Land snail fauna and Holocene environmental changes in Mediterranean France: A digest from three representative sedimentary sequences

2022 ◽  
Vol 276 ◽  
pp. 107303
Author(s):  
Frédéric Magnin ◽  
Stéphane Bonnet ◽  
Carine Cenzon-Salvayre
Keyword(s):  
Environmental Changes ◽  
Land Snail ◽  
Sedimentary Sequences ◽  
Mediterranean France

Pleistocene–Holocene environmental change in the Canary Archipelago as inferred from the stable isotope composition of land snail shells

2011 ◽  
Vol 75 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Yurena Yanes ◽  
Crayton J. Yapp ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Julio De-la-Nuez ◽  
...  
Keyword(s):  
Environmental Change ◽  
Canary Islands ◽  
Environmental Changes ◽  
Isotope Composition ◽  
Moving Average ◽  
Land Snail ◽  
Balance Model ◽  
Low Latitude ◽  
The Times

AbstractThe isotopic composition of land snail shells was analyzed to investigate environmental changes in the eastern Canary Islands (28–29°N) over the last ~ 50 ka. Shell δ13C values range from −8.9‰ to 3.8‰. At various times during the glacial interval (~ 15 to ~ 50 ka), moving average shell δ13C values were 3‰ higher than today, suggesting a larger proportion of C4 plants at those periods. Shell δ18O values range from −1.9‰ to 4.5‰, with moving average δ18O values exhibiting a noisy but long-term increase from 0.1‰ at ~ 50 ka to 1.6–1.8‰ during the LGM (~ 15–22 ka). Subsequently, the moving average δ18O values range from 0.0‰ at ~ 12 ka to 0.9‰ at present. Calculations using a published snail flux balance model for δ18O, constrained by regional temperatures and ocean δ18O values, suggest that relative humidity at the times of snail activity fluctuated but exhibited a long-term decline over the last ~ 50 ka, eventually resulting in the current semiarid conditions of the eastern Canary Islands (consistent with the aridification process in the nearby Sahara). Thus, low-latitude oceanic island land snail shells may be isotopic archives of glacial to interglacial and tropical/subtropical environmental change.

Active and passive dispersal of an invading land snail in Mediterranean France

2006 ◽  
Vol 75 (3) ◽  
pp. 802-813 ◽  
Author(s):  
SEBASTIEN AUBRY ◽  
CORINNE LABAUNE ◽  
FREDERIC MAGNIN ◽  
PHILIP ROCHE ◽  
LAURENCE KISS
Keyword(s):  
Land Snail ◽  
Passive Dispersal ◽  
Mediterranean France

scholarly journals Late Holocene environmental changes from fluvio-aeolian morpho-sedimentary sequences (Santa María Valley, northwest Argentina).

2018 ◽  
Vol 129 (4) ◽  
pp. 647-669 ◽  
Author(s):  
M.M. Sampietro Vattuone ◽  
J.L. Peña Monné ◽  
M.G. Maldonado ◽  
C. Sancho Marcén ◽  
W. Báez ◽  
...  
Keyword(s):  
Late Holocene ◽  
Environmental Changes ◽  
Northwest Argentina ◽  
Sedimentary Sequences ◽  
Santa Maria

Submerged landscapes of the eastern Adriatic – from the river across the lake all the way to the sea

2021 ◽  
Author(s):  
Slobodan Miko ◽  
Keyword(s):  
Sea Level ◽  
Environmental Changes ◽  
Late Quaternary ◽  
River Estuary ◽  
Integrated System ◽  
Submarine Channels ◽  
Side Scan Sonar ◽  
Sedimentary Sequences ◽  
Marine Sedimentation ◽  
Geophysical Surveys

