1,462 research outputs found
Project Chariot - Phase III: Progress Report
This is a preliminary report and is NOT FOR PUBLICATIONBotanical investigations of the Cape Thompson - Ogotoruk Creek
region of northwest Alaska were initiated in May, 1959 by the
University of Alaska under contract with the United States Atomic
Energy Commission (Contract No. AT (04 -3 ) - 310). The first
summer's field work was largely exploratory and descriptive in
nature and included a species inventory of the vascular plants,
mosses, and lichens; a qualitative description of the main vegetation
types in Ogotoruk Valley; and a preliminary mapping of the
vegetation types within the valley.
The results of the first summer's field work and winter visits have been partially reported in two reports: Ogotoruk Valley
Botanical Project, December, 1959 Report, and the Phase II Interim
Pinal Report, Ogotoruk Valley Botanical Project, June, 1960. For
brevity, these will be referred to as the December, 1959 Botanical
Report, and the June, 1960 Botanical Report. Materials reported
in these earlier reports will not be repeated in this December,
1960 report.
Botanical investigations were continued during the summer and
fall of 1960. The objectives of the 1960 field season were as
follows: 1. To measure the frequency, cover, and synthetic features
of the main vegetation types in Ogotoruk Valley.
2. To establish control vegetation plots in areas outside
the potential blast and fallout area and to extend our
understanding of the vegetation of the northwestern
Alaska Coast.
3. To complete records of species occurrence in the area
by continuing plant collections and identifications.
4. To revise and complete the vegetation map of the area.
5. To continue seed germination studies on certain species.
6. To commence palynological studies of bog and lacustrine
sediments.
7. To initiate studies on some of the ecological problems
in the Ogotoruk Valley area.
a. to understand the relationship between permafrost,
annual freezing-thawing cycles, and plant distribution.
b. to understand the inter-relationships of the activities
of the arctic ground squirrel and vegetation in
the valley.
Preliminary results of the 1960 field work and additional information
from the 1959 season are included in this report
Vector bundles on the projective line and finite domination of chain complexes
Finitely dominated chain complexes over a Laurent polynomial ring in one
indeterminate are characterised by vanishing of their Novikov homology. We
present an algebro-geometric approach to this result, based on extension of
chain complexes to sheaves on the projective line. We also discuss the
K-theoretical obstruction to extension.Comment: v1: 11 page
Fitting a sum of exponentials to lattice correlation functions using a non-uniform prior
Excited states are extracted from lattice correlation functions using a
non-uniform prior on the model parameters. Models for both a single exponential
and a sum of exponentials are considered, as well as an alternate model for the
orthogonalization of the correlation functions. Results from an analysis of
torelon and glueball operators indicate the Bayesian methodology compares well
with the usual interpretation of effective mass tables produced by a
variational procedure. Applications of the methodology are discussed.Comment: 12 pages, 8 figures, 8 tables, major revision, final versio
On asymptotically equivalent shallow water wave equations
The integrable 3rd-order Korteweg-de Vries (KdV) equation emerges uniquely at
linear order in the asymptotic expansion for unidirectional shallow water
waves. However, at quadratic order, this asymptotic expansion produces an
entire {\it family} of shallow water wave equations that are asymptotically
equivalent to each other, under a group of nonlinear, nonlocal, normal-form
transformations introduced by Kodama in combination with the application of the
Helmholtz-operator. These Kodama-Helmholtz transformations are used to present
connections between shallow water waves, the integrable 5th-order Korteweg-de
Vries equation, and a generalization of the Camassa-Holm (CH) equation that
contains an additional integrable case. The dispersion relation of the full
water wave problem and any equation in this family agree to 5th order. The
travelling wave solutions of the CH equation are shown to agree to 5th order
with the exact solution
Penrose Limits and RG Flows
The Penrose-Gueven limit simplifies a given supergravity solution into a
pp-wave background. Aiming at clarifying its relation to renormalization group
flow we study the Penrose-Guven limit of supergravity backgrounds that are dual
to non-conformal gauge theories. The resulting backgrounds fall in a class
simple enough that the quantum particle is exactly solvable. We propose a map
between the effective time-dependent quantum mechanical problem and the RG flow
in the gauge theory. As a testing ground we consider explicitly two Penrose
limits of the infrared fixed point of the Pilch-Warner solution. We analyze the
corresponding gauge theory picture and write down the operators which are the
duals of the low lying string states. We also address RG flows of a different
nature by considering the Penrose-Gueven limit of a stack of N D_p branes. We
note that in the far IR (for p<3)the limit generically has negative
mass-squared. This phenomenon signals, in the world sheet picture, the
necessity to transform to another description. In this regard, we consider
explicitly the cases of M2 from D2 and F1 from D1 .Comment: 35 pp, 6 figure
Technological Devices in the Archives: A Policy Analysis
Doing research in the archive is the cornerstone of humanities scholarship.
