3,620 research outputs found
Towards low-latency real-time detection of gravitational waves from compact binary coalescences in the era of advanced detectors
Electromagnetic (EM) follow-up observations of gravitational wave (GW) events
will help shed light on the nature of the sources, and more can be learned if
the EM follow-ups can start as soon as the GW event becomes observable. In this
paper, we propose a computationally efficient time-domain algorithm capable of
detecting gravitational waves (GWs) from coalescing binaries of compact objects
with nearly zero time delay. In case when the signal is strong enough, our
algorithm also has the flexibility to trigger EM observation before the merger.
The key to the efficiency of our algorithm arises from the use of chains of
so-called Infinite Impulse Response (IIR) filters, which filter time-series
data recursively. Computational cost is further reduced by a template
interpolation technique that requires filtering to be done only for a much
coarser template bank than otherwise required to sufficiently recover optimal
signal-to-noise ratio. Towards future detectors with sensitivity extending to
lower frequencies, our algorithm's computational cost is shown to increase
rather insignificantly compared to the conventional time-domain correlation
method. Moreover, at latencies of less than hundreds to thousands of seconds,
this method is expected to be computationally more efficient than the
straightforward frequency-domain method.Comment: 19 pages, 6 figures, for PR
Contact of Single Asperities with Varying Adhesion: Comparing Continuum Mechanics to Atomistic Simulations
Atomistic simulations are used to test the equations of continuum contact
mechanics in nanometer scale contacts. Nominally spherical tips, made by
bending crystals or cutting crystalline or amorphous solids, are pressed into a
flat, elastic substrate. The normal displacement, contact radius, stress
distribution, friction and lateral stiffness are examined as a function of load
and adhesion. The atomic scale roughness present on any tip made of discrete
atoms is shown to have profound effects on the results. Contact areas, local
stresses, and the work of adhesion change by factors of two to four, and the
friction and lateral stiffness vary by orders of magnitude. The microscopic
factors responsible for these changes are discussed. The results are also used
to test methods for analyzing experimental data with continuum theory to
determine information, such as contact area, that can not be measured directly
in nanometer scale contacts. Even when the data appear to be fit by continuum
theory, extracted quantities can differ substantially from their true values
Early hospital readmissions postâkidney transplantation are associated with inferior clinical outcomes
Unplanned hospital readmissions are common early postâkidney transplantation. We investigated the relationship between early hospital readmissions and clinical outcomes in a singleâcenter retrospective study that included all adult kidney transplant patients between 2004 and 2008 with followâup to December 2012. The early hospital readmissions within the first 30 d were numbered and the diagnosis ascertained. Patients were grouped as none, once, and twice or more readmissions. Predictors of early readmissions were assessed, and clinical outcomes and patient and deathâcensored kidney survival were compared. Among 1064 patients, 203 (19.1%) patients had once and 83 (7.8%) patients had twice or more readmissions within 30 d. Surgical complications, infections, and acute kidney injuries/acute rejection were three most common diagnoses. The length of initial hospital stay and African American race were among the variables associated significantly with readmissions. Patients with early readmissions had lower baseline renal function (p < 0.01) and more early acute rejection (p < 0.01). During followâup, only frequent readmissions, twice or more, within 30 d were associated with increased risk of death ( AHR 1.75, p  =  0.01) and deathâcensored kidney failure ( AHR 2.20, p < 0.01). Frequent early hospital readmissions postâtransplantation identify patients at risk for poor longâterm outcomes, and more studies are needed to understand the mechanisms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106830/1/ctr12347.pd
Brassinosteroids Regulate Anthocyanin Biosynthesis in the Ripening of Grape Berries
Anthocyanins are important components in the skins of grapes and in the development of wine colour.Various environmental factors cause poor coloration in some areas, even for the same cultivars planted indifferent production areas. The objective of this study was to evaluate the effect of exogenous brassinosteroids(BR) on the accumulation of anthocyanins and gene expression of anthocyanin biosynthesis in wine grapeberry skins. The results show that total anthocyanin content in BR-treated grapes was higher than that inthe control (CT) grapes, and that 0.4 mg/L was the most effective treatment concentration. The effect ofBR on downstream genes was more effective than that on upstream genes. Full coloration of BR-treatedgrapes was achieved seven days earlier than in the case of CT. Moreover, BR enhanced the transcriptlevel of the downstream genes of anthocyanin biosynthesis, which caused the total anthocyanin contentto increase. The induction of structural and regulatory genes of the flavonoid pathway suggests that theinterrelationships between developmental and environmental signalling pathways were magnified by BRtreatment, which actively promoted fruit coloration, namely anthocyanin biosynthesis
Characterization of high-resolution aerosol mass spectra of primary organic aerosol emissions from Chinese cooking and biomass burning
Aerosol mass spectrometry has proved to be a powerful tool to measure
submicron particulate composition with high time resolution. Factor analysis
of mass spectra (MS) collected worldwide by aerosol mass spectrometer (AMS)
demonstrates that submicron organic aerosol (OA) is usually composed of
several major components, such as oxygenated (OOA), hydrocarbon-like (HOA),
biomass burning (BBOA), and other primary OA. In order to help
interpretation of component MS from factor analysis of ambient OA datasets,
AMS measurements of different primary sources is required for comparison.
