21,326 research outputs found
Outer planet probe missions, designs and science
The similarities and differences of atmosphere entry probe mission designs and sciences appropriate to certain solar system objects, are reviewed. Candidate payloads for Saturn and Titan probes are suggested. Significant supporting research and technology efforts are required to develop mission-peculiar technology for probe exploration of the Saturnian system
Relaxation time for the temperature in a dilute binary mixture from classical kinetic theory
The system of our interest is a dilute binary mixture, in which we consider
that the species have different temperatures as an initial condition. To study
their time evolution, we use the full version of the Boltzmann equation, under
the hypothesis of partial local equilibrium for both species. Neither a
diffusion force nor mass diffusion appears in the system. We also estimate the
time in which the temperatures of the components reach the full local
equilibrium. In solving the Boltzmann equation, we imposed no assumptions on
the collision term. We work out its solution by using the well known
Chapman-Enskog method to first order in the gradients. The time in which the
temperatures relax is obtained following Landau's original idea. The result is
that the relaxation time for the temperatures is much smaller than the
characteristic hydrodynamical times but greater than a collisional time. The
main conclusion is that there is no need to study binary mixtures with
different temperatures when hydrodynamical properties are sought
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Continuous Theta Burst Stimulation of the Posterior Medial Frontal Cortex to Experimentally Reduce Ideological Threat Responses.
Decades of behavioral science research have documented functional shifts in attitudes and ideological adherence in response to various challenges, but little work to date has illuminated the neural mechanisms underlying these dynamics. This paper describes how continuous theta burst transcranial magnetic stimulation may be employed to experimentally assess the causal contribution of cortical regions to threat-related ideological shifts. In the example protocol provided here, participants are exposed to a threat prime-an explicit reminder of their own inevitable death and bodily decomposition-following a downregulation of the posterior medial frontal cortex (pMFC) or a sham stimulation. Next, disguised within a series of distracter tasks, participants' relative degree of ideological adherence is assessed-in the present example, with regard to coalitional prejudice and religious belief. Participants for whom the pMFC has been downregulated exhibit less coalitionally biased responses to an immigrant critical of the participants' national in-group, and less conviction in positive afterlife beliefs (i.e., God, angels, and heaven), despite having recently been reminded of death. These results complement prior findings that continuous theta burst stimulation of the pMFC influences social conformity and sharing and illustrate the feasibility of investigating the neural basis of high-level social cognitive shifts using transcranial magnetic stimulation
The recent rise in the value of education: market forces at work
A market-based approach to understanding the widening income gap between college graduates and less-educated workers in the 1980s--a phenomenon that reflects the changes fueled by foreign competition and by technological advances--and an analysis of the far-reaching implications of continued schooling-based wage disparities.Education ; Income
Job growth and finance : are some financial institutions better suited to early stages of development than others?
This paper combines firm-level data from 89 countries with updated country-level data on financial structure, and uses two estimation approaches. It finds that in low-income countries, labor growth is swifter in countries with a higher level of private credit/gross domestic product; the positive effect of bank credit is especially pronounced in industries that depend heavily on external finance; and banking development is positively associated with more physical and human capital investment. These findings are consistent with predictions from new structural economics. In high-income countries, labor growth rates are increasing in the level of stock market capitalization, which is also consistent with predictions from new structural economics, although the analysis is unable to provide evidence that the association is causal. It finds no evidence that small-scale firms in low-income countries benefit most from private credit market development. Rather, the labor growth rates of larger, capital-intensive firms increase more with the level of private credit market development, a finding consistent with the history-based political economy view that banking systems in low-income countries serve the interests of the elite, rather than providing broad-based access to financial services.Debt Markets,Banks&Banking Reform,Access to Finance,Economic Theory&Research,Emerging Markets
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