2,347,203 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
The biopsychology of maternal behavior in nonhuman mammals
The term “maternal behavior,” when applied to nonhuman mammals, includes the behaviors exhibited in preparation for the arrival of newborn, in the care and protection of the newly arrived young, and in the weaning of those young, and represents a complex predictable pattern that is often regarded as a single, comprehensive, species-specific phenomenon. Although the delivering first-time mammalian mother is immediately and appropriately maternal, a maternal “virgin” with no prior exposure to young does not show immediate and appropriate behavior toward foster young. Nevertheless, the virgin female, and indeed the male, possess the neural circuitry that underlies the pattern referred to as maternal behavior, despite not exhibiting the pattern under normal circumstances. At parturition, or after extensive exposure to young, what emerges appears to be a single stereotyped maternal behavior pattern. However, it is actually a smoothly coordinated constellation of simpler actions with proximate causes that, when sequenced properly, have the appearance of a motivated, purposive, adaptive, pattern of caretaking. Over the past 50 years, much research has focused on finding the principal external and internal factors that convert the nonmaternal behavior patterns of the nonpregnant nullipara, the virgin, to the almost immediate and intense maternal behavior characteristic of the puerpera, the mother. This review is an attempt to summarize the many comprehensive, even encyclopedic, reviews of these factors, with an emphasis on brain mechanisms, and to highlight the gaps that remain in understanding the processes involved in the almost immediate onset of maternal caretaking behaviors observed in mammals at delivery. Where possible, the reader is directed to some of those excellent reviews
Creative destruction and business cycles
In a dynamic general equilibrium setup, this paper aims at providing a general framework for the analysis of the role of vintages and creative destruetion on business fluctuations. By stressing the forward-looking behavior of the optimal scrapping rule, we use a standard rational expectations argument to show) in the linear utility case, the time independence of the scrapping function. Secondly, we prove that equilibrium output shows a purely periodic behavior around an exponential growth trend, the pattern of the cycle being deterrnined by the pattern of initial conditions. The vintage capital model presented in this paper provides a new view on business fluctuations: historical conditions are at the basis of business fluctuations, in the sense that historically volatile or stable econornies will reproduce their own historical pattern in the future
The influence of land use and mobility policy on travel behavior : a comparative case study of Flanders and the Netherlands
Numerous transportation studies have indicated that the local built environment can have an important effect on travel behavior; people living in suburban neighborhoods travel more by car than people living in urban neighborhoods. In this paper, however, we will analyze whether the regional land use has an important influence on travel behavior by comparing two regions with a varying land-use pattern: Flanders (Belgium) and the Netherlands. The different land-use pattern seems to have influenced travel behavior in both regions. An active spatial planning policy in the Netherlands, clustering activities in urban surroundings, appears to have realized a sustainable travel behavior, as a substantial share of residents frequently walk, cycle or use public transportation. The rather passive spatial planning in Flanders, resulting in urban sprawl, seems to stimulate car use. The applied mobility policy also has an impact on the travel behavior and land use of the Flemings and the Dutch. Infrastructure is concentrated in Dutch urban environments, whereas Flanders has a more widespread network of infrastructure and cheap public transportation, resulting in a further increase of suburbanization
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