scholarly journals Microstratigraphic preservation of ancient faunal and hominin DNA in Pleistocene cave sediments

2021 ◽  
Vol 119 (1) ◽  
pp. e2113666118
Author(s):  
Diyendo Massilani ◽  
Mike W. Morley ◽  
Susan M. Mentzer ◽  
Vera Aldeias ◽  
Benjamin Vernot ◽  
...  
Keyword(s):  
North America ◽  
Genetic Information ◽  
Taxonomic Composition ◽  
Altai Mountains ◽  
Small Particles ◽  
Environmental Diversity ◽  
Dna Preservation ◽  
Cave Sediments ◽  
Close Proximity ◽  
Over Time

Ancient DNA recovered from Pleistocene sediments represents a rich resource for the study of past hominin and environmental diversity. However, little is known about how DNA is preserved in sediments and the extent to which it may be translocated between archaeological strata. Here, we investigate DNA preservation in 47 blocks of resin-impregnated archaeological sediment collected over the last four decades for micromorphological analyses at 13 prehistoric sites in Europe, Asia, Africa, and North America and show that such blocks can preserve DNA of hominins and other mammals. Extensive microsampling of sediment blocks from Denisova Cave in the Altai Mountains reveals that the taxonomic composition of mammalian DNA differs drastically at the millimeter-scale and that DNA is concentrated in small particles, especially in fragments of bone and feces (coprolites), suggesting that these are substantial sources of DNA in sediments. Three microsamples taken in close proximity in one of the blocks yielded Neanderthal DNA from at least two male individuals closely related to Denisova 5, a Neanderthal toe bone previously recovered from the same layer. Our work indicates that DNA can remain stably localized in sediments over time and provides a means of linking genetic information to the archaeological and ecological records on a microstratigraphic scale.

scholarly journals Is there an imbalance in the supply and demand for universal accessibility knowledge? Twenty years of UAIS papers viewed through the lens of WCAG

2021 ◽  
Author(s):  
Frode Eika Sandnes
Keyword(s):  
Latin America ◽  
North America ◽  
Supply And Demand ◽  
Research Focus ◽  
Universal Accessibility ◽  
Geographical Regions ◽  
Research Profile ◽  
The Impact ◽  
Over Time

AbstractPurpose: Some universal accessibility practitioners have voiced that they experience a mismatch in the research focus and the need for knowledge within specialized problem domains. This study thus set out to identify the balance of research into the main areas of accessibility, the impact of this research, and how the research profile varies over time and across geographical regions. Method: All UAIS papers indexed in Scopus were analysed using bibliometric methods. The WCAG taxonomy of accessibility was used for the analysis, namely perceivable, operable, and understandable. Results: The results confirm the expectation that research into visual impairment has received more attention than papers addressing operable and understandable. Although papers focussing on understandable made up the smallest group, papers in this group attracted more citations. Funded research attracted fewer citations than research without funding. The breakdown of research efforts appears consistent over time and across different geographical regions. Researchers in Europe and North America have been active throughout the last two decades, while Southeast Asia, Latin America, and Middle East became active in during the last five years. There is also seemingly a growing trend of out-of-scope papers. Conclusions: Based on the findings, several recommendations are proposed to the UAIS editorial board.

Climatic implications of latest Pleistocene and earliest Holocene mammalian sympatries in eastern Washington state, USA

2008 ◽  
Vol 70 (3) ◽  
pp. 426-432 ◽  
Author(s):  
R. Lee Lyman
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Rocky Mountains ◽  
Taxonomic Composition ◽  
Washington State ◽  
The West ◽  
Mammalian Faunas ◽  
Eastern Washington

AbstractFor more than fifty years it has been known that mammalian faunas of late-Pleistocene age are taxonomically unique and lack modern analogs. It has long been thought that nonanalog mammalian faunas are limited in North America to areas east of the Rocky Mountains and that late-Pleistocene mammalian faunas in the west were modern in taxonomic composition. A late-Pleistocene fauna from Marmes Rockshelter in southeastern Washington State has no modern analog and defines an area of maximum sympatry that indicates significantly cooler summers than are found in the area today. An earliest Holocene fauna from Marmes Rockshelter defines an area of maximum sympatry, including the site area, but contains a single tentatively identified taxon that may indicate slightly cooler than modern summers.