<p>Submerged paleolandscapes constitute records of long-term paleoenvironmental change, climate, and sea level. To date, there is a very limited knowledge concerning the submerged karst paleolandscapes of the eastern Adriatic coast and the Late Quaternary sedimentary sequences along the eastern part of the Mid Adriatic Deep (MAD). We aim to improve this through the project “Sediments between source and sink during a Late Quaternary eustatic cycle: The Krka and the Mid Adriatic Deep System” (QMAD). The QMAD project supports multidisciplinary research by application of the high-resolution geophysical surveys (multibeam, side-scan sonar and sub-bottom profiler), in combination with sedimentological, petrophysical, geochemical (trace elements and isotopes), micropaleontological (ostracod and foraminifera), mineralogical and aDNA techniques. This suite of analyses will enable tracking of the paleoenvironmental evolution from fluvial/lake to deeper marine environments, on a short transect less than 100 km in length (Lake Prokljan in the Krka River estuary to the eastern part of MAD). The submerged Late Pleistocene and Holocene environments that occur include isolation basins, lagoons, deltas, estuaries, submarine channels and shelf. The continuous marine sedimentation during the Late Quaternary is investigated in the MAD. In the case of the central part of the eastern side of the Adriatic Sea (Krka catchment - MAD) these different environments compose an integrated system; thus, they can’t be analysed separately. The main goals of this project fill the existing gaps in understanding of the climatic and environmental changes, including sea-level related landscape changes and their interplay during the Late Quaternary eustatic cycle. More data on the Pleistocene environments, especially from the region of Krka estuary that was land during the Last Glacial Maximum (LGM), will complete the picture of the evolution and environmental adaptation of Paleolithic humans and their relationship with vegetation changes. Attention is also paid to potential anthropogenic environments, recent sedimentation rates, landscape features and artefacts. All results of the multi-proxy approach applied in this project will eventually be merged into a comprehensive Late Quaternary paleoenvironmental and paleoclimatic reconstruction of the eastern Adriatic landscapes that contribute to the understanding of these changes in the Mediterranean region.</p>

Bromine as indicator of source of lacustrine sedimentary organic matter in paleolimnological studies

2019 ◽  
Vol 92 (1) ◽  
pp. 257-271 ◽  
Author(s):  
Sergio Ribeiro Guevara ◽  
Andrea Rizzo ◽  
Romina Daga ◽  
Natalia Williams ◽  
Stefania Villa
Keyword(s):  
Organic Matter ◽  
Primary Productivity ◽  
Concentration Ratio ◽  
Environmental Changes ◽  
Morphometric Parameters ◽  
Deep Lakes ◽  
Shoreline Development ◽  
North Patagonia ◽  
Sedimentary Sequences ◽  
Lake Moreno

AbstractBromine (Br) to organic matter (OM) concentration ratio is studied in lake sediment sequences to provide information on environmental changes modifying OM production. The sequences studied were extracted from shallow lakes Morenito, El Trébol, Escondido, and Portezuelo; and deep lakes Futalaufquen, Moreno, and Traful (North Patagonia Andean range). Lake Morenito, a former Lake Moreno bay until its closure in AD 1960, showed a decrease in Br:OM ratios from 1.38 to 0.74 after lake closure, associated with an increase of primary autochthonous productivity attributable to the development of submerged and emerging macrophytes. Sedimentary sequences from Lakes Escondido, Portezuelo, and El Trébol (with large participation of macrophytes in primary productivity), and from Lakes Moreno, Futalaufquen, and Traful (with little development of littoral macrophytes), showed Br:OM ratios consistent with the Lake Morenito pattern. Consistently, the morphometric parameters mean depth and shoreline development correlate with Br:OM ratios. Therefore, Br:OM ratios can be associated with the composition of primary autochthonous productivity, with values of about 0.7 associated to significant macrophyte contributions, and higher values associated with more pelagic contributions. Accordingly, Br:OM variations along a sedimentary sequence can be associated with modifications on the composition of the primary autochthonous productivity of the water body, providing information on environmental changes.

scholarly journals HOLOCENE ENVIRONMENTAL CHANGE IN SOUTH-EAST ALTAI EVIDENCED BY SOIL RECORD

2019 ◽  
Vol 11 (4) ◽  
pp. 100-111 ◽  
Author(s):  
Maria A. Bronnikova ◽  
Yuliya V. Konoplianikova ◽  
Anna R. Agatova ◽  
Roman K. Nepop ◽  
Marina P. Lebedeva
Keyword(s):  
Environmental Change ◽  
Water Deficit ◽  
Environmental Changes ◽  
Soil Formation ◽  
Forest Steppe ◽  
Buried Soils ◽  
Surface Soils ◽  
Sedimentary Sequences ◽  
Cryogenic Processes ◽  
Holocene Environmental Change

