2011) : 31735–67. http://dx.doi.org/10.5194/acpd-11-31735-2011.

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Abstract. The radiative forcing of dust emitted from the Great Basin Desert (GBD) and its impact on monsoon circulation and precipitation over the North America monsoon (NAM) region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem) for 15 yr (1995–2009). During the monsoon season, dust has a cooling effect (−0.90 W m−2) at the surface, a warming effect (0.40 W m−2) in the atmosphere, and a negative top-of-the-atmosphere (TOA) forcing (−0.50 W m−2) over the GBD region on 24-h average. Most of the dust emitted from the GBD concentrates below 800 hPa and stacks over the western slope of the Rocky Mountains and Mexican Plateau. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.5 K day−1 over the western slope of the Mountains. Model sensitivity simulations with and without dust for 15 summers (June-July-August) show that dust heating of the lower atmosphere over the GBD region remotely strengthens the low-level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in an eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. These monsoonal circulation changes lead to a statistically significant increase of precipitation by up to ~40% over the eastern slope of the Mountains (Arizona-New Mexico-Texas regions). This study highlights the interaction between dust and the NAM system and motivates further investigation of possible dust feedback on monsoon precipitation under climate change and the mega-drought conditions projected for the future.

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Roelofs, G. J., H. A. Scheeren, J. Heland, H. Ziereis et J. Lelieveld. « A model study of ozone in the eastern Mediterranean free troposphere during MINOS (August 2001) ». Atmospheric Chemistry and Physics 3, n^o 4 (14 août 2003) : 1199–210. http://dx.doi.org/10.5194/acp-3-1199-2003.

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Abstract. A coupled tropospheric chemistry-climate model is used to analyze tropospheric ozone distributions observed during the MINOS campaign in the eastern Mediterranean region (August, 2001). Modeled ozone profiles are generally in good agreement with the observations. Our analysis shows that the atmospheric dynamics in the region are strongly influenced by the occurrence of an upper tropospheric anti-cyclone, associated with the Asian summer monsoon and centered over the Tibetan Plateau. The anti-cyclone affects the chemical composition of the upper troposphere, where ozone concentrations of about 50 ppbv were measured, through advection of boundary layer air from South-East Asia. A layer between 4-6 km thickness was present beneath, containing up to 120 ppbv of ozone with substantial contributions by transport from the stratosphere and through lightning NOx. Additionally, pollutant ozone from North America was mixed in. Ozone in the lower troposphere originated mainly from the European continent. The stratospheric influence may be overestimated due to too strong vertical diffusion associated with the relatively coarse vertical resolution. The estimated tropospheric ozone column over the eastern Mediterranean is ~50 DU in summer, to which ozone from recent stratospheric origin contributes about 30%, ozone from lightning 13%, and from South-East Asia, North America and Europe about 7%, 8% and 14%, respectively, adding to a long-term hemispheric background of 25% of the column.

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Savidge, Rodney Arthur. « Evidence for early glaciation of southeastern Beringia ». Canadian Journal of Earth Sciences 57, n^o 2 (février 2020) : 199–226. http://dx.doi.org/10.1139/cjes-2019-0048.

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Between the Klondike Plateau and Yukon–Tanana highlands of Yukon and Alaska, respectively, current maps explain glaciated alpine locales and periglacial areas in terms of localized Pliocene–Pleistocene montane ice caps, alpine glaciers, and periglacial changes. However, this region’s plateau topography is populated with long undulating ridges having wide flattened tops; it contrasts with relief of other regions of northwestern North America also affected by ice caps, cryoplanation, and erosion over similar duration during the same epochs. This region has received minimal research and appears to present a new opportunity for resolving outstanding glaciological and stratigraphy issues. The glaciological history is reviewed, placing particular emphasis upon the low-elevation ridges within the “unglaciated” region, suggesting that those ridges are relict arête/cirque remnants. Sites of subalpine glacial grooving and mountaintop planing are also identified, and a conglomeratic red bed containing erratic clasts is described. All indications point to the “unglaciated” region having been glaciated before late Pliocene. Two working hypotheses are proposed: (1) The landscape once supported a range of young mountains that became glaciated then overridden and pared to a plateau by an ice sheet. (2) Following deglaciation, an extended period of paraglacial activity removed most of the former drift and excised new valleys to give the region an unglaciated appearance, which thereafter became modified into its present state by local montane/alpine glaciations, interglacial cryoplanation, periglacial gelifraction, and erosion. In addition to Pliocene–Pleistocene glaciations, a northeastward advancing Miocene ice sheet seems plausible and, on the basis of paleographic considerations and lithology, a Cretaceous glaciation evidently is also not out of the question.

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GARFIAS-ESPEJO, TANIA, MANUEL ELÍAS-GUTIÉRREZ et MARCELO SILVA-BRIANO. « On Macrothrix agsensis Dumont, Silva-Briano & ; Babu, 2002 (Cladocera : Anomopoda : Macrothricidae), with description of the male and ephippial females, and comments on the distribution of the genus in Mexico ». Zootaxa 1632, n^o 1 (7 novembre 2007) : 49–60. http://dx.doi.org/10.11646/zootaxa.1632.1.4.

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The Macrothrix rosea-triserialis group of species (Cladocera: Macrothricidae) is characterized by (1) a well developed postabdomen heel; (2) rows of strong spines on preanal margin of postabdomen and (3) scraper 5 of limb II with enlarged subapical teeth. Macrothrix agsensis, a member of this group, was recently described from the Mexican Central Plateau based on parthenogenetic females only. It is characterized by five rows of long spines in the female antenna I, and five thick spines on setae 4–5 of endite 2 of limb I. Here we describe its ephippial females and males, as well as development of the latter. The ephippium is strongly chitinized, with a special ornamentation in the form of hexagonal cells. The male is characterized by peculiar groups of long and short spinules in the anterior half of the antenna I, three furrows with spinules on the male copulatory hook on limb I, and a longer seta in the outer distal lobe, armed with bean-like projections. With regard to the known distribution of Macrothrix in Mexico, it is now feasible to consider the existence of four possible endemic species in this region: Macrothrix mexicanus, M. agsensis, M. sierrafriatiensis and M. marthae. All of them, except the last one, are restricted to the Central Plateau. Another species, Macrothrix smirnovi, was described from Mexico and later found in Sacramento (USA). Among the widespread species are Macrothrix elegans and M. spinosa, the former one of the most common macrothricids in the Neotropics. It shows a northern distributional limit at the northwest of Mexico and it is possible to find it from north to south. Macrothrix hirsuticornis, restricted to North America has a southern limit in the north. Macrotrhix spinosa is found from north to south of Mexico, but its distribution range extends to South America. Other old records are doubtful, such as Macrothrix triserialis, M. rosea and M. laticornis, because they seem to be restricted to the old world.