Aquaculture in North America: An Assessment of Future Prospects

1982 ◽  
Vol 39 (1) ◽  
pp. 151-154 ◽  
Author(s):  
P. A. Larkin
Keyword(s):  
North America ◽  
Large Scale ◽  
Geographical Location ◽  
Aquatic Environments ◽  
Future Prospects ◽  
Growing Period ◽  
Close Proximity ◽  
Cheap Alternative ◽  
Alternative Sources ◽  
Simple Technology

The farming of aquatic environments is already a large-scale world enterprise involving relatively simple technology, but aquacultural production in North America is only a small part of the world total. Aquaculture is only economically rewarding where high rates of production over a long growing period can be coupled with close proximity to large markets in which there are few cheap alternative sources of protein. Much of North American aquaculture is aimed at meeting demands of recreational fishermen rather than as a way of producing food. There are many opportunities for development of aquaculture in North America and it seems reasonable to project substantial increases in production in the next two decades.Key words: aquaculture, geographical location, North America, future prospects, economics

scholarly journals STUDY OF GEOLOGICAL SECTIONS OF THE ORDOVIK AGE OF GORNY ALTAI

2021 ◽  
Vol 6 ◽  
pp. 109-115
Author(s):  
Danil A. Ilyin ◽  
Irina P. Kokorina
Keyword(s):  
Taxonomic Composition ◽  
Geological Survey ◽  
Altai Mountains ◽  
Siberian Branch ◽  
Russian Academy Of Sciences ◽  
Gorny Altai ◽  
The Future ◽  
Lithological Composition ◽  
Academy Of Sciences ◽  
Faunistic Composition

The article deals with the study of geological sections of the Ordovic age in Gorny Altai. On the territory of the Altai Mountains, outcrops of rocks of the Ordovic age were found. As a result of the work on the sections, the lithological composition was analyzed and the fauna was collected, the taxonomic composition of which was then determined in the Paleozoic laboratory of the Institute of Geological and Geological Development of the Siberian Branch of the Russian Academy of Sciences. On the basis of the data of geological survey, mapping of the territory, the results of the study of geological sections, their lithology and faunistic composition, it is planned to create an interactive cartographic service in the future.

scholarly journals Paleogene community change among terrestrial vertebrates of the Western Hemisphere

1992 ◽  
Vol 6 ◽  
pp. 282-282
Author(s):  
Richard K. Stucky
Keyword(s):  
North America ◽  
South America ◽  
Community Change ◽  
Taxonomic Composition ◽  
Western Hemisphere ◽  
Dental Morphology ◽  
Predator Prey ◽  
Terrestrial Vertebrates ◽  
Morphological Adaptations ◽  
Dinosaur Extinction

Paleogene vertebrate communities in North and South America show dramatic changes in taxonomic composition and ecological organization. Worldwide, mammals diversified substantially following dinosaur extinction (Fig. 1). Most families of living vertebrates appear by the end of the Paleogene. In North America, placental omnivores, herbivores and carnivores dominate mammalian communities, but in South America marsupial carnivores and omnivores and placental herbivores dominate them. Immigration from Asia and Europe to North America of taxa from several placental orders (Perissodactyla, Primates, Artiodactyla, Rodentia, Carnivora, Mesonychia, Creodonta) occurred periodically during the Paleogene. South America, however, was completely isolated from the Paleocene to the Oligocene when Rodentia and perhaps Primates first appear. Despite the independent evolutionary histories of these continents, their constituent species show remarkable convergences in morphological adaptations including body size distributions, dental morphology, and other features. Low resolution chronostratigraphic data for the Paleogene of South America precludes correlation with North American faunas. In North America, patterns of diversification and extinction appear to be related to climatic events. Morphological convergences appear to be related to climate and concomitant habitat change, but may also be a function of coevolution via predator-prey interactions and diffuse competition among guild members.

scholarly journals 21. The separation of small particles from meteor bodies, and its influence on some parameters of meteors

1968 ◽  
Vol 33 ◽  
pp. 207-216 ◽  
Author(s):  
A. N. Simonenko
Keyword(s):  
A Priori ◽  
Small Particles ◽  
Earth’S Atmosphere ◽  
Close Proximity ◽  
Meteor Body ◽  
Earth's Atmosphere