The soils of Russian Altai highlands were used as a paleoenvironmental archive, as a source of dating material, and as a chronostratigraphic marker to describe Holocene environmental change in the studied area. Based on calibration intervals of 14C dates obtained for buried humus horizons (11 buried soils in 6 studied soil-sedimentary sequences) and some dates from pendants of contemporary soils, following stages of pedogenesis were recorded in studied soil-sedimentary systems and surface soils: 6.4 – 11.5 ky cal BP; about 4.9-5.3 cal BP; 2.5-3.8 cal BP; 0.6 – 1.2 cal BP. All studied surface soils in the basins nowadays develop in cold, ultra-continental water deficit conditions: Skeletic Kastanozems Cambic, Skeletic Cambisols Protocalcic, Skeletic Cambic Calcisol Yermic. The most extreme conditions of soil formation within Holocene were within the last 1-2 kyr. All buried soils were formed in better conditions, more balanced in water, with higher biological activity, mostly within steppe or forest-steppe landscapes. Cryogenic features had been insisting all over the Holocene till nowadays. Water demandant cryogenic features are met in buried soils up to the age of 1-2 ky cal BP. In the last millennia cryogenic processes are suppressed, water demandant features gave way to those which can be formed in contemporary water deficit conditions: simple fissures, frost sorting, and shattering. At lower levels (Kuraj basin) more or less arid cold steppe conditions insisted within the most part of Holocene. Initial stages of soil formation were often ground water affected, or at least shortly waterlogged. At the highest positions humid and relatively warm Early Holocene stage of forest pedogenesis is recorded for the beginning of Holocene, and a Late Holocene (last 3-4 kyr) cold humid phase, presumably under mountain tundra and/or alpines. Microsedimentary intra-soil record in carbonatehumus pendants imprints fine fluctuations of soil water regime at initial stages of soil formation, controlled by local topography, and climatic changes in the second half of Holocene. General trends of environmental changes in the region recorded in soil and soil sedimentary systems are in well correspondence with other records of paleonvironment.

Linking transcription, RNA polymerase II elongation and alternative splicing

2020 ◽  
Vol 477 (16) ◽  
pp. 3091-3104 ◽  
Author(s):  
Luciana E. Giono ◽  
Alberto R. Kornblihtt
Keyword(s):  
Gene Expression ◽  
Alternative Splicing ◽  
Rna Polymerase Ii ◽  
Environmental Changes ◽  
Transcription Elongation ◽  
Single Gene ◽  
Regulation Of Gene Expression ◽  
Regulation Of Transcription ◽  
Stepping Stones ◽  
Eukaryotic Transcription

Gene expression is an intricately regulated process that is at the basis of cell differentiation, the maintenance of cell identity and the cellular responses to environmental changes. Alternative splicing, the process by which multiple functionally distinct transcripts are generated from a single gene, is one of the main mechanisms that contribute to expand the coding capacity of genomes and help explain the level of complexity achieved by higher organisms. Eukaryotic transcription is subject to multiple layers of regulation both intrinsic — such as promoter structure — and dynamic, allowing the cell to respond to internal and external signals. Similarly, alternative splicing choices are affected by all of these aspects, mainly through the regulation of transcription elongation, making it a regulatory knob on a par with the regulation of gene expression levels. This review aims to recapitulate some of the history and stepping-stones that led to the paradigms held today about transcription and splicing regulation, with major focus on transcription elongation and its effect on alternative splicing.

Seeking to uncover biology's chemical roots

2019 ◽  
Vol 3 (5) ◽  
pp. 435-443 ◽  
Author(s):  
Addy Pross
Keyword(s):  
Environmental Changes ◽  
Biological Systems ◽  
Significant Development ◽  
The Road ◽  
Physical Chemical ◽  
Systems Chemistry ◽  
Biological World ◽  
Inanimate Matter ◽  
The Origin Of Life ◽  
Opening Up

Despite the considerable advances in molecular biology over the past several decades, the nature of the physical–chemical process by which inanimate matter become transformed into simplest life remains elusive. In this review, we describe recent advances in a relatively new area of chemistry, systems chemistry, which attempts to uncover the physical–chemical principles underlying that remarkable transformation. A significant development has been the discovery that within the space of chemical potentiality there exists a largely unexplored kinetic domain which could be termed dynamic kinetic chemistry. Our analysis suggests that all biological systems and associated sub-systems belong to this distinct domain, thereby facilitating the placement of biological systems within a coherent physical/chemical framework. That discovery offers new insights into the origin of life process, as well as opening the door toward the preparation of active materials able to self-heal, adapt to environmental changes, even communicate, mimicking what transpires routinely in the biological world. The road to simplest proto-life appears to be opening up.

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