Space Station Centrifuge: A Requirement for Life Science Research

A centrifuge with the largest diameter that can be accommodated on Space Station Freedom is required to conduct life science research in the microgravity environment of space. (This was one of the findings of a group of life scientists convened at the University of California, Davis, by Ames Research Center.) The centrifuge will be used as a research tool to understand how gravity affects biological processes; to provide an on-orbit one-g control; and to assess the efficacy of using artificial gravity to counteract the deleterious biological effect of space flight. The rationale for the recommendation and examples of using ground-based centrifugation for animal and plant acceleration studies are presented. Included are four appendixes and an extensive bibliography of hypergravity studies

Tragedy of the common canal

This paper uses laboratory experiments to investigate the effects of alternative solutions to a common-pool resource with a unidirectional flow. The focus is on the comparative economic efficiency of communications, bilateral “Coasian” bargaining, auctions and price-based allocations. All treatments improve allocative efficiency relative to a baseline environment. Communication and bilateral bargaining are not generally as effective as market allocations. An exogenously imposed, optimal fee results in the greatest efficiency gain, followed by auction allocations that determine the usage fee endogenously.externalities, experiments, auctions, Coasian bargaining, common pool resource

Knowledge Management: The Role of EPSS

Knowledge Management (KM) has become a key business strategy. KM involves the systematic mapping, harvesting, storing, sharing, maintaining, and refreshing knowledge from many sources. An Electronic Performance Support System (EPSS) can perform an essential role of encapsulating and delivering knowledge at the time needed. Expanding globalization and reliance on distributed knowledge means that the EPSS delivered via networks should have a high priority. We present an argument to show the linkage between components of a KM system and EPSS. The approach involves the creation of software that is designed to assist decisionmakers and performers while they accomplish organizational processes

High Reynolds number tests of a Douglas DLBA 032 airfoil in the Langley 0.3-meter transonic cryogenic tunnel

A wind-tunnel investigation of a Douglas advanced-technology airfoil was conducted in the Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3-m TCT). The temperature was varied from 227 K (409 R) to 100 K (180 R) at pressures ranging from about 159 kPa (1.57 atm) to about 514 kPa (5.07 atm). Mach number was varied from 0.50 to 0.78. These variables provided a Reynolds number range (based on airfoil chord) from 6.0 to 30.0 x 10 to the 6th power. This investigation was specifically designed to: (1) test a Douglas airfoil from moderately low to flight-equivalent Reynolds numbers, and (2) evaluate sidewall-boundary-layer effects on transonic airfoil performance characteristics by a systematic variation of Mach number, Reynolds number, and sidewall-boundary-layer removal. Data are included which demonstrate the effects of fixing transition, Mach number, Reynolds number, and sidewall-boundary-layer removal on the aerodynamic characteristics of the airfoil. Also included are remarks on model design and model structural integrity

The distribution of muscle and bone weight in swamp buffalo (Bubalus bubalis), bos indicus and bos taurus Steers

The muscle weight distribution and bone weight distribution of 15 buffalo (Bubalus bubalis) steers were compared with that of 15 steers from each of three breeds ofcattle, Angus, Hereford and Brahman. For both muscle weight distribution and bone weight distribution, buffaloes showed a "shift" towards the forequarter. This involved the cervical, thoracic and forelimb bones and standard muscle groups 5, 7 and 9. Brahmans showed a similar but less pronounced distribution to that of the buffaloes. The scapula was an exception in the forequarter of the buffaloes. It was lighter relative to the other breeds with clearly enlarged mm. supraspinatus and infraspinatus but a lighter m. subscapularis. It is suggested that these distribution differences reflect the traction history of buffaloes and Brahmans

ESTIMATION OF THE MAXIMUM MULTIPLICITY OF AN EIGENVALUE IN TERMS OF THE VERTEX DEGREES OF THE GRAPH

Abstract. The maximum multiplicity among eigenvaluesof matriceswith a given graph cannot generally be expressed in terms of the degrees of the vertices (even when the graph is a tree). Given are best possible lower and upper bounds, and characterization of the cases of equality in these bounds. A by-product is a sequential algorithm to calculate the exact maximum multiplicity by simple counting. Key words. Eigenvalues, multiplicity, symmetric matrix, tree, vertex degrees. AMS subject classifications. 15A18, 15A57, 05C50, 05C05, 05C0

Police and Older Persons: Criteria Developed to Assess Training Materials, Methods

This article as revised was published as Johnson, Knowlton W.; Beirnard, Charles A.; & Stiles, Stephen R. (1981). "Police and Older Persons: Criteria Developed to Assess Training Materials, Methods." Training Aids Digest 6(11), November 1981.In what ways do law enforcement personnel and agencies use knowledge about the elderly? This article presents the findings of a recent study conducted by the International Training Research and Evaluation Council on how law enforcement trainees make use of the knowledge they gained through training materials developed by the National Retired Teachers Association/American Association of Retired Persons.[Introduction] / Different Types of Knowledge Use / The Study / Knowledge Into Practice: Some Implication

Eigenvalue assignments and the two largest multiplicities in a Hermitian matrix whose graph is a tree

Among the possible multiplicity lists for the eigenvalues of Hermitian matrices whose graph is a tree we focus upon M(2), the maximum value of the sum of the two largest multiplicities. The corresponding M(1) is already understood. The notion of assignment (of eigenvalues to subtrees) is formalized and applied. Using these ideas, simple upper and lower bounds are given for M(2) (in terms of simple graph theoretic parameters), cases of equality are indicated, and a combinatorial algorithm is given to compute M(2) precisely. In the process, several techniques are developed that likely have more general uses. (C) 2009 Elsevier B.V. All rights reserved