On September 12, 2019 at 12:49:48 (UT) a bolide was observed by hundreds of eye-witnesses from the Netherlands, Germany, Belgium, Denmark and the UK. One day later a small meteorite stone was found ...by accident in Flensburg. The presence of short-lived cosmogenic radionuclides with half-lives as short as 16 days proves the recent exposure of the found object to cosmic rays in space linking it clearly to the bolide event. An exceptionally short exposure time of ∼5000 years was determined. The 24.5 g stone has a fresh black fusion crust, a low density of <2 g/cm(exp 3), and a magnetic susceptibility of logχ = 4.35 (χ in 10−9 m(exp 3)/kg). The rock consists of relict chondrules and clusters of sulfide and magnetite grains set in a fine-grained matrix. The most abundant phases are phyllosilicates. Carbonates (∼3.9 vol.%) occur as calcites, dolomites, and a Na-rich phase. The relict chondrules (often surrounded by sulfide laths) are free of anhydrous silicates and contain abundant serpentine. Lithic clasts are also surrounded by similar sulfide laths partly intergrown with carbonates. Mn-53-Cr-53 ages of carbonates in Flensburg indicate that brecciation and contemporaneous formation of the pyrrhotite-carbonate intergrowths by hydrothermal activities occurred no later than 4564.6 ± 1.0 Ma (using the angrite D'Orbigny as the Mn-Cr age anchor). This corresponds to 2.6 ± 1.0 or 3.4 ± 1.0 Ma after formation of CAIs, depending on the exact absolute age of CAIs. This is the oldest dated evidence for brecciation and carbonate formation, which likely occurred during parent body growth and incipient heating due to decay of Al-26.
In the three oxygen isotope diagram, Flensburg plots at the 16O-rich end of the CM chondrite field and in the transition field to CV-CK-CR chondrites. The mass-dependent Te isotopic composition of Flensburg is slightly different from mean CM chondrites and is most similar to those of the ungrouped C2 chondrite Tagish Lake. On the other hand, Ti-50 and Cr-54 isotope anomalies indicate that Flensburg is similar to CM chondrites, as do the ∼10 wt.% H2O of the bulk material. Yet, the bulk Zn, Cu, and Pb concentrations are about 30% lower than those of mean CM chondrites. The He, Ne, and Ar isotopes of Flensburg show no solar wind contribution; its trapped noble gas signature is similar to that of CMs with a slightly lower concentration of Ne(sub tr)-20.
Based on the bulk H, C, and N elemental abundances and isotopic compositions, Flensburg is unique among chondrites, because it has the lightest bulk H and N isotopic compositions of any type 1 or 2 chondrite investigated so far. Moreover, the number of soluble organic compounds in Flensburg is even lower than that of the brecciated CI chondrite Orgueil.
The extraordinary significance of Flensburg is evident from the observation that it represents the oldest chondrite sample in which the contemporaneous episodes of aqueous alteration and brecciation have been preserved. The characterization of a large variety of carbonaceous chondrites with different alteration histories is important for interpreting returned samples from the OSIRIS-REx and Hayabusa 2 missions.
A particular adaptation to survival under limited water availability has been realized in the desiccation-tolerant resurrection plants, which tend to grow in a habitat with seasonal rainfall and long ...dry periods. One of the best-studied examples is Craterostigma plantagineum. Here we report an unexpected finding: Lindernia brevidens, a close relative of C. plantagineum, exhibits desiccation tolerance, even though it is endemic to the montane rainforests of Tanzania and Kenya, where it never experiences seasonal dry periods. L. brevidens has been found exclusively in two fragments of the ancient Eastern Arc Mountains, which were protected from the devastating Pleistocene droughts by the stable Indian Ocean temperature. Analysis of the microhabitat reveals that L. brevidens is found in the same habitat as hygrophilous plant species, which further indicates that the plant never dries out completely. The objective of this investigation was to address whether C. plantagineum and L. brevidens have desiccation-related pathways in common, or whether L. brevidens has acquired novel pathways. A third, closely related, desiccation-sensitive species, Lindernia subracemosa, has been included for comparison. Mechanisms that confer cellular protection during extreme water loss are well conserved between C. plantagineum and L. brevidens, including the interconversion of 2-octulose to sucrose within the two desiccation-tolerant species. Furthermore, transcriptional control regions of desiccation-related genes belonging to the late embryogenesis abundant (LEA) protein family are also highly conserved. We propose that L. brevidens is a neoendemic species that has retained desiccation tolerance through genome stability, despite tolerance being superfluous to environmental conditions.
