‘Antiflammins’: Two nonapeptide fragments of uteroglobin and lipocortin I have no phospholipase A2 -inhibitory and anti-inflammatory activity

AbstractThe ‘antiflammin’ nonapeptides P1 and P2 [(1988) Nature 335, 726-730] were synthesized and tested for inhibition of phospholipase A2 and release of prostaglandin E2, and leukotriene C4 in stimulated cells in vitro, and in vivo for anti-inflammatory activity in rats with carrageenan-induced paw oedema. Porcine pancreatic phospholipase A2, was not inhibited at concentrations of 0.5–50 μM. Prostaglandin E2, and leukotriene C4 release by mouse macrophages stimulated with zymosan or ATP was not affected up to a concentration of 10 μm, nor was prostaglandin release by interleukin 1β-stimulated mesangial cells and angiotensin II-stimulated smooth muscle cells. Both peptides exhibited no anti-inflammatory activity in carrageenan-induced rat paw oedema after topical (250 μg/paw) or systemic administration (1 or 4 mgkg s.c.). These results do not support the claim of potent phospholipase A2-inhibitory and anti-imflammatory activity of the ‘antiflammins’ P1 and P2 [1]

Warming and elevated CO2 promote rapid incorporation and degradation of plant-derived organic matter in an ombrotrophic peatland

Rising temperatures have the potential to directly affect carbon cycling in peatlands by enhancing organic matter (OM) decomposition, contributing to the release of CO2 and CH4 to the atmosphere. In turn, increasing atmospheric CO2 concentration may stimulate photosynthesis, potentially increasing plant litter inputs belowground and transferring carbon from the atmosphere into terrestrial ecosystems. Key questions remain about the magnitude and rate of these interacting and opposing environmental change drivers. Here, we assess the incorporation and degradation of plant- and microbe-derived OM in an ombrotrophic peatland after 4 years of whole-ecosystem warming (+0, +2.25, +4.5, +6.75 and +9°C) and two years of elevated CO2 manipulation (500 ppm above ambient). We show that OM molecular composition was substantially altered in the aerobic acrotelm, highlighting the sensitivity of acrotelm carbon to rising temperatures and atmospheric CO2 concentration. While warming accelerated OM decomposition under ambient CO2, new carbon incorporation into peat increased in warming × elevated CO2 treatments for both plant- and microbe-derived OM. Using the isotopic signature of the applied CO2 enrichment as a label for recently photosynthesized OM, our data demonstrate that new plant inputs have been rapidly incorporated into peat carbon. Our results suggest that under current hydrological conditions, rising temperatures and atmospheric CO2 levels will likely offset each other in boreal peatlands

Diverse soil carbon dynamics expressed at the molecular level

The stability and potential vulnerability of soil organic matter (SOM) to global change remains incompletely understood due to the complex processes involved in its formation and turnover. Here we combine compound-specific radiocarbon analysis with fraction-specific and bulk-level radiocarbon measurements in order to further elucidate controls on SOM dynamics in a temperate and sub-alpine forested ecosystem. Radiocarbon contents of individual organic compounds isolated from the same soil interval generally exhibit greater variation than those among corresponding operationally-defined fractions. Notably, markedly older ages of long-chain plant leaf wax lipids (n-alkanoic acids) imply that they reflect a highly stable carbon pool. Furthermore, marked 14C variations among shorter- and longer-chain n-alkanoic acid homologues suggest that they track different SOM pools. Extremes in SOM dynamics thus manifest themselves within a single compound class. This exploratory study highlights the potential of compound-specific radiocarbon analysis for understanding SOM dynamics in ecosystems potentially vulnerable to global change

Whole-soil warming decreases abundance and modifies the community structure of microorganisms in the subsoil but not in surface soil

