2,418 research outputs found
Work Hours, Wages, and Vacation Leave
Using the Panel Study of Income Dynamics and the Health and Retirement Study, we provide a set of facts about vacation leave and its relationship to hours worked, hours constraints, wage rates, worker characteristics, spouse's vacation leave, labor market experience, job tenure, occupation, industry, and labor market conditions. We show that on average vacation time taken rises 1 to 1 with paid vacation but varies around it, that annual hours worked fall by about 1 full time week with every week of paid vacation, that the gap between time taken and time paid for is higher for women, union members, and government workers, that hourly wage rates have a strong positive relationship with paid vacation weeks both in the cross section and across jobs, and that nonwage compensation is positively related to vacation weeks. We provide evidence that vacation leave is determined by broad employer policy rather than by negotiation between the worker and firm. In particular, it is strongly related to job seniority but depends very little on labor market experience, and for job changers it is only weakly related to the amount of vacation on the previous job.
A Comparative Study of Infrared Asteroid Surveys: IRAS, AKARI, and WISE
We present a comparative study of three infrared asteroid surveys based on
the size and albedo data from the Infrared Astronomical Satellite (IRAS), the
Japanese infrared satellite AKARI, and the Wide-field Infrared Survey Explorer
(WISE). Our study showed that: (i) the total number of asteroids detected with
diameter and albedo information with these three surveyors is 138,285, which is
largely contributed by WISE; (ii) the diameters and albedos measured by the
three surveyors for 1,993 commonly detected asteroids are in good agreement,
and within +/-10% in diameter and +/-22% in albedo at 1sigma deviation level.
It is true that WISE offers size and albedo of a large fraction (>20%) of known
asteroids down to a few km bodies, but we would suggest that the IRAS and AKARI
catalogs compensate for larger asteroids up to several hundred km, especially
in the main belt region. We discuss the complementarity of these three catalogs
in order to facilitate the use of these data sets for characterizing the
physical properties of minor planets.Comment: 21 pages, 19 figures, and 2 tables, accepted for publication in PAS
Pupillometry, a bioengineering overview
The pupillary control system is examined using a microprocessor based integrative pupillometer. The real time software functions of the microprocessor include: data collection, stimulus generation and area to diameter conversion. Results of an analysis of linear and nonlinear phenomena are presented
Pollination and Breeding System of Lowbush Blueberries, Vaccinium angustifolium Ait. and V. myrtilloides Michx. (Ericacaeae), in the Boreal Forest
Breeding systems and pollination requirements of two wild lowbush blueberries, Vaccinium angustifolium and V. myrtilloides, in the Canadian boreal forest in the Chapleau Crown Game Preserve, Ontario, were tested. Fruit production, size and seediness were significantly higher in samples exposed to natural pollination than in those cross- or self-pollinated by hand. There were no significant differences among artificial treatments (variously hand-pollinated and bagged) except when cross-pollination (xenogamy) was done by insect pins. In V. angustifolium, the density of flowering varied with forest age (canopy closure). It was most in open areas and least in the sites with the most mature forest. Although fruit-set and seediness varied among forest habitats of different ages, there were no significant differences between sites in forests of different ages. Thus, pollination seems to be similarly effective no matter the age of the forest. In both species, fruit-set in 1992, which had severe June frosts, was markedly poorer than that in 1993 when the flowers suffered little frost damage. The combined number of complete and incomplete seeds from the fruit among the breeding and pollination systems tested were similar; however, the ratio of complete seeds to total seeds was greater from cross-pollinated than from self-pollinated flowers. Our observations indicate that there is little natural fruit-set without insect-mediated cross-pollination and that cross-pollination provides much better fruit and seed-set than does self-pollination
Simulation of electromagnetically and magnetically induced transparency in a magnetized plasma
Electromagnetically induced transparency (EIT), a phenomenon well known in atomic systems, has a natural analogy in a classical magnetized plasma. The magnetized plasma has a resonance for right-hand polarized electromagnetic waves at the electron cyclotron frequency Omega(0), so that a probe wave with frequency omega(1) = Omega(0) cannot propagate through the plasma. The plasma can be made transparent to such a probe by the presence of a pump wave. The pump may be an electromagnetic wave or magnetostatic wiggler. Simulations and theory show that the physical reason for the transparency is that the beating of the probe wave with the pump wave sets up a plasma oscillation, and the upper sideband of the pump wave cancels the resonant plasma current due to the probe. The theory of plasma EIT derived here extends that found in the earlier work to include the effects of the lower sideband of the pump and renormalization of the plasma frequency and an analysis of the transient response. A detailed comparison of theory to one-dimensional particle-in-cell simulations is presented and estimates for the performance ion accelerator using the EIT interaction are given. The dispersion relation and estimates for the phase velocity and amplitude of the plasma wave are in good agreement with particle-in-cell simulations.open151
GROWTH-STIMULATING FACTOR IN REGENERATING CANINE LIVER
Extracts from dog livers which had been regenerating for 24, 48, and 72 h after hepatectomy were infused for 6 h into the left portal vein of animals which had fresh portacaval shunts (Eck fistula) and which were killed 2 and 3 days later. The brief exposure to the 48-h and especially the 72-h regenerating liver extracts induced a delayed proliferative response predominantly in the left liver lobes, with a slight spillover effect to the right liver lobes but none to the kidney. The response reached its peak 3 days later. In the left but not the right liver lobes, both the 48-h and the 72-h regenerating liver extract reversed the atrophy ordinarily caused by Eck fistula in 3 days and partly prevented the ultrastructural hepatocyte deterioration characteristic of Eck fistula. The active liver extracts apparently contained a growth-control factor or factors which is (are) not insulin or glucagon. © 1979
6′-Amino-3′-methyl-2-oxo-1′-phenyl-1′,3a′,4′,7a′-tetrahydrospiro[1H-indole-3(2H),4′-pyrano[2,3-d]pyrazole]-5′-carbonitrile
In the crystal structure of the title compound, C21H15N5O2, the planar indolone unit and the pyran ring are almost perpendicular to each other [dihedral angle = 89.41 (2)°], and the pyrazole and phenyl rings are oriented at an angle of 25.74 (1)°. The molecular packing is stabilized by inter- and intramolecular C—H⋯O, N—H⋯O and C—H⋯π hydrogen bonds
Revised Relativistic Hydrodynamical Model for Neutron-Star Binaries
We report on numerical results from a revised hydrodynamic simulation of
binary neutron-star orbits near merger. We find that the correction recently
identified by Flanagan significantly reduces but does not eliminate the
neutron-star compression effect. Although results of the revised simulations
show that the compression is reduced for a given total orbital angular
momentum, the inner most stable circular orbit moves to closer separation
distances. At these closer orbits significant compression and even collapse is
still possible prior to merger for a sufficiently soft EOS. The reduced
compression in the corrected simulation is consistent with other recent studies
of rigid irrotational binaries in quasiequilibrium in which the compression
effect is observed to be small. Another significant effect of this correction
is that the derived binary orbital frequencies are now in closer agreement with
post-Newtonian expectations.Comment: Submitted to Phys. Rev.
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