Demographic Changes and the Gains from Globalisation: An Overlapping Generations CGE Analysis

This paper develops a multi-country overlapping-generations general equilibrium model to gauge the economic impacts of demographic changes in the global economy and its transmission effects on different countries. Although severe demographic pressures contribute to significantly lower real GDP per capita across several regions in the world, globalisation through international trade generates an improvement in the terms of trade of older OECD countries, which sustains their real consumption per capita, while globalisation through capital flows stimulates capital deepening and therefore growth in younger countries such as India and various parts of the Rest of the World. The general equilibrium nature of the ageing process is crucial to understand the net foreign asset dynamics of countries during the demographic transition, and this is particularly relevant for a country like China that is caught, in the global economy, between relatively older and younger countries. On this regard China, unlike older countries, does not benefit from a terms of trade improvement which could otherwise sustain its consumption, nor does it benefit, unlike India, from capital deepening, which could otherwise sustain its GDP growth.Inequality Demographic transition, ageing, globalisation, overlapping generations, computable general equilibrium modeling

Comparison of life history parameters for landed and discarded fish captured off the southeastern United States

Commercial fisheries that are managed with minimum size limits protect small fish of all ages and may affect size-selective mortality by the differential removal of fast growing fish. This differential removal may decrease the average size at age, maturation, or sexual transition of the exploited population. When fishery-independent data are not available, a comparison of life history parameters of landed with those of discarded fish (by regulation) will indicate if differential mortality is occurring with the capture of young but large fish (fast growing phenotypes). Indications of this differential size-selective mortality would include the following: the discarded portion of the target fish would have similar age ranges but smaller sizes at age, maturation, and sexual transition as that of landed fish. We examined three species with minimum size limits but different exploitation histories. The known heavily exploited species (Rhomboplites aurorubens [vermilion snapper] and Pagrus pagrus [red porgy]) show signs of this differential mortality. Their landed catch includes many young, large fish, whereas discarded fish had a similar age range and mean ages but smaller sizes at age than the landed fish. The unknown exploited species, Mycteroperca phenax (scamp), showed no signs of differential mortality due to size-selective fishing. Landed catch consisted of old, large fish and discarded scamp had little overlap in age ranges, had significantly different mean ages, and only small differences in size at age when compared to comparable data for landed fish

Wave packet dynamics in triplet states of Na2 attached to helium nanodroplets

The dynamics of vibrational wave packets excited in Na2 dimers in the triplet ground and excited states is investigated by means of helium nanodroplet isolation (HENDI) combined with femtosecond pump-probe spectroscopy. Different pathways in the employed resonant multi-photon ionization scheme are identified. Within the precision of the method, the wave packet dynamics appears to be unperturbed by the helium droplet environment

Numerical simulation of the magnetization of high-temperature superconductors: 3D finite element method using a single time-step iteration

We make progress towards a 3D finite-element model for the magnetization of a high temperature superconductor (HTS): We suggest a method that takes into account demagnetisation effects and flux creep, while it neglects the effects associated with currents that are not perpendicular to the local magnetic induction. We consider samples that are subjected to a uniform magnetic field varying linearly with time. Their magnetization is calculated by means of a weak formulation in the magnetostatic approximation of the Maxwell equations (A-phi formulation). An implicit method is used for the temporal resolution (Backward Euler scheme) and is solved in the open source solver GetDP. Picard iterations are used to deal with the power law conductivity of HTS. The finite element formulation is validated for an HTS tube with large pinning strength through the comparison with results obtained with other well-established methods. We show that carrying the calculations with a single time-step (as opposed to many small time-steps) produce results with excellent accuracy in a drastically reduced simulation time. The numerical method is extended to the study of the trapped magnetization of cylinders that are drilled with different arrays of columnar holes arranged parallel to the cylinder axis

Regulation of Cx45 hemichannels mediated by extracellular and intracellular calcium

Connexin45 (Cx45) hemichannels (HCs) open in the absence of Ca2+ and close in its presence. To elucidate the underlying mechanisms, we examined the role of extra- and intracellular Ca2+ on the electrical properties of HCs. Experiments were performed on HeLa cells expressing Cx45 using electrical (voltage clamp) and optical (Ca2+ imaging) methods. HCs exhibit a time- and voltage-dependent current (I hc), activating with depolarization and inactivating with hyperpolarization. Elevation of [Ca2+]o from 20nM to 2μM reversibly decreases I hc, decelerates its rate of activation, and accelerates its deactivation. Our data suggest that [Ca2+]o modifies the channel properties by adhering to anionic sites in the channel lumen and/or its outer vestibule. In this way, it blocks the channel pore and reversibly lowers I hc and modifies its kinetics. Rapid lowering of [Ca2+]o from 2mM to 20nM, achieved early during a depolarizing pulse, led to an outward I hc that developed with virtually no delay and grew exponentially in time paralleled by unaffected [Ca2+]i. A step increase of [Ca2+]i evoked by photorelease of Ca2+ early during a depolarizing pulse led to a transient decrease of I hc superimposed on a growing outward I hc; a step decrease of [Ca2+]i elicited by photoactivation of a Ca2+ scavenger provoked a transient increase in I hc. Hence, it is tempting to assume that Ca2+ exerts a direct effect on Cx45 hemichannel

Neural correlates of intentional and stimulus-driven inhibition: a comparison

People can inhibit an action because of an instruction by an external stimulus, or because of their own internal decision. The similarities and differences between these two forms of inhibition are not well understood. Therefore, in the present study the neural correlates of intentional and stimulus-driven inhibition were tested in the same subjects. Participants performed two inhibition tasks while lying in the scanner: the marble task in which they had to choose for themselves between intentionally acting on, or inhibiting a prepotent response to measure intentional inhibition, and the classical stop signal task in which an external signal triggered the inhibition process. Results showed that intentional inhibition decision processes rely on a neural network that has been documented extensively for stimulus-driven inhibition, including bilateral parietal and lateral prefrontal cortex and pre-supplementary motor area. We also found activation in dorsal frontomedian cortex and left inferior frontal gyrus during intentional inhibition that depended on the history of previous choices. Together, these results indicate that intentional inhibition and stimulus-driven inhibition engage a common inhibition network, but intentional inhibition is also characterized by additional context-dependent neural activation in medial prefrontal cortex