2,063 research outputs found
Additions and Corrections to the Stoneflies (Plecoptera) of Iowa, U.S.A.
(exerpt)
Until recently, Iowa’s stonefly fauna was poorly documented. Heimdal et al. (2004) published a comprehensive report on stonefly distributions within the state, reporting seven families and 43 species. Five species, Allocapnia pygmaea (Burmeister) (Capiniidae), Leuctra tenuis (Pictet) (Leuctridae), Amphinemura linda (Ricker) (Nemouridae), Nemoura trispinosa Claassen (Nemouridae), and Soyedina vallicularia (Wu) (Nemouridae), were recommended for state protection because of their limited distribution within Iowa. Four species, Amphinemura delosa (Ricker), Isogenoides doratus (Frison) (Perlodidae), I. krumholzi (Ricker), and I. varians (Walsh), had limited distributions, but were not listed because their observed habitat preferences appeared common or were difficult to sample and poorly collected. From 2004 to 2006, fifteen county, state, and federal parks and preserves in east and northeast Iowa were sampled during the spring and summer in an effort to find additional locations for these nine species. The surveys yielded new distributional data for five species, including two new state records, and one species deletion, updating the total number of species recorded from Iowa to 44. A discussion for these records and corrections is presented below. Material collected from these surveys was deposited in the University of Iowa Hygienic Laboratory Collection (UHL) and the Illinois Natural History Survey Insect Collection (INHS)
Superspace Gauge Fixing of Topological Yang-Mills Theories
We revisit the construction of topological Yang-Mills theories of the Witten
type with arbitrary space-time dimension and number of ``shift supersymmetry''
generators, using a superspace formalism. The super-BF structure of these
theories is exploited in orderto determine their actions uniquely, up to the
ambiguities due to the fixing of the Yang-Mills and BF gauge invariance. UV
finiteness to all orders of perturbation theory is proved in a gauge of the
Landau type.Comment: 26 pages, no figures, Late
Observables in Topological Yang-Mills Theories With Extended Shift Supersymmetry
We present a complete classification, at the classical level, of the
observables of topological Yang-Mills theories with an extended shift
supersymmetry of N generators, in any space-time dimension. The observables are
defined as the Yang-Mills BRST cohomology classes of shift supersymmetry
invariants. These cohomology classes turn out to be solutions of an N-extension
of Witten's equivariant cohomology. This work generalizes results known in the
case of shift supersymmetry with a single generator.Comment: 27 pages, Late
Comment on 4D Lorentz invariance violations in the brane-world
The brane-world scenario offers the possibility for signals to travel outside
our visible universe and reenter it. We find the condition for a signal emitted
from the brane to return to the brane. We study the propagation of such signals
and show that, as seen by a 4D observer, these signals arrive earlier than
light traveling along the brane. We also study the horizon problem and find
that, while the bulk signals can travel far enough to homogenize the visible
universe, it is unlikely that they have a significant effect since they are
redshifted in the gravitational field of the bulk black hole.Comment: 21 pages, 6 figures, REVTEX, New section adde
Synthesis of multiple-input change asynchronous finite state machines
Asynchronous finite state machines (AFSMS) have been limited because multiple-input changes have been disallowed. In this paper, we present an architecture and synthesis system to overcome this limitation. The AFSM marks potentially hazardous state transitions, and prevents output during them. A synthesis tool to create the AFS M incorporates novel algorithms to detect the hazardous states
Effect Of Lipid Solvents On Protein, Dna, And Collagen Synthesis In Human Skin: An Electron Microscopic Autoradiographic Study
The effect of acetone and kerosene on the synthesis of protein, DNA, and collagen was studied by electron microscopic autoradiography using [3H]leucine, [3H]thymidine, and [3H]proline as tracers in human skin. Quantitative analyses following concomitant administration of tritiated leucine and acetone or kerosene demonstrated, at 90 min, a marked decrease in silver grains as compared to control or nonexposed areas. Incorporation of tritiated thymidine is moderately stimulated only by acetone, whereas radioactive proline distribution is not significantly affected. Electron microscopic autoradiograms revealed that tritiated leucine is distributed over all epidermal cells, mostly in the stratum spinosum of control epidermis; a marked decrease of silver grains from [3H]leucine followed both lipid solvent exposures. The autoradiographic reaction is specifically located over cytoplasmic organelles, such as polysomes, endoplasmic reticulum, and especially tonofilaments. Tritiated thymidine resulted in silver grains mostly over nuclear chromatin and these were moderately increased after acetone application, whereas the incorporation of radioactive proline in the fibroblasts and collagen fibrils were not significantly influenced. These investigations indicate a dissociated effect of lipid solvents on protein, DNA, and collagen synthesis in human skin
A Comprehensive Trainable Error Model for Sung Music Queries
We propose a model for errors in sung queries, a variant of the hidden Markov
model (HMM). This is a solution to the problem of identifying the degree of
similarity between a (typically error-laden) sung query and a potential target
in a database of musical works, an important problem in the field of music
information retrieval. Similarity metrics are a critical component of
query-by-humming (QBH) applications which search audio and multimedia databases
for strong matches to oral queries. Our model comprehensively expresses the
types of error or variation between target and query: cumulative and
non-cumulative local errors, transposition, tempo and tempo changes,
insertions, deletions and modulation. The model is not only expressive, but
automatically trainable, or able to learn and generalize from query examples.
We present results of simulations, designed to assess the discriminatory
potential of the model, and tests with real sung queries, to demonstrate
relevance to real-world applications
Gauge symmetry breaking on orbifolds
We discuss a new method for gauge symmetry breaking in theories with one
extra dimension compactified on the orbifold S^1/Z_2. If we assume that fields
and their derivatives can jump at the orbifold fixed points, we can implement a
generalized Scherk-Schwarz mechanism that breaks the gauge symmetry. We show
that our model with discontinuous fields is equivalent to another with
continuous but non periodic fields; in our scheme localized lagrangian terms
for bulk fields appear.Comment: 6 pages, 2 figures. Talk given at the XXXVIIth Rencontres de Moriond,
"Electroweak interactions and unified theories", Les Arcs, France, 9-16 Mar
2002. Minor changes, one reference adde
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