57 research outputs found
The method of double averaging: an approach for modeling power-factor-correction switching converters
Cloud Forensics Investigation: Tracing Infringing Sharing of Copyrighted Content in Cloud
Cloud Computing is becoming a significant technology trend nowadays, but its abrupt rise also creates a brand new front for cybercrime investigation with various challenges. One of the challenges is to track down infringing sharing of copyrighted content in cloud. To solve this problem, we study a typical type of content sharing technologies in cloud computing, analyze the challenges that the new technologies bring to forensics, formalize a procedure to get digital evidences and obtain analytical results based on the evidences to track down illegal uploader. Furthermore, we propose a reasoning model based on the probability distribution in a Bayesian Network to evaluate the analytical result of forensics examinations. The proposed method can accurately and scientifically track down the origin infringing content uploader and owner.
Keywords: cloud forensics, peer to peer, file sharing, tracking, CloudFron
Cardiovascular outcomes associated with use of clarithromycin: population based study
Study question
What is the association between clarithromycin use and cardiovascular outcomes?
Methods
In this population based study the authors compared cardiovascular outcomes in adults aged 18 or more receiving oral clarithromycin or amoxicillin during 2005-09 in Hong Kong. Based on age within five years, sex, and calendar year at use, each clarithromycin user was matched to one or two amoxicillin users. The cohort analysis included patients who received clarithromycin (n=108 988) or amoxicillin (n=217 793). The self controlled case series and case crossover analysis included those who received Helicobacter pylori eradication treatment containing clarithromycin. The primary outcome was myocardial infarction. Secondary outcomes were all cause, cardiac, or non-cardiac mortality, arrhythmia, and stroke.
Study answer and limitations
The propensity score adjusted rate ratio of myocardial infarction 14 days after the start of antibiotic treatment was 3.66 (95% confidence interval 2.82 to 4.76) comparing clarithromycin use (132 events, rate 44.4 per 1000 person years) with amoxicillin use (149 events, 19.2 per 1000 person years), but no long term increased risk was observed. Similarly, rate ratios of secondary outcomes increased significantly only with current use of clarithromycin versus amoxicillin, except for stroke. In the self controlled case analysis, there was an association between current use of H pylori eradication treatment containing clarithromycin and cardiovascular events. The risk returned to baseline after treatment had ended. The case crossover analysis also showed an increased risk of cardiovascular events during current use of H pylori eradication treatment containing clarithromycin. The adjusted absolute risk difference for current use of clarithromycin versus amoxicillin was 1.90 excess myocardial infarction events (95% confidence interval 1.30 to 2.68) per 1000 patients.
What this study adds
Current use of clarithromycin was associated with an increased risk of myocardial infarction, arrhythmia, and cardiac mortality short term but no association with long term cardiovascular risks among the Hong Kong population
Ground state of a polydisperse electrorheological solid: Beyond the dipole approximation
The ground state of an electrorheological (ER) fluid has been studied based
on our recently proposed dipole-induced dipole (DID) model. We obtained an
analytic expression of the interaction between chains of particles which are of
the same or different dielectric constants. The effects of dielectric constants
on the structure formation in monodisperse and polydisperse electrorheological
fluids are studied in a wide range of dielectric contrasts between the
particles and the base fluid. Our results showed that the established
body-centered tetragonal ground state in monodisperse ER fluids may become
unstable due to a polydispersity in the particle dielectric constants. While
our results agree with that of the fully multipole theory, the DID model is
much simpler, which offers a basis for computer simulations in polydisperse ER
fluids.Comment: Accepted for publications by Phys. Rev.
Design of symmetrical class E power amplifiers for very low harmonic-content applications
Selegiline Is a Mechanism-Based Inactivator of CYP2A6 Inhibiting Nicotine Metabolism in Humans and Mice
A novel method for elimination of line-current harmonics in single-stage PFC switching regulators
a2 ion derived from triglycine: an N1-protonated 4-imidazolidinone
Fragmentation of protonated peptides in the gas phase constitutes the basis for gas-phase sequencing of peptides using tandem mass spectrometry. Several mechanistic studies have indicated possible loss of b(n) ion sequence information as a consequence of macrocycle formation from internal nucleophilic attacks. Here, we show by infrared multiple-photon dissociation spectroscopy and density functional theory that the prototypical a(2) ion generated from protonated triglycine is predominantly a cyclic N-1-protonated 4-imidazolidinone. Cyclization resulting from internal nucleophilic attacks therefore may be a more general phenomenon than anticipated
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