Effects of Basal Debris on Glacier Flow Iverson, Neal R.; Cohen, Denis; Hooyer, Thomas S. ...
Science (American Association for the Advancement of Science),
07/2003, Letnik:
301, Številka:
5629
Journal Article
Recenzirano
Glacier movement is resisted partially by debris, either within glaciers or under glaciers in water-saturated layers. In experiments beneath a thick, sliding glacier, ice containing 2 to 11% debris ...exerted shear traction of 60 to 200 kilopascals on a smooth rock bed, comparable to the total shear traction beneath glaciers and contrary to the usual assumption that debris-bed friction is negligible. Imposed pore-water pressure that was 60 to 100% of the normal stress in a subglacial debris layer reduced shear traction on the debris sufficiently to halt its deformation and cause slip of ice over the debris. Slip resistance was thus less than debris shearing resistance.
Access to high quality weather and climate data is crucial for a wide range of societal and economic issues. It allows optimising industrial processes, supports the identification of potential risks ...related to climate change or allows the development of corresponding adaptation and mitigation strategies. Although such data is freely available through Germany’s national meteorological service DWD (Deutscher Wetterdienst) since 2017, the application potential in industry and society has certainly not yet been fully unlocked. Major obstacles are the complexity of the raw data, as well as missing tools for their simple integration into existing industrial applications. The goal of the research project FAIR is to simplify the information exchange between the DWD and economical players. In order to reach this goal a requirement analysis with end-users of weather data from three different sectors was conducted. A central requirement regarding the site assessment of wind plants is quick and easy access to historical wind-series at specific sites. Preferably downloadable in formats like CSV or via an API. Event planning partners are interested in a quick access to health relevant weather information at their event location, and the E-mobility sector in temperature data along planned routes. In this paper, we summarize the results of the requirement analysis and present the deduced technical architecture and FAIR services aiming at a user-friendly exchange of weather data.
In 2016, the World Health Assembly adopted the resolution to eliminate viral hepatitis by 2030. This study aims to provide an overview of the burdens of hepatitis B virus (HBV) and hepatitis C virus ...(HCV) in Europe and their changes from 2010 to 2019 using estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019.
We used GBD 2019 estimates of the burden associated with HBV-related and HCV-related diseases: acute hepatitis, cirrhosis and other chronic liver diseases, and liver cancer. We report total numbers and age-standardised rates per 100 000 for mortality, prevalence, incidence, and disability-adjusted life-years (DALYs) from 2010 to 2019. For each HBV-related and HCV-related disease and each measure, we analysed temporal changes and percentage changes for the 2010-19 period.