The separation of very small particles from meteor bodies as a part of the process of their ablation in the Earth's atmosphere is assumed by many investigators. But when the particle is small relative to the meteor body the path of the particle is a priori thought to be small relative to the length of the meteor path, i.e. the particle is expected to evaporate in close proximity to the point of separation. This assumption is not acceptable after McCrosky's work (1958) that has shown for one particular case the small particles (m = 10−5−10−6 g) go a long path before their mass is exhausted. The assumption made until now has caused incorrect conclusions, e.g. the luminosity at any point of the meteor path is proportional to the mass ablated from the meteor body at that point (Kramer, 1965).

scholarly journals Potential Impact of Oat Ingredient Type on Oral Fragmentation of Biscuits and Oro-Digestibility of Starch—An In Vitro Approach

Foods ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 148 ◽  
Author(s):  
Amparo Gamero ◽  
Quoc Cuong Nguyen ◽  
Paula Varela ◽  
Susana Fiszman ◽  
Amparo Tarrega ◽  
...  
Keyword(s):  
Starch Hydrolysis ◽  
Fragmentation Pattern ◽  
Small Particles ◽  
Percentage Area ◽  
Oat Flour ◽  
Potential Impact ◽  
Fragmentation Patterns ◽  
Instrumental Texture ◽  
Over Time

The aim of the present study was to determine how variation in the biscuit matrix affects both the degree of in vitro fragmentation and the starch hydrolysis that occurs during the oral phase of digestion. Using three different oat ingredient types (oat flour, small flakes, and big flakes) and baking powder (or none), six biscuits with different matrices were obtained. The instrumental texture (force and sound measurements) of the biscuits was analyzed. The samples were then subjected to in vitro fragmentation. The particle size distribution and in vitro oral starch hydrolysis over time of the fragmented samples were evaluated. The results showed that the samples presented different fragmentation patterns, mainly depending on the oat ingredient type, which could be related to their differences in texture. The biscuits made with oat flour were harder, had a more compact matrix and showed more irregular fragmentation and a higher percentage area of small particles than those made with big oat flakes, which were more fragile and crumbly. The highest degree of starch hydrolysis corresponded to the biscuits made with flour. Conclusions: Differences in the mechanical properties of the biscuit matrix, in this case due to differences in the oat ingredient, play a role in the in vitro fragmentation pattern of biscuits and in the oral phase of starch hydrolysis.

scholarly journals Mechanisms of Seasonal Soil Moisture Drought Onset and Termination in the Southern Great Plains

2019 ◽  
Vol 20 (4) ◽  
pp. 751-771 ◽  
Author(s):  
Richard Seager ◽  
Jennifer Nakamura ◽  
Mingfang Ting
Keyword(s):  
Soil Moisture ◽  
North America ◽  
Great Plains ◽  
Land Surface ◽  
Tropical Pacific ◽  
Moisture Change ◽  
Southern Plains ◽  
Southern Great Plains ◽  
Continental Scale ◽  
Over Time

AbstractMechanisms of drought onset and termination are examined across North America with a focus on the southern Plains using data from land surface models and regional and global reanalyses for 1979–2017. Continental-scale analysis of covarying patterns reveals a tight coupling between soil moisture change over time and intervening precipitation anomalies. The southern Great Plains are a geographic center of patterns of hydrologic change. Drying is induced by atmospheric wave trains that span the Pacific and North America and place northerly flow anomalies above the southern Plains. In the southern Plains winter is least likely, and fall most likely, for drought onset and spring is least likely, and fall or summer most likely, for drought termination. Southern Plains soil moisture itself, which integrates precipitation over time, has a clear relationship to tropical Pacific sea surface temperature (SST) anomalies with cold conditions favoring dry soils. Soil moisture change, however, though clearly driven by precipitation, has a weaker relation to SSTs and a strong relation to internal atmospheric variability. Little evidence is found of connection of drought onset and termination to driving by temperature anomalies. An analysis of particular drought onsets and terminations on the seasonal time scale reveals commonalities in terms of circulation and moisture transport anomalies over the southern Plains but a variety of ways in which these are connected into the large-scale atmosphere and ocean state. Some onsets are likely to be quite predictable due to forcing by cold tropical Pacific SSTs (e.g., fall 2010). Other onsets and all terminations are likely not predictable in terms of ocean conditions.

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