4,787 research outputs found
Efficient Wage Subsidies in Private Firms and Deadweight Spending
This paper links the old literature on employment subsidies with the current theories of contract and regulation. One important source of inefficiency of employment subsidies is deadweight spending. This refers to the cases in which private firms receive a subsidy for employment creation that would have been reached without this financial support. We identify the asymmetry of information between the regulator and the private firm as the source of this deadweight spending. The private firm knows its hiring capability while the government does not. We then derive the optimal incentive contracts for the government. In these contracts deadweight spending is reduced to the information rent to private firms. We derive conditions for which this deadweight spending is zero.Contract-Theory; Principal-Agent; Economic-Policy; Employment-Subsidy; Cost-Benefit-Analysis
Preventing pain on injection of propofol: A comparison between lignocaine pre-treatment and lignocaine added to propofol
Publisher's copy made available with the permission of the publisherA randomized double-blind study compared two methods of preventing the pain from injection of propofol, lignocaine pre-treatment followed by propofol and lignocaine added to propofol. One hundred patients received a 4 ml solution intravenously with a venous tourniquet for 1 minute, followed by propofol mixed with 2 ml of solution. Patients were divided into two treatment groups of 50 patients each: 4 ml 1% lignocaine pre-treatment followed by propofol and 2 ml saline, or 4 ml saline followed by propofol and 2 ml 2% lignocaine. Pain was assessed with a 100 mm visual analogue scale after induction and in recovery. The incidence of injection pain was 8% in the propofol mixed with lignocaine group, and 28% in the lignocaine pre-treatment group. This difference is statistically significant (P=0.017). For those patients who had pain, the mean pain score was 26.5 on induction for the propofol with lignocaine group (n=4), while the mean score was 44.4 for the pre-treatment group (n=13). The difference was not statistically significant (P=0.25). None of the propofol mixed with lignocaine group recalled pain, while 13 of the pre-treatment group did so. Lignocaine pre-treatment does not improve the immediate or the recalled comfort of patients during propofol induction when compared to lignocaine added to propofol. It is recommended that lignocaine should be added to propofol for induction rather than given before induction.P. Lee, W. J. Russellhttp://www.aaic.net.au/Article.asp?D=200339
Characterization of a dense aperture array for radio astronomy
EMBRACE@Nancay is a prototype instrument consisting of an array of 4608
densely packed antenna elements creating a fully sampled, unblocked aperture.
This technology is proposed for the Square Kilometre Array and has the
potential of providing an extremely large field of view making it the ideal
survey instrument. We describe the system,calibration procedures, and results
from the prototype.Comment: 17 pages, accepted for publication in A&
Constitutive association of BRCA1 and c-Abl and its ATM-dependent disruption after irradiation
BRCA1 plays an important role in mechanisms of response to double-strand breaks, participating in genome surveillance, DNA repair, and cell cycle checkpoint arrests. Here, we identify a constitutive BRCA1-c-Abl complex and provide evidence for a direct interaction between the PXXP motif in the C terminus of BRCA1 and the SH3 domain of c-Abl. Following exposure to ionizing radiation (IR), the BRCA1-c-Abl complex is disrupted in an ATM-dependent manner, which correlates temporally with ATM-dependent phosphorylation of BRCA1 and ATM-dependent enhancement of the tyrosine kinase activity of c-Abl. The BRCA1-c-Abl interaction is affected by radiation-induced modification to both BRCA1 and c-Abl. We show that the C terminus of BRCA1 is phosphorylated by c-Abl in vitro. In vivo, BRCA1 is phosphorylated at tyrosine residues in an ATM-dependent, radiation-dependent manner. Tyrosine phosphorylation of BRCA1, however, is not required for the disruption of the BRCA1-c-Abl complex. BRCA1-mutated cells exhibit constitutively high c-Abl kinase activity that is not further increased on exposure to IR. We suggest a model in which BRCA1 acts in concert with ATM to regulate c-Abl tyrosine kinase activity
Distributed Minimum Cut Approximation
We study the problem of computing approximate minimum edge cuts by
distributed algorithms. We use a standard synchronous message passing model
where in each round, bits can be transmitted over each edge (a.k.a.
the CONGEST model). We present a distributed algorithm that, for any weighted
graph and any , with high probability finds a cut of size
at most in
rounds, where is the size of the minimum cut. This algorithm is based
on a simple approach for analyzing random edge sampling, which we call the
random layering technique. In addition, we also present another distributed
algorithm, which is based on a centralized algorithm due to Matula [SODA '93],
that with high probability computes a cut of size at most
in rounds for any .
