443 research outputs found
Asynchronous Graph Pattern Matching on Multiprocessor Systems
Pattern matching on large graphs is the foundation for a variety of
application domains. Strict latency requirements and continuously increasing
graph sizes demand the usage of highly parallel in-memory graph processing
engines that need to consider non-uniform memory access (NUMA) and concurrency
issues to scale up on modern multiprocessor systems. To tackle these aspects,
graph partitioning becomes increasingly important. Hence, we present a
technique to process graph pattern matching on NUMA systems in this paper. As a
scalable pattern matching processing infrastructure, we leverage a
data-oriented architecture that preserves data locality and minimizes
concurrency-related bottlenecks on NUMA systems. We show in detail, how graph
pattern matching can be asynchronously processed on a multiprocessor system.Comment: 14 Pages, Extended version for ADBIS 201
Modeling of the processing and removal of trace gas and aerosol species by Arctic radiation fogs and comparison with measurements
A Lagrangian radiation fog model is applied to a fog event at Summit, Greenland. The model simulates the formation and dissipation of fog. Included in the model are detailed gas and aqueous phase chemistry, and deposition of chemical species with fog droplets. Model predictions of the gas phase concentrations of H2O2, HCOOH, SO2, and HNO3 as well as the fog fluxes of S(VI), N(V), H2O2, and water are compared with measurements. The predicted fluxes of S(VI), N(V), H2O2, and fog water generally agree with measured values. Model results show that heterogeneous SO2 oxidation contributes to approximately 40% of the flux of S(VI) for the modeled fog event, with the other 60% coming from preexisting sulfate aerosol. The deposition of N(V) with fog includes contributions from HNO3 and NO2 initially present in the air mass. HNO3 directly partitions into the aqueous phase to create N(V), and NO2 forms N(V) through reaction with OH and the nighttime chemistry set of reactions which involves N2O5 and water vapor. PAN contributes to N(V) by gas phase decomposition to NO2, and also by direct aqueous phase decomposition. The quantitative contributions from each path are uncertain since direct measurements of PAN and NO2 are not available for the fog event. The relative contributions are discussed based on realistic ranges of atmospheric concentrations. Model results suggest that in addition to the aqueous phase partitioning of the initial HNO3 present in the air mass, the gas phase decomposition of PAN and subsequent reactions of NO2 with OH as well as nighttime nitrate chemistry may play significant roles in depositing N(V) with fog. If a quasi-liquid layer exists on snow crystals, it is possible that the reactions taking place in fog droplets also occur to some extent in clouds as well as at the snow surface
The role of sea-salt emissions and heterogeneous chemistry in the air quality of polluted coastal areas
International audienceOpen-ocean and surf-zone sea-salt aerosol (SSA) emissions algorithms are incorporated in the CAMx aerosol model and applied over an area with an extended Archipelago (Greece), with a fine grid nested over the highly populated Attica peninsula. The maximum indirect impact of SSA on PM10 mass (35%) is located over a marine area with moderate SSA production and elevated shipping emissions (central Aegean Sea) where SSA interacts with anthropogenic nitric acid forming sodium nitrate. SSA increases PM10 levels in the Athens city center up to 27% during stable onshore winds. Under such conditions both open-ocean and surf-zone mechanisms contribute to aerosol production over Attica. A hybrid scheme for gas-to-particle mass transfer is necessary for accurately simulating semi-volatile aerosol components when coarse SSA is included. Dynamically simulating mass transfer to the coarse particles leads to a quadrupling of predicted PM10 nitrate in the Athens city center and up to two orders of magnitude in its coarse mass in comparison to using a bulk equilibrium approach
The effect of orthodontic treatment on smile attractiveness: a systematic review.
BACKGROUND
Smile attractiveness is a primary factor for patients to seek orthodontic treatment, however, there is yet no systematic evaluation of this topic in the literature.
OBJECTIVES
To assess the current evidence on the effect of orthodontic treatment on smile attractiveness.
