758 research outputs found
An Incentive Compatible, Efficient Market for Air Traffic Flow Management
We present a market-based approach to the Air Traffic Flow Management (ATFM)
problem. The goods in our market are delays and buyers are airline companies;
the latter pay money to the FAA to buy away the desired amount of delay on a
per flight basis. We give a notion of equilibrium for this market and an LP
whose solution gives an equilibrium allocation of flights to landing slots as
well as equilibrium prices for the landing slots. Via a reduction to matching,
we show that this equilibrium can be computed combinatorially in strongly
polynomial time. Moreover, there is a special set of equilibrium prices, which
can be computed easily, that is identical to the VCG solution, and therefore
the market is incentive compatible in dominant strategy.Comment: arXiv admin note: substantial text overlap with arXiv:1109.521
Accurate inspiral-merger-ringdown gravitational waveforms for non-spinning black-hole binaries including the effect of subdominant modes
We present an analytical waveform family describing gravitational waves (GWs)
from the inspiral, merger and ringdown of non-spinning black-hole binaries
including the effect of several non-quadrupole modes [( apart from ].
We first construct spin-weighted spherical harmonics modes of hybrid waveforms
by matching numerical-relativity simulations (with mass ratio )
describing the late inspiral, merger and ringdown of the binary with
post-Newtonian/effective-one-body waveforms describing the early inspiral. An
analytical waveform family is constructed in frequency domain by modeling the
Fourier transform of the hybrid waveforms making use of analytical functions
inspired by perturbative calculations. The resulting highly accurate,
ready-to-use waveforms are highly faithful (unfaithfulness ) for observation of GWs from non-spinning black hole binaries and are
extremely inexpensive to generate.Comment: 10 pages, 5 figure
Bacteriological profile of urinary tract infections at a tertiary care hospital in Western Uttar Pradesh, India
Background: This prospective study was intended to identify the bacterial pathogens causing urinary tract infections and their antimicrobial resistance patterns in a tertiary care teaching hospital of Western Uttar Pradesh, India.Methods: Clean-catch mid-stream urine samples were collected from patients symptomatic for UTI. Samples were cultured aerobically on CLED agar and strains having significant growth (>105cfu/ml) were further processed for identification using standard microbiological techniques and their antimicrobial susceptibility pattern evaluated by Kirby Bauer disk diffusion as per CLSI guidelines.Results: Out of the 2250 urine samples processed, 750 showed significant growth on aerobic culture. Thus, the prevalence of UTI in the population was 33.3%. E. coli was the commonest isolate (33.3%) followed by S. aureus (20 %), Klebsiella spp. (13.3%), Coagulase Negative Staphylococci (13.3%), Enterococcus spp. (6.7%), Pseudomonas spp. (6.7%) and Candida spp. (6.7%). Amongst these isolates, Gram negative bacilli have shown a high susceptibility to imipenem, levofloxacin, nitrofurantoin, linezolid and amoxyclav and Gram positive organisms towards levofloxacin, nitrofurantoin, linezolid, vancomycin and amikacin.Conclusions: This study has shown nitrofurantoin and fluoroquinolones to be the most effective drugs for the empirical therapy of UTI in our region. The study of antimicrobial susceptibility pattern of UTI in a particular area can guide the clinicians in the rational choice of antibiotic treatment so that misuse of antibiotics can be prevented
Can data cooperatives sustain themselves?
Data cooperatives are emerging to empower consumers amidst a fast-changing data governance landscape. But they are not alone, and IT-enabled data marketplaces can be effective competitors. Sameer Mehta, Milind Dawande, and Vijay Mookerjee write that data cooperatives are not indispensable. They suggest four steps for data cooperatives to sustain themselves and thrive in this competitive market
Fractionation of antibacterial extracts of Syzygium cumini (Myrtaceae) seeds
Antibacterial activity of Syzygium cumini seed extracts prepared in methanol and ethanol was evaluated by disc diffusion and broth dilution assays. Both extracts exerted a broad spectrum of bacteriostatic action against different gram-positive and gram-negative bacteria. Their minimum inhibitory concentration (MIC) against susceptible organisms ranged from 154-656 μg/mL. Highest total activity was registered by the ethanol extract against Staphylococcus epidermidis. Extracts were separated on TLC (thin-layer chromatography) plates, and separated components were individually tested for their antibacterial activity. HPLC (high performance liquid chromatography) analysis indicated presence of gallic acid and quercetin in the methanolic extract
An auction-based market equilibrium algorithm for a production model
AbstractWe present an auction-based algorithm for computing market equilibrium prices in a production model, in which producers have a single linear production constraint, and consumers have linear utility functions. We provide algorithms for both the Fisher and Arrow–Debreu versions of the problem
Testing the no-hair nature of binary black holes using the consistency of multipolar gravitational radiation
Gravitational-wave (GW) observations of binary black holes offer the best probes of the relativistic, strong-field regime of gravity. Gravitational radiation in the leading order is quadrupolar. However, nonquadrupole (higher order) modes make appreciable contribution to the radiation from binary black holes with large mass ratios and misaligned spins. The multipolar structure of the radiation is fully determined by the intrinsic parameters (masses and spin angular momenta of the companion black holes) of a binary in quasicircular orbit. Following our previous work [S. Dhanpal, A. Ghosh, A. K. Mehta, P. Ajith, and B. S. Sathyaprakash, Phys. Rev. D 99, 104056 (2019).], we develop multiple ways of testing the consistency of the observed GW signal with the expected multipolar structure of radiation from binary black holes in general relativity. We call this a no-hair test of binary black holes as this is similar to testing the no-hair theorem for isolated black holes through mutual consistency of the quasinormal mode spectrum. We use Bayesian inference on simulated GW signals that are consistent/inconsistent with binary black holes in general relativity to demonstrate the power of the proposed tests. We also make estimate systematic errors arising as a result of neglecting companion spins
Multimodal Behavior Program for ADHD Incorporating Yoga and Implemented by High School Volunteers: A Pilot Study
A low-cost resource approach to ADHD therapy would be a practical approach to treating children in developing countries. Research has shown that ADHD is prevalent in all areas of the world, and yet treatment for children in more impoverished countries is still lacking. The approach taken was to combine yoga and meditation combined with multimodal behavioral therapy program for children ageing 6 to 11. The program was kept low cost by using trained high school volunteers and integrating the program within the public school. After 6 weeks of the program, 90.5% of children showed improvement as measured by their performance impairment score, a measurement of academic performance. Parent and Teacher evaluations of behavior also found improvement as 25 of the 64 children (39.1%) improved into the normal range as measured by the Vanderbilt questionnaire. Moreover, children could successfully learn both yoga and meditation from high school students irrespective of their age, ADHD type, or initial performance impairment. The results demonstrate efficacy of a multimodal behavioral program incorporating yoga and meditation. The use of high school volunteers from schools in the area demonstrates an effective low-cost and universally applicable approach
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