1,324 research outputs found
Projected Deaths of Despair from COVID-19
More Americans could lose their lives to deaths of despair, deaths due to drug, alcohol, and suicide, if we do not do something immediately. Deaths of despair have been on the rise for the last decade, and in the context of COVID-19, deaths of despair should be seen as the epidemic within the pandemic. The goal of this report is to predict what deaths of despair we might see based on three assumptions during COVID-19: economic recovery, relationship between deaths of despair and unemployment, and geography. Across nine different scenarios, additional deaths of despair range from 27,644 (quick recovery, smallest impact of unemployment on deaths of despair) to 154,037 (slow recovery, greatest impact of unemployment on deaths of despair), with somewhere in the middle being around 68,000. However, these data are predictions. We can prevent these deaths by taking meaningful and comprehensive action as a nation
Electromagnetic Fields of Slowly Rotating Magnetized Gravastars
We study the dipolar magnetic field configuration and present solutions of
Maxwell equations in the internal background spacetime of a a slowly rotating
gravastar. The shell of gravastar where magnetic field penetrated is modeled as
sphere consisting of perfect highly magnetized fluid with infinite
conductivity. Dipolar magnetic field of the gravastar is produced by a circular
current loop symmetrically placed at radius at the equatorial plane.Comment: 5 pages, 2 figures, accepted for publication to Mod. Phys. Lett.
Sexist Ideology and Endorsement of Men's Control over Women's Decisions in Reproductive Health
Feminist scholars have argued that men’s control over women’s reproductive autonomy is a central feature of male dominance. Building on recent research that shows sexist ideology informs support for restricting women’s reproductive autonomy, we examined the relation of sexism and the belief that men should be able to restrict the behavior of women. Study 1 (N = 366 undergraduate psychology students in the United Kingdom) and Study 2 (N = 281 Amazon MTurk workers in the United States), showed that controlling for various demographics and ideological measures (e.g., right-wing authoritarianism, support for abortion rights), hostile sexism was related to support for men having the right to prevent their pregnant partner from having an abortion. Further, hostile sexism was also related to the endorsement of men’s right to withdraw financial support for the child if a woman chooses not to terminate her pregnancy. Hostile sexism was also uniquely related to support for men’s right to veto their female partner’s decisions during pregnancy and childbirth. The present studies show that hostile sexism is associated with perceptions that men have the right to constrain women’s reproductive choices. Our findings highlight the adverse pressures on women’s reproductive autonomy, including sexist ideology, and may suggest that practitioners should be mindful of this when assisting women in discussing reproductive questions. Further, by creating awareness about the different factors that shape the perception of men’s role in reproductive decisions, sexual health educators could potentially help affirm women’s autonomy in reproductive health
New homogeneous iron abundances of double-mode Cepheids from high-resolution echelle spectroscopy
Aims: We define the relationship between the double-mode pulsation of
Cepheids and metallicity in a more accurate way, determine the empirical
metallicities of double-mode Cepheids from homogeneous, high-resolution
spectroscopic data, and study of the period-ratio -- metallicity dependence.
Methods: The high S/N echelle spectra obtained with the FEROS spectrograph were
analyzed using a self-developed IRAF script, and the iron abundances were
determined by comparing with synthetic spectra assuming LTE. Results: Accurate
[Fe/H] values of 17 galactic beat Cepheids were determined. All these stars
have solar or slightly subsolar metallicity. Their period ratio P1/P0 shows
strong correlation with their derived [Fe/H] values. The corresponding period
ratio -- metallicity relation has been evaluated.Comment: 10 pages, 7 figures, accepted in A&
Realizability of stationary spherically symmetric transonic accretion
The spherically symmetric stationary transonic (Bondi) flow is considered a
classic example of an accretion flow. This flow, however, is along a
separatrix, which is usually not physically realizable. We demonstrate, using a
pedagogical example, that it is the dynamics which selects the transonic flow.Comment: 4 pages in REVTeX with 2 figures. Typos have been corrected and some
alterations have been made in the version published in Physical Review
A Toy Model for Blandford-Znajek Mechanism
A toy model for the Blandford-Znajek mechanism is investigated: a Kerr black
hole with a toroidal electric current residing in a thin disk around the black
hole. The toroidal electric current generates a poloidal magnetic field
threading the black hole and disk. Due to the interaction of the magnetic field
with remote charged particles, the rotation of the black hole and disk induces
an electromotive force, which can power an astrophysical load at remote
distance. The power of the black hole and disk is calculated. It is found that,
for a wide range of parameters specifying the rotation of the black hole and
the distribution of the electric current in the disk, the power of the disk
exceeds the power of the black hole. The torque provided by the black hole and
disk is also calculated. The torque of the disk is comparable to the torque of
the black hole. As the disk loses its angular momentum, the mass of the disk
gradually drifts towards the black hole and gets accreted. Ultimately the power
comes from the gravitational binding energy between the disk and the black
hole, as in the standard theory of accretion disk, instead of the rotational
energy of the black hole. This suggests that the Blandford-Znajek mechanism may
be less efficient in extracting energy from a rotating black hole with a thin
disk. The limitations of our simple model and possible improvements deserved
for future work are also discussed.Comment: 16 pages, 4 figures. Accepted for publication in Physical Review
On the orbital and physical parameters of the HDE 226868/Cygnus X-1 binary system
In this paper we explore the consequences of the recent determination of the
mass m=(8.7 +/- 0.8)M_Sun of Cygnus X-1, obtained from the Quasi-Periodic
Oscillation (QPO)-photon index correlation scaling, on the orbital and physical
properties of the binary system HDE 226868/Cygnus X-1. By using such a result
and the latest spectroscopic optical data of the HDE 226868 supergiant star we
get M=(24 +/- 5)M_Sun for its mass. It turns out that deviations from the third
Kepler law significant at more than 1-sigma level would occur if the
inclination i of the system's orbital plane to the plane of the sky falls
outside the range 41-56 deg: such deviations cannot be due to the first
post-Newtonian (1PN) correction to the orbital period because of its smallness;
interpreted in the framework of the Newtonian theory of gravitation as due to
the stellar quadrupole mass moment Q, they are unphysical because Q would take
unreasonably large values. By conservatively assuming that the third Kepler law
is an adequate model for the orbital period we obtain i=(48 +/- 7) deg which
yields for the relative semimajor axis a=(42 +/- 9)R_Sun. Our estimate for the
Roche's lobe of HDE 226868 is r_M = (21 +/- 6)R_Sun.Comment: Latex2e, 7 pages, 1 table, 4 figures. To appear in ApSS (Astrophysics
and Space Science
- …