Modelled dispersal patterns for wood and grass charcoal are different: implications for paleofire reconstruction

Sedimentary charcoal records provide useful perspectives on the long-term controls and behavior of fire in the Earth system. However, a comprehensive understanding of the nuances, biases, and limitations of charcoal as a fire proxy is necessary for reliable paleofire interpretations. Here, we use a charcoal dispersal model to answer the following questions: (1) How does the dispersal of wood and grass charcoal particles differ? (2) Do traditional conceptual models of charcoal dispersal reliably characterize grass charcoal dispersal? We find that small differences in shape (L:W) and density of grass and wood charcoal can cause substantial differences in particle dispersal and source area. Whereas the modelled dispersal of wood charcoal shows a localized deposition signal which decays with distance, grass charcoal shows more diffuse deposition lacking a localized center (for both >125 µm and >60 µm). Although paleofire research has typically not distinguished between fuel types, we show that the dispersal of charcoal derived from different fuels is unlikely to be uniform. Because differences in localization, production, and preservation could bias aggregate charcoal accumulation, caution should be taken when interpreting wood and grass-derived charcoal particles preserved in the same record. Additionally, we propose an alternative, dual background conceptual model of grass charcoal dispersal, as the traditional, two-component (peak and background) conceptual model does not accurately characterize the modelled dispersal of grass charcoal. Lastly, this mismatch of conceptualizations of dispersal mechanics implies that grass charcoal may not fit the criteria necessary for peak analysis techniques

Phase formation in ion‐irradiated and annealed Ni‐rich Ni‐Al thin films

Phase formation was studied in ion‐irradiated multilayer and coevaporated Ni‐20 at. % Al films supported by Cu, Mo, and Ni transmission electron microscopy (TEM) grids. Irradiation with either 700‐keV Xe or 1.7‐MeV Xe, to doses sufficient to homogenize the multilayers (≥7.5×1015 cm−2), resulted in the formation of metastable supersaturated γ and HCP phases in both film types. Post‐irradiation annealing of multilayers at 450 °C for 1 h transformed the metastable phases to a two‐phase γ+γ′ microstructure. In the absence of Cu, the formation of γ′ appeared to proceed by a traditional diffusional growth mechanism, resulting in small (<50 Å) γ′ precipitates in γ matrix grains. The presence of Cu caused the formation of a dual‐phase γ+γ′ structure (i.e., distinct, equal‐sized grains of γ and γ′) during post‐irradiation annealing. It is suggested that copper affected the nucleation of γ′ precipitates and increased the kinetics of growth resulting in the dual‐phase morphology. Strong irradiation‐induced textures were observed in the multilayers that were less pronounced in the coevaporated films. The texture in the multilayers was attributed to the presence of a slight as‐evaporated texture combined with the enhanced atomic mobility due to the heat‐of‐mixing released during irradiation. The irradiation‐induced texture appeared to be necessary for the formation of the dual‐phase structure since it likely provided high‐diffusivity paths for Cu to diffuse into the film from the TEM grid.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70874/2/JAPIAU-69-4-2021-1.pd

The heat‐of‐mixing effect on ion‐induced grain growth

Irradiation experiments were conducted on multilayer (ML) and coevaporated (CO) thin films in order to examine the role that the heat‐of‐mixing (ΔHmix) has in ion‐induced grain growth. Room‐temperature irradiations using 1.7‐MeV Xe ions were performed in the High Voltage Electron Microscope at Argonne National Laboratory. The ML films (Pt‐Ti, Pt‐V, Pt‐Ni, Au‐Co, and Ni‐Al) spanned a large range of calculated ΔHmix values. Comparison of grain growth rates between ML and CO films of a given alloy confirmed a heat‐of‐mixing effect. With the exception of the Pt‐V system, differences in grain growth rates between ML and CO films varied according to the sign of the calculated ΔHmix of the system. Substantial variations in growth rates among CO alloy films experiencing similar displacement damage demonstrated that a purely collisional approach is inadequate for describing ion‐induced grain growth. Therefore consideration must also be given to material‐specific properties, such as cohesive energy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70305/2/JAPIAU-70-3-1252-1.pd

Effect of Prehospital Red Blood Cell Transfusion on Mortality and Time of Death in Civilian Trauma Patients.