Such work, however, has been very scarce in the literature, especially for
high resolution MS (HR-MS) measurements, which performs improved
characterization by separating the ions of different elemental composition
at each <i>m</i>/<i>z</i> in comparison with unit mass resolution MS (UMR-MS)
measurements. In this study, primary emissions from four types of Chinese
cooking (CC) and six types of biomass burning (BB) were simulated
systematically and measured using an Aerodyne High-Resolution Time-of-Flight
AMS (HR-ToF-AMS). The MS of the CC emissions show high similarity, with <i>m</i>/<i>z</i>
41 and <i>m</i>/<i>z</i> 55 being the highest signals; the MS of the BB emissions also
show high similarity, with <i>m</i>/<i>z</i> 29 and <i>m</i>/<i>z</i> 43 being the highest signals. The
MS difference between the CC and BB emissions is much bigger than that
between different CC (or BB) types, especially for the HR-MS. The O/C ratio
of OA ranges from 0.08 to 0.13 for the CC emissions and from 0.18 to 0.26
for the BB emissions. The UMR ions of <i>m</i>/<i>z</i> 43, <i>m</i>/<i>z</i> 44, <i>m</i>/<i>z</i> 57, and <i>m</i>/<i>z</i> 60,
usually used as tracers in AMS measurements, were examined for their HR-MS
characteristics in the CC and BB emissions. In addition, the MS of the CC
and BB emissions are also compared with component MS from factor analysis of
ambient OA datasets observed in China, as well as with other AMS
measurements of primary sources in the literature. The MS signatures of
cooking and biomass burning emissions revealed in this study can be used as
important reference for factor analysis of ambient OA datasets, especially
for the relevant studies in East Asia
Neural correlates of explicit and implicit emotion processing in relation to treatment response in pediatric anxiety
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136676/1/jcpp12658_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136676/2/jcpp12658.pd
Low-Dose, Ionizing Radiation and Age-Related Changes in Skeletal Microarchitecture
Osteoporosis can profoundly affect the aged as a consequence of progressive bone loss; high-dose ionizing radiation can cause similar changes, although less is known about lower doses (â€100âcGy). We hypothesized that exposure to relatively low doses of gamma radiation accelerates structural changes characteristic of skeletal aging. Mice (C57BL/6J-10âwk old, male) were irradiated (total body; 0-sham, 1, 10 or 100âcGy 137Cs) and tissues harvested on the day of irradiation, 1 or 4âmonths later. Microcomputed tomography was used to quantify microarchitecture of high turnover, cancellous bone. Irradiation at 100âcGy caused transient microarchitectural changes over one month that were only evident at longer times in controls (4 months). Ex vivo bone cell differentiation from the marrow was unaffected by gamma radiation. In conclusion, acute ionizing gamma irradiation at 100âcGy (but not at 1âcGy or 10âcGy) exacerbated microarchitectural changes normally found during progressive, postpubertal aging prior to the onset of age-related osteoporosis
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Hydrothermal oxidation of organic wastes using reclaimed ammonium nitrate
Ammonium nitrate is being studied as an alternative for ammonium perchlorate as an oxidizing agent in Department of Defense 1.1 and 1.3 rocket propellants. Use of ammonium nitrate would eliminate the HCl produced by ammonium perchlorate upon thermal decomposition. To stabilize the ammonium nitrate, which suffers from phase instability, potassium dinitramide (KDN) is added. This increased use of ammonium nitrate will ultimately create a need for environmentally responsible processes to reuse ammonium nitrate extracted from demilitarized rocket motors. Ammonium Nitrate was investigated as an oxidizing agent for methanol, acetic acid and phenol. High removal of organic, ammonia and nitrate was achieved at stoichiometric concentrations. The oxidation of ammonia by nitrate was much faster than the oxidation of either methanol or acetic acid. Phenol, however, was in strong competition with ammonia for the oxidizer (nitrate). Nitrogen products included N{sub 2}, N{sub 2}O, NO{sub 2{sup {minus}}} as well as toxic NO and trace amounts of NO{sub 2}. Carbon products were CO{sub 2}, HCO{sub 3{sup {minus}}}, CO{sub 3}{sup 2{minus}}, and CO
Isorhamnetin: A review of pharmacological effects.
Isorhamnetin is one of the most important active ingredients in the fruits of Hippophae rhamnoides L. and the leaves of Ginkgo biloba L., which possesses extensive pharmacological activities. At present, there have been numerous investigations on isorhamnetin, which has the effects of cardiovascular and cerebrovascular protection, anti-tumor, anti-inflammatory, anti-oxidation, organ protection, prevention of obesity, etc. The related mechanisms involve the regulation of PI3K/AKT/PKB, NF-ÎșB, MAPK and other signaling pathways as well as the expression of related cytokines and kinases. Isorhamnetin has a high value of development and application. However, the investigations on its mechanism of action are limited and lack of detailed scientific validation. The manuscript reviewed the pharmacological effects of isorhamnetin and related mechanisms of action for the development of its medicinal properties further
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