Propertius Book IV: Themes and Structures

published or submitted for publicatio

Biological control of conifer seed damage by the deer mouse (Peromyscus maniculatus)

This paper describes the development of a biological technique that successfully controls conifer seed damage by the deer mouse. Eleven experiments have been conducted on three study areas at the University of British Columbia Research Forest, Maple Ridge, B.C. Populations of deer mice have been monitored in all experiments with data from 56,000 trap nights. The technique involves a mixture of conifer seed (Douglas fir) with sunflower seed and oats which is uniformly distributed on logged areas in the late winter-early spring. Survival of conifer seed with these alternate foods was excellent, compared with control Douglas fir by itself, for an 8-week period during this time of year. Populations of seed-eating birds and chipmunks are not present on clearcut areas from late October to early April. In addition, deer mice are at their lowest density during the spring. Thus, the use of alternate foods with Douglas fir seed in a direct-seeding operation at the appropriate time of year will result in successful regeneration of cutover forest lands

Ethical Leadership: Guiding Principles for Educators and Administrators

Rooted in Biblical principles, this discussion of eight values associated with ethical leadership will provide educators and administrators with “food for thought” as they adopt their own personal code of ethics or guiding principles on which to base their leadership style

Concurrent validity of the Sensory Organization Test measures in unilateral transtibial amputees

This article is available open access through the publisher’s website at the link below. Copyright @ The International Society for Prosthetics and Orthotics 2012.Background and Aim: The physical asymmetries associated with a prosthesis raises the question of validity of the Sensory Organization Test (SOT) measures (equilibrium score (ES) and strategy score (SS)) in lower limb amputees. This study explores the validity of these measures in transtibial amputees by correlating with their corresponding centre of pressure (COP) excursion/velocity measures. Technique: Fifteen transtibial amputees (69.5 ± 6.5 years) completed three trials for each of the six SOT conditions. Discussion: The Spearman’s rank correlation coefficients between ESs and global COP excursion/velocity measures ranged from 0.52 to 0.71 for Conditions 1, 4 and 5, 0.79 to 0.85 for Conditions 2 and 3, and 0.39 to 0.43 for Condition 6. The coefficients for SSs ranged between 0.78 and 0.97 for Conditions 1 to 5 and 0.55 to 0.67 for Condition 6. The corresponding sound and prosthetic side COP variables demonstrated varying strengths of association with ES and SS. Clinical relevance Of the two clinical measures examined, the SSs are strongly reflective of COP excursion/velocity measures and these findings have application in the interpretation of SOT when evaluating balance in transtibial amputees.New Zealand Artificial Limb Boar

Learning From Complexity: Effects Of Prior Accidents And Incidents On Airlines' Learning

Using data on accidents and incidents experienced by U.S. commercial airlines from 1983 to 1997, we investigated variation in firm learning by examining whether firms learn more from errors with heterogeneous or homogeneous causes. We measured learning by a reduction in airline accident and incident rates, while controlling for other factors related to accidents and incidents. Our results show that heterogeneity is generally better for learning, as prior heterogeneity in the causes of errors decreases subsequent accident rates, producing a deeper, broader search for causality than simple explanations like >blame the pilot.> The benefits of heterogeneity, however, apply mainly to specialist airlines. Generalist airlines learn, instead, from outside factors such as the experience of others and general improvements in technology. These results suggest a theory of learning across organizational forms: complex forms benefit from simple information, and simple forms benefit from complex information. The implications of our study for learning theories and work on organizational errors are discussed.Business Administratio

Performance of wind turbines in a turbulent atmosphere

The effect of atmospheric turbulence on the power fluctuations of large wind turbines was studied. The significance of spatial non-uniformities of the wind is emphasized. The turbulent wind with correlation in time and space is simulated on the computer by Shinozukas method. The wind turbulence is modelled according to the Davenport spectrum with an exponential spatial correlation function. The rotor aerodynamics is modelled by simple blade element theory. Comparison of the spectrum of power output signal between 1-D and 3-D turbulence, shows the significant power fluctuations centered around the blade passage frequency