BACKGROUND: Current management principles of hemorrhagic shock after trauma emphasize earlier transfusion therapy to prevent dilution of clotting factors and correct coagulopathy. London's Air Ambulance (LAA) was the first UK civilian prehospital service to routinely offer prehospital red blood cell (RBC) transfusion (phRTx). We investigated the effect of phRTx on mortality. METHODS: Retrospective trauma database study comparing mortality before implementation with after implementation of phRTx in exsanguinating trauma patients. Univariate logistic regression was performed for the unadjusted association between phRTx and mortality was performed, and multiple logistic regression adjusting for potential confounders. RESULTS: We identified 623 subjects with suspected major hemorrhage. We excluded 84 (13.5%) patients due to missing data on survival status. Overall 187 (62.3%) patients died in the before phRTx period and 143 (59.8%) died in the after phRTx group. There was no significant improvement in overall survival after the introduction of phRTx (P = 0.554). Examination of prehospital mortality demonstrated 126 deaths in the pre-phRTx group (42.2%) and 66 deaths in the RBC administered group (27.6%). There was a significant reduction in prehospital mortality in the group who received RBC (P < 0.001). CONCLUSIONS: phRTx was associated with increased survival to hospital, but not overall survival. The "delay death" effect of phRTx carries an impetus to further develop inhospital strategies to improve survival in severely bleeding patients.The Norwegian Air Ambulance Foundation funded MR and JR expenses and publishing costs, but had no role in manuscript writing, study design, collection, analysis, or interpretation of data

Increased angiogenic factor secretion by decidual natural killer cells from pregnancies with high uterine artery resistance alters trophoblast function.

STUDY QUESTION Are the concentrations of factors secreted by decidual natural killer (dNK) cells from pregnancies at high risk of poor spiral artery remodelling different to those secreted from pregnancies at low risk? SUMMARY ANSWER Expression levels of PLGF, sIL-2R, endostatin and angiogenin were significantly increased by dNK cells from high-risk pregnancies, and angiogenin and endostatin were found to alter trophoblast function. WHAT IS KNOWN ALREADY During early pregnancy, maternal uterine spiral arteries are remodelled from small diameter, low-flow, high-resistance vessels into larger diameter, higher flow vessels, with low-resistance. This change is essential for the developing fetus to obtain sufficient oxygen and nutrients. dNK cells have been implicated in this process. STUDY DESIGN, SIZE, DURATION dNK cells were isolated from first trimester terminations of pregnancies (obtained with local ethical approval) screened for normal- or high-resistance index, indicative of cases least (21%) likely to have developed pre-eclampsia had the pregnancy not been terminated (n = 18 each group). Secreted factors and the effects of these on the trophoblast cell line, SGHPL-4, were assessed in vitro. PARTICIPANTS/MATERIALS, SETTING, METHODS A multiplex assay was used to assess dNK cell-secreted factors. SGHPL-4 cell functions were assessed using time-lapse microscopy, 3D invasion assays, endothelial-like tube formation ability and western blot analysis. MAIN RESULTS AND THE ROLE OF CHANCE The expression levels of PLGF (P < 0.01), sIL-2R (P < 0.01), endostatin (P < 0.05) and angiogenin (P < 0.05) were significantly increased by dNK cells from high-risk pregnancies. Endostatin significantly decreased SGHPL-4 invasion (P < 0.05), SGHPL-4 tube formation (P < 0.05) and SGHPL-4 Aktser473 phosphorylation (P < 0.05). Angiogenin significantly decreased SGHPL-4 invasion (P < 0.05), but increased SGHPL-4 tube formation (P < 0.01) and decreased SGHPL-4 Aktser473 phosphorylation (P < 0.05). LIMITATIONS, REASONS FOR CAUTION The culture of dNK cells and protein concentrations in vitro may not fully represent the in vivo situation. Although SGHPL-4 cells are extravillous trophoblast derived, further studies would be needed to confirm the roles of angiogenin and endostatin in vivo. WIDER IMPLICATIONS OF THE FINDINGS The altered expression of secreted factors of dNK cells may contribute to pregnancy disorders associated with poor spiral artery remodelling. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the Wellcome Trust (project reference 091550). R.F. was a recipient of a PhD studentship from the Division of Biomedical Sciences, St. George's, University of London. The authors have no conflict of interests