The microbial community composition in subsoils remains understudied, and it is largely unknown whether subsoil microorganisms show a similar response to global warming as microorganisms at the soil surface do. Since microorganisms are the key drivers of soil organic carbon decomposition, this knowledge gap causes uncertainty in the predictions of future carbon cycling in the subsoil carbon pool (> 50 % of the soil organic carbon stocks are below 30 cm soil depth). In the Blodgett Forest field warming experiment (California, USA) we investigated how +4 ∘C warming in the whole-soil profile to 100 cm soil depth for 4.5 years has affected the abundance and community structure of microorganisms. We used proxies for bulk microbial biomass carbon (MBC) and functional microbial groups based on lipid biomarkers, such as phospholipid fatty acids (PLFAs) and branched glycerol dialkyl glycerol tetraethers (brGDGTs). With depth, the microbial biomass decreased and the community composition changed. Our results show that the concentration of PLFAs decreased with warming in the subsoil (below 30 cm) by 28 % but was not affected in the topsoil. Phospholipid fatty acid concentrations changed in concert with soil organic carbon. The microbial community response to warming was depth dependent. The relative abundance of Actinobacteria increased in warmed subsoil, and Gram+ bacteria in subsoils adapted their cell membrane structure to warming-induced stress, as indicated by the ratio of anteiso to iso branched PLFAs. Our results show for the first time that subsoil microorganisms can be more affected by warming compared to topsoil microorganisms. These microbial responses could be explained by the observed decrease in subsoil organic carbon concentrations in the warmed plots. A decrease in microbial abundance in warmed subsoils might reduce the magnitude of the respiration response over time. The shift in the subsoil microbial community towards more Actinobacteria might disproportionately enhance the degradation of previously stable subsoil carbon, as this group is able to metabolize complex carbon sources

Global wood anatomical perspective on the onset of the Late Antique Little Ice Age (LALIA) in the mid-6th century CE

Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this exceptional cold phase are, however, still under debate because of the limited resolution and geographical distribution of the available proxy archives. Here, we use 106 wood anatomical thin sections from 23 forest sites and 20 tree species in both hemispheres to search for cell-level fingerprints of ephemeral summer cooling between 530 and 550 CE. After cross-dating and double-staining, we identified 89 Blue Rings (lack of cell wall lignification), nine Frost Rings (cell deformation and collapse), and 93 Light Rings (reduced cell wall thickening) in the Northern Hemisphere. Our network reveals evidence for the strongest temperature depression between mid-July and early-August 536 CE across North America and Eurasia, whereas more localised cold spells occurred in the summers of 532, 540–43, and 548 CE. The lack of anatomical signatures in the austral trees suggests limited incursion of stratospheric volcanic aerosol into the Southern Hemisphere extra-tropics, that any forcing was mitigated by atmosphere-ocean dynamical responses and/or concentrated outside the growing season, or a combination of factors. Our findings demonstrate the advantage of wood anatomical investigations over traditional dendrochronological measurements, provide a benchmark for Earth system models, support cross-disciplinary studies into the entanglements of climate and history, and question the relevance of global climate averages. © 2022 Science China PressFritz & Elisabeth Schweingruber FoundationNational Science Foundation, NSF, (1203749, 1902625, 2002454, 2112314, 2124885, RSF 18-14-00072P, RSF 21-14-00330)Engineering Research Centers, ERCEuropean Research Council, ERC, (AdG 882727, CZ.02.1.01/0.0/0.0/16_019/0000797)Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, SNF, (CRSII5 183571)Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT, (1201411, 1221307)Vetenskapsrådet, VR, (2018-01272)Universität BielefeldRussian Science Foundation, RSF, (RSF 21-17-00006)Fondo de Financiamiento de Centros de Investigación en Áreas Prioritarias, FONDAP, (15110009, BASAL FB210018)Neurosciences Foundation, NSFAgencia Nacional de Investigación y Desarrollo, ANIDFunding text 1: Ulf Büntgen and Jan Esper received funding from the ERC Advanced Project MONOSTAR (AdG 882727). Ulf Büntgen, Jan Esper, and Mirek Trnka received funding from SustES: adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797). Ulf Büntgen, Jan Esper, and Clive Oppenheimer discussed many aspects of this study at the Center for Interdisciplinary Research (ZiF) at the University of Bielefeld, Germany. Alan Crivellaro received funding from the Fritz & Elisabeth Schweingruber Foundation. Duncan A. Christie and Carlos Le Quesne received funding from the ANID (FONDECYT 1201411, 1221307, FONDAP 15110009, BASAL FB210018). Olga V. Churakova (Sidorova) received funding from the Russian Science Foundation grant (RSF 21-17-00006). Rosanne D'Arrigo received funding from NSF Arctic Social Science 2112314 and NSF Arctic Natural Science 2124885, as well as the NSF P2C2 (Paleo Perspectives on Climatic Change) program (various grants). Rashit M. Hantemirov received funding from the Russian Science Foundation grant (RSF 21-14-00330). Alexander V. Kirdyanov received funding from the Russian Science Foundation grant (RSF 18-14-00072P). Fredrik C. Ljungqvist was supported by the Swedish Research Council (2018-01272). Patrick Fonti and Markus Stoffel received funding from the Swiss National Science Foundation through the SNSF Sinergia CALDERA project (CRSII5 183571). Matthew Salzer and Malcolm K. Hughes received funding from the National Science Foundation's P2C2 Program (1902625 and 1203749) and from the Malcolm H. Wiener Foundation. Greg Wiles was funded through NSF P2C2 Program (2002454). Ulf Büntgen designed the study and wrote the first draft of this manuscript with input from Jan Esper, Paul J. Krusic, and Clive Oppenheimer. Samples were processed and analysed by Alma Piermattei and Alan Crivellaro. All authors provided data and/or contributed to discussion and improving the article.Funding text 2: Ulf Büntgen and Jan Esper received funding from the ERC Advanced Project MONOSTAR (AdG 882727). Ulf Büntgen, Jan Esper, and Mirek Trnka received funding from SustES : adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797). Ulf Büntgen, Jan Esper, and Clive Oppenheimer discussed many aspects of this study at the Center for Interdisciplinary Research (ZiF) at the University of Bielefeld, Germany. Alan Crivellaro received funding from the Fritz & Elisabeth Schweingruber Foundation . Duncan A. Christie and Carlos Le Quesne received funding from the ANID ( FONDECYT 1201411 , 1221307, FONDAP 15110009 , BASAL FB210018). Olga V. Churakova (Sidorova) received funding from the Russian Science Foundation grant ( RSF 21-17-00006 ). Rosanne D’Arrigo received funding from NSF Arctic Social Science 2112314 and NSF Arctic Natural Science 2124885 , as well as the NSF P2C2 (Paleo Perspectives on Climatic Change) program (various grants). Rashit M. Hantemirov received funding from the Russian Science Foundation grant (RSF 21-14-00330). Alexander V. Kirdyanov received funding from the Russian Science Foundation grant (RSF 18-14-00072P). Fredrik C. Ljungqvist was supported by the Swedish Research Council (2018-01272). Patrick Fonti and Markus Stoffel received funding from the Swiss National Science Foundation through the SNSF Sinergia CALDERA project (CRSII5 183571). Matthew Salzer and Malcolm K. Hughes received funding from the National Science Foundation’s P2C2 Program (1902625 and 1203749) and from the Malcolm H. Wiener Foundation . Greg Wiles was funded through NSF P2C2 Program (2002454)