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Fan, Hongdou, Lin Wang, Yang Zhang, Youmin Tang, Wansuo Duan et Lei Wang. « Predictable Patterns of Wintertime Surface Air Temperature in Northern Hemisphere and Their Predictability Sources in the SEAS5 ». Journal of Climate 33, n^o 24 (15 décembre 2020) : 10743–54. http://dx.doi.org/10.1175/jcli-d-20-0542.1.

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AbstractBased on 36-yr hindcasts from the fifth-generation seasonal forecast system of the European Centre for Medium-Range Weather Forecasts (SEAS5), the most predictable patterns of the wintertime 2-m air temperature (T2m) in the extratropical Northern Hemisphere are extracted via the maximum signal-to-noise (MSN) empirical orthogonal function (EOF) analysis, and their associated predictability sources are identified. The MSN EOF1 captures the warming trend that amplifies over the Arctic but misses the associated warm Arctic–cold continent pattern. The MSN EOF2 delineates a wavelike T2m pattern over the Pacific–North America region, which is rooted in the tropical forcing of the eastern Pacific-type El Niño–Southern Oscillation (ENSO). The MSN EOF3 shows a wavelike T2m pattern over the Pacific–North America region, which has an approximately 90° phase difference from that associated with MSN EOF2, and a loading center over midlatitude Eurasia. Its sources of predictability include the central Pacific-type ENSO and Eurasian snow cover. The MSN EOF4 reflects T2m variability surrounding the Tibetan Plateau, which is plausibly linked to the remote forcing of the Arctic sea ice. The information on the leading predictable patterns and their sources of predictability is further used to develop a calibration scheme to improve the prediction skill of T2m. The calibrated prediction skill in terms of the anomaly correlation coefficient improves significantly over midlatitude Eurasia in a leave-one-out cross-validation, implying a possible way to improve the wintertime T2m prediction in the SEAS5.

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Kuznetsov, Igor V. « On the Evolution of the Northwest Coast Indian Communities (A Soviet-American Discussion and Its Sequel) ». Antropologicheskij forum 17, n^o 51 (décembre 2021) : 141–72. http://dx.doi.org/10.31250/1815-8870-2021-17-51-141-172.

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The article is devoted to the discussion among Soviet and U.S. scholars about the social organization of the Indians of the Northwest Coast of North America. In the classic textbooks on “primitive history”, the Indians of this region—the Tlingit, Haida, Tsimshian and Kwakwaka’wakw (Kwakiutl)—are mentioned as examples of a high degree of social differentiation based on a (fishing and maritime) foraging economy and even as instances of pre-state structures. The proposed concepts were, to varying degrees, determined by external factors: personal political views, high-profile events, or government pressure. In 1897, Franz Boas recognized the potlatch ceremony—demonstrative exchanges of gifts and destructions of surplus, a practice exotic to Europeans—as an analogue of a credit operation. This interpretation, not empirically substantiated, originated from a public campaign to legalize potlatch. In the 1930s, Julia Averkieva, a Soviet intern of Boas, interpreted some fragments of her mentor’s teaching through the Marxist class theory framework, shifting the emphasis from potlatch to slavery: the Northwest Indians allegedly began the transition to slavery from a classless system in which the potlatch was an instrument for preserving property equality. Averkieva’s interpretation became canonical in the USSR, whilst also finding some reception outside the socialist camp. In the United States, relativistic cultural interpretations dominated; domestic evolutionary Marxist models were marginal and were not rooted in the Soviet tradition. However, after the collapse of the USSR, they also became part of the research mainstream, being criticized not only from the right, but also from the left—from anarchist viewpoints.

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HEDIN, MARSHAL, et Bob Dellinger. « Descriptions of a new species and previously unknown males of Nesticus ( Araneae : Nesticidae) from caves in Eastern North America, with comments on species rarity ». Zootaxa 904, n^o 1 (18 mars 2005) : 1. http://dx.doi.org/10.11646/zootaxa.904.1.1.

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We describe the new species, Nesticus pecki, an apparently cave-limited (but not troglomorphic) species from the southeastern edge of the Cumberland Plateau in southern Tennessee. Previously unknown males of N. dilutus Gertsch, N. stygius Gertsch, and N. furtivus Gertsch are illustrated and described. These male specimens, along with additional females, are all taken from their respective type localities. Nesticus valentinei Gertsch is considered a junior subjective synonym of N. barri Gertsch (new synonymy). Several cave-limited species in the region are single-site endemics, including N. furtivus, N. dilutus, and N. pecki. We discuss the conservation status and biological factors that may potentially threaten the continued existence of these populations.

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Luo, Yali, Renhe Zhang, Weimiao Qian, Zhengzhao Luo et Xin Hu. « Intercomparison of Deep Convection over the Tibetan Plateau–Asian Monsoon Region and Subtropical North America in Boreal Summer Using CloudSat/CALIPSO Data ». Journal of Climate 24, n^o 8 (15 avril 2011) : 2164–77. http://dx.doi.org/10.1175/2010jcli4032.1.