Report of the QCD Working Group

The activities of the QCD working group concentrated on improving the understanding and Monte Carlo simulation of multi-jet final states due to hard QCD processes at LEP, i.e. quark-antiquark plus multi-gluon and/or secondary quark production, with particular emphasis on four-jet final states and b-quark mass effects. Specific topics covered are: relevant developments in the main event generators PYTHIA, HERWIG and ARIADNE; the new multi-jet generator APACIC++; description and tuning of inclusive (all-flavour) jet rates; quark mass effects in the three- and four-jet rates; mass, higher-order and hadronization effects in four-jet angular and shape distributions; b-quark fragmentation and gluon splitting into b-quarks.Comment: 95 pages, 48 figures, contribution to Proceedings of the LEP2 Monte Carlo Workshop. References for NLO 4-jet matrix elements adde

Origin of atomic clusters during ion sputtering

Previous studies have shown that the size distributions of small clusters ( n&#60;=40 n = number of atoms/cluster) generated by sputtering obey an inverse power law with an exponent between -8 and -4. Here we report electron microscopy studies of the size distributions of larger clusters ( n&#62;=500) sputtered by high-energy ion impacts. These new measurements also yield an inverse power law, but one with an exponent of -2 and one independent of sputtering yield, indicating that the large clusters are produced when shock waves, generated by subsurface displacement cascades, ablate the surface

Endorsement of clinical practice guidelines by the Scandinavian Society of Anaesthesiology and Intensive Care Medicine

Clinical practice guidelines from other organizations or societies with assumed clinical and contextualized relevance for Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI) members, may trigger a formal evaluation by The Clinical Practice Committee (CPC) for possible SSAI endorsement. This avoids unnecessary duplicate processes and minimizes resource-waste. Identified guidelines are assessed for endorsement using the Appraisal of Guidelines for REsearch and Evaluation (AGREE) II instrument. The SSAI CPC utilizes the AGREE II online coordinated group appraisal platform to assess the methodological rigor and transparency in which the guideline was developed. The results of the assessment, including the decision to endorse or not, are presented to the SSAI Board for sanctioning. This document briefly outlines the process for evaluation of non-SSAI guidelines by the CPC for possible SSAI endorsement.Peer reviewe

Therapeutics and COVID-19-A living WHO guideline : Endorsement by the Scandinavian Society of Anaesthesiology and Intensive Care Medicine

The Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine endorses the Living WHO guideline on therapeutics and COVID-19. This trustworthy continuously updated guideline serves as a highly useful decision aid for Nordic anaesthesiologists caring for patients with COVID-19.Non peer reviewe

Regional anaesthesia in patients on antithrombotic drugs - a joint ESAIC/ESRA guideline : Endorsement by the Scandinavian Society of Anaesthesiology and Intensive Care Medicine

The Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine endorses the clinical practice guideline Regional anaesthesia in patients on antithrombotic drugs - a joint ESAIC/ESRA guideline. This clinical practice guideline serves as a useful decision aid for Nordic anaesthesiologists providing regional anaesthesia to adult patients on antithrombotic drugs.Non peer reviewe