164 research outputs found
Electron excitation and energy transfer rates for H2O in the upper atmosphere
Recent measurements of the cross sections for electronic state excitations in
H2O have made it possible to calculate rates applicable to these excitation
processes. We thus present here calculations of electron energy transfer rates
for electronic and vibrational state excitations in H2O, as well as rates for
excitation of some of these states by atmospheric thermal and auroral secondary
electrons. The calculation of these latter rates is an important first step
towards our aim of including water into a statistical equilibrium model of the
atmosphere under auroral conditions.Comment: 15 pages, 8 figure
PICS-Ord: unlimited coding of ambiguous regions by pairwise identity and cost scores ordination
<p>Abstract</p> <p>Background</p> <p>We present a novel method to encode ambiguously aligned regions in fixed multiple sequence alignments by 'Pairwise Identity and Cost Scores Ordination' (PICS-Ord). The method works via ordination of sequence identity or cost scores matrices by means of Principal Coordinates Analysis (PCoA). After identification of ambiguous regions, the method computes pairwise distances as sequence identities or cost scores, ordinates the resulting distance matrix by means of PCoA, and encodes the principal coordinates as ordered integers. Three biological and 100 simulated datasets were used to assess the performance of the new method.</p> <p>Results</p> <p>Including ambiguous regions coded by means of PICS-Ord increased topological accuracy, resolution, and bootstrap support in real biological and simulated datasets compared to the alternative of excluding such regions from the analysis a priori. In terms of accuracy, PICS-Ord performs equal to or better than previously available methods of ambiguous region coding (e.g., INAASE), with the advantage of a practically unlimited alignment size and increased analytical speed and the possibility of PICS-Ord scores to be analyzed together with DNA data in a partitioned maximum likelihood model.</p> <p>Conclusions</p> <p>Advantages of PICS-Ord over step matrix-based ambiguous region coding with INAASE include a practically unlimited number of OTUs and seamless integration of PICS-Ord codes into phylogenetic datasets, as well as the increased speed of phylogenetic analysis. Contrary to word- and frequency-based methods, PICS-Ord maintains the advantage of pairwise sequence alignment to derive distances, and the method is flexible with respect to the calculation of distance scores. In addition to distance and maximum parsimony, PICS-Ord codes can be analyzed in a Bayesian or maximum likelihood framework. RAxML (version 7.2.6 or higher that was developed for this study) allows up to 32-state ordered or unordered characters. A GTR, MK, or ORDERED model can be applied to analyse the PICS-Ord codes partition, with GTR performing slightly better than MK and ORDERED.</p> <p>Availability</p> <p>An implementation of the PICS-Ord algorithm is available from <url>http://scit.us/projects/ngila/wiki/PICS-Ord</url>. It requires both the statistical software, R <url>http://www.r-project.org</url> and the alignment software Ngila <url>http://scit.us/projects/ngila</url>.</p
Systematic Reviews and Meta-Analyses of the Procedure-specific Risks of Thrombosis and Bleeding in General Abdominal, Colorectal, Upper Gastrointestinal, and Hepatopancreatobiliary Surgery
\ua9 2024 Lippincott Williams and Wilkins. All rights reserved.Objective: To provide procedure-specific estimates of symptomatic venous thromboembolism (VTE) and major bleeding after abdominal surgery. Background: The use of pharmacological thromboprophylaxis represents a trade-off that depends on VTE and bleeding risks that vary between procedures; their magnitude remains uncertain. Methods: We identified observational studies reporting procedure-specific risks of symptomatic VTE or major bleeding after abdominal surgery, adjusted the reported estimates for thromboprophylaxis and length of follow-up, and estimated cumulative incidence at 4 weeks postsurgery, stratified by VTE risk groups, and rated evidence certainty. Results: After eligibility screening, 285 studies (8,048,635 patients) reporting on 40 general abdominal, 36 colorectal, 15 upper gastrointestinal, and 24 hepatopancreatobiliary surgery procedures proved eligible. Evidence certainty proved generally moderate or low for VTE and low or very low for bleeding requiring reintervention. The risk of VTE varied substantially among procedures: in general abdominal surgery from a median of <0.1% in laparoscopic cholecystectomy to a median of 3.7% in open small bowel resection, in colorectal from 0.3% in minimally invasive sigmoid colectomy to 10.0% in emergency open total proctocolectomy, and in upper gastrointestinal/hepatopancreatobiliary from 0.2% in laparoscopic sleeve gastrectomy to 6.8% in open distal pancreatectomy for cancer. Conclusions: VTE thromboprophylaxis provides net benefit through VTE reduction with a small increase in bleeding in some procedures (eg, open colectomy and open pancreaticoduodenectomy), whereas the opposite is true in others (eg, laparoscopic cholecystectomy and elective groin hernia repairs). In many procedures, thromboembolism and bleeding risks are similar, and decisions depend on individual risk prediction and values and preferences regarding VTE and bleeding
Personality traits and metacognitions as predictors of positive mental health in college students
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
Interventions for psychosexual dysfunction in women treated for gynaecological malignancy
Backgroun
Developing adaptive control:Age-related differences in task choices and awareness of proactive and reactive control demands