SEARCH METHODS
Seven electronic databases (MEDLINE, Cochrane Library, Virtual Health Library, SCOPUS, Web of Science, Google Scholar and Embase) were searched on 14 September 2022.
SELECTION CRITERIA
Studies evaluating smile attractiveness before and after orthodontic treatment or only after completion of orthodontic treatment.
DATA COLLECTION AND ANALYSIS
Extracted data included study design and setting, sample size and demographics, malocclusion type, treatment modality and method for outcome assessment. Risk of bias was assessed with the ROBINS-I tool for non-randomised studies. Random-effects meta-analyses of mean differences and their 95% confidence intervals (CIs) were planned a priori.
METHODS
After elimination of duplicate studies, data extraction and risk of bias assessment according to the Cochrane guidelines, an evaluation of the overall evidence was performed. The included studies were evaluated based on the characteristics of their study and control groups and based on their main research question. Also, all outcome measures were standardized into a common assessment scale (0-100), in order to obtain more easily interpretable results.
RESULTS
Ten studies were included in this review, nine of which were assessed as being at serious risk of bias and one at moderate risk of bias. The large heterogeneity between the included studies did not allow for a meta-analysis. Orthodontic treatment has a moderately positive effect on smile attractiveness. When compared to no treatment, orthodontic treatment with premolar extractions improves smile attractiveness by 22%. Also, surgical correction of Class III cases increases smile attractiveness by 7.5% more than camouflage treatment. No other significant differences were shown between different types of treatment.
CONCLUSION
Based on the available data, orthodontic treatment seems to moderately improve the attractiveness of the smile. There is significant bias in the current literature assessing the effect of orthodontics on smile attractiveness; therefore, the results cannot be accepted with certainty
CCN activity and droplet growth kinetics of fresh and aged monoterpene secondary organic aerosol
International audienceThe ability of secondary organic aerosol (SOA) produced from the ozonolysis of ?-pinene and monoterpene mixtures (?-pinene, ?-pinene, limonene and 3-carene) to become cloud droplets was investigated. Monoterpene SOA is quite active and would likely be a good source of cloud condensation nuclei (CCN) in the atmosphere. A static CCN counter and a Scanning Mobility CCN Analyser (a Scanning Mobility Particle Sizer coupled with a Continuous Flow counter) were used for the CCN measurements. A decrease in CCN activation diameter for ?-pinene SOA of approximately 3 nm h?1 was observed as the aerosol continued to react with oxidants. Hydroxyl radicals further oxidize the SOA particles thereby enhancing the particle CCN activity with time. The initial concentrations of ozone and monoterpene precursor (for concentrations lower than 40 ppb) do not appear to affect the activity of the resulting SOA. Köhler Theory Analysis (KTA) is used to infer the molar mass of the SOA sampled online and offline from atomized filter samples. KTA suggests that the aged aerosol (both from ?-pinene and the mixed monoterpene oxidation) is primarily water-soluble (around 70?80%), with an estimated average molar mass of 180±55 g mol?1 (consistent with existing SOA speciation studies). CCN activity measurements of the SOA mixed with (NH4)2SO4 suggest that the organic can depress surface tension by as much as 10 nM m?1 (with respect to pure water). The droplet growth kinetics of SOA samples are similar to (NH4)2SO4, except at low supersaturation, where SOA tends to grow more slowly. The CCN activity of ?-pinene and mixed monoterpene SOA can be modelled by a very simple implementation of Köhler theory, assuming complete dissolution of the particles, no dissociation into ions, molecular weight of 180 g mol?1, density of 1.5 g cm?3, and surface tension to within 10?15% of water
Health-related quality of life aspects of the âPeriodontitis prevalence in ulcerative colitis and Crohn's diseaseâ (PPCC) cohort
