Slender Wing Theory Including Regions of Embedded Total Pressure Loss

An aerodynamic theory of the flow about slender delta wings is described. The theory includes a treatment of the self-consistent development of the vortex wake patterns above the wing necessary to maintain smooth flow at the wing edges. The paper focuses especially on the formation within the wake of vortex \u27cores\u27 as embedded regions of total pressure loss, fed and maintained by umbilical vortex sheets emanating from the wing edges. Criteria are developed for determining the growing size and location of these cores, as well as the distribution and strength of the vorticity within them. In this paper, however, the possibility of vortex breakup is omitted. The aerodynamic consequences of the presence and evolution of the cores and the associated wake structure are illustrated and discussed. It is noted that wake history effects can have substantial influence on the distribution of normal force on the wing as well as on its magnitude

Developing Adaptability: A Theory for the Design of Integrated-Embedded Training Systems

[Excerpt] This convergence of forces – environmental, technological, and economic – is driving a reconceptualization of the nature of training systems. Training is shifting from an inefficient, time consuming, and expensive enterprise to one that can be delivered efficiently, as needed, and just-in-time. It is shifting from an off-site single episode to a systematic series of learning experiences that are integrated in the workplace and embedded in work technology. It is shifting from a primary emphasis on retention and reproduction to a broader emphasis that also includes the development of adaptive knowledge and skills (Kozlowski, 1998). Training will not be a separate activity, but a continuous activity that is an integral part of the workplace and its systems. This reconceptualization of training systems is highlighted by three key terms in our title which constitute the theoretical and application focus of this chapter: · Integrate – to form, coordinate, or blend into a functioning or unified whole; · Embed – to enclose closely; to make something an integral part of; · Adapt – to make fit; implies a modification according to changing circumstances; (Webster