Assuring quality

- This paper considers how the quality of higher education in general, and dental education in particular, is assessed. -It then considers how the principles of quality assurance have been applied to dental distance learning. -It concludes that, to date, it appears that relatively little work has been done to formulate quality guidelines for e-learning in dentistry. All those involved in education have a strong motivation to ensure that all its aspects, including content and teaching practice, are of the highest standard. This paper describes how agencies such as the Quality Assurance Agency for Higher Education (QAA) and the General Dental Council (GDC) have established frameworks and specifications to monitor the quality of education provided in dental schools and other institutes that provide education and training for dentists and dental care professionals (DCPs). It then considers quality issues in programme and course development, techniques for assessing the quality of education, including content and presentation, and the role of students. It goes on to review the work that has been done in developing quality assessment for distance learning in dentistry. It concludes that, to date, much of the work on quality applies to education as a whole and that the assessment of the quality of e-learning in dentistry is in its infancy

Warming promotes loss of subsoil carbon through accelerated degradation of plant-derived organic matter

Increasing global temperatures have the potential to stimulate decomposition and alter the composition of soil organic matter (SOM). However, questions remain about the extent to which SOM quality and quantity along the soil profile may change under future warming. In this study we assessed how +4 °C whole-soil warming affected the quantity and quality of SOM down to 90 cm depth in a mixed-coniferous temperate forest using biomarker analyses. Our findings indicate that 4.5 years of soil warming led to divergent responses in subsoils (>20 cm) as compared to surface soils. Warming enhanced the accumulation of plant-derived n-alkanes over the whole soil profile. In the subsoil, this was at the expense of plant- and microorganism-derived fatty acids, and the relative abundance of SOM molecular components shifted from less microbially transformed to more transformed organic matter. Fine root mass declined by 24.0 ± 7.5% with warming over the whole soil profile, accompanied by reduced plant-derived inputs and accelerated decomposition of aromatic compounds and plant-derived fatty acids in the subsoils. Our study suggests that warming accelerated microbial decomposition of plant-derived inputs, leaving behind more degraded organic matter. The non-uniform, and depth dependent SOM composition and warming response implies that subsoil carbon cycling is as sensitive and complex as in surface soils