Developmental changes in executive function are often explained in terms of core cognitive processes and associated neural substrates. For example, younger children tend to engage control reactively in the moment as needed, whereas older children increasingly engage control proactively, in anticipation of needing it. Such developments may reflect increasing capacities for active maintenance dependent upon dorsolateral prefrontal cortex. However, younger children will engage proactive control when reactive control is made more difficult, suggesting that developmental changes may also reflect decisions about whether to engage control, and how. We tested awareness of temporal control demands and associated task choices in 5-year-olds and 10-year-olds and adults using a demand selection task. Participants chose between one task that enabled proactive control and another task that enabled reactive control. Adults reported awareness of these different control demands and preferentially played the proactive task option. Ten-year-olds reported awareness of control demands but selected task options at chance. Five-year-olds showed neither awareness nor task preference, but a subsample who exhibited awareness of control demands preferentially played the reactive task option, mirroring their typical control mode. Thus, developmental improvements in executive function may in part reflect better awareness of cognitive demands and adaptive behavior, which may in turn reflect changes in dorsal anterior cingulate in signaling task demands to lateral prefrontal cortex
Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano, Chile
Unconsolidated pyroclastic flow deposits of the
1993 eruption of Lascar Volcano, Chile, have, with time,
become increasingly dissected by a network of deeply
penetrating fractures. The fracture network comprises
orthogonal sets of decimeter-wide linear voids that form a
pseudo-polygonal grid visible on the deposit surface. In this
work, we combine shallow surface geophysical imaging
tools with remote sensing observations and direct field
measurements of the deposit to investigate these fractures
and their underlying causal mechanisms. Based on ground
penetrating radar images, the fractures are observed to have
propagated to depths of up to 10 m. In addition, orbiting radar interferometry shows that deposit subsidence of up to
1 cm/year occurred between 1993 and 1996 with continued
subsidence occurring at a slower rate thereafter. In situ
measurements show that 1 m below the surface, the 1993
deposits remain 5°C to 15°C hotter, 18 years after
emplacement, than adjacent deposits. Based on the observed
subsidence as well as estimated cooling rates, the fractures are
inferred to be the combined result of deaeration, thermal
contraction, and sedimentary compaction in the months to
years following deposition. Significant environmental factors,
including regional earthquakes in 1995 and 2007, accelerated
settling at punctuated moments in time. The spatially variable
fracture pattern relates to surface slope and lithofacies
variations as well as substrate lithology. Similar fractures
have been reported in other ignimbrites but are generally
exposed only in cross section and are often attributed to
formation by external forces. Here we suggest that such
interpretations should be invoked with caution, and deformation
including post-emplacement subsidence and fracturing of
loosely packed ash-rich deposits in the months to years postemplacement
is a process inherent in the settling of pyroclastic
material
Modular Architecture and Unique Teichoic Acid Recognition Features of Choline-Binding Protein L (CbpL) Contributing to Pneumococcal Pathogenesis
The human pathogen Streptococcus pneumoniae is decorated with a special class of surface-proteins known as choline-binding proteins (CBPs) attached to phosphorylcholine (PCho) moieties from cell-wall teichoic acids. By a combination of X-ray crystallography, NMR, molecular dynamics techniques and in vivo virulence and phagocytosis studies, we provide structural information of choline-binding protein L (CbpL) and demonstrate its impact on pneumococcal pathogenesis and immune evasion. CbpL is a very elongated three-module protein composed of (i) an Excalibur Ca 2+ -binding domain -reported in this work for the very first time-, (ii) an unprecedented anchorage module showing alternate disposition of canonical and non-canonical choline-binding sites that allows vine-like binding of fully-PCho-substituted teichoic acids (with two choline moieties per unit), and (iii) a Ltp-Lipoprotein domain. Our structural and infection assays indicate an important role of the whole multimodular protein allowing both to locate CbpL at specific places on the cell wall and to interact with host components in order to facilitate pneumococcal lung infection and transmigration from nasopharynx to the lungs and blood. CbpL implication in both resistance against killing by phagocytes and pneumococcal pathogenesis further postulate this surface-protein as relevant among the pathogenic arsenal of the pneumococcus.We gratefully acknowledge Karsta Barnekow and Kristine Sievert-Giermann, for technical assistance and Lothar
Petruschka for in silico analysis (all Dept. of Genetics, University of Greifswald). We are further grateful to the staff
from SLS synchrotron beamline for help in data collection. This work was supported by grants from the Deutsche
Forschungsgemeinschaft DFG GRK 1870 (to SH) and the Spanish Ministry of Economy and Competitiveness
(BFU2014-59389-P to JAH, CTQ2014-52633-P to MB and SAF2012-39760-C02-02 to FG) and S2010/BMD-
2457 (Community of Madrid to JAH and FG).Peer Reviewe
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