5,132 research outputs found
The anatomy and the histology of bud- formation in the serpulid Filograna implexa and with some cytological observations on the nuclei of the neoblasts
External Features ā¢
1. General, 11 ā¢
2. Phases of life history . 22 ā¢
3. Configuration of buds . . 24 ā¢
4. Grouping of segments considered numerically . . 36Description of two abnormal buds , 55Alimentary canal , . 58Body wall ā¢
1. Epithelium , . . . 63 ā¢
2. Musculature ,
. . . . . . 70 ā¢
3. Central nervous system . . . . . 85Blood system . . . . . . 05Coelomic cavities . . . . 114Glandular sac and excretion. . . . 116Histology of bud -formation, together with cytological
observations on the nuclei of the embryonic cells. 123.Summary. 152
Narrative, identity, and recovery from serious mental illness: A life history of a runner
In recent years, researchers have investigated the psychological effects of exercise for people with mental health problems, often by focusing on how exercise may alleviate symptoms of mental illness. In this article I take a different tack to explore the ways in which exercise contributed a sense of meaning, purpose, and identity to the life of one individual named Ben, a runner diagnosed with schizophrenia. Drawing on life history data, I conducted an analysis of narrative to explore the narrative types that underlie Ben's stories of mental illness and exercise. For Ben, serious mental illness profoundly disrupted a pre-existing athletic identity removing agency, continuity, and coherence from his life story. By returning to exercise several years later, Ben reclaimed his athletic identity and reinstated some degree of narrative agency, continuity, and coherence. While the relationships between narrative, identity, and mental health are undoubtedly complex, Ben's story suggests that exercise can contribute to recovery by being a personally meaningful activity which reinforces identity and sense of self
The absorption of methane at low temperature in the 0.84 micron region
The absorption spectra of methane at low temperature with application to Jupiter atmospheric methane absorption is discussed. Experiments were made between 11,900 and 11950/cm. Attempts were made to observe single lines and determine the intensity of the spectra
New stability results for Einstein scalar gravity
We consider asymptotically anti de Sitter gravity coupled to a scalar field
with mass slightly above the Breitenlohner-Freedman bound. This theory admits a
large class of consistent boundary conditions characterized by an arbitrary
function . An important open question is to determine which admit stable
ground states. It has previously been shown that the total energy is bounded
from below if is bounded from below and the bulk scalar potential
admits a suitable superpotential. We extend this result and show that the
energy remains bounded even in some cases where can become arbitrarily
negative. As one application, this leads to the possibility that in
gauge/gravity duality, one can add a double trace operator with negative
coefficient to the dual field theory and still have a stable vacuum
Deconstructing holographic liquids
We argue that there exist simple effective field theories describing the
long-distance dynamics of holographic liquids. The degrees of freedom
responsible for the transport of charge and energy-momentum are Goldstone
modes. These modes are coupled to a strongly coupled infrared sector through
emergent gauge and gravitational fields. The IR degrees of freedom are
described holographically by the near-horizon part of the metric, while the
Goldstone bosons are described by a field-theoretical Lagrangian. In the cases
where the holographic dual involves a black hole, this picture allows for a
direct connection between the holographic prescription where currents live on
the boundary, and the membrane paradigm where currents live on the horizon. The
zero-temperature sound mode in the D3-D7 system is also re-analyzed and
re-interpreted within this formalism.Comment: 21 pages, 2 figure
Holographic fermions in charged Gauss-Bonnet black hole
We study the properties of the Green's functions of the fermions in charged
Gauss-Bonnet black hole. What we want to do is to investigate how the presence
of Gauss-Bonnet coupling constant affects the dispersion relation,
which is a characteristic of Fermi or non-Fermi liquid, as well as what
properties such a system has, for instance, the Particle-hole (a)symmetry. One
important result of this research is that we find for , the behavior of
this system is different from that of the Landau Fermi liquid and so the system
can be candidates for holographic dual of generalized non-Fermi liquids. More
importantly, the behavior of this system increasingly similar to that of the
Landau Fermi liquid when is approaching its lower bound. Also we find
that this system possesses the Particle-hole asymmetry when , another
important characteristic of this system. In addition, we also investigate
briefly the cases of the charge dependence.Comment: 22 pages, 6 figures; version published in JHE
Mixed RG Flows and Hydrodynamics at Finite Holographic Screen
We consider quark-gluon plasma with chemical potential and study
renormalization group flows of transport coefficients in the framework of
gauge/gravity duality. We first study them using the flow equations and compare
the results with hydrodynamic results by calculating the Green functions on the
arbitrary slice. Two results match exactly. Transport coefficients at arbitrary
scale is ontained by calculating hydrodynamics Green functions. When either
momentum or charge vanishes, transport coefficients decouple from each other.Comment: 22 pages, 6 figure
Magnetic Field Induced Quantum Criticality via new Asymptotically AdS_5 Solutions
Using analytical methods, we derive and extend previously obtained numerical
results on the low temperature properties of holographic duals to
four-dimensional gauge theories at finite density in a nonzero magnetic field.
We find a new asymptotically AdS_5 solution representing the system at zero
temperature. This solution has vanishing entropy density, and the charge
density in the bulk is carried entirely by fluxes. The dimensionless magnetic
field to charge density ratio for these solutions is bounded from below, with a
quantum critical point appearing at the lower bound. Using matched asymptotic
expansions, we extract the low temperature thermodynamics of the system. Above
the critical magnetic field, the low temperature entropy density takes a simple
form, linear in the temperature, and with a specific heat coefficient diverging
at the critical point. At the critical magnetic field, we derive the scaling
law s ~ T^{1/3} inferred previously from numerical analysis. We also compute
the full scaling function describing the region near the critical point, and
identify the dynamical critical exponent: z=3.
These solutions are expected to holographically represent boundary theories
in which strongly interacting fermions are filling up a Fermi sea. They are
fully top-down constructions in which both the bulk and boundary theories have
well known embeddings in string theory.Comment: 50 page
Virtual-crystal approximation that works: Locating a composition phase boundary in Pb(Zr_{1-x}Ti_3)O_3
We present a new method for modeling disordered solid solutions, based on the
virtual crystal approximation (VCA). The VCA is a tractable way of studying
configurationally disordered systems; traditionally, the potentials which
represent atoms of two or more elements are averaged into a composite atomic
potential. We have overcome significant shortcomings of the standard VCA by
developing a potential which yields averaged atomic properties. We perform the
VCA on a ferroelectric oxide, determining the energy differences between the
high-temperature rhombohedral, low-temperature rhombohedral and tetragonal
phases of Pb(Zr_{1-x}Ti_x)O_3 at x=0.5 and comparing these results to
superlattice calculations and experiment. We then use our new method to
determine the preferred structural phase at x=0.4. We find that the
low-temperature rhombohedral phase becomes the ground state at x=0.4, in
agreement with experimental findings.Comment: 5 pages, no figure
Anomalous Zero Sound
We show that the anomalous term in the current, recently suggested by Son and
Yamamoto, modifies the structure of the zero sound mode in the Fermi liquid in
a magnetic field.Comment: 14 pages, 2 figure
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