The time complexities of both of these algorithms almost match the
lower bound of Das Sarma et al. [STOC '11], thus
leading to an answer to an open question raised by Elkin [SIGACT-News '04] and
Das Sarma et al. [STOC '11].
Furthermore, we also strengthen the lower bound of Das Sarma et al. by
extending it to unweighted graphs. We show that the same lower bound also holds
for unweighted multigraphs (or equivalently for weighted graphs in which
bits can be transmitted in each round over an edge of weight ),
even if the diameter is . For unweighted simple graphs, we show
that even for networks of diameter , finding an -approximate minimum cut
in networks of edge connectivity or computing an
-approximation of the edge connectivity requires rounds
Female Blow Flies As Vertebrate Resource Indicators
Rapid vertebrate diversity evaluation is invaluable for monitoring changing ecosystems worldwide. Wild blow flies naturally recover DNA and chemical signatures from animal carcasses and feces. We demonstrate the power of blow flies as biodiversity monitors through sampling of flies in three environments with varying human influences: Indianapolis, IN and two national parks (the Great Smoky Mountains and Yellowstone). Dissected fly guts underwent vertebrate DNA sequencing (12S and 16S rRNA genes) and fecal metabolite screening. Integrated Nested Laplace Approximation (INLA) was used to determine the most important abiotic factor influencing fly-derived vertebrate richness. In 720 min total sampling time, 28 vertebrate species were identified, with 42% of flies containing vertebrate resources: 23% DNA, 5% feces, and 14% contained both. The species of blow fly used was not important for vertebrate DNA recovery, however the use of female flies versus male flies directly influenced DNA detection. Temperature was statistically relevant across environments in maximizing vertebrate detection (mean = 0.098, sd = 0.048). This method will empower ecologists to test vertebrate community ecology theories previously out of reach due practical challenges associated with traditional sampling
Pulsed laser ignition of reactive multilayer films
Nanostructured Al/PtAl∕Pt multilayer films were ignited by single pulse irradiation from a Ti:sapphire femtosecond laser system. Critical ignition fluences (0.9–22 J/cm2)(0.9–22J∕cm2) required to initiate a self-propagating reaction were quantified for different multilayer designs. Multilayers with smaller bilayer thickness required relatively lower fluence for ignition. Ignition threshold fluence was also found to be 1.4–3.6 times higher for Al-capped multilayers than for Pt-capped multilayers. Ablation threshold fluences were measured for Al (860±70 mJ/cm2)(860±70mJ∕cm2) and Pt (540±50 mJ/cm2)(540±50mJ∕cm2) and related to the observed difference in ignition fluences for Al- and Pt-capped multilayers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87770/2/144102_1.pd
Closed trajectories of a particle model on null curves in anti-de Sitter 3-space
We study the existence of closed trajectories of a particle model on null
curves in anti-de Sitter 3-space defined by a functional which is linear in the
curvature of the particle path. Explicit expressions for the trajectories are
found and the existence of infinitely many closed trajectories is proved.Comment: 12 pages, 1 figur
Role of a native oxide on femtosecond laser interaction with silicon (100) near the damage threshold
Si (100) with and without a 14–25 Å14–25Å thick native oxide was laser machined at grazing incidence using a Ti:sapphire femtosecond pulsed laser under ultrahigh vacuum conditions. The resulting damage feature size and morphology indicate that the presence or absence of the native oxide significantly affects the mechanism for femtosecond laser-induced damage. We propose that a fluence-dependent modification of the oxide by the incident laser pulse must be considered when studying femtosecond laser damage of Si (100) with a native oxide. Data are also presented that are consistent with a dose-dependent phase transformation in the amorphous oxide. The implications of the native oxide, including relative damage thresholds of the underlying Si (100) and the role of the oxide in damage morphology are addressed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87851/2/264103_1.pd
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