1,001 research outputs found
All Through the Love of You!
https://digitalcommons.library.umaine.edu/mmb-vp/3933/thumbnail.jp
“Okay Okay Okay, Now the Video Is On”: An Analysis of Young Children’s Orientations to the Video Camera in Recordings of Family Interactions
This paper explores 3- to 6-year-old children’s orientations to the video camera in video recordings of everyday family interactions. Children’s orientations to the video camera in these recordings were identified and analyzed using the constant comparative method. Types of orientations to the video camera included talking about the camera, engaging in camera-directed talk and/or action, and interacting with the camera. In some cases, these orientations occurred after a parent or sibling first oriented to the video camera; however, in other cases no prior orientation was evident. Theoretical and practical implications of the results are discussed
The Steady State Fluctuation Relation for the Dissipation Function
We give a proof of transient fluctuation relations for the entropy production
(dissipation function) in nonequilibrium systems, which is valid for most time
reversible dynamics. We then consider the conditions under which a transient
fluctuation relation yields a steady state fluctuation relation for driven
nonequilibrium systems whose transients relax, producing a unique
nonequilibrium steady state. Although the necessary and sufficient conditions
for the production of a unique nonequilibrium steady state are unknown, if such
a steady state exists, the generation of the steady state fluctuation relation
from the transient relation is shown to be very general. It is essentially a
consequence of time reversibility and of a form of decay of correlations in the
dissipation, which is needed also for, e.g., the existence of transport
coefficients. Because of this generality the resulting steady state fluctuation
relation has the same degree of robustness as do equilibrium thermodynamic
equalities. The steady state fluctuation relation for the dissipation stands in
contrast with the one for the phase space compression factor, whose convergence
is problematic, for systems close to equilibrium. We examine some model
dynamics that have been considered previously, and show how they are described
in the context of this work.Comment: 30 pages, 1 figur
Diffusion of Lithium Ions in Lithium-Argyrodite Solid-State Electrolytes from Equilibrium and Nonequilibrium Molecular Dynamics Simulations
The use of solid-state electrolytes to provide safer, next-generation
rechargeable batteries is becoming more feasible as new materials with greater
stability and higher ionic diffusion coefficients are designed. However,
accurate determination of diffusion coefficients in solids is problematic and
reliable calculations are highly sought-after. In this paper we compare
diffusion coefficients calculated using nonequilibrium and equilibrium ab
initio molecular dynamics simulations for highly diffusive solid-state
electrolytes for the first time, to demonstrate the accuracy that can be
obtained. Moreover, we show that ab initio nonequilibrium molecular dynamics
can be used to determine diffusion coefficients when the diffusion is too slow
for it to be feasible to obtain them using ab initio equilibrium simulations.
Thereby, using ab initio nonequilibrium molecular dynamics simulations we are
able to obtain accurate estimates of the diffusion coefficients of Li ions in
LiPSCl and LiPSCl, two promising electrolytes for
all-solid-state batteries. Furthermore, these calculations show that the
diffusion coefficient of lithium ions in LiPSCl is higher than many
other potential all-solid-state electrolytes, making it promising for future
technologies. The reasons for variation in conductivities determined using
computational and experimental methods are also discussed. It is demonstrated
that small degrees of disorder and vacancies can result in orders of magnitude
differences in diffusivities of Li ions in LiPSCl, and these factors
are likely to contribute to inconsistencies observed in experimentally reported
values. Notably, the introduction of Li-vacancies and disorder can enhance the
ionic conductivity of LiPSCl.Comment: 32 pages, 8 figures, 2 table
On the Fluctuation Relation for Nose-Hoover Boundary Thermostated Systems
We discuss the transient and steady state fluctuation relation for a
mechanical system in contact with two deterministic thermostats at different
temperatures. The system is a modified Lorentz gas in which the fixed
scatterers exchange energy with the gas of particles, and the thermostats are
modelled by two Nos\'e-Hoover thermostats applied at the boundaries of the
system. The transient fluctuation relation, which holds only for a precise
choice of the initial ensemble, is verified at all times, as expected. Times
longer than the mesoscopic scale, needed for local equilibrium to be settled,
are required if a different initial ensemble is considered. This shows how the
transient fluctuation relation asymptotically leads to the steady state
relation when, as explicitly checked in our systems, the condition found in
[D.J. Searles, {\em et al.}, J. Stat. Phys. 128, 1337 (2007)], for the validity
of the steady state fluctuation relation, is verified. For the steady state
fluctuations of the phase space contraction rate \zL and of the dissipation
