An Evolutionary Model of Endogenous Business Cycles

In this paper, we present an evolutionary model of industry dynamics yielding endogenous business cycles with ‘Keynesian’ features. The model describes an economy composed of firms and consumers/workers. Firms belong to two industries. The first one performs R&D and produces heterogeneous machine tools. Firms in the second industry invest in new machines and produce a homogenous consumption good. Consumers sell their labor and fully consume their income. In line with the empirical literature on investment patterns, we assume that the investment decisions by firms are lumpy and constrained by their financial structures. Moreover, drawing from behavioral theories of the firm, we assume boundedly rational expectation formation. Simulation results show that the model is able to deliver self-sustaining patterns of growth characterized by the presence of endogenous business cycles. The model can also replicate the most important stylized facts concerning micro- and macro-economic dynamics. Indeed, we find that investment is more volatile than GDP; consumption is less volatile than GDP; investment, consumption and change in stocks are procyclical and coincident variables; employment is procyclical; unemployment rate is anticyclical; firm size distributions are skewed but depart from log-normality; firm growth distributions are tent-shaped. JEL Classifications: C15, C22, C49, E17, E22, E32.     

Prolonged rewarding stimulation of the rat medial forebrain bundle: Neurochemical and behavioral consequences.

Extracellular dopamine levels were measured in the rat nucleus accumbens by means of in vivo microdialysis. Delivery of rewarding medial forebrain bundle stimulation at a low rate (5 trains/min) produced a sustained elevation of dopamine levels, regardless of whether train onset was predictable. When the rate of train delivery was increased to 40 trains/min, dopamine levels rose rapidly during the first 40 min but then declined toward the baseline range. The rewarding impact of the stimulation was reduced following prior delivery of stimulation at the high, but not the low, rate. These results support the idea that dopamine tone plays an enabling role in brain stimulation reward and is elevated similarly by predictable and unpredictable stimulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An android for enhancing social skills and emotion recognition in people with autism.

It is well documented that the processing of social and emotional information is impaired in people with autism. Recent studies have shown that individuals, particularly those with high functioning autism, can learn to cope with common social situations if they are made to enact possible scenarios they may encounter in real life during therapy. The main aim of this work is to describe an interactive life-like facial display (FACE) and a supporting therapeutic protocol that will enable us to verify if the system can help children with autism to learn, identify, interpret, and use emotional information and extend these skills in a socially appropriate, flexible, and adaptive context. The therapeutic setup consists of a specially equipped room in which the subject, under the supervision of a therapist, can interact with FACE. The android display and associated control system has automatic facial tracking, expression recognition, and eye tracking. The treatment scheme is based on a series of therapist-guided sessions in which a patient communicates with FACE through an interactive console. Preliminary data regarding the exposure to FACE of two children are reported.     

DARWIN'S NAVIDAD EMBAYMENT, SANTIAGO REGION, CHILE, AS A MODEL OF THE SOUTHEASTERN PACIFIC SHELF

The sedimentary sequence of Darwin's Navidad embayment overlies a Carboniferous metamorphic basement, and was deposited in a NNW-striking basin, open toward the sea. The sediments formed in a temperate climate and consist of three marine sequences—Cretaceous, Eocene, and Miocene-Pliocene. They exihibit some potential for oil and gas. The uppermost sediments of the Navidad Group were deposited in a more extensive sea, which was deeper, with lower wave energy. Near the present Pacific coastline, the sediments are tectonically disturbed. Farther east-and northward, the sediments are not affected by great disturbances. Some good types of stratigraphical traps, such as eolian sand beaches, may be expected.
Key Idea:The model adopted here is considered as one potential basin model for petroleum exploration in the southeastern Pacific shelf, where six or more NNW-striking open embayments are present.     

The water relaxation in polymers containing the amide group

The low temperature water relaxation of synthetic polymers containing the amide group is usually attributed to the motion of a water-polymer complex in the amorphous region. According to Puffr and Sebenda the complex is formed by water and amide group in the stoichiometric ratio 1.5. Elastin, an insoluble protein of vessels and ligaments, seems the ideal polymer for testing the model, being practically free of polar side groups and having a glass transition at 200°C, so that its “water peak” can be easily investigated. Calorimetric investigations show that the molar ratio for “bound water-amide group” is indeed 1.5, as predicted by the model. The activation energy of the “water peak” is very close, for the “dry” protein, to that of nylons, but it decreases with increasing hydration to a limit of 9 kcal/mole. The results give additional support to the traditional interpretation of the polyamide beta relaxation and to the Puffr and Sabenda model for the interaction of water and amide groups in synthetic polymers.     

Application of multi-way models to the time-resolved fluorescence of polycyclic aromatic hydrocarbons mixtures in water

The time-resolved laser-induced fluorescence of a series of polycyclic aromatic compounds (PAHs) and mixtures of these latter in aqueous solution was measured by means of an apparatus equipped with optical fibers, which allows their real time in situ monitoring. The potential of such spectroscopic technique, yielding 4-way fluorescence data arrays, together with the application of multi-way models to the matricized data, was tested for the resolution of complex aqueous mixtures containing low concentrations of PAHs, as typical fluorescent pollutants in aquatic systems. PARAllel FACtors analysis was employed for the qualitative resolution of PAHs mixtures and for calculating the fluorescence lifetimes of single PAHs; n-way partial least squares analysis was applied for evaluating the concentration of the single PAHs in the aqueous mixtures.