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Abstract Deep convection in the Tibetan Plateau–southern Asian monsoon region (TP–SAMR) is analyzed using CloudSat and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data for the boreal summer season (June–August) from 2006 to 2009. Three subregions are defined—the TP, the southern slope of the plateau (PSS), and the SAMR—and deep convection properties (such as occurrence frequency, internal vertical structure, system size, and local environment) are compared among these subregions. To cast them in a broader context, four additional regions that bear some similarity to the TP–SAMR are also discussed: East Asia (EA), tropical northwestern Pacific (NWP), and western and eastern North America (WNA and ENA, respectively). The principal findings are as follows: 1) Compared to the other two subregions of the TP–SAMR, deep convection over the TP is shallower, less frequent, and embedded in smaller-size convection systems, but the cloud tops are more densely packed. These characteristics of deep convection over the TP are closely related to the unique local environment, namely, a significantly lower level of neutral buoyancy (LNB) and much drier atmosphere. 2) In a broader context in which all seven regions are brought together, deep convection in the two tropical regions (NWP and SAMR; mostly over ocean) is similar in many regards. A similar conclusion can be drawn among the four subtropical continental regions (TP, EA, WNA, and ENA). However, tropical oceanic and subtropical land regions present some significant contrasts: deep convection in the latter region occurs less frequently, has lower cloud tops but comparable or slightly higher tops of large radar echo (e.g., 0 and 10 dBZ), and is embedded in smaller systems. The cloud tops of the subtropical land regions are generally more densely packed. Hence, the difference between the TP and SAMR is more of a general contrast between subtropical land regions and tropical oceanic regions during the boreal summer. 3) Deep convection over the PSS possesses some uniqueness of its own because of the distinctive terrain (slopes) and moist low-level monsoon flow. 4) Results from a comparison between the daytime (1:30 p.m.) and nighttime (1:30 a.m.) overpasses are largely consistent with researchers’ general understanding of the diurnal variation of tropical and subtropical deep convection.

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Zhao, C., X. Liu et L. R. Leung. « Impact of the Desert dust on the summer monsoon system over Southwestern North America ». Atmospheric Chemistry and Physics 12, n^o 8 (24 avril 2012) : 3717–31. http://dx.doi.org/10.5194/acp-12-3717-2012.

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Abstract. The radiative forcing of dust emitted from the Southwest United States (US) deserts and its impact on monsoon circulation and precipitation over the North America monsoon (NAM) region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem) for 15 years (1995–2009). During the monsoon season, dust has a cooling effect (−0.90 W m−2) at the surface, a warming effect (0.40 W m−2) in the atmosphere, and a negative top-of-the-atmosphere (TOA) forcing (−0.50 W m−2) over the deserts on 24-h average. Most of the dust emitted from the deserts concentrates below 800 hPa and accumulates over the western slope of the Rocky Mountains and Mexican Plateau. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.5 K day−1 over the western slope of the Mountains. Model sensitivity simulations with and without dust for 15 summers (June-July-August) show that dust heating of the lower atmosphere over the deserts strengthens the low-level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in an eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. These monsoonal circulation changes lead to a statistically significant increase of precipitation by up to ~40 % over the eastern slope of the Mountains (Arizona-New~Mexico-Texas regions). This study highlights the interaction between dust and the NAM system and motivates further investigation of possible dust feedback on monsoon precipitation under climate change and the mega-drought conditions projected for the future.

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Gray, Keith D., V. Isakson, D. Schwartz et Jeffrey D. Vervoort. « Orogenic link ∼41°N–46°N : Collisional mountain building and basin closure in the Cordillera of western North America ». Geosphere 16, n^o 1 (5 décembre 2019) : 136–81. http://dx.doi.org/10.1130/ges02074.1.

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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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Locklear, James H. « Endemic plants of the central grassland of North America : distribution, ecology, and conservation status ». Journal of the Botanical Research Institute of Texas 11, n^o 1 (24 juillet 2017) : 193–234. http://dx.doi.org/10.17348/jbrit.v11.i1.1172.

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This paper enumerates the endemic plants of the Central Grassland of North America. The Central Grassland encompasses the full extent of the tallgrass, mixed-grass, and shortgrass prairie ecological systems of North America plus floristically related plant communities that adjoin and/or interdigitate with the midcontinental grasslands including savanna-open woodland systems, shrub-steppe, and rock outcrop communities. There are 382 plant taxa endemic to the Central Grassland, 300 endemic species (eight of which have multiple subspecific taxa endemic to the region) and 72 endemic subspecies/varieties of more widely distributed species. Nine regional concentrations of endemic taxa were identified and are described as centers of endemism for the Central Grassland: Arkansas Valley Barrens, Edwards Plateau, Llano Estacado Escarpments, Llano Uplift, Mescalero-Monahans Dunes, Niobrara-Platte Tablelands, Raton Tablelands, Red Bed Plains, and Reverchon Rocklands. In addition to hosting localized endemics, these areas are typically enriched with more widely-distributed Central Grassland endemics as well as peripheral or disjunct occurrences of locally-rare taxa, making them regions of high floristic diversity for the Central Grassland. Most of the endemics (299 or 78%) are habitat specialists, associated with rock outcrop, sand, hydric, or riparian habitats. There is a strong correlation between geology and endemism in the Central Grassland, with 59% of the endemics (225 taxa) associated with rock outcrop habitat. Of the 382 Central Grassland endemics, 124 or 33% are of conservation concern (NatureServe ranking of G1/T1 to G3/T3). Of these at-risk taxa, 78 or 63% are primarily associated with one of the centers of endemism identified in the study. It is hoped these findings will be useful in focusing conservation action on the habitats, ecological associations, and regions of the Central Grassland that host the highest concentrations of unique and at-risk plant species and associated biological diversity.

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ZHANG, ZHONG-SHUAI, XIANG-YUN ZHU, LING-LU LI, SHAN-WEN JIANG et WEN-LI CHEN. « A new synonym of Ptilagrostis yadongensis and a new record of Stipa bhutanica to the flora of China (Poaceae) ». Phytotaxa 272, n^o 1 (26 août 2016) : 94. http://dx.doi.org/10.11646/phytotaxa.272.1.7.

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Ptilagrostis Grisebach (1852: 447) is a small genus of the grass family, including approximately 11 species (Wu & Phillips 2006, Barkworth 2007). It occurs in both Asia and North America with about eight species distributed in Qinghai-Tibet Plateau, its diversity center. Ptilagrostis yadongensis Keng & Tang (1985: 44) is one of the species that occurs in this region, which was described based on materials from Yadong, China, the southern slope of Himalayas. The paper was published in a Chinese journal, viz. Journal of Southwest Agriculural University, and had not been noticed until 2005 (Peterson et al. 2005, Wu & Phillips 2006). The author pointed out that P. yadongensis is distinguished from its morphological close, Ptilagrostis concinna (Hooker 1897: 230) Roshevitz (1934: 75) by linear panicles with fewer spikelets, longer and unequal glumes, and shorter and glabrous anthers.

