2,366 research outputs found
Dynamic Labyrinthine Pattern in an Active Liquid Film
We report the generation of a dynamic labyrinthine pattern in an active
alcohol film. A dynamic labyrinthine pattern is formed along the contact line
of air/pentanol/aqueous three phases. The contact line shows a clear
time-dependent change with regard to both perimeter and area of a domain. An
autocorrelation analysis of time-development of the dynamics of the perimeter
and area revealed a strong geometric correlation between neighboring patterns.
The pattern showed autoregressive behavior. The behavior of the dynamic pattern
is strikingly different from those of stationary labyrinthine patterns. The
essential aspects of the observed dynamic pattern are reproduced by a
diffusion-controlled geometric model
Urban Demand for Wild Foods in Northeast Thailand: A survey of edible wild species sold in the Khon Kaen municipal market
Rural people in Northeast Thailand consume a wide range of wild species. Little is known, however, about the extent to which the urban populations of the region’s rapidly growing towns and cities consume these products, and no detailed study has been made of the edible wild species that are sold in urban markets. To help fill this knowledge gap, this paper presents findings of a survey about the wild species sold in the main urban market in Khon Kaen Municipality. The survey included identification of all species of plants, fungi, and animals being sold and recording of the quantities and prices of each species. Data were obtained by interviewing vendors selling these products in the market on 18 randomly selected nights in the dry season and 12 nights in the rainy season. The diversity of wild species sold in the market is high. Eighty-one species were identified, of which 54 were plants, 6 were fungi, and 21 were animals. Species diversity was greater in the rainy season, when 65 species were on sale, than in the dry season, when 49 species were available. Plant species were much more diverse in the rainy season than in the dry season, reflecting the better growth conditions for vegetation when water is not a limiting factor. Many species were available only in a specific season. The wild species were obtained from several different habitats. Upland fields were the habitat for the largest number of species, followed by house areas, forests, and paddy fields. Gardens and aquatic ecosystems were habitats for a smaller number of species. The supply-shed for the urban market in Khon Kaen Municipality is quite a large one. Wild species sold in the market are obtained from 8 provinces in the Northeast, although rural areas of Khon Kaen Province itself are the source of the largest number of species. Collection of wild species to supply the urban market can have both negative and positive effects on rural biodiversity in Northeast Thailand. In their desire to earn cash income, villagers may over-exploit some of these species, causing wild populations to decline in numbers or even become locally extinct. On the other hand, villagers may intensify their efforts to cultivate them so as to allow more stable production, thus contributing to biodiversity conservation. This has already begun to happen in the case of some highly valued species
Effective Sampling in the Configurational Space by the Multicanonical-Multioverlap Algorithm
We propose a new generalized-ensemble algorithm, which we refer to as the
multicanonical-multioverlap algorithm. By utilizing a non-Boltzmann weight
factor, this method realizes a random walk in the multi-dimensional,
energy-overlap space and explores widely in the configurational space including
specific configurations, where the overlap of a configuration with respect to a
reference state is a measure for structural similarity. We apply the
multicanonical-multioverlap molecular dynamics method to a penta peptide,
Met-enkephalin, in vacuum as a test system. We also apply the multicanonical
and multioverlap molecular dynamics methods to this system for the purpose of
comparisons. We see that the multicanonical-multioverlap molecular dynamics
method realizes effective sampling in the configurational space including
specific configurations more than the other two methods. From the results of
the multicanonical-multioverlap molecular dynamics simulation, furthermore, we
obtain a new local-minimum state of the Met-enkephalin system.Comment: 15 pages, (Revtex4), 9 figure
Has the Middle Class Been Pressured Most?
The study is a multivariate analysis on parental contributions of dependent financial aid students in 1983 and 1987. A comparison of the findings indicate that parental contributions significantly increased in general and for the 50K income group in particular
Chiral Phase Transitions in QCD at Finite Temperature: Hard-Thermal-Loop Resummed Dyson-Schwinger Equation in the Real Time Formalism
Chiral phase transition in thermal QCD is studied by using the
Dyson-Schwinger (DS) equation in the real time hard thermal loop approximation.
Our results on the critical temperature and the critical coupling are
significantly different from those in the preceding analyses in the ladder DS
equation, showing the importance of properly taking into account the essential
thermal effects, namely the Landau damping and the unstable nature of thermal
quasiparticles.Comment: 4 pages including 2 figures (ps file), to appear in the proceedings
of the 4th International Conference on Physics and Astrophysics of
Quark-Gluon Plasma (ICPAQGP-2001), 26-30 November 2001, Jaipur, Indi
Introduction to the Minitrack on Emerging Issues in e-Collaboration Distributed Group Decision-Making: Opportunities and Challenges
Multidimensional replica-exchange method for free-energy calculations
We have developed a new simulation algorithm for free-energy calculations.
The method is a multidimensional extension of the replica-exchange method.
While pairs of replicas with different temperatures are exchanged during the
simulation in the original replica-exchange method, pairs of replicas with
different temperatures and/or different parameters of the potential energy are
exchanged in the new algorithm. This greatly enhances the sampling of the
conformational space and allows accurate calculations of free energy in a wide
temperature range from a single simulation run, using the weighted histogram
analysis method.Comment: 13 pages, (ReVTeX), 9 figures. J. Chem. Phys. 113 (2000), in pres
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