In 2019, across all age groups, there were an estimated 2·08 million (95% uncertainty interval UI 1·66 to 2·54) incident cases of acute hepatitis B and 0·49 million (0·42 to 0·57) of hepatitis C in Europe. There were an estimated 8·24 million (7·56 to 8·88) prevalent cases of HBV-related cirrhosis and 11·87 million (9·77 to 14·41) of HCV-related cirrhosis, with 24·92 thousand (19·86 to 31·03) deaths due to HBV-related cirrhosis and 36·89 thousand (29·94 to 45·56) deaths due to HCV-related cirrhosis. Deaths were estimated at 9·00 thousand (6·88 to 11·62) due to HBV-related liver cancer and 23·07 thousand (18·95 to 27·31) due to HCV-related liver cancer. Between 2010 and 2019, the age-standardised incidence rate of acute hepatitis B decreased (-22·14% 95% UI -35·44 to -5·98) as did its age-standardised mortality rate (-33·27% -43·03 to -25·49); the age-standardised prevalence rate (-20·60% -22·09 to -19·10) and mortality rate (-33·19% -37·82 to -28·13) of HBV-related cirrhosis also decreased in this time period. The age-standardised incidence rate of acute hepatitis C decreased by 3·24% (1·17 to 5·02) and its age-standardised mortality rate decreased by 35·73% (23·48 to 47·75) between 2010 and 2019; the age-standardised prevalence rate (-6·37% -8·11 to -4·32), incidence rate (-5·87% -11·24 to -1·01), and mortality rate (-11·11% -16·54 to -5·53) of HCV-related cirrhosis also decreased. No significant changes were observed in age-standardised rates of HBV-related and HCV-related liver cancer, although we observed a significant increase in numbers of cases of HCV-related liver cancer across all ages between 2010 and 2019 (16·41% 2·81 to 30·91 increase in prevalent cases). Substantial reductions in DALYs since 2010 were estimated for acute hepatitis B (-27·82% -36·92 to -20·24), acute hepatitis C (-27·07% -15·97 to -39·34), and HBV-related cirrhosis (-30·70% -35·75 to -25·03). A moderate reduction in DALYs was estimated for HCV-related cirrhosis (-6·19% -0·19 to -12·57). Only HCV-related liver cancer showed a significant increase in DALYs (10·37% 4·81-16·63). Changes in age-standardised DALY rates closely resembled those observed for overall DALY counts, except for HCV-liver related cancer (-2·84% -7·75 to 2·63).
Although decreases in some HBV-related and HCV-related diseases were estimated between 2010 and 2019, HBV-related and HCV-related diseases are still associated with a high burden, highlighting the need for more intensive and coordinated interventions within European countries to reach the goal of elimination by 2030.
Bill & Melinda Gates Foundation.
Potato leafroll polerovirus (PLRV) genomic RNA acts as a polycistronic mRNA for the production of proteins P0, P1, and P2 translated from the 5′-proximal half of the genome. Within the P1 coding ...region we identified a 5-kDa replication-associated protein 1 (Rap1) essential for viral multiplication. An internal ribosome entry site (IRES) with unusual structure and location was identified that regulates Rap1 translation. Core structural elements for internal ribosome entry include a conserved AUG codon and a downstream GGAGAGAGAGG motif with inverted symmetry. Reporter gene expression in potato protoplasts confirmed the internal ribosome entry function. Unlike known IRES motifs, the PLRV IRES is located completely within the coding region of Rap1 at the center of the PLRV genome.
COVID-19 was initially characterized as a disease primarily of the lungs, but it is becoming increasingly clear that the SARS-CoV2 virus is able to infect many organs and cause a broad pathological ...response. The primary infection site is likely to be a mucosal surface, mainly the lungs or the intestine, where epithelial cells can be infected with virus. Although it is clear that virus within the lungs can cause severe pathology, driven by an exaggerated immune response, infection within the intestine generally seems to cause minor or no symptoms. In this review, we compare the disease processes between the lungs and gastrointestinal tract, and what might drive these different responses. As the microbiome is a key part of mucosal barrier sites, we also consider the effect that microbial species may play on infection and the subsequent immune responses. Because of difficulties obtaining tissue samples, there are currently few studies focused on the local mucosal response rather than the systemic response, but understanding the local immune response will become increasingly important for understanding the mechanisms of disease in order to develop better treatments.
Coronavirus disease 2019 has generated a rapidly evolving field of research, with the global scientific community striving for solutions to the current pandemic. Characterizing humoral responses ...towards SARS-CoV-2, as well as closely related strains, will help determine whether antibodies are central to infection control, and aid the design of therapeutics and vaccine candidates. This review outlines the major aspects of SARS-CoV-2-specific antibody research to date, with a focus on the various prophylactic and therapeutic uses of antibodies to alleviate disease in addition to the potential of cross-reactive therapies and the implications of long-term immunity.
The health care dilemma Armstrong, Elizabeth G; Fischer, Martin R; Parsa-Parsi, Ramin W ...
2011., 2011-01-07
eBook
The Health Care Dilemma should be of interest to local and international health care constituencies, including leaders of health care delivery networks, academic professionals, students, and ...government and ministerial authorities globally with interest in health care systems and policy development.
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