Spike processing model of the brain

The timing of a spike within a specific time period is used to identify a place in space (input terminal) and/or sense changes in energy or position in the environment, and is used to determine the motion of an actuator or the activation of a place in space (output terminal). The timing of a spike is specified by a sensor or a time delay memory cell that is preset (predetermined) or set through experience (empirical). Time delay memory cells are arranged in decoding networks that activate specific output terminals based upon the timing of incoming spike trains, or arranged in encoding networks that generate spike trains from activated input terminals. These spike trains form semi-axes that can transmit large quantities of information in one direction through a single conductor, and are essential in the transmission of information from peripheral neurons to and from the brain through the spinal chord

The Grey Islands by John Steffler

Review of John Steffler\u27s The Grey Islands

Anthropocene or Capitalocene? Nature, History, and the Crisis of Capitalism edited by Jason W. Moore

Review of Jason W. Moore\u27s Capitalocene or Anthropocene? Nature, History, and the Crisis of Capitalis

Understanding Something About Nothing: Radiation Zeros

Radiation symmetry is briefly reviewed, along with its historical, experimental, computational, and theoretical relevance. A sketch of the proof of a theorem for radiation zeros is used to highlight the connection between gauge-boson couplings and Poincare transformations. It is emphasized that while mostly bad things happen to good zeros, the weak-boson self-couplings continue to be intimately tied to the best examples of exact or approximate zeros.Comment: 12 pages, revtex. Two minor figures can be obtained by request; to appear in the Proceedings of the International Symposium on Vector Boson Self-Interactions, UCLA, Feb. 1-3, 199

New Completeness Methods for Estimating Exoplanet Discoveries by Direct Detection

We report new methods for evaluating realistic observing programs that search stars for planets by direct imaging, where observations are selected from an optimized star list, and where stars can be observed multiple times. We show how these methods bring critical insight into the design of the mission & its instruments. These methods provide an estimate of the outcome of the observing program: the probability distribution of discoveries (detection and/or characterization), & an estimate of the occurrence rate of planets (eta). We show that these parameters can be accurately estimated from a single mission simulation, without the need for a complete Monte Carlo mission simulation, & we prove the accuracy of this new approach. Our methods provide the tools to define a mission for a particular science goal, for example defined by the expected number of discoveries and its confidence level. We detail how an optimized star list can be built & how successive observations can be selected. Our approach also provides other critical mission attributes, such as the number of stars expected to be searched, & the probability of zero discoveries. Because these attributes depend strongly on the mission scale, our methods are directly applicable to the design of such future missions & provide guidance to the mission & instrument design based on scientific performance. We illustrate our new methods with practical calculations & exploratory design reference missions for JWST operating with a distant starshade to reduce scattered and diffracted starlight on the focal plane. We estimate that 5 habitable Earth-mass planets would be discovered & characterized with spectroscopy, with a probability of 0 discoveries of 0.004, assuming a small fraction of JWST observing time (7%), eta=0.3, and 70 observing visits, limited by starshade fuel.Comment: 27 pages, 4 figures, 6 tables, accepted for publication by Ap

Experiment at Nebraska The First Two Years of a Cluster College

In November 1968 the Board of Regents of the University of Nebraska was asked to react to a document coming from a faculty-student committee charged with examining the feasibility of establishing an innovating college on the Lincoln campus. It attempted to spell out the need for such innovation, and it offered a plan for fulfilling the need that it delineated. This is that document: 1 Within the past generation a new kind of student, a new kind of faculty, and a new kind of university have developed. To meet the challenges which these changes present and to provide for an educational and national future whose nature is unforseeable, many persons have concluded that there is a need for experiments in university curriculum and organization. The purpose of such endeavors should be a graduate who is sharply aware of himself, his society, and his world, able and desirous of continuing his liberal and professional education beyond the classroom. The New Students Students who come to the University are different from those who came twenty years ago.! A larger number of high school graduates choose to enroll than before and, of those who come, a larger number graduate. Though the numbers are greater, their quality is not inferior often. Television and other instruments of mass communication have provided them with astonishing funds of miscellaneous information, some of it inaccurate, much of it irrelevant, and part of it useful. In addition, many have traveled widely. The new students come to us with new formal preparation. High school science programs have been set up by distinguished scientists, the new math has become widespread-and public school English has undergone elaborate revision. In the future, advanced placement programs promise to change drastically the relation of entering students to the University. Perhaps more important, the temper of the undergraduates seems to be changing. The students have learned to react quickly to situations far from home ground, and echoes of Vietnam and Berkeley can be heard in Lincoln. In some universities the students have not hesitated to bite the hand that presumes to feed them, and generally students are becoming increasingly critical of their courses, professors, and colleges. They complain that universities have made them numbers on IBM cards, anonymous to teachers and advisers, and a gray mass to their administrators. They resent a lack of individual attention. For the past two years-at least responsible students through their official channels (e.g. ASUN [Associated Students of University of Nebraska]) have undertaken to scrutinize university programs. It is significant that the disgruntled students are not the weakest. The most critical are often the brightest, the most committed socially, and the most responsible morally. The best seem to be the most critical