Various archives institute policies regarding the use of technological
devices, such as mobile phones, laptops, and cameras in their reading rooms.
Such policies directly affect the scholars as the devices mediate the nature of
their interaction with the source materials in terms of capturing, organizing,
note taking, and record keeping for future use of found materials. In this paper,
we present our analysis of the policies of thirty archives regarding the use of
technology in their reading rooms. This policy analysis, along with data from
interviews of scholars and archivists, is intended to serve as a basis for developing
mobile applications for assisting scholars in their research activities. In this
paper we introduce an early prototype of such a mobile applicationâ
AMTracker.Informatio
Mutations in valosin-containing protein (VCP) decrease ADP/ATP translocation across the mitochondrial membrane and impair energy metabolism in human neurons
Mutations in the gene encoding valosin-containing protein (VCP) lead to multisystem proteinopathies including frontotemporal dementia. We have previously shown that patient-derived VCP mutant fibroblasts exhibit lower mitochondrial membrane potential, uncoupled respiration, and reduced ATP levels. This study addresses the underlying basis for mitochondrial uncoupling using VCP knockdown neuroblastoma cell lines, induced pluripotent stem cells (iPSCs), and iPSC-derived cortical neurons from patients with pathogenic mutations in VCP. Using fluorescent live cell imaging and respiration analysis we demonstrate a VCP mutation/knockdown-induced dysregulation in the adenine nucleotide translocase, which results in a slower rate of ADP or ATP translocation across the mitochondrial membranes. This deregulation can explain the mitochondrial uncoupling and lower ATP levels in VCP mutation-bearing neurons via reduced ADP availability for ATP synthesis. This study provides evidence for a role of adenine nucleotide translocase in the mechanism underlying altered mitochondrial function in VCP-related degeneration, and this new insight may inform efforts to better understand and manage neurodegenerative disease and other proteinopathies
Ownership and control in a competitive industry
We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry profits are maximized within a symmetric two product monopoly, the investor attains this only in exceptional cases. Instead, she sometimes acquires a noncontrolling stake. Or she invests asymmetrically rather than pursuing a full takeover if she acquires a controlling one. Generally, she invests indirectly if she only wants to affect the product market outcome, and directly if acquiring shares is profitable per se. --differentiated products,separation of ownership and control,private benefits of control
Precision Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetries A2
We have measured the spin structure functions g2p and g2d and the virtual
photon asymmetries A2p and A2d over the kinematic range 0.02 < x < 0.8 and 0.7
< Q^2 < 20 GeV^2 by scattering 29.1 and 32.3 GeV longitudinally polarized
electrons from transversely polarized NH3 and 6LiD targets. Our measured g2
approximately follows the twist-2 Wandzura-Wilczek calculation. The twist-3
reduced matrix elements d2p and d2n are less than two standard deviations from
zero. The data are inconsistent with the Burkhardt-Cottingham sum rule if there
is no pathological behavior as x->0. The Efremov-Leader-Teryaev integral is
consistent with zero within our measured kinematic range. The absolute value of
A2 is significantly smaller than the sqrt[R(1+A1)/2] limit.Comment: 12 pages, 4 figures, 2 table
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