改良大脑真的好吗?

人类有能力测定和操纵基因,这一革命激起了各种各样的伦理争议.同样具有深远意义的脑科学革命,引起的注意却少得让人吃惊.     

Future themes of mathematics education research: an international survey before and during the pandemic

Educational Studies in Mathematics - Before the pandemic (2019), we asked: On what themes should research in mathematics education focus in the coming decade? The 229 responses from 44...     

Virtual Processes and Quantum Tunnelling as Fictions

In this paper it is argued that virtual processes are dispensable fictions. The argument proceeds by a comparison with the phenomenon of quantum tunnelling. Building on an analysis of Lévy-Leblond and Balibar, it is argued that, although the phenomenon known as quantum tunnelling certainly occurs and is at the basis of many paradigmatic quantum effects, the implied conceptualization of it as a free particle burrowing through a potential barrier is flawed. An alpha particle, for example, does not exist as a free particle inside a uranium nucleus and then ??burrow through?? the massive potential barrier of the repulsive Coulomb potential: rather, it can be interpreted as existing in a bound state which gives it a corresponding (absolutely tiny, but) finite probability of appearing on the other side of the barrier. If the part of the state function representing the transmission through the barrier is conceived as representing a particle trajectory, the particle will have imaginary momentum and negative kinetic energy. A similar analysis then applies to virtual processes. For example, if (as in Hawking??s conception of black hole radiation) one imagines a pair of particles created at the Schwarzschild radius, one of which drops into the black hole, at its creation that particle will have imaginary momentum and negative kinetic energy; so will the pion that is imagined as mediating the nuclear exchange force on the standard model. In each case, it is argued, the phenomenon can be understood in terms of a finite probability of transmission predicted by quantum theory, without appealing to particle trajectories. The idea that a particle ??penetrates?? a barrier that it does not have the energy to surmount, or that a pair of particles is ??virtually?? produced one on either side of the Schwarzschild radius, in defiance of energy conservation, should be discarded as unphysical.     

USE OF CRITICAL INCIDENTS FOR PLANNING,IMPLEMENTING, AND EVALUATING A TRAINING PROGRAM FOR FOSTER GRANDPARENTS

The authors report the planning, implementation, and evaluation of a training program for foster grandparents employed at a residential diagnostic and treatment center for disturbed children and youth. The training needs were assessed by task and performance analysis procedures, including the use of critical incident technique. A scoring procedure derived values for various responses to a set of problem situations presented to each foster grandparent. The training objectives focused on the role of the foster grandparents in helping their charges to develop socially acceptable behavior. A cognitive problem‐solving strategy was taught by use primarily of role‐modeling and role‐playing methods. The effectiveness of training was evaluated by comparing pretraining scores on a problem situation test with posttraining scores. Foster grandparents who had been highly rated by supervisors on an independent criterion improved with training; the others did not.