21,259 research outputs found
Critical Review of Richard Moran, The Exchange of Words
Moran's book is sure to be widely read. It does more to bring to light the moral psychology characteristic of tellings understood as assurances than any other work I know. His book raises challenges for other views, introduces interesting and evocative distinctions, and puts together in one place Moran's sustained reflections on the way we provide others a distinctive kind of reason for belief though normatively binding ourselves though the exchange of words. I agree that assurances and acceptances in Moran's sense play a part in a total understanding of the epistemology of testimony. But I do not agree they cover the whole terrain. There is much more to the metaphysics and epistemology of testimony still to explore
Localizing Gravitational Wave Sources with Single-Baseline Atom Interferometers
Localizing sources on the sky is crucial for realizing the full potential of
gravitational waves for astronomy, astrophysics, and cosmology. We show that
the mid-frequency band, roughly 0.03 to 10 Hz, has significant potential for
angular localization. The angular location is measured through the changing
Doppler shift as the detector orbits the Sun. This band maximizes the effect
since these are the highest frequencies in which sources live several months.
Atom interferometer detectors can observe in the mid-frequency band, and even
with just a single baseline can exploit this effect for sensitive angular
localization. The single baseline orbits around the Earth and the Sun, causing
it to reorient and change position significantly during the lifetime of the
source, and making it similar to having multiple baselines/detectors. For
example, atomic detectors could predict the location of upcoming black hole or
neutron star merger events with sufficient accuracy to allow optical and other
electromagnetic telescopes to observe these events simultaneously. Thus,
mid-band atomic detectors are complementary to other gravitational wave
detectors and will help complete the observation of a broad range of the
gravitational spectrum.Comment: 16 pages, 3 figures, 2 table
A Second Crystal Polymorph of Anilinium Picrate
The crystal structure of a second monoclinic polymorph of anilinium picrate shows a three-dimensional hydrogen-bonded polymer with strong primary interspecies interactions involving the proximal phenolate and adjacent nitro group O-atom acceptors and separate anilinium H-atom donors in two cyclic R (6) associations. Other nitro-O-anilinium-H hydrogen bonds together with heteromolecular interactions are also present
Disentangling the effects of geographic and ecological isolation on genetic differentiation
Populations can be genetically isolated both by geographic distance and by
differences in their ecology or environment that decrease the rate of
successful migration. Empirical studies often seek to investigate the
relationship between genetic differentiation and some ecological variable(s)
while accounting for geographic distance, but common approaches to this problem
(such as the partial Mantel test) have a number of drawbacks. In this article,
we present a Bayesian method that enables users to quantify the relative
contributions of geographic distance and ecological distance to genetic
differentiation between sampled populations or individuals. We model the allele
frequencies in a set of populations at a set of unlinked loci as spatially
correlated Gaussian processes, in which the covariance structure is a
decreasing function of both geographic and ecological distance. Parameters of
the model are estimated using a Markov chain Monte Carlo algorithm. We call
this method Bayesian Estimation of Differentiation in Alleles by Spatial
Structure and Local Ecology (BEDASSLE), and have implemented it in a
user-friendly format in the statistical platform R. We demonstrate its utility
with a simulation study and empirical applications to human and teosinte
datasets
Guanidinium 2-Carboxy-6-Nitrobenzoate Monohydrate: A Two-Dimensional Hydrogen-Bonded Network Structure
In the structure of the title compound, CH6N3+ . C8H4NO6- . H2O, obtained from the reaction of guanidine carbonate with 3-nitrophthalic acid, the 2-carboxylic acid group is deprotonated and participates in an asymmetric cyclic R2/1(6) hydrogen-bonding associatiuon with the guanidine cation together with a bridging water molecule of solvation. A conjoint R2/1(7) facial association involving a nitro O-atom acceptor together with a further five guanidinium N-H...O hydrogen bonds, as well as a strong carboxyl-water interaction [2.528(3) Ang.], give a two-dimensiional network structure
Luminous Dark Matter
We propose a dark matter model in which the signal in direct detection
experiments arises from electromagnetic, not nuclear, energy deposition. This
can provide a novel explanation for DAMA while avoiding many direct detection
constraints. The dark matter state is taken nearly degenerate with another
state. These states are naturally connected by a dipole moment operator, which
can give both the dominant scattering and decay modes between the two states.
The signal at DAMA then arises from dark matter scattering in the Earth into
the excited state and decaying back to the ground state through emission of a
single photon in the detector. This model has unique signatures in direct
detection experiments. The density and chemical composition of the detector is
irrelevant, only the total volume affects the event rate. In addition, the
spectrum is a monoenergetic line, which can fit the DAMA signal well. This
model is readily testable at experiments such as CDMS and XENON100 if they
analyze their low-energy, electronic recoil events.Comment: 23 pages, 3 figures, journal version, added discussion of daily
modulation, changed axes label of figure
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