239 research outputs found
Atmospheric dynamics over Europe during the Younger Dryas revealed by palaeoglaciers
A dataset of 120 palaeoglaciers ranging from Morocco in the south to Svalbard in the north and from Ireland in
the west to Turkey in the east, has been assembled from the literature. A robust quality control on the chronology
was undertaken and, when derived from cosmogenic nuclides, ages were recalculated using the most up-to-date
production rates. All the reconstructed glaciers date to the Younger Dryas. Frontal moraines/limits were used to
initiate the palaeoglacier reconstructions using GlaRe, a GIS tool which generates an equilibrium profile ice surface
along a single flowline and extrapolates this to out to a 3D ice surface. From the resulting glacier surfaces
palaeo-ELAs were calculated within the GIS. Where multiple glaciers were reconstructed within in a region, a
single ELA value was generated. Results show that ELAs decrease with latitude but have a more complex pattern
with longitude. A database of 121 sites, spanning the same geographical range as the palaeoglaciers, was compiled
for Younger Dryas temperature, determined from palaeoproxies, for example pollen, diatoms, coleoptera,
chironimids etc. These proxy data were merged and interpolated to generate maps of average temperature for the
warmest and coldest months and annual average temperature. Results show that, in general, temperature decreases
with latitude. Temperature at the palaeo-ELAs were determined from the temperature maps using a lapse rate of
0.65C/100m and the precipitation required for equilibrium was calculated. Positive precipitation anomalies are
found along much of the western seaboard of Europe, with the most striking positive anomalies present in the
eastern Mediterranean. Negative precipitation anomalies appear on the northern side of the Alps. This pattern is
interpreted to represent a southward displaced polar frontal jet stream with a concomitant track of Atlantic midlatitude depressions, leading to more frequent incursions of low pressure systems especially over the relatively
warm eastern Mediterranean, enhancing cyclogenesis. This is similar to the modern Scandinavia (SCAND) pattern
which, in its positive phase, is characterised by a high pressure anomaly over Fennoscandia and western Russia,
negative pressure anomalies around the Iberian Peninsula and enhanced cyclogenesis in the central and eastern
Mediterranean. During the YD the Fennoscandian Ice Sheet and permafrost across much of northern continental
Europe and Russia would have generated a high pressure region leading to a persistent, enhanced SCAND
circulation
Multi-scale Web Mapping for Geoheritage Visualisation and Promotion
Due to the renewed interest for sites of geological interest, both in nature conservation and tourist sectors, numerous regional and national geosite inventories have been carried out in several countries during the last two decades. For this purpose, various assessment methods have been developed and published. The issue of the representation of the results of inventoriesâin particular, the mapping system, the question of updating dataâremains open. Moreover, if in the field of nature conservation, practitioners are used to working with GIS, it is not the case in the tourist sector where data must be delivered to the users in open-access and easy-to-use formats. This paper discusses what opportunities of web mapping methods and techniques there are in the domain of geoheritage assessment and promotion. A web mapping application in Google Maps application programming interface (API) framework is proposed to disseminate the results of geosite inventories carried out in Switzerland both at national and regional scales. The interest of the proposed application is discussed according to three main criteria: mapping interests and limitations, management purposes and interpretive issues
Life on the ice-edge: Paleoenvironmental significance of the radiolarian species Amphimelissa setosa in the northern hemisphere
The high-latitude Northern Hemisphere is a key region in the global climate balance. Variations in sea-ice extent affect biological productivity, CO2 exchange and carbon drawdown. Marine proxies indicative of proximity of the ice-marginal zone are therefore essential to understand these processes. Amphimelissa setosa is nowadays a dominant radiolarian species in the Arctic basin and very abundant in the high-latitude North Atlantic. This species, now absent from the North Pacific, has been widely used as a qualitative proxy of modern and past environmental conditions in the high-latitude Northern Hemisphere. Using our new and published data on the distribution of A. setosa in plankton, sediment trap, surface sediment and downcore samples, we provide a quantitative ecological context for the occurrence of this species. We find that the optimal depth and season of A. setosa in the modern North Atlantic and the Chukchi Sea are 160 m and the late boreal summer/early fall (AugustâOctober), respectively. A regression model combining environmental variables (temperature, salinity, silicate and chlorophyll-a concentrations, apparent oxygen utilization, sea-ice) at that season and depth, are able to explain 43% of the distribution of this species in surface sediments. Based on these new findings, we conclude that the presence of A. setosa in surface sediments is closely related to high primary production in the proximity of the sea-ice and areas of ice rafting. The onset of this species started at ca. 1.5 Ma in the North Pacific, linked to a gradual cooling, increased silica availability and southward advance of the ice-margins since the Early Pleistocene. Amphimelissa setosaâs decline in this region was likely caused by the development of a quasi-permanent halocline, perennial sea-ice and depletion of silica during marine isotope stage 4. In the high-latitude North Atlantic, the relative abundance of A. setosa appears to be related to cooling and supply of dissolved silica from the continent during ice-rafting events. The comprehensive approach taken in this study suggest that A. setosa is a useful proxy to explore past variations in the ice-cover in the high-latitude Northern Hemisphere.Shirshov Institute of Oceanology | Ref. 0149-2019-000
Evaluation of motivational stages and processes of change for weight management in obesity and after bariatric surgery
Poster abstrac
Manual mapping of drumlins in synthetic landscapes to assess operator effectiveness
