4,684 research outputs found
New Keynesian versus old Keynesian government spending multipliers
Renewed interest in fiscal policy has increased the use of quantitative models to evaluate policy. Because of modeling uncertainty, it is essential that policy evaluations be robust to alternative assumptions. We find that models currently being used in practice to evaluate fiscal policy stimulus proposals are not robust. Government spending multipliers in an alternative empirically-estimated and widely-cited new Keynesian model are much smaller than in these old Keynesian models; the estimated stimulus is extremely small with GDP and employment effects only one-sixth as large
The Level-0 Muon Trigger for the LHCb Experiment
A very compact architecture has been developed for the first level Muon
Trigger of the LHCb experiment that processes 40 millions of proton-proton
collisions per second. For each collision, it receives 3.2 kBytes of data and
it finds straight tracks within a 1.2 microseconds latency. The trigger
implementation is massively parallel, pipelined and fully synchronous with the
LHC clock. It relies on 248 high density Field Programable Gate arrays and on
the massive use of multigigabit serial link transceivers embedded inside FPGAs.Comment: 33 pages, 16 figures, submitted to NIM
QTL Analysis of Mineral Content in Perennial Ryegrass (\u3cem\u3eLolium Perenne\u3c/em\u3e L.)
Variation in mineral content of grasses can be strongly influenced by genetic factors. Grass tetany (hypomagnesemia) of cattle and sheep is due to disturbances in serum magnesium levels. In Southern Australia, resultant levels of mortality in cattle vary between 0.5-1.5% of total stock numbers. Serum magnesium variation may be due to feed deficits, or dietary imbalances that interfere with magnesium metabolism. High levels of potassium appear to exert negative effects on the levels of magnesium in the blood. Italian ryegrass genotypes with high levels of magnesium can alleviate the incidence of grass tetany. The genetic control of mineral content, including magnesium, in perennial ryegrass has been investigated using molecular marker-based analysis
Conception and Validation Software Tools for the Level 0 Muon Trigger of LHCb
The Level-0 muon trigger processor of the LHCb experiment looks for straight particules crossing muon detector and measures their transverse momentum. It processes 40Ă—106 proton-proton collisions per second. The tracking uses a road algorithm relying on the projectivity of the muon detector. The architecture of the Level-0 muon trigger is complex with a dense network of data interconnections. The design and validation of such an intricate system has only been possible with intense use of software tools for the detector simulation, the modelling of the hardware components behaviour and the validation. A database describing the dataflow is the corner stone between the software and hardware components
Multiwavelength Observations of 1ES 1959+650, One Year After the Strong Outburst of 2002
In April-May 2003, the blazar 1ES 1959+650 showed an increased level of X-ray
activity. This prompted a multiwavelength observation campaign with the Whipple
10 m gamma-ray telescope, the Rossi X-ray Timing Explorer, the Bordeaux Optical
Observatory, and the University of Michigan Radio Astrophysical Observatory. We
present the multiwavelength data taken from May 2, 2003 to June 7, 2003 and
compare the source characteristics with those measured during observations
taken during the years 2000 and 2002. The X-ray observations gave a data set
with high signal-to-noise light curves and energy spectra; however, the
gamma-ray observations did not reveal a major TeV gamma-ray flare. Furthermore,
we find that the radio and optical fluxes do not show statistically significant
deviations from those measured during the 2002 flaring periods. While the X-ray
flux and X-ray photon index appear correlated during subsequent observations,
the apparent correlation evolved significantly between the years 2000, 2002,
and 2003. We discuss the implications of this finding for the mechanism that
causes the flaring activity.Comment: 17 pages, 6 figures, 2 table
Tuning coordination chemistry through the second sphere in designed metallocoiled coils
The metal hydration state within a designed coiled coil can be progressively tuned across the full integer range (3 → 0 aqua ligands), by careful choice of a second sphere terminal residue, including the lesser used Trp. Potential implications include a four-fold change in MRI relaxivity when applied to lanthanide coiled coils.</p
Genetic Analysis of the Interaction Between the Host Perennial Ryegrass and the Crown Rust Pathogen (\u3cem\u3ePuccinia Coronata\u3c/em\u3e F.SP. \u3cem\u3eLolii\u3c/em\u3e)
Crown rust (Puccinia coronata f.sp lolii) is the most important fungal pathogen of perennial ryegrass (L.perenne L.). The physiological effects associated with infection include reduction of water soluble carbohydrate (WSC) reserves, causing decreased dry matter yield, digestibility and palatability for herbivores reared for meat, milk and wool production. Phenotypic variability of rust-infection in perennial ryegrass is likely to be due to environmental effects, as well as the interaction of defence and resistance genes in the grass and virulence genes in the pathogen. Classical and molecular genetic marker-based studies have previously detected both qualitative and quantitative resistance, due respectively to major genes and quantitative trait loci (QTL). In addition, evidence for physiological race variation has been demonstrated for P. coronata f.sp. avenae, the causative organisms of crown rust in oat, and has been inferred for P. coronata f.sp. lolii. Evaluation of genotypic variation in both the host and pathogen is consequently important for the analysis of the interaction
SNP Discovery and Haplotypic Variation in Full-Length Herbage Quality Genes of Perennial Ryegrass (Lolium Perenne L.)
The development of forages with enhanced nutritive value through improvements of herbage quality (digestibility, carbohydrate content) is potentially capable of increasing both meat and milk production by up to 25%. However, the expense and time-consuming nature of the relevant biochemical and biophysical assays has limited breeding improvement for forage quality. The development of accurate high-throughput molecular marker-based selection systems such as single nucleotide polymorphisms (SNPs) permits evaluation of genetic variation and selection of favourable variants to accelerate the production of elite new varieties
Evaluation of Genetic Diversity in White Clover (\u3cem\u3eTrifolium Repens\u3c/em\u3e L.) Through Measurement of Simple Sequence Repeat (SSR) Polymorphism
White clover (Trifolium repens L.) is a key important temperate pasture legume. Due to the obligate outbreeding nature of white clover, individual genotypes within cultivars are highly genetically heterogeneous. Genetic diversity has been assessed within and between 16 elite cultivars derived from Europe, North and South America, New Zealand and Australia
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