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Hajdas, Irka, Georges Bonani, Patricio I. Moreno et Daniel Ariztegui. « Precise radiocarbon dating of Late-Glacial cooling in mid-latitude South America ». Quaternary Research 59, n^o 1 (janvier 2003) : 70–78. http://dx.doi.org/10.1016/s0033-5894(02)00017-0.

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AbstractVariability of atmospheric 14C content often complicates radiocarbon-based chronologies; however, specific features such as periods of constant 14C age or steep changes in radiocarbon ages can be useful stratigraphic markers. The Younger Dryas event in the Northern Hemisphere is one of those periods, showing conspicuous 14C wiggles. Although the origin of those variations is not fully understood, we can make practical use of them and determine: (i) whether the Younger Dryas was global in extent; if so, (ii) were the initial cooling and the final warming synchronous worldwide; and (iii) what are the implications of these similarities/differences? Here we report high-resolution AMS 14C chronologies from the mid-latitudes of South America that pinpoint a cool episode between 11,400 and 10,20014C yr B.P. The onset of the final cool episode of the Late Glacial in the southern mid-latitudes, i.e., the Huelmo/Mascardi Cold Reversal, preceded the onset of the Younger Dryas cold event by ∼550 calendar years. Both events ended during a radiocarbon-age plateau at ∼10,20014C yr B.P. Thus, the Huelmo/Mascardi Cold Reversal encompasses the Younger Dryas, as well as a couple of short-term cool/warm oscillations that immediately preceded its onset in the North Atlantic region.

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Sukhobokova, Olga. « The British-French struggle for Canada (the end of the 1680s – the beginning of the 1760s) ». American History & ; Politics : Scientific edition, n^o 15 (2023) : 96–111. http://dx.doi.org/10.17721/2521-1706.2023.15.8.

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The article is devoted to the four wars between Great Britain and France in the late 1680s and early 1760s, as a result of which it was determined who would own the territory of modern Canada: King William’s War or War of the League of Augsburg, Queen Anne’s War (or War of the Spanish Succession), King George’s War (War of the Austrian Succession) and the Seven Years’ War (Conquest). The purpose of the article is to consider the British-French wars of the 17th – 18th centuries on the territory of Canada, which determined its future. The research methodology is based on the principle of historicism and problem-chronological and complex approaches. Comparative and analytical methods made it possible to compare the starting positions of Great Britain and France in North America and the course and results of their armed struggle for Canada in the context of the wars of both empires on different continents. The scientific novelty of the study consists in an attempt to show the complexity, consistency and patterns of the British-French struggle for Canada. Its circumstances and main milestones are traced, which influenced not only the results of the struggle, but also laid the foundation for the development of Canada for the following centuries. This, as well as insufficient attention to the problem in Ukrainian Canadian studies, strengthens the relevance of this article. Conclusions. As a result of the British-French wars, Great Britain became the victor and the most powerful colonial and maritime empire. Instead, France ceded positions and possessions, in particular in North America. The first three wars began in Europe, and later hostilities also began in North America, involving mainly the colonists and their Native American allies. But the last, Seven Years’ War began precisely in North America. The British used regular troops in it. The British fleet also played a significant role, as well as the larger population and production capacity of their colonies compared to the French. If in the first three wars the French were able to compensate for these factors due to more effective mobilization and the involvement of Indians as allies, then in the fourth and last war they were defeated. The main consequence was the termination of the existence of New France and the consolidation of dominance in the region of Great Britain, which determined the further development of Canada as a colony, and later the dominion of Great Britain.

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Movsesian, A. A. « Variations in the anatomical structure of the pterion among populations from various global regions ». VESTNIK ARHEOLOGII, ANTROPOLOGII I ETNOGRAFII, n^o 2(65) (15 juin 2024) : 148–57. http://dx.doi.org/10.20874/2071-0437-2024-65-2-12.

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Anatomical variations in the structure of the pterion were examined in various craniological series represent-ing modern populations from Australia, Melanesia, Southeast Asia, North Asia, America, and Europe, encom-passing 2035 adult crania. The comparison of populations based on the frequency of nonmetric traits revealed significant diversity across regions. Notably, the sphenoparietal connection is most frequent in European and South Asian populations, as well as among Native Americans, while it is least common among African groups. The frontotemporal connection predominates among Australian Aborigines and Melanesians and is also common in African populations but is almost non-existent in Europeans. The X-shaped pterion is most frequently observed in the Eskimos of Chukotka and the Chukchi, as well as among Somali and Tanzanian populations. A high fre-quency of epipteric bones is particularly characteristic of Southern Indians, Burmese, Australians, and Melane-sians. Pairwise comparisons of populations were conducted using Smith's Mean Measure of Divergence (MMD). To visualize the data from individual regions, the method of Multidimensional Scaling (MDS) was applied to the matrices of biological distances. The MDS plot for the North Asian region revealed distinct clusters of the Arctic, Baikal, Cen-tral Asian, and Ural groups, aligning with G.F. Debetz's classification based on morphological similarities among populations. In the MDS plot for the South and Southeast Asian, American, and African populations, Australians and Melanesians formed a separate cluster; Pueblo Indians were closely aligned with Peruvians, South Indians with Burmese, Malays merged with Papuans, and African populations were positioned relatively close to each other. In Europe, Caucasian groups formed a distinct cluster. On the combined graph, the populations were clearly divided by regions. The results obtained indicate that the spatial arrangement of populations on the graphs approximately mir-rors their genetic connections and shared origins. This suggests that nonmetric variations in the pterion area are more likely determined by genetic rather than ecological factors and can be considered taxonomically valuable traits at the regional level. Investigating the structure of the pterion in an evolutionary context may shed light on broader questions concerning the evolution of the skull and the mechanisms influencing its formation.

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Sadras, Victor O., et John F. Angus. « Benchmarking water-use efficiency of rainfed wheat in dry environments ». Australian Journal of Agricultural Research 57, n^o 8 (2006) : 847. http://dx.doi.org/10.1071/ar05359.

