12,343 research outputs found
Thermal equilibrium of a macroscopic quantum system in a pure state
We consider the notion of thermal equilibrium for an individual closed
macroscopic quantum system in a pure state, i.e., described by a wave function.
The macroscopic properties in thermal equilibrium of such a system, determined
by its wave function, must be the same as those obtained from thermodynamics,
e.g., spatial uniformity of temperature and chemical potential. When this is
true we say that the system is in macroscopic thermal equilibrium (MATE). Such
a system may however not be in microscopic thermal equilibrium (MITE). The
latter requires that the reduced density matrices of small subsystems be close
to those obtained from the microcanonical, equivalently the canonical, ensemble
for the whole system. The distinction between MITE and MATE is particularly
relevant for systems with many-body localization (MBL) for which the energy
eigenfunctions fail to be in MITE while necessarily most of them, but not all,
are in MATE. We note however that for generic macroscopic systems, including
those with MBL, most wave functions in an energy shell are in both MATE and
MITE. For a classical macroscopic system, MATE holds for most phase points on
the energy surface, but MITE fails to hold for any phase point
Euhrychiopsis lecontei distribution, abundance, and experimental augmentations for Eurasian watermilfoil control in Wisconsin lakes
The specialist aquatic herbivore Euhrychiopsis lecontei (Dietz)
is currently being researched as a potential biological control
agent for Eurasian watermilfoil (Myriophyllum spicatum L.).
Our research in Wisconsin focused on 1) determining milfoil
weevil distribution across lakes, 2) assessing limnological
characteristics associated with their abundance, and 3) evaluating
milfoil weevil augmentation as a practical management
tool for controlling Eurasian watermilfoil
New Records for \u3ci\u3eEuhrychiopsis Lecontei\u3c/i\u3e (Coleoptera: Curculionidae) and Their Densities in Wisconsin Lakes
The native aquatic weevil, Euhrychiopsis lecontei is currently being researched as a potential biological control for the exotic aquatic macrophyte Eurasian watermilfoil (Myriophyllum spicatum), yet little is known about its specific distribution in North America. In this study, E. lecontei was collected in 25 of 27 lakes surveyed for the weevil in Wisconsin, greatly increasing the known distribution of the species in this state. E. lecontei densities evaluated in 14 Wisconsin lakes ranged from \u3c0.01 to 1.91 weevils per apical stem of milfoil. These new records indicate that E. lecontei is widespread throughout Wisconsin and is associated with natural declines of M. spicatum in some lakes. Additional sampling for E. lecontei and research on its ecology and life history are needed to understand the role of this organism in aquatic ecosystems
Temporal and spatial changes in milfoil distribution and biomass associated with weevils in Fish Lake, WI
During the course of an eight year monitoring effort, the
Wisconsin Department of Natural Resources documented a
significant decline in milfoil biomass and distribution in Fish
Lake, Wisconsin. Average milfoil biomass declined by 40-
50% from 374-524 g dw m
-2
during 1991-93 to 265 g dw m
-2
during both 1994 and 1995. Milfoil recovered fully in 1996-
98 to 446- 564 g dw m
-2
. The size of the milfoil bed, as discerned
from aerial photographs, shrank from a maximum
coverage of 40 ha in 1991 to less than 20 ha during 1995.
During the “crash” of 1994-95, milfoil plants exhibited typical
signs of weevil-induced damage, including darkened, brittle,
hollowed-out growing tips, and the arching and collapse
of stems associated with loss of buoyancy. Monitoring of weevils
and stem damage during 1995-98 showed highest densities
and heaviest damage occurred near shore and subsequently
fanned out into deeper water from core infestation
sites each spring. The extent of milfoil stem damage was positively
correlated with weevil densities (monthly sampling).
However, weevil densities and stem damage were lower during
1995 (when milfoil biomass was in decline) than during
1996-98 (when milfoil biomass was fully recovered)
Organizing to Win: Introduction
[Excerpt] The American labor movement is at a watershed. For the first time since the early years of industrial unionism sixty years ago, there is near-universal agreement among union leaders that the future of the movement depends on massive new organizing. In October 1995, John Sweeney, Richard Trumka, and Linda Chavez-Thompson were swept into the top offices of the AFL-CIO, following a campaign that promised organizing at an unprecedented pace and scale. Since taking office, the new AFL-CIO leadership team has created a separate organizing department and has committed $20 million to support coordinated large-scale industry-based organizing drives. In addition, in the summer of 1996, the AFL-CIO launched the Union Summer program, which placed more than a thousand college students and young workers in organizing campaigns across the country
An Integrative Reading-Language Approach
This study sought to determine whether third-grade children identified as poor readers (6-12 mos. delay) were able to improve their reading performances after being provided instruction using an integrated reading-language approach. It was speculated that the basis for some or most reading difficulties were language problems resulting from deficiencies in constructing meaning from a spoken or printed message, difficulty understanding and/or remembering the message proposition(s), and incongruities between a child\u27s knowledge of language and linguistic information presented
Integrating Language Activities into Reading Instruction
This study determines if second grade children, who have been identified as having possible listening comprehension problems and language deficiencies, demonstrate improved reading performance with an integrated reading-language treatment approach. A quasi-experimental design included sixteen children in the experimental group and nineteen subjects in the control group. Six operationally defined language behaviors were studied during eleven weeks of treatment. the data were interpreted to imply that certain aspects of an integrative reading-language approach were effective for reading instruction
An Informal Reading--Language Test
Professionals working with children who need help in language development and reading have reported a positive relationship between reading performance and the development of language skills (Mattingly, 1972; Goodm3n, reported in Gutknecht and Keenan, 1978; Berger, 1978; Semel and Wiig, 1975; Stark, 1975). Semel and Wiig (1975) report that many reading problems are due to a child I s difficulty or inability to understand the ideas being expressed by complex syntactic structures, and Rupley (1974) states that problems in understanding the vocabulary used in reading texts may contribute to reading problems. The relationship and parallelism between reading and language development becomes more evident when considering some of the the correlates that can have an effect on either or both of them: auditory or visual preceptual problems; motivation. Although such correlates are not synonymous with etiologies for poor developmental reading skills, they are conditions often accompanying an inability to read (Kirk, Kliebhan and Lerner, 1978)
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Progressions of Conceptual Models of Cardiovascular Physiology and their Relationship to Expertise
The application of scientific principles in diverse science domains is widely regarded as a hallmark of expertise. However, in medicine, the role of basic science knowledge is the subject of considerable controversy. In this paper, w e present a study that examines students' and experts* understanding of complex biomedical concepts related to cardiovascular physiology. In the experiment, subjects were presented with questions and problems pertaining to cardiac output, venous return, and the mechanical properties of the cardiovascular system. The results indicated a progression of conceptual models as a function of expertise, which was evident in predictive accuracy, and the explanation and application of these concepts. The study also documented and characterized the etiology of significant misconceptions that impeded subjects' ability to reason about the cardiovascular and circulatory system. Certain conceptual errors were evident even in the responses of physicians. The scope of application of basic science principles is not as evident in the practice of medicine, as in the applied physical domains. Students and medical practitioners do not experience the same kinds of epistemic challenges to counter their naive intuitions
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