761 research outputs found
The intermediate-mass star-forming region Lynds 1340. An optical view
We have performed an optical spectroscopic and photometric search for young
stellar objects associated with the molecular cloud Lynds 1340, and examined
the structure of the cloud by constructing an extinction map, based on SDSS
data. The new extinction map suggests a shallow, strongly fragmented cloud,
having a mass of some 3700~Msun. Longslit spectroscopic observations of the
brightest stars over the area of L1340 revealed that the most massive star
associated with L1340 is a B4 type, about 5 solar mass star. The new
spectroscopic and photometric data of the intermediate mass members led to a
revised distance of 825 (+110 /-80) pc, and revealed seven members of the young
stellar population with M > 2 solar masses. Our search for H alpha emission
line stars, conducted with the Wide Field Grism Spectrograph 2 on the 2.2-meter
telescope of the University of Hawaii and covering a 30 arcmin x 40 arcmin
area, resulted in the detection of 75 candidate low-mass pre-main sequence
stars, 58 of which are new. We constructed spectral energy distributions of our
target stars, based on SDSS, 2MASS, Spitzer, and WISE photometric data, derived
their spectral types, extinctions, and luminosities from BVRIJ fluxes,
estimated masses by means of pre-main sequence evolutionary models, and
examined the disk properties utilizing the 2-24 micron interval of the spectral
energy distribution. We measured the equivalent width of the H alpha lines and
derived accretion rates. The optically selected sample of pre-main sequence
stars has a median effective temperature of 3970 K, stellar mass 0.7 Msun, and
accretion rate of 7.6 10^{-9} Msun/yr.Comment: 47 pages, 15 figures, 10 tables; accepted for publication in ApJ,
typos correcte
Detecting Wage Under-reporting Using a Double Hurdle Model
We estimate a double hurdle (DH) model of the Hungarian wage distribution assuming censoring at the minimum wage and wage under-reporting (i.e. compensation consisting of the minimum wage, subject to taxation, and an unreported cash supplement). We estimate the probability of under-reporting for minimum wage earners, simulate their genuine earnings and classify them and their employers as 'cheaters' and 'non-cheaters'. In the possession of the classification we check how cheaters and non-cheaters reacted to the introduction of a minimum social security contribution base, equal to 200 per cent of the minimum wage, in 2007. The findings suggest that cheaters were more likely to raise the wages of their minimum wage earners to 200 per cent of the minimum wage thereby reducing the risk of tax audit. Cheating firms also experienced faster average wage growth and slower output growth. The results suggest that the DH model is able to identify the loci of wage under-reporting with some precision.tax evasion, double hurdle model, Hungary
Expansive actions on uniform spaces and surjunctive maps
We present a uniform version of a result of M. Gromov on the surjunctivity of
maps commuting with expansive group actions and discuss several applications.
We prove in particular that for any group and any field \K, the
space of -marked groups such that the group algebra \K[G] is
stably finite is compact.Comment: 21 page
Detecting wage under-reporting using a double hurdle model
We estimate a double hurdle (DH) model of the Hungarian wage distribution assuming censoring at the minimum wage and wage under-reporting (i.e. compensation consisting of the minimum wage, subject to taxation, and an unreported cash supplement). We estimate the probability of under-reporting for minimum wage earners, simulate their genuine earnings and classify them and their employers as 'cheaters' and 'non-cheaters'. In the possession of the classification we check how cheaters and non-cheaters reacted to the introduction of a minimum social security contribution base, equal to 200 per cent of the minimum wage, in 2007. The findings suggest that cheaters were more likely to raise the wages of their minimum wage earners to 200 per cent of the minimum wage thereby reducing the risk of tax audit. Cheating firms also experienced faster average wage growth and slower output growth. The results suggest that the DH model is able to identify the loci of wage under-reporting with some precision
Detecting wage under-reporting using a double hurdle model
We estimate a double hurdle (DH) model of the Hungarian wage distribution assuming censoring at the minimum wage and wage under-reporting (i.e. compensation consisting of the minimum wage, subject to taxation, and an unreported cash supplement). We estimate the probability of under-reporting for minimum wage earners, simulate their genuine earnings and classify them and their employers as 'cheaters' and 'non-cheaters'. In the possession of the classification we check how cheaters and non-cheaters reacted to the introduction of a minimum social security contribution base, equal to 200 per cent of the minimum wage, in 2007. The findings suggest that cheaters were more likely to raise the wages of their minimum wage earners to 200 per cent of the minimum wage thereby reducing the risk of tax audit. Cheating firms also experienced faster average wage growth and slower output growth. The results suggest that the DH model is able to identify the loci of wage under-reporting with some precision
Investigation of the composition of the Luna 16 lunar sample
The concentrations of aluminum, manganese, sodium, chromium, iron, cobalt, and 12 rare earth elements were determined by neutron activation analysis using slow neutrons. Oxygen and silicon were determined using a fast neutron generator. Mossbauer spectroscopy was used to investigate iron compounds in Luna 16 regolith samples from the upper part of the core
NLRC5 Functions beyond MHC I Regulation—What Do We Know So Far?
NLRC5 is a member of the NLR family that acts as a transcriptional activator of MHC class I genes. In line with the function of several related NLR proteins in innate immune responses, there is, however, also ample evidence that NLRC5 contributes to innate and adaptive immune responses beyond the regulation of MHC class I genes. In human and murine cells, for example, NLRC5 was proposed to contribute to inflammatory and type I interferon responses. The role of NLRC5 in these and other cellular processes is hitherto still not well understood and blurred by discrepancies in the reported data. Here, we provide a detailed and critical discussion of the available experimental data on the emerging biological functions of NLRC5 in innate immune responses in men and mice. Better awareness of the multiple roles of NLRC5 will help to define its overall contribution to immune responses and cancer
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