function \zW, a similar relaxation regime at shorter averaging times is
found. The quantity \zW satisfies with good accuracy the fluctuation relation
for times larger than the mesoscopic time scale; the quantity \zL appears to
begin a monotonic convergence after such times. This is consistent with the
fact that \zW and \zL differ by a total time derivative, and that the tails
of the probability distribution function of \zL are Gaussian.Comment: Major revision. Fig.10 was added. Version to appear in Journal of
Statistical Physic
Superstatistical generalization of the work fluctuation theorem
We derive a generalized version of the work fluctuation theorem for
nonequilibrium systems with spatio-temporal temperature fluctuations. For
chi-square distributed inverse temperature we obtain a generalized fluctuation
theorem based on q-exponentials, whereas for other temperature distributions
more complicated formulae arise. Since q-exponentials have a power law decay,
the decay rate in this generalized fluctuation theorem is much slower than the
conventional exponential decay. This implies that work fluctuations can be of
relevance for the design of micro and nano structures, since the work done on
the system is relatively much larger than in the conventional fluctuation
theorem.Comment: 13 pages. Contribution to the Proceedings of `Trends and Perspectives
in Extensive and Nonextensive Statistical Mechanics', in honour of
Constantino Tsallis' 60th birthday (to appear in Physica A
Deep-water macroalgae from the Canary Islands: new records and biogeographical relationships
Due to the geographical location and paleobiogeography of the Canary Islands, the
seaweed flora contains macroalgae with different distributional patterns. In this contribution, the biogeographical relations of several new records of deep-water macroalgae recently collected around the Canarian archipelago are discussed. These are Bryopsidella neglecta (Berthotd) Rietema,Discosporangium mesarthrocarpum (Meneghini) Hauck, Hincksia onslowensis (Amsler et Kapraun)P.C. Silva, Syringoderma floridana Henry, Peyssonnelia harveyana J. Agardh, Cryptonemia seminervis(C. Agardh) J. Agardh, Botryodadia wynnei Ballantine, Gloiocladia blomquistii (Searles) R. E.Norris, PIahchrysis peltata (W. R. Taylor) P. Huv4 et H. Huv4, Leptofauchea brasiliensis Joly, and Sarcodiotheca divaricata W. R. Taylor. These new records, especially those in the Florideophyceae,support the strong affinity of the Canary Islands seaweed flora with the warm-temperate Mediterranean-Atlantic region. Some species are recorded for the first time from the east coast of the Atlantic Ocean, enhancing the biogeographic relations of the Canarian marine flora with that of the western Atlantic regions
The Ursinus Weekly, April 3, 1975
Someone old, someone new • Come to Ursinus: Land of the Pennsylvania Dutch • CCC student success seen • Newman Club • The Birds • Free, but show invitations • Editorial: Visitation - time for reality? • Letter to the editor: Breakage reply • Gymnastics • Record review: For earth below, Robin Trower • Wanted: More Lantern contributors • Spring sports special: 1975! • 1975 Ursinus baseball outlook • 1975 track prospectus • Another season, another title! • A.L. spotlight • Interview: Pat Williams • National League previewhttps://digitalcommons.ursinus.edu/weekly/1033/thumbnail.jp
Fluctuation Relations for Diffusion Processes
The paper presents a unified approach to different fluctuation relations for
classical nonequilibrium dynamics described by diffusion processes. Such
relations compare the statistics of fluctuations of the entropy production or
work in the original process to the similar statistics in the time-reversed
process. The origin of a variety of fluctuation relations is traced to the use
of different time reversals. It is also shown how the application of the
presented approach to the tangent process describing the joint evolution of
infinitesimally close trajectories of the original process leads to a
multiplicative extension of the fluctuation relations.Comment: 38 page
A subset of malignant mesothelioma tumors retain osteogenic potential
Malignant mesothelioma (MM) is an aggressive serosal tumor associated with asbestos exposure. We previously demonstrated that mesothelial cells differentiate into cells of different mesenchymal lineages and hypothesize that osseous tissue observed in a subset of MM patients is due to local differentiation of MM cells. In this study, the capacity of human and mouse MM cells to differentiate into osteoblast-like cells was determined in vitro using a functional model of bone nodule formation and in vivo using an established model of MM. Human and murine MM cell lines cultured in osteogenic medium expressed alkaline phosphatase and formed mineralized bone-like nodules. Several human and mouse MM cell lines also expressed a number of osteoblast phenotype markers, including runt-related transcription factor 2 (RUNX2), osteopontin, osteonectin and bone sialoprotein mRNA and protein. Histological analysis of murine MM tumors identified areas of ossification within the tumor, similar to those observed in human MM biopsies. These data demonstrate the ability of MM to differentiate into another mesenchymal cell type and suggest that MM cells may contribute to the formation of the heterologous elements observed in MM tumors
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