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Attainable water-use efficiency relates attainable yield, i.e. the best yield achieved through skilful use of available technology, and seasonal evapotranspiration (ET). For wheat crops in south-eastern Australia, there is a common, often large gap between actual and attainable water-use efficiency. To evaluate whether this gap is only an Australian problem or a general feature of dry environments, we compared water-use efficiency of rainfed wheat in south-eastern Australia, the North American Great Plains, China Loess Plateau, and the Mediterranean Basin. A dataset of published data was compiled (n = 691); water-use efficiency (WUEY/ET) was calculated as the ratio between actual grain yield and seasonal ET. Maximum WUEY/ET was 22 kg grain/ha.mm. Average WUEY/ET (kg grain/ha.mm) was 9.9 for south-eastern Australia, 9.8 for the China Loess Plateau, 8.9 for the northern Great Plains of North America, 7.6 for the Mediterranean Basin, and 5.3 for the southern-central Great Plains; the variation in average WUEY/ET was largely accounted for by reference evapotranspiration around flowering. Despite substantial differences in important factors including soils, precipitation patterns, and management practices, crops in all these environments had similarly low average WUEY/ET, between 32 and 44% of attainable efficiency. We conclude that low water-use efficiency of Australian crops is not a local problem, but a widespread feature of dry environments. Yield gap analysis for crops in the Mallee region of Australia revealed low availability of phosphorus, late sowing, and subsoil chemical constraints as key factors reducing water-use efficiency, largely through their effects on soil evaporation.

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Lewis, Julian, et Salisa Lewis. « Freshwater isopods of the genus Lirceus from caves and springs of the Interior Highlands, USA, with description of three new species (Isopoda : Asellidae) ». Journal of Cave and Karst Studies 85, n^o 3/4 (31 décembre 2023) : 86–101. http://dx.doi.org/10.4311/2022lsc0113.

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Eleven species of the freshwater isopod genus Lirceus occur in the Interior Highlands, a region of the south-central United States comprised of the Ozark and Ouachita physiographic provinces. As part of research on the morphology and molecular genetics of eastern North American asellid isopods, three new species of Lirceus were discovered in the Interior Highlands. Lirceus slayorum, n. sp., is described from Greathouse Spring, Washington County, Arkansas and occurs in caves and springs associated with the Ozark Springfield Plateau. Lirceus ozarkensis, n. sp., is described from Maxey Cave, Pulaski County, Missouri and was originally identified in 1949 by Hubricht and Mackin as a subspecies of Lirceus hoppinae. In actuality, L. ozarkensis is quite distinct from L. hoppinae, and occurs allopatrically in caves and springs of the southern Ozark Salem Plateau in southern Missouri. Lirceus robisoni, n. sp., is described from Abernathy Spring, Polk County, Arkansas and is found in only a few springs in a narrow area of the Ouachita Mountains in western Arkansas. Eight other species of Lirceus occur in the Interior Highlands, most of which are confined to springs and caves. New localities are presented and the ranges of the species are established. Illustrations of the genital pleopods demonstrate a common theme across the species of the Interior Highlands, with all possessing a sperm-transfer cannula arising adjacent to a variously papillate or dentate digitiform lateral process, and nestled under a dominant broadly rounded or subtriangular apex. Within this morphological template, some of the Ozark species, like Lirceus bidentatus, are among the most anatomically bizarre in North America.

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Roelofs, G. J., B. Scheeren, J. Heland, H. Ziereis et J. Lelieveld. « Distribution and origin of ozone in the eastern Mediterranean free troposphere during MINOS (August 2001) ». Atmospheric Chemistry and Physics Discussions 3, n^o 2 (5 mars 2003) : 1247–72. http://dx.doi.org/10.5194/acpd-3-1247-2003.

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Abstract. A coupled tropospheric chemistry – climate model is used to reproduce and analyze tropospheric ozone distributions observed during the MINOS campaign in the eastern Mediterranean region (August, 2001). Generally, regional atmospheric dynamics in summer are strongly influenced by the occurrence of an upper tropospheric anti-cyclone, associated with the Asian summer monsoon and centered over the Tibetan Plateau. The anti-cyclone affects the chemical composition of the upper troposphere, where ozone concentrations of about 50 ppbv were measured, through advection of boundary layer air from South-East Asia. A layer between 4–6 km thickness and containing up to 120 ppbv of ozone was present beneath. Ozone from stratospheric origin and from lightning NOx contributed to this layer. Additionally, pollutant ozone from North America was mixed in. Ozone in the lower troposphere originated mainly from the European continent. Modeled ozone profiles are in reasonable agreement with the observations. The stratospheric influence is sometimes overestimated by the model due to too strong vertical diffusion associated with the relatively coarse vertical resolution of the model, and specific convective events are not reproduced realistically. The modeled tropospheric ozone column over the eastern Mediterranean is ~50 DU in summer, to which ozone from recent stratospheric origin contributes about 30%, ozone from lightning 13%, and from South-East Asia, North America and Europe about 7%, 8% and 14%, respectively, adding to a long-term hemispheric background of 25% of the column.

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Alfaro, René I., Lara van Akker et Brad Hawkes. « Characteristics of forest legacies following two mountain pine beetle outbreaks in British Columbia, Canada ». Canadian Journal of Forest Research 45, n^o 10 (octobre 2015) : 1387–96. http://dx.doi.org/10.1139/cjfr-2015-0042.

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The mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera, Curculionidae), a native insect of North America, periodically reaches population sizes that cause serious economic impact to the forest industry in western North America. The most recent outbreak in British Columbia (BC), Canada, which began in the late 1990s, is only now (2015) abating, after causing unprecedented tree mortality in lodgepole pine (Pinus contorta Douglas ex. Loudon) forests. In this paper, we make use of permanent research plots to report on the condition of lodgepole pine forests in the Chilcotin Plateau of central BC, which underwent two fully documented mountain pine beetle outbreaks. In this region, the first outbreak started in the late 1970s and lasted until the mid-1980s; the second outbreak began in the early 2000s and ended in 2010. We measured the impacts of these outbreaks in terms of tree mortality and describe the characteristics of the legacies that remain following these outbreaks, including survivors in various canopy layers and levels of existing and new regeneration. We provide evidence in support of the existence of postdisturbance legacies that classify into five distinct stand structure types. Abundant regeneration and surviving intermediate canopy layers in most stands indicate that management actions to restock pine stands in this area will not likely be necessary. The information provided by this study is important for estimating future forest development and timber supply and for forest planning and management.

