Activation of Long Descending Propriospinal Neurons in Cat Spinal Cord

Isolated mammalian spinal cord has been shown capable of generating locomotor activity. Propriospinal systems assumed to coordinate fore- and hindlimb activity are poorly understood. This study characterizes the long descending propriospinal (LDP) neurons in terms of the location of the somas and their peripheral inputs by direct neuronal recording. Anatomical studies using axonal retrograde transport of horseradish peroxidase from the lumbar to the cervical spinal cord as a tracer first described these neurons. Two hundred and thirty-one LDP neurons were identified in electrophysiological experiments. Of these, 123 responded to natural stimulation, and about 50% of the others were activated only by electrical stimulation. The majority of cells were located in laminae VII and VIII in agreement with anatomical data. The most effective stimuli were mechanical stimulation of skin, deep pressure to subcutaneous tissues, and paw joint movement. Bot excitatory and inhibitory responses were observed

Juniperus of Canada and the United States: Taxonomy, Key and Distribution.

The taxonomy of Juniperus of Canada and the United States is reviewed and keys to the 18 species, 5 varieties and 3 formas are presented as well as distribution maps.Integrative Biolog

The Case for Improving U.S. Computer Science Education

Despite the growing use of computers and software in every facet of our economy, not until recently has computer science education begun to gain traction in American school systems. The current focus on improving science, technology, engineering, and mathematics (STEM) education in the U.S. school system has disregarded differences within STEM fields. Indeed, the most important STEM field for a modern economy is not only one that is not represented by its own initial in "STEM" but also the field with the fewest number of high school students taking its classes and by far has the most room for improvement—computer science

Market Power in Outputs and Inputs: An Empirical Application to Banking

This paper provides evidence on the empirical separability of input and output market imperfections. We specify a model of banking competition and simultaneously estimate bank conduct in output (loan) and input (deposit) markets. Our results suggest that firms display some degree of noncompetitive behavior in both the loan and the deposit markets. Moreover, we find that the input side and the output side are empirically separable, that is the measurement of market power on one side of the market is not affected by assuming that the other side of the market is perfectly competitive. Our results suggest that empirical studies of market power that concentrate on either the input side or the output side, are not subject to significant misspecification error. ZUSAMMENFASSUNG - (Marktmacht auf Input- und Outputmärkten: Eine Empirische Anwendung auf den Bankensektor) Der Aufsatz untersucht den Zusammenhang von Unvollkommenheiten auf Input- und auf Outputmärkten. Im Rahmen eines Wettbewerbsmodells für den Bankensektor wird die Wechselwirkung zwischen Outputmarkt, d.h. bei der Kreditvergabe, und Inputmarkt (Geldanlage) empirisch untersucht. Die Ergebnisse zeigen, dass Banken auf beiden Seiten des Marktes eine gewisse Marktmacht ausüben können. Allerdings ist die Wechselwirkung begrenzt, sodass eine separate Betrachtungsweise von Input- und Outputmärkten möglich ist. Dies bedeutet wiederum, dass empirische Untersuchungen, die jeweils nur eine Seite des Marktes analysieren, keinen signifikanten Verzerrungen unterliegen.Measuring Market Power, Banking

EFFECTS OF EEP ON CANADIAN/UNITED STATES WHEAT TRADE

Agricultural and Food Policy, International Relations/Trade,

Flutter suppression using eigenspace freedoms to meet requirements

A constrained optimization methodology has been developed which allows specific use of eigensystem freedoms to meet design requirements. A subset of the available eigenvector freedoms was employed. The eigenvector freedoms associated with a particular closed-loop eigenvalue are coefficients of basis vectors which span the subspace in which that closed-loop vector must lie. Design requirements are included as a vector of inequality constraints. The procedure was successfully applied to develop an unscheduled controller which stabilizes symmetric flutter of an aeroelastic vehicle to a dynamic pressure 44 percent above the open-loop flutter point. The design process proceeded from full-state feedback to the inclusion of a full-order observer to the selection of an eighth-order controller which preserved the full-state sensitivity characteristics. Only a subset of the design freedoms was utilized (i.e., assuming full-state feedback only four out of 26 eigenvectors were used, and no variations were made in the closed-loop eigenvalues). Utilization of additional eigensystem freedoms could further improve the controller

Is the ridge formed by aligned jet propagation and medium flow?

Motivated by the recent observation that the ridge decreases with trigger particle angle ($\phi_s$) relative to the event plane, it is theorized that the ridge is formed by interplay between jet propagation and medium flow. Such interplay may produce asymmetry in the ridge azimuthal correlation at a fixed $\phi_s$. We present an analysis of this asymmetry from STAR data. We found an asymmetric ridge with maximum asymmetry at $\phi_s\approx45^{\circ}$ concurrent with a symmetric jet at all $\phi_s$.Comment: 2 pages, 2 figures, Quark Matter 200

On evaluating parallel computer systems

A workshop was held in an attempt to program real problems on the MIT Static Data Flow Machine. Most of the architecture of the machine was specified but some parts were incomplete. The main purpose for the workshop was to explore principles for the evaluation of computer systems employing new architectures. Principles explored were: (1) evaluation must be an integral, ongoing part of a project to develop a computer of radically new architecture; (2) the evaluation should seek to measure the usability of the system as well as its performance; (3) users from the application domains must be an integral part of the evaluation process; and (4) evaluation results should be fed back into the design process. It is concluded that the general organizational principles are achievable in practice from this workshop

Reliability and performance evaluation of systems containing embedded rule-based expert systems

A method for evaluating the reliability of real-time systems containing embedded rule-based expert systems is proposed and investigated. It is a three stage technique that addresses the impact of knowledge-base uncertainties on the performance of expert systems. In the first stage, a Markov reliability model of the system is developed which identifies the key performance parameters of the expert system. In the second stage, the evaluation method is used to determine the values of the expert system's key performance parameters. The performance parameters can be evaluated directly by using a probabilistic model of uncertainties in the knowledge-base or by using sensitivity analyses. In the third and final state, the performance parameters of the expert system are combined with performance parameters for other system components and subsystems to evaluate the reliability and performance of the complete system. The evaluation method is demonstrated in the context of a simple expert system used to supervise the performances of an FDI algorithm associated with an aircraft longitudinal flight-control system