51,469 research outputs found
Science Fiction Double Feature: Trans Liberation on Twin Earth
What is it to be a woman? What is it to be a man? We start by laying out desiderata for an analysis of 'woman' and 'man': descriptively, it should link these gender categories to sex biology without reducing them to sex biology, and politically, it should help us explain and combat traditional sexism while also allowing us to make sense of the activist view that gendering should be consensual. Using a Putnam-style 'Twin Earth' example, we argue that none of the existing analyses in the feminist literature succeeds in meeting all of our desiderata. Finally, we propose a positive account that we believe can satisfy all the desiderata outlined. According to our theory, the genders 'woman' and 'man' are individuated not by their contemporary connections to sex biology, but by their historical continuity with classes that were originally closely connected to sex biology
AIR POLLUTION AND FARM-LEVEL CROP YIELDS: AN EMPIRICAL ANALYSIS OF CORN AND SOYBEANS
While many studies have estimated the impacts of air pollution on crop yields on experimental plots, few have estimated these impacts under actual farm production conditions. This study econometrically estimates the impact of air pollution on corn and soybean yields, controlling for weather, soil quality and management practices, using farm-level data for the eastern United States. Ozone pollution was found to reduce yields for both crops. The mean elasticity of yield with respect to ozone exposure was -0.19 for corn and -0.54 for soybeans. The benefits of ozone standards to protect crops, measured in terms of crop revenues, range from 82 million depending on the stringency of the standard. Over 85 percent of the revenue gains are captured by three states: Maryland, North Carolina, and Virginia.Crop Production/Industries, Environmental Economics and Policy,
Low-frequency absorption cross section of the electromagnetic waves for the extreme Reissner-Nordstrom black holes in higher dimensions
We investigate the low-frequency absorption cross section of the
electromagnetic waves for the extreme Reissner-Nordstrom black holes in higher
dimensions. We first construct the exact solutions to the relevant wave
equations in the zero-frequency limit. In most cases it is possible to use
these solutions to find the transmission coefficients of partial waves in the
low-frequency limit. We use these transmission coefficients to calculate the
low-frequency absorption cross section in five and six spacetime dimensions. We
find that this cross section is dominated by the modes with l=2 in the
spherical-harmonic expansion rather than those with l=1, as might have been
expected, because of the mixing between the electromagnetic and gravitational
waves. We also find an upper limit for the low-frequency absorption cross
section in dimensions higher than six.Comment: 7 pages, 1 figure, Phys. Rev. D (to appear
The Unruh effect and its applications
It has been thirty years since the discovery of the Unruh effect. It has
played a crucial role in our understanding that the particle content of a field
theory is observer dependent. This effect is important in its own right and as
a way to understand the phenomenon of particle emission from black holes and
cosmological horizons. Here, we review the Unruh effect with particular
emphasis to its applications. We also comment on a number of recent
developments and discuss some controversies. Effort is also made to clarify
what seems to be common misconceptions.Comment: 53 pages, 11 figures, submitted to Reviews of Modern Physic
Interaction of Hawking radiation and a static electric charge
We investigate whether the equality found for the response of static scalar
sources interacting (i) with {\em Hawking radiation in Schwarzschild spacetime}
and (ii) with the Fulling-Davies-Unruh thermal bath in the Rindler wedge is
maintained in the case of electric charges. We find a finite result in the
Schwarzschild case, which is computed exactly, in contrast with the divergent
result associated with the infrared catastrophe in the Rindler case, i.e. in
the case of uniformly accelerated charges in Minkowski spacetime. Thus, the
equality found for scalar sources does not hold for electric charges.Comment: 8 pages (REVTEX
Fast cooling of trapped ions using the dynamical Stark shift gate
A laser cooling scheme for trapped ions is presented which is based on the
fast dynamical Stark shift gate, described in [Jonathan etal, PRA 62, 042307].
Since this cooling method does not contain an off resonant carrier transition,
low final temperatures are achieved even in traveling wave light field. The
proposed method may operate in either pulsed or continuous mode and is also
suitable for ion traps using microwave addressing in strong magnetic field
gradients.Comment: 4 pages 5 figure
Polarization of the \lya Halos Around Sources Before Cosmological Reionization
In Loeb & Rybicki (1999; paper I) it was shown that before reionization, the
scattering of \lya photons from a cosmological source might lead to a fairly
compact () \lya halo around the source. Observations of such halos
could constrain the properties of the neutral intergalactic medium (IGM), and
in particular yield the cosmological density parameters of baryons and matter
on scales where the Hubble flow is unperturbed. Paper I did not treat the
polarization of this scattered radiation, but did suggest that the degree of
such polarization might be large. In this Letter we report on improved
calculations for these \lya halos, now accounting for the polarization of the
radiation field. The polarization is linear and is oriented tangentially to the
projected displacement from the center of the source. The degree of
polarization is found to be 14% at the core radius, where the intensity has
fallen to half of the central value. It rises to 32% and 45% at the radii where
the intensity has fallen to one-tenth and one-hundreth of the central
intensity, respectively. At larger radii the degree of polarization rises
further, asymptotically to 60%. Such high values of polarization should be
easily observable and provide a clear signature of the phenomenon of \lya halos
surrounding sources prior to reionization.Comment: 8 pages, 2 Postscript figures, accepted by Astrophysical Journal
Letters; some typos corrected; added two paragraphs at the end of section 3
concerning detectability of Lyman alpha halo
Fast Fourier Transform algorithm design and tradeoffs
The Fast Fourier Transform (FFT) is a mainstay of certain numerical techniques for solving fluid dynamics problems. The Connection Machine CM-2 is the target for an investigation into the design of multidimensional Single Instruction Stream/Multiple Data (SIMD) parallel FFT algorithms for high performance. Critical algorithm design issues are discussed, necessary machine performance measurements are identified and made, and the performance of the developed FFT programs are measured. Fast Fourier Transform programs are compared to the currently best Cray-2 FFT program
Manual for starch gel electrophoresis: A method for the detection of genetic variation
The procedure to conduct horizontal starch gel electrophoresis on enzymes is described in detail. Areas covered are (I) collection and storage of specimens, (2)
preparation of tissues, (3) preparation of a starch gel, (4) application of enzyme extracts to a gel, (5) setting up a gel for electrophoresis, (6) slicing a gel, and (7)
staining a gel. Recipes are also included for 47 enzyme stains and 3 selected gel buffers. (PDF file contains 26 pages.
Validity of the Impact on Participation and Autonomy questionnaire – a comparison between the Netherlands and the UK
- …