Bounds for the zeros of polynomials Final report, 1 Apr. 1966 - 30 Sep. 1967

Theorem application to companion matrix of polynomia

Rotor systems research aircraft airplane configuration flight-test results

The rotor systems research aircraft (RSRA) has undergone ground and flight tests, primarily as a compound aircraft. The purpose was to train pilots and to check out and develop the design flight envelope. The preparation and flight test of the RSRA in the airplane, or fixed-wind, configuration are reviewed and the test results are discussed

Conceptual design study of advanced acoustic composite nacelle

Conceptual nacelle designs for wide-bodied and for advanced-technology transports were studied with the objective of achieving significant reductions in community noise with minimum penalties in airplane weight, cost, and in operating expense by the application of advanced composite materials to nacelle structure and sound suppression elements. Nacelle concepts using advanced liners, annular splitters, radial splitters, translating centerbody inlets, and mixed-flow nozzles were evaluated and a preferred concept selected. A preliminary design study of the selected concept, a mixed flow nacelle with extended inlet and no splitters, was conducted and the effects on noise, direct operating cost, and return on investment determined

Analysis of the extraterrestrial life detection problem

Analysis of extraterrestrial life detection proble

The Effect of Mutators on Adaptability in Time-Varying Fitness Landscapes

This Letter studies the quasispecies dynamics of a population capable of genetic repair evolving on a time-dependent fitness landscape. We develop a model that considers an asexual population of single-stranded, conservatively replicating genomes, whose only source of genetic variation is due to copying errors during replication. We consider a time-dependent, single-fitness-peak landscape where the master sequence changes by a single point mutation every time $\tau$. We are able to analytically solve for the evolutionary dynamics of the population in the point-mutation limit. In particular, our model provides an analytical expression for the fraction of mutators in the dynamic fitness landscape that agrees well with results from stochastic simulations.Comment: 4 pages, 3 figure

Travelling waves in hyperbolic chemotaxis equations

Mathematical models of bacterial populations are often written as systems of partial differential equations for the densities of bacteria and concentrations of extracellular (signal) chemicals. This approach has been employed since the seminal work of Keller and Segel in the 1970s [Keller and Segel, J. Theor. Biol., 1971]. The system has been shown to permit travelling wave solutions which correspond to travelling band formation in bacterial colonies, yet only under specific criteria, such as a singularity in the chemotactic sensitivity function as the signal approaches zero. Such a singularity generates infinite macroscopic velocities which are biologically unrealistic. In this paper, we formulate a model that takes into consideration relevant details of the intracellular processes while avoiding the singularity in the chemotactic sensitivity. We prove the global existence of solutions and then show the existence of travelling wave solutions both numerically and analytically

Improving Lay Helper Effectiveness: Teaching Living Prayer as a Gateway to a Focused Kingdom Lifestyle

It is common for those entering counseling at the Lake Church Counseling Center to lack intimacy with God. When one lacks intimacy with God, they are in imminent danger of becoming influenced exclusively by the world\u27s thinking in one or more areas of life. It is the effort of the LCCC to provide services to those suffering from emotional, spiritual, relational, and personal development struggles. Initially, the counseling center treats such conditions using Living Prayer to help clients strengthen their connection with God and transition to behaviors influenced only by the kingdom of God. This project aims to help Lake Church members learn to use Living Prayer as a gateway to a focused kingdom lifestyle. The intervention\u27s value is that a more focused kingdom lifestyle benefits anyone experiencing a life struggle and that those who will eventually attend counseling sessions at the LCCC will already be familiar with Living Prayer. To deploy the Living Prayer concept to all church members, the researcher selected a group of lay leaders already involved in supporting those with struggles. The group attended a four-hour training seminar followed by a four-week trial period. After the seminar and the trial period, surveys revealed that participants overwhelmingly embraced Living Prayer and their new role as Living Prayer Coaches. The results of this project demonstrate that lay leaders and helpers value training programs aimed at improving their proficiencies and augmenting their gifts

Oral contraception and eye disease: findings in two large cohort studies

AIM : To investigate the relation between oral contraceptive use and certain eye diseases. \ud \ud METHODS : Abstraction of the relevant data from the two large British cohort studies of the effects of oral contraception, the Royal College of General Practitioners' (RCGP) Oral Contraception Study and the Oxford-Family Planning Association (Oxford-FPA) Contraceptive Study. Both cohort studies commenced in 1968 and were organised on a national basis. Between them they have accumulated over 850 000 person years of observation involving 63 000 women. \ud \ud RESULTS : The conditions considered in the analysis were conjunctivitis, keratitis, iritis, lacrimal disease, strabismus, cataract, glaucoma, retinal detachment, and retinal vascular lesions. With the exception of retinal vascular lesions, there was no consistent evidence of important increases in risk of eye diseases in users of oral contraception. There was about a twofold increase in the risk of retinal vascular lesions in recent pill users in both studies (statistically significant only in the RCGP study). The increase was not limited to any specific type of lesion and may well reflect diagnostic bias. \ud \ud CONCLUSION : Oral contraceptive use does not appear to increase the risk of eye disease, with the possible exception of retinal vascular lesions. \ud \ud Keywords: oral contraception; eye disease; cohort studie

The fractal geometry of nutrient exchange surfaces does not provide an explanation for 3/4-power metabolic scaling

BACKGROUND: A prominent theoretical explanation for 3/4-power allometric scaling of metabolism proposes that the nutrient exchange surface of capillaries has properties of a space-filling fractal. The theory assumes that nutrient exchange surface area has a fractal dimension equal to or greater than 2 and less than or equal to 3 and that the volume filled by the exchange surface area has a fractal dimension equal to or greater than 3 and less than or equal to 4. RESULTS: It is shown that contradicting predictions can be derived from the assumptions of the model. When errors in the model are corrected, it is shown to predict that metabolic rate is proportional to body mass (proportional scaling). CONCLUSION: The presence of space-filling fractal nutrient exchange surfaces does not provide a satisfactory explanation for 3/4-power metabolic rate scaling