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Martinez-Serna, Gabriel. « Jesuit Missionaries, Indian Polities, and Environmental Transformation in the Lagoon March of Northeastern New Spain ». Journal of Early American History 3, n^o 2-3 (2013) : 207–34. http://dx.doi.org/10.1163/18770703-00303008.

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The introduction of European agriculture and livestock transformed the natural and human landscape of the Americas profoundly. In the borderlands of the continent, it was often missionaries who introduced these practices to areas where mobile Indians groups had adapted their cultures to an environment that was irrevocably changed. Transforming a landscape usually doomed a mobile ethnic group to forced adaptation, migration or extinction, but could also prove a catalyst to an ethnogenesis that could not have occurred without the effects the Columbian Exchange brought about by the missionaries. The so-called Lagoon March (Comarca Lagunera) of the northeastern borderlands of New Spain experienced perhaps the most dramatic of these episodes in this story of Colonial North America. This region was home to the Lagunero Indians, the most populous pre-contact group in the borderlands, and as late as the last decade of the sixteenth century it was a lush lagoon environment surrounded by wooded mountains. The Jesuits founded the Parras mission there in 1598, and within two generations, the Laguneros had largely disappeared, and the area was transformed into an archipelago of highly productive oasis surrounded by scrub barely suitable for livestock. Viticulture made the area the richest non-mining region of the entire frontier, and a magnet for population. Tlaxcalan (Nahua) colonist that had lived in the mission and survived the Lagunero extinction became a borderlands community intrinsically attached to viticulture and communal rights to water from the region’s only major spring, giving them a legal status that distinguished them from other Indian groups (including other Tlaxcalans) and underlining a social cohesion that lasted until the Independence period. Thus, the unintended effects of the Jesuit presence transformed the Parras environment and the way Indian identity related to it.

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Okolnishnikova, I. Yu, A. V. Keller et V. Ya Konks. « Marketing analysis of the global market of telematics transport and information management systems ». Vestnik Universiteta 1, n^o 12 (15 février 2023) : 46–54. http://dx.doi.org/10.26425/1816-4277-2022-12-46-54.

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The article presents the results of marketing analysis of the global high-tech market of telematics transport and information management systems. The main trends in and factors of development of automotive telematics devices’ product line are analyzed. Dynamics of growth of the most important segments of the market under study are identified and described. The existing specifics of the development of key geographical consumer microsegments, that is, the markets of North America, Europe and the Asia-Pacific region, are provided, and corresponding forecast indicators are presented. The main product macrosegments, namely navigation and satellite systems, unmanned vehicles, ADAS systems and insurance telematics, are studied in the same manner. Based on the data obtained, the authors describe the existing levels of vehicle autonomy, which significantly affect the indicators of market growth. An overview of the key high technologies ensuring the stability of the transport telematics market is provided, and the average time needed to reach the plateau of their productivity is measured.

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Napolskikh, Vladimir V. « “PERSONAL TREE” IN NORTHERN EURASIA AND TRACES OF MERIAN SUBSTRATE IN THE RUSSIANS’ CULTURE OF THE KOSTROMA REGION ». Ural Historical Journal 83, n^o 2 (2024) : 6–15. http://dx.doi.org/10.30759/1728-9718-2024-2(83)-6-15.

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In the rites of seeing off the conscripts in the Kostroma and Vologda regions the Ural Federal University Toponymic expedition recorded the custom of decorating a tree at the exit from the village or hanging such a decorated tree on the pediment of a recruit’s house, and the custom of breaking or wrapping the trees tops on the edge of the village (this was done also to mark some other significant events in human life). The article shows that these customs have different origins, they were included from different sources into the recruit’s leaving rite during its formation in the 18th–19th centuries. The custom of decorating trees is a direct borrowing from the wedding ceremony and comes from the common Slavic tradition to decorate a wedding tree, symbolizing “girlish beauty”. The custom of breaking a tree top has a substratum origin and probably goes back to the tradition of the Kostroma Meria, which is reconstructed on the basis of Uralo-Yukaghir concepts about a person’s connection with a tree and the ancient custom of marking important events in human life (rites de passages) by making a personal tree by breaking off branches on coniferous trees preserved by Karelians (karsikko), Udmurts and Yukaghirs, which penetrated into North America in ancient times and was found among the Karok Indians in Northern California.

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Favre, Adrien, James S. Pringle et Peng-Cheng Fu. « Phylogenetics Support the Description of a New Sichuanese Species, Susanne’s Gentian, Gentiana susanneae (Gentianaceae) ». Systematic Botany 47, n^o 2 (15 juin 2022) : 506–13. http://dx.doi.org/10.1600/036364422x16512564801579.

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Abstract— The region of the Qinghai-Tibet Plateau hosts a remarkable biodiversity, including a plethora of endemics. There, the process of documenting biodiversity is still ongoing, and recently, an unusual plant of Gentiana section Frigida was discovered at Cuopu Lakes (Sichuan, China). Although Flora of China identified these specimens as G. algida based upon unmistakable traits (e.g. corolla colour and length, sessile flowers), it was obvious that the Sichuanese plants strongly differed morphologically from G. algida specimens from Siberia and North America. In order to clarify their relationships, we used an integrative approach, investigating not only morphological traits, but also phylogenetic relationships (based upon plastome and rDNA-cistron), as well as chloroplast structure. Whereas the rDNA-cistron phylogeny was poorly resolved, the plastome phylogeny was well supported in both Bayesian inference and maximum likelihood analyses. Our findings indicate that the samples of G. algida from Cuopu Lakes are morphologically and genetically distinct from those collected elsewhere, supporting the recognition of a new species, G. susanneae. The new species differs from G. purdomii (another similar species) by having sessile flowers, and from G. algida by being a generally much taller plant with more and longer flowers, and by having a smaller calyx. Gentiana susanneae clusters with other species from the region of the Qinghai-Tibet Plateau from which it differs morphologically, and is only distantly related to the G. algida/G. frigida clade, which stems from a dispersal event out of Tibet. Based upon these solid lines of evidence, G. susanneae is described and illustrated (drawings and photographs). In addition, a conservation assessment and an identification key modified from Flora of China are provided.