Ambient noise autocorrelation scheme for imaging the P-wave reflectivity of the lithosphere

SUMMARYAmbient noise autocorrelations can be used to reconstruct the seismic reflection response of the Earth structure beneath single stations using continuous recordings without the need for either active sources or earthquakes. In the last decade, this technique has emerged as an inexpensive approach with the potential to provide similar information to that from the classical receiver function (RF) analysis. Previous studies have located and mapped discontinuities at different crustal depths with ambient noise autocorrelations by applying different processing techniques. An ambient noise autocorrelation function (ACF) provides the body-wave reflectivity of the local structure, assuming a homogeneous distribution of noise sources. However, an effective method design is required in order to determine a reliable reflection response. Here, we review the theory behind the ambient noise ACF method and design a workflow to obtain the P-wave reflectivity with a special focus on the Moho depth. In particular, we calculate a smooth function to fit and subtract the zero-lag component in the time domain, that is, the large-amplitude signal near 0 lag time in the ACF. The zero-lag component can interfere with the reflection component, so its removal allows us to increase the frequency band to use. We bandpass filter the ACFs between 1 and 6 s. We also derive and apply a phase shift correction in the ACFs due to the integration of a homogeneously distributed noise field dominated by distant sources from deep below, such as teleseismic sources. Both linear and nonlinear, phase-weighted stacks are used. Linear stacking is used to identify the main interfaces since it ensures the linearity of the processing steps; nevertheless, nonlinear, phase-weighted stacking help validate the coherent signals. We test and apply our method to continuous vertical recordings from three stations in Ireland and five stations in different cratons and obtain clear P-wave reflection from the Moho and other crustal and upper-mantle discontinuities in most cases. However, noise coming from local heterogeneities, non-homogeneous distribution of the ambient noise sources or instrumental noise is also expected. Therefore, additional, a priori information is desirable to help identify key phases in single ACFs. We compute synthetic ACFs using P-wave velocity (VP) models from controlled-source profiles in Ireland. The relatively complex ACF traces obtained at the stations in Ireland show a close data-synthetic match for the Moho and mid-crustal discontinuities. The ACF traces from the stations in different cratons are directly compared with receiver functions showing overall agreement and offering complementary information on the origin of the signal.</jats:p

A 3-D crustal shear wave velocity model and Moho map below the Semail Ophiolite, eastern Arabia

International audienceThe Semail Ophiolite in eastern Arabia is the largest and best-exposed slice of oceanic lithosphere on land. Detailed knowledge of the tectonic evolution of the shallow crust, in particular during and after ophiolite obduction in Late Cretaceous times is contrasted by few constraints on physical and compositional properties of the middle and lower continental crust below the obducted units. The role of inherited, pre-obduction crustal architecture remains therefore unaccounted for in our understanding of crustal evolution and the present-day geology. Based on seismological data acquired during a 27-month campaign in northern Oman, Ambient Seismic Noise Tomography and Receiver Function analysis provide for the first time a 3-D radially anisotropic shear wave velocity (VS) model and a consistent Moho map below the iconic Semail Ophiolite. The model highlights deep crustal boundaries that segment the eastern Arabian basement in two distinct units. The previously undescribed Western Jabal Akhdar Zone separates Arabian crust with typical continental properties and a thickness of ~40-45 km in the northwest from a compositionally different terrane in the southeast that is interpreted as a terrane accreted during the Pan-African orogeny in Neoproterozoic times. East of the Ibra Zone, another deep crustal boundary, crustal thickness decreases to 30-35 km and very high lower crustal VS suggest large-scale mafic intrusions into, and possible underplating of the Arabian continental crust that occurred most likely during Permian breakup of Pangea. Mafic reworking is sharply bounded by the (upper crustal) Semail Gap Fault Zone, northwest of which no such high velocities are found in the crust. Topography of the Oman Mountains is supported by a mild crustal root and Moho depth below the highest topography, the Jabal Akhdar Dome, is ~42 km. Radial anisotropy is robustly resolved in the upper crust and aids in discriminating dipping allochthonous units from autochthonous sedimentary rocks that are indistinguishable by isotropic VS alone. Lateral thickness variations of the ophiolite highlight the Haylayn Ophiolite Massif on the northern flank of Jabal Akhdar Dome and the Hawasina Window as the deepest reaching unit. Ophiolite thickness is ~10 km in the southern and northern massifs, and ≤5 km elsewhere