Aim: To assess whether oral health problems affect disease-specific quality of life (QoL) of inflammatory bowel disease (IBD) patients, and vice versa, whether IBD affects oral-health-related QoL. Materials and Methods: Individuals reporting IBD and matched controls were surveyed on general anamnestic information, oral-health-related questions and the Oral Health Impact Profile (OHIP)-5. IBD patients were additionally surveyed on years since diagnosis, disease activity and severity as well as health-related QoL (Short Inflammatory Bowel Disease Questionnaire, sIBDQ). OHIP-5 and sIBDQ were defined as primary outcome parameters, and several predictors and confounders were used in adjusted univariable and multivariable regression analyses. Results: Answers from 1108 IBD patients and 3429 controls were analysed. Compared with controls, IBD patients reported significantly more frequently an oral impact on daily life and worse oral-health-related QoL, with Crohn's disease (CD) patients being more severely affected than ulcerative colitis (UC) patients. The diagnosis of UC and CD, having <20 teeth, severe periodontitis and stressful daily-life experience were associated with a higher prevalence of poor oral-health-related QoL. Among IBD patients, an impaired IBD-specific, health-related QoL was significantly associated with the diagnosis of CD and depression, IBD activity and severity, having <20 teeth, presence of oral lesions and stressful daily-life experience, while a longer time since diagnosis was significantly associated with an improved IBD-specific, health-related QoL. Conclusions: The results of the present study indicate, for the first time, that oral health problems are associated with an impairment of IBD-specific health-related QoL, and vice versa, IBD is associated with an impaired oral health-related QoL. This emphasizes the potential advantages of including dental professionals in the multi-disciplinary treatment teams of IBD patients
Changes in PM2.5 concentrations and their sources in the US from 1990 to 2010
Significant reductions in emissions of SO2, NOx, volatile organic compounds (VOCs), and primary particulate matter (PM) took place in the US from 1990 to 2010. We evaluate here our understanding of the links between these emissions changes and corresponding changes in concentrations and health outcomes using a chemical transport model, the Particulate Matter Comprehensive Air Quality Model with Extensions (PMCAMx), for 1990, 2001, and 2010. The use of the Particle Source Apportionment Algorithm (PSAT) allows us to link the concentration reductions to the sources of the corresponding primary and secondary PM. The reductions in SO2 emissions (64â%, mainly from electric-generating units) during these 20 years have dominated the reductions in PM2.5, leading to a 45â% reduction in sulfate levels. The predicted sulfate reductions are in excellent agreement with the available measurements. Also, the reductions in elemental carbon (EC) emissions (mainly from transportation) have led to a 30â% reduction in EC concentrations. The most important source of organic aerosol (OA) through the years according to PMCAMx is biomass burning, followed by biogenic secondary organic aerosol (SOA). OA from on-road transport has been reduced by more than a factor of 3. On the other hand, changes in biomass burning OA and biogenic SOA have been modest. In 1990, about half of the US population was exposed to annual average PM2.5 concentrations above 20â”gâmâ3, but by 2010 this fraction had dropped to practically zero. The predicted changes in concentrations are evaluated against the observed changes for 1990, 2001, and 2010 in order to understand whether the model represents reasonably well the corresponding processes caused by the changes in emissions.This work was supported by the Center for Air, Climate, and Energy Solutions (CACES), which was supported under assistance agreement no. R835873 awarded by the U.S. Environmental Protection Agency and the Horizon-2020 Project REMEDIA of the European Union under grant agreement no. 874753.Peer ReviewedPostprint (published version
CONSORT 2010 statement: extension checklist for reporting within person randomised trials.