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Werhahn, Geraldine, Helen Senn, Jennifer Kaden, Jyoti Joshi, Susmita Bhattarai, Naresh Kusi, Claudio Sillero-Zubiri et David W. Macdonald. « Phylogenetic evidence for the ancient Himalayan wolf : towards a clarification of its taxonomic status based on genetic sampling from western Nepal ». Royal Society Open Science 4, n^o 6 (juin 2017) : 170186. http://dx.doi.org/10.1098/rsos.170186.

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Wolves in the Himalayan region form a monophyletic lineage distinct from the present-day Holarctic grey wolf Canis lupus spp. (Linnaeus 1758) found across Eurasia and North America. Here, we analyse phylogenetic relationships and the geographic distribution of mitochondrial DNA haplotypes of the contemporary Himalayan wolf (proposed in previous studies as Canis himalayensis ) found in Central Asia. We combine genetic data from a living Himalayan wolf population collected in northwestern Nepal in this study with already published genetic data, and confirm the Himalayan wolf lineage based on mitochondrial genomic data (508 bp cytochrome b and 242 bp D-loop), and X- and Y-linked zinc-finger protein gene (ZFX and ZFY) sequences. We then compare the genetic profile of the Himalayan wolf lineage found in northwestern Nepal with canid reference sequences from around the globe with maximum likelihood and Bayesian phylogeny building methods to demonstrate that the Himalayan wolf forms a distinct monophyletic clade supported by posterior probabilities/bootstrap for D-loop of greater than 0.92/85 and cytochrome b greater than 0.99/93. The Himalayan wolf shows a unique Y-chromosome (ZFY) haplotype, and shares an X-chromosome haplotype (ZFX) with the newly postulated African wolf. Our results imply that the Himalayan wolf distribution range extends from the Himalayan range north across the Tibetan Plateau up to the Qinghai Lakes region in Qinghai Province in the People's Republic of China. Based on its phylogenetic distinction and its older age of divergence relative to the Holarctic grey wolf, the Himalayan wolf merits formal classification as a distinct taxon of special conservation concern.

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Tesche, Matthias, et Vincent Noel. « Locations for the best lidar view of mid-level and high clouds ». Atmospheric Measurement Techniques 15, n^o 14 (21 juillet 2022) : 4225–40. http://dx.doi.org/10.5194/amt-15-4225-2022.

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Abstract. Mid-level altocumulus clouds (Ac) and high cirrus clouds (Ci) can be considered natural laboratories for studying cloud glaciation in the atmosphere. While their altitude makes them difficult to access with in situ instruments, they can be conveniently observed from the ground with active remote-sensing instruments such as lidar and radar. However, active remote sensing of Ac and Ci at visible wavelengths with lidar requires a clear line of sight between the instrument and the target cloud. It is therefore advisable to carefully assess potential locations for deploying ground-based lidar instruments in field experiments or for long-term observations that are focused on mid- or high-level clouds. Here, observations of clouds with two spaceborne lidars are used to assess where ground-based lidar measurements of mid- and high-level clouds are least affected by the light-attenuating effect of low-level clouds. It is found that cirrus can be best observed in the tropics, the Tibetan Plateau, the western part of North America, the Atacama region, the southern tip of South America, Greenland, Antarctica, and parts of western Europe. For the observation of altocumulus, a ground-based lidar is best placed at Greenland, Antarctica, the western flank of the Andes and Rocky Mountains, the Amazon, central Asia, Siberia, western Australia, or the southern half of Africa.

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Grubbs, Scott, Boris Kondratieff, Bill P. Stark et R. DeWalt. « A review of the Nearctic genus Zealeuctra Ricker (Plecoptera, Leuctridae), with the description of a new species from the Cumberland Plateau region of eastern North America ». ZooKeys 344 (22 octobre 2013) : 17–47. http://dx.doi.org/10.3897/zookeys.344.5912.

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Sharma, Aseem R., et Stephen J. Déry. « Linking Atmospheric Rivers to Annual and Extreme River Runoff in British Columbia and Southeastern Alaska ». Journal of Hydrometeorology 21, n^o 11 (novembre 2020) : 2457–72. http://dx.doi.org/10.1175/jhm-d-19-0281.1.

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AbstractThis study quantifies the contribution of atmospheric rivers (ARs) to annual and extreme river runoff and evaluates the relationships between watershed characteristics and AR-related maximum river runoff across British Columbia and southeastern Alaska (BCSAK). Datasets used include gauged runoff from 168 unregulated watersheds, topographic characteristics of those watersheds, a regional AR catalog, and integrated vapor transport fields for water years (WYs) 1979–2016. ARs contribute ~22% of annual river runoff along the Coast and Insular Mountains watersheds, which decreases inland to ~11% in the watersheds of the Interior Mountains and Plateau. Average association between ARs and annual maximum river runoff attains >80%, >50%, and <50% along the watersheds of the western flanks of the Coast Mountains, the Interior Mountains, and Interior Plateau, respectively. There is no significant change in AR-related extreme annual maximum runoff across BCSAK during 1979–2016. AR conditions occur during 25 out of 32 of the flood-related natural disasters in British Columbia during WYs 1979–2016. AR-related annual maximum runoff magnitude is significantly higher than non-AR-related annual maximum runoff for 30% of the watersheds studied. Smaller and steeper watersheds closer to the coast are more susceptible to AR-related annual maximum runoff than their inland counterparts. These results illustrate the importance of AR activity as a major control for the distribution of peak runoff in BCSAK. This work provides insights on the hydrological response of watersheds of northwestern North America to landfalling ARs that may improve flood risk assessment and disaster management in this region.

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Van Gunst, K. Jane, Christy Klinger, Bryan Hamilton, Kathleen Slocum et Dylan J. Rhea-Fournier. « Rapid Biodiversity Sampling for Bat Assemblages in Northwestern Nevada ». Journal of Fish and Wildlife Management 11, n^o 1 (19 février 2020) : 300–310. http://dx.doi.org/10.3996/022019-jfwm-009.

