836 research outputs found
Centering Social Equity in the Climate Action Planning Process: Lessons for Richmond, Virginia
The client of this plan is the City of Richmond\u27s Office of Sustainability. The purpose is to assist RVAgreen 2050\u27s in its equity-centered climate action planning and to reach the City of Richmond\u27s frontline communities (those impacted first and worst to climate impacts of intense heat, low-lying flooding, and severe storm events). The method and approach include the content analysis of ten cities\u27 climate action, sustainability, or resiliency plans. It makes suggestions of best practices and recommendations for the City of Richmond to reach those historically left out of the planning process and to shift power from the local government to the frontline community (from community engagement to ownership). It includes lessons learned during the early stage of the RVAgreen 2050 planning process, as well as the ten cities\u27 definitions of equity, stages in the planning process, and implementation
New RR Lyrae variables in binary systems
Despite their importance, very few RR Lyrae (RRL) stars have been known to
reside in binary systems. We report on a search for binary RRL in the OGLE-III
Galactic bulge data. Our approach consists in the search for evidence of the
light-travel time effect in so-called observed minus calculated ()
diagrams. Analysis of 1952 well-observed fundamental-mode RRL in the OGLE-III
data revealed an initial sample of 29 candidates. We used the recently released
OGLE-IV data to extend the baselines up to 17 years, leading to a final sample
of 12 firm binary candidates. We provide diagrams and binary parameters
for this final sample, and also discuss the properties of 8 additional
candidate binaries whose parameters cannot be firmly determined at present. We
also estimate that per cent of the RRL reside in binary systems.Comment: MNRAS Letters, in pres
Gray Whale Distribution and Catch by Alaskan Eskimos: A Replacement for the Bowhead Whale?
The catch of gray whales, Eschrichtius robustus, by Alaskan Eskimos from 1925 to 1980 has been documented to the extent possible by a search of the literature and personal communications with knowledgeable sources. During the period 1950-1980, 47 gray whales were landed by hunters at 12 villages. During this same period, 505 bowhead whales, Balaena mysticetus, were landed at nine coastal whaling villages. Alaskan Eskimos traditionally have been bowhead whalers, principally because of the predictive nature of the bowheads' migration. Gray whaling has never been an important subsistence activity. Because the bowhead population is thought to be depleted, gray whales have been suggested as a possible substitute for subsistence. The distribution of gray whales in Alaskan coastal waters is such that reliable annual whaling for this species is possible only at villages on the shores of the northern Bering Sea; it is unlikely for villages north of Bering Strait to Cape Lisburne, and more unlikely for villages north of Cape Lisburne and east of Point Barrow. Based on cultural and biological grounds, substituting gray whales for bowheads does not appear to be a reliable alternative for the residents of four to six of the nine Eskimo villages that currently participate in bowhead whaling.Key words: gray whale, Eschrichitus robustus; bowhead whale, Balaena mysticetus; Eskimos; subsistence whaling; AlaskaMots clés: baleine grise de Californie, Eschrichtius robustus; balaine boréale, Balaena mysticetus; Esquimaux, chasse à la baleine comme activité de subsistance, Alask
An infinite family of superintegrable systems from higher order ladder operators and supersymmetry
We will discuss how we can obtain new quantum superintegrable Hamiltonians
allowing the separation of variables in Cartesian coordinates with higher order
integrals of motion from ladder operators. We will discuss also how higher
order supersymmetric quantum mechanics can be used to obtain systems with
higher order ladder operators and their polynomial Heisenberg algebra. We will
present a new family of superintegrable systems involving the fifth Painleve
transcendent which possess fourth order ladder operators constructed from
second order supersymmetric quantum mechanics. We present the polynomial
algebra of this family of superintegrable systems.Comment: 8 pages, presented at ICGTMP 28, accepted for j.conf.serie
Third order superintegrable systems separating in polar coordinates
A complete classification is presented of quantum and classical
superintegrable systems in that allow the separation of variables in
polar coordinates and admit an additional integral of motion of order three in
the momentum. New quantum superintegrable systems are discovered for which the
potential is expressed in terms of the sixth Painlev\'e transcendent or in
terms of the Weierstrass elliptic function
Organizing pneumonia: What is it? A conceptual approach and pictorial review
AbstractOrganizing pneumonia (formerly named bronchiolitis obliterans with organizing pneumonia or BOOP) is a clinical, radiological and histological entity that is classified as an Interstitial Lung Disease. The understanding of this family of diseases has seen great progress over the past twenty years. CT presentation of organizing pneumonia is polymorphous but a few patterns have been recently recognized as being more specific to this diagnosis. The aim of this work is to summarize new understandings of the clinical and histological presentation of the disease and to review the most relevant CT features
Superintegrability and higher order polynomial algebras II
In an earlier article, we presented a method to obtain integrals of motion
and polynomial algebras for a class of two-dimensional superintegrable systems
from creation and annihilation operators. We discuss the general case and
present its polynomial algebra. We will show how this polynomial algebra can be
directly realized as a deformed oscillator algebra. This particular algebraic
structure allows to find the unitary representations and the corresponding
energy spectrum. We apply this construction to a family of caged anisotropic
oscillators. The method can be used to generate new superintegrable systems
with higher order integrals. We obtain new superintegrable systems involving
the fourth Painleve transcendent and present their integrals of motion and
polynomial algebras.Comment: 11 page
Families of superintegrable Hamiltonians constructed from exceptional polynomials
We introduce a family of exactly-solvable two-dimensional Hamiltonians whose
wave functions are given in terms of Laguerre and exceptional Jacobi
polynomials. The Hamiltonians contain purely quantum terms which vanish in the
classical limit leaving only a previously known family of superintegrable
systems. Additional, higher-order integrals of motion are constructed from
ladder operators for the considered orthogonal polynomials proving the quantum
system to be superintegrable
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