Evidence shows that the quality of reporting of randomised controlled trials (RCTs) is not optimal. The lack of transparent reporting impedes readers from judging the reliability and validity of trial findings and researchers from extracting information for systematic reviews and results in research waste. The Consolidated Standards of Reporting Trials (CONSORT) statement was developed to improve the reporting of RCTs. Within person trials are used for conditions that can affect two or more body sites, and are a useful and efficient tool because the comparisons between interventions are within people. Such trials are most commonly conducted in ophthalmology, dentistry, and dermatology. The reporting of within person trials has, however, been variable and incomplete, hindering their use in clinical decision making and by future researchers. This document presents the CONSORT extension to within person trials. It aims to facilitate the reporting of these trials. It extends 16 items of the CONSORT 2010 checklist and introduces a modified flowchart and baseline table to enhance transparency. Examples of good reporting and evidence based rationale for CONSORT within person checklist items are provided
Insights into the morphology of multicomponent organic and inorganic aerosols from molecular dynamics simulations
We explore the
morphologies of multicomponent nanoparticles through atomistic molecular
dynamics simulations under atmospherically relevant conditions. The particles
investigated consist of both organic (cis-pinonic acid â CPA,
3-methyl-1,2,3-butanetricarboxylic acid â MBTCA,
n-C20H42, n-C24H50,
n-C30H62 or mixtures thereof) and inorganic (sulfate,
ammonium and water) compounds. The effects of relative humidity, organic mass
content and type of organic compound present in the nanoparticle are
investigated. Phase separation is predicted for almost all simulated
nanoparticles either between organics and inorganics or between hydrophobic
and hydrophilic constituents. For oxygenated organics, our simulations
predict an enrichment of the nanoparticle surface in organics, often in the
form of islands depending on the level of humidity and organic mass fraction,
giving rise to coreâshell structures. In several cases the organics separate
from the inorganics, especially from the ions. For particles containing
water-insoluble linear alkanes, separate hydrophobic and hydrophilic domains
are predicted to develop. The surface partitioning of organics is enhanced as
the humidity increases. The presence of organics in the interior of the
nanoparticle increases as their overall mass fraction in the nanoparticle
increases, but this also depends on the humidity conditions. Apart from the
organicsâinorganics and hydrophobicsâhydrophilics separation, our
simulations predict a third type of separation (layering) between CPA and
MBTCA molecules under certain conditions.</p
Positive matrix factorization of organic aerosol: insights from a chemical transport model
Factor analysis of aerosol mass spectrometer measurements
(organic aerosol mass spectra) is often used to determine the sources of
organic aerosol (OA). In this study we aim to gain insights regarding the
ability of positive matrix factorization (PMF) to identify and quantify the
OA sources accurately. We performed PMF and multilinear engine (ME-2)
analysis on the predictions of a state-of-the-art chemical transport model
(PMCAMx-SR, Particulate Matter Comprehensive Air Quality Model with
extensions â source resolved) during a photochemically active period for
specific sites in Europe in an effort to interpret the diverse factors
usually identified by PMF analysis of field measurements. Our analysis used
the predicted concentrations of 27 OA components, assuming that each of them
is âchemically differentâ from the others.
The PMF results based on the chemical transport model predictions are quite
consistent (same number of factors and source types) with those of the
analysis of AMS measurements. The estimated uncertainty of the contribution
of fresh biomass burning is less than 30 % and of the other primary
sources less than 40 %, when these sources contribute more than 20 % to
the total OA. The PMF uncertainty increases for smaller source
contributions, reaching a factor of 2 or even 3 for sources which
contribute less than 10 % to the OA.
One of the major questions in PMF analysis of AMS measurements concerns the
sources of the two or more oxygenated OA (OOA) factors often reported in
field studies. Our analysis suggests that these factors include secondary OA
compounds from a variety of anthropogenic and biogenic sources and do not
correspond to specific sources. Their characterization in the literature as
low- and high-volatility factors is probably misleading, because they have
overlapping volatility distributions. However, the average volatility of the
one often characterized as a low-volatility factor is indeed lower than that
of the other (high-volatility factor). Based on the analysis of the
PMCAMx-SR predictions, the first oxygenated OA factor includes mainly
highly aged OA transported from outside Europe, but also highly aged
secondary OA from precursors emitted in Europe. The second oxygenated OA
factor contains fresher secondary organic aerosol from volatile, semivolatile, and intermediate
volatility anthropogenic and biogenic organic compounds. The exact
contribution of these OA components to each OA factor depends on the site
and the prevailing meteorology during the analysis period.</p
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