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Abstract Bat (Chiroptera) assemblages in the western North America remain understudied despite their importance to ecosystem function and vulnerability to multiple anthropogenic stressors. We present the first large-scale survey that we are aware of for bat fauna in the Black Rock Plateau of northwestern Nevada in the northern Great Basin Desert. We conducted surveys using both acoustic and mist net methods, documenting 14 species across 19 sites sampled during a four-night period in August 2016. We surveyed over water sources, usually surrounded by cliff and canyon habitat, and in salt desert scrub, sagebrush, and woodland habitats, detecting multiple sensitive bat species (spotted bat Euderma maculatum, little brown bat Myotis lucifugus, canyon bat Parastrellus hesperus) in the canyon habitats of the High Rock region. We analyzed regional species diversity and present the utility of using multiple detection methods to enhance understanding of Chiroptera biodiversity at both local and regional scales. Our results demonstrate the utility of “BioBlitz” approaches in documenting local and regional diversity and provide insight into areas with species assemblages or vulnerable species. Knowledge of these sites is increasingly important for future disease surveillance and population monitoring.

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Shi, H. X., et C. H. Wang. « Projected 21st century changes in snow water equivalent over Northern Hemisphere landmasses from the CMIP5 model ensemble ». Cryosphere 9, n^o 5 (13 octobre 2015) : 1943–53. http://dx.doi.org/10.5194/tc-9-1943-2015.

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Abstract. Changes in snow water equivalent (SWE) over Northern Hemisphere (NH) landmasses are investigated for the early (2016–2035), middle (2046–2065) and late (2080–2099) 21st century using a multi-model ensemble from 20 global climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). The multi-model ensemble was found to provide a realistic estimate of observed NH mean winter SWE compared to the GlobSnow product. The multi-model ensemble projects significant decreases in SWE over the 21st century for most regions of the NH for representative concentration pathways (RCPs) 2.6, 4.5 and 8.5. This decrease is particularly evident over the Tibetan Plateau and North America. The only region with projected increases is eastern Siberia. Projected reductions in mean annual SWE exhibit a latitudinal gradient with the largest relative changes over lower latitudes. SWE is projected to undergo the largest decreases in the spring period where it is most strongly negatively correlated with air temperature. The reduction in snowfall amount from warming is shown to be the main contributor to projected changes in SWE during September to May over the NH.

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Fu, X. W., X. Feng, P. Liang, H. Zhang, J. Ji et P. Liu. « Temporal trend and sources of speciated atmospheric mercury at Waliguan GAW station, Northwestern China ». Atmospheric Chemistry and Physics 12, n^o 4 (20 février 2012) : 1951–64. http://dx.doi.org/10.5194/acp-12-1951-2012.

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Abstract. Measurements of speciated atmospheric mercury were conducted at a remote mountain-top station (Waliguan (WLG) Baseline Observatory) at the edge of northeastern part of the Qinghai-Xizang Plateau, Western China. Mean concentrations of total gaseous mercury (TGM), particulate bound mercury (PBM), and gaseous oxidized mercury (GOM) during the whole sampling campaign were 1.98±0.98 ng m−3, 19.4±18.1 pg m−3, and 7.4±4.8 pg m−3, respectively. Levels of speciated Hg at WLG were slightly higher than those reported from remote areas of North America and Europe. Both regional sources and long-rang transport played important roles in the distribution of atmospheric TGM and PBM at WLG, whereas GOM showed major links to the regional sources, likely as well as the in-situ productions via photochemical processes. Regional sources for speciated Hg were mostly located to the east of WLG, which is the most industrial and urbanized areas of Qinghai province. Potential source contribution function (PSCF) results showed that eastern Gansu, western Ningxia and Shanxi Province were likely the potential source regions of WLG, with good accordance with locations of urban areas and industrial centers. Moreover, we found that Northern India may be a significant source region for WLG during the sampling campaign, and this is the first published evidence suggesting long-range transport of atmospheric Hg from India to the Northeastern Tibetan Plateau. Seasonal and diurnal variations of TGM were in contrast to most of the previous studies in China, with relatively higher levels in warm seasons and night, respectively. The temporal trend of TGM also highlighted the impact of long-range transport on the distribution of TGM in ambient air at WLG.

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Fan, Chaoqun, Ruizhe Sun, Mingjian Nie, Mei Wang, Zhi Yao, Qiang Feng, Wenfeng Xu et al. « The Cardiorespiratory fitness of children and adolescents in Tibet at altitudes over 3,500 meters ». PLOS ONE 16, n^o 8 (19 août 2021) : e0256258. http://dx.doi.org/10.1371/journal.pone.0256258.

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Background Cardiorespiratory fitness (CRF) is the core element of health-related physical fitness evaluation. High pressure and low oxygen in Tibet (over 3,500 m above sea level) may negatively impact the residents’ CRF. The 20-m shuttle run test (20mSRT) is the most popular field-based assessment and estimate of CRF in children and adolescents worldwide. However, normative CRF data for the children and adolescents residing in China’s plateau region are unavailable, which prevents comparability among those living at high-altitudes around the world. Purpose To measure the CRF of Chinese children and adolescents aged 9–18 years living in Tibet at altitudes exceeding 3,500 m, and to identify correlations between this metric and demographic characteristics (age, sex, and ethnicity). These data were then compared with those generated in the lowland (Shanghai, China) and various global regions. Methods 20mSRT performance (number of completed laps) and predicted peak oxygen consumption (VO2peak) were used as indicators of CRF. We measured the CRF of 1,717 healthy children and adolescents aged 9–18 years living in Tibet. The CRF data from school-age subjects in Shanghai (2,437 boys and 2,396 girls) and worldwide (1,142,026 students from 50 countries/regions in Africa, Asia, Europe, Latin America, North America, and Oceania) were collated from published papers. Results The average CRF of the participants from Tibet was 39.8 mL/kg/min. The male subjects (n = 876; 41.1 ± 4.42 mL/kg/min) had a higher average CRF than their female counterparts (n = 841; 37.8 ± 5.40 mL/kg/min). CRF decreased with age in both sexes at statistical significance (F = 1249.9, p for trend 0.05). The indigenous Tibetans (n = 1289; 40.1 ± 3.71 mL/kg/min) had a significant higher average CRF than those of Han descent (n = 394; 38.9 ± 4.70 mL/kg/min) (p < 0.05). Conclusions Children and adolescents aged 7–18 years residing above 3,500 m in Tibet displayed lower CRF traits compared with their counterparts from the plains area and other high altitude places. CRF varied according to age, sex, and ethnic group. Given the importance of CRF in children and adolescents, effective intervention strategies should be implemented to improve CRF in children and adolescents on the plateau.

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