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Dynamics of living cells in a cytomorphological state space.
Cells are nonequilibrium systems that exchange matter and energy with the environment to sustain their metabolic needs. The nonequilibrium nature of this system presents considerable challenges to developing a general theory describing its behavior; however, when studied at appropriate spatiotemporal scales, the behavior of ensembles of nonequilibrium systems can resemble that of a system at equilibrium. Here we apply this principle to a population of cells within a cytomorphological state space and demonstrate that cellular transition dynamics within this space can be described using equilibrium formalisms. We use this framework to map the effective energy landscape underlying the cytomorphological state space of a population of mouse embryonic fibroblasts (MEFs) and identify topographical nonuniformity in this space, indicating nonuniform occupation of cytomorphological states within an isogenic population. The introduction of exogenous apoptotic agents fundamentally altered this energy landscape, inducing formation of additional energy minima that correlated directly with changes in sensitivity to apoptosis induction. An equilibrium framework allows us to describe the behavior of an ensemble of single cells, suggesting that although cells are complex nonequilibrium systems, the application of formalisms derived from equilibrium thermodynamics can provide insight into the basis of nongenetic heterogeneities within cell populations, as well as the relationship between cytomorphological and functional heterogeneity
Entry and access : how shareability comes about
Shareability is a design principle that refers to how a system, interface, or device engages a group of collocated, co-present users in shared interactions around the same content (or the same object). This is broken down in terms of a set of components that facilitate or constrain the way an interface (or product) is made shareable. Central are the notions of access points and entry points. Entry points invite and entice people into engagement, providing an advance overview, minimal barriers, and a honeypot effect that draws observers into the activity. Access points enable users to join a group's activity, allowing perceptual and manipulative access and fluidity of sharing. We show how these terms can be useful for informing analysis and empirical research
Energy Efficient Engine: Flight propulsion system final design and analysis
The Energy Efficient Engine (E3) is a NASA program to create fuel saving technology for future transport engines. The Flight Propulsion System (FPS) is the engine designed to achieve E3 goals. Achieving these goals required aerodynamic, mechanical and system technologies advanced beyond that of current production engines. These technologies were successfully demonstrated in component rigs, a core engine and a turbofan ground test engine. The design and benefits of the FPS are presented. All goals for efficiency, environmental considerations, and economic payoff were met. The FPS has, at maximum cruise, 10.67 km (35,000 ft), M0.8, standard day, a 16.9 percent lower installed specific fuel consumption than a CF6-50C. It provides an 8.6 percent reduction in direct operating cost for a short haul domestic transport and a 16.2 percent reduction for an international long distance transport
Statistical determination of the length dependence of high-order polarization mode dispersion
We describe a method of characterizing high-order polarization mode dispersion (PMD).Using a new expansion to approximate the Jones matrix of a polarization-dispersive medium, we study the length dependence of high-order PMD to the fourth order. A simple rule for the asymptotic behavior of PMD for short and long fibers is found. It is also shown that, in long fibers (~1000 km), at 40 Gbits/s the third- and fourth-order PMD may become comparable to the second-order PMD
Automatic landmarking for building biological shape models
We present a new method for automatic landmark extraction from the contours of biological specimens. Our ultimate goal is to enable automatic identification of biological specimens in photographs and drawings held in a database. We propose to use active appearance models for visual indexing of both photographs and drawings. Automatic landmark extraction will assist us in building the models. We describe the results of using our method on drawings and photographs of examples of diatoms, and present an active shape model built using automatically extracted data
Numerical Studies of the Compressible Ising Spin Glass
We study a two-dimensional compressible Ising spin glass at constant volume.
The spin interactions are coupled to the distance between neighboring particles
in the Edwards-Anderson model with +/- J interactions. We find that the energy
of a given spin configuration is shifted from its incompressible value, E_0, by
an amount quadratic in E_0 and proportional to the coupling strength. We then
construct a simple model expressed only in terms of spin variables that
predicts the existence of a critical value of the coupling above which the
spin-glass transition disappears.Comment: REVTeX, 4 pages, 4 figures. Submitted to Phys. Rev. Let
Conditions for entanglement transformation between a class of multipartite pure states with generalized Schmidt decompositions
In this note we generalize Nielsen's marjoization criterion for the
convertibility of bipartite pure states [Phys. Rev. Lett \textbf{83},
436(1999)] to a special class of multipartite pure states which have
generalized Schmidt decompositions.Comment: 3 pages (Revetex 4), no figures. A brief note on entanglement
transformation. Comments are welcom
A Fistful of NIL: Have We Entered a “Wild West” Recruiting Era?
Changes about the National Collegiate Athletic Association’s (NCAA) Name, Image, and Likeness (NIL) policy impacted the world of college sports in the summer of 2021. Emerging from the dust of this seismic event was an apparent new frontier for athletes, coaches, and universities to explore. In the eyes of many, college sports had now entered a “Wild West” frontier because of NIL, especially as it pertains to recruiting athletes. But what does that really mean, “Wild West”? And further, if such a comparison is at least somewhat accurate, are there lessons that can be learned from other sectors who likewise experienced supposed western-like eras? The purpose of this article is to address these two pressing questions
Soil nematode population studies of some selected plantation crops and uncultivated coastal thicket
The study was conducted on citrus, plantain and pineapple plantations on the Teaching and Research Farm of the School of Agriculture, University of Cape Coast. The survey also covered undisturbed coastal thicket near the site of the study. The aim of the survey was to identify types and population levels of plant parasitic nematodes in soils of the different plantation crops and to find out whether the populations and nematode species differed from those in soils of undisturbed vegetation. The investigations were carried out from April to July 1993. Nematodes were extracted from 100 ml soil samples by an improvised Baerman’s Tray technique and the mean recorded. Nematode counts were determined from 1ml aliquots repeated tree times. Three genera, namely Rotylenchulus, Meloidogyne and Pratylenchus as endo-parasites, Tylenchus (semi-endoparasitic) and eight ecto-parasitics forms which included Xiphimena, a known virus vector, were identified. Meloidogyne, Pratylenchus, Helicotylenchus and Tylenchus occurred in all the plots studied. Hemicyclophora and Xiphimena were the least genera and occurred in low numbers. Plantain supported the greatest number of genera and also the highest nematode populations. There were positive correlations between crop types, soil pH, soil moisture and nematode numbers. Similarly, significant differences were observed between means of initial nematodes numbers at the beginning and end of the season
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