Mapped topographic features are important for understanding processes that sculpt the Earth's surface. This paper presents maps that are the primary product of an exercise that brought together 27 researchers with an interest in landform mapping wherein the efficacy and causes of variation in mapping were tested using novel synthetic DEMs containing drumlins. The variation between interpreters (e.g. mapping philosophy, experience) and across the study region (e.g. woodland prevalence) opens these factors up to assessment. A priori known answers in the synthetics increase the number and strength of conclusions that may be drawn with respect to a traditional comparative study. Initial results suggest that overall detection rates are relatively low (34â40%), but reliability of mapping is higher (72â86%). The maps form a reference dataset
Stress-inducible phosphoprotein 1 (HOP/STI1/STIP1) regulates the accumulation and toxicity of α-synuclein in vivo
The predominantly pre-synaptic intrinsically disordered protein α-synuclein is prone to misfolding and aggregation in synucleinopathies, such as Parkinsonâs disease (PD) and Dementia with Lewy bodies (DLB). Molecular chaperones play important roles in protein misfolding diseases and members of the chaperone machinery are often deposited in Lewy bodies. Here, we show that the Hsp90 co-chaperone STI1 co-immunoprecipitated α-synuclein, and co-deposited with Hsp90 and Hsp70 in insoluble protein fractions in two mouse models of α-synuclein misfolding. STI1 and Hsp90 also co-localized extensively with filamentous S129 phosphorylated α-synuclein in ubiquitin-positive inclusions. In PD human brains, STI1 transcripts were increased, and in neurologically healthy brains, STI1 and α-synuclein transcripts correlated. Nuclear Magnetic Resonance (NMR) analyses revealed direct interaction of α-synuclein with STI1 and indicated that the STI1 TPR2A, but not TPR1 or TPR2B domains, interacted with the C-terminal domain of α-synuclein. In vitro, the STI1 TPR2A domain facilitated S129 phosphorylation by Polo-like kinase 3. Moreover, mice over-expressing STI1 and Hsp90Ă presented elevated α-synuclein S129 phosphorylation accompanied by inclusions when injected with α-synuclein pre-formed fibrils. In contrast, reduced STI1 function decreased protein inclusion formation, S129 α-synuclein phosphorylation, while mitigating motor and cognitive deficits as well as mesoscopic brain atrophy in α-synuclein-over-expressing mice. Our findings reveal a vicious cycle in which STI1 facilitates the generation and accumulation of toxic α-synuclein conformers, while α-synuclein-induced proteostatic stress increased insoluble STI1 and Hsp90
Geodiversity assessment of ParanĂĄ state (Brazil): an innovative approach
Geodiversity is considered as the natural range of geological, geomorphological, and soil features, including their assemblages, relationships, properties, interpretations, and systems. A method developed for the quantitative assessment of geodiversity was applied to Parana Ì , a Brazilian state with an area of about 200,000 km2. The method is based on the overlay of a grid over different maps at scales ranging from 1/500,000 to 1/650,000, with the final Geodiversity Index the sum of five partial indexes calculated on a 25 9 25 km grid. The partial indexes represent the main components of geodi- versity, including geology (stratigraphy and lithology), geomorphology, paleontology, and soils. The fifth partial index covers mineral occurrences of geodiversity, such precious stones and metals, energy and industrial minerals, mineral waters, and springs. The Geodiversity Index takes the form of an isoline map that can be used as a tool in land-use planning, particularly in identifying priority areas for conservation, management, and use of natural resources at the state level.The Portuguese authors express their gratitude for the financial support given by the Fundacao para a Ciencia e a Tecnologia to the Centro de Geologia da Universidade do Porto, which partially supports this research. The Brazilian author expresses his gratitude for the financial support given by the CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) (Process Number 200074/2011-3)
Metal-organic framework glasses with permanent accessible porosity.
To date, only several microporous, and even fewer nanoporous, glasses have been produced, always via post synthesis acid treatment of phase separated dense materials, e.g. Vycor glass. In contrast, high internal surface areas are readily achieved in crystalline materials, such as metal-organic frameworks (MOFs). It has recently been discovered that a new family of melt quenched glasses can be produced from MOFs, though they have thus far lacked the accessible and intrinsic porosity of their crystalline precursors. Here, we report the first glasses that are permanently and reversibly porous toward incoming gases, without post-synthetic treatment. We characterize the structure of these glasses using a range of experimental techniques, and demonstrate pores in the range of 4 - 8âĂ
. The discovery of MOF glasses with permanent accessible porosity reveals a new category of porous glass materials that are elevated beyond conventional inorganic and organic porous glasses by their diversity and tunability
Regional development gaps in Argentina: A multidimensional approach to identify the location of policy priorities
Spatial inequalities within Latin American countries have historically attracted the interest ofacademics, policy-makers, and international agencies. This article aims to provide amultidimensional diagnosis of provincial development gaps in Argentina, in order to identifythe location of policy priorities. Therefore, we built a large database, which covers sevendevelopment dimensions, and applied multivariate analysis techniques to overcome someanalytical limitations of previous studies. Results show the stability of provincial developmentgaps between 2003 and 2013 and some heterogeneity within geographic regions. Instead,cluster analysis offers a better classification of Argentine provinces according to theirdevelopment gaps, which can help the government to prioritize the places wheredevelopment policies are strategic.Fil: Niembro, AndrĂ©s Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte; Argentina. Universidad Nacional de RĂo Negro; ArgentinaFil: Sarmiento, Jesica Isabel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte; Argentina. Universidad Nacional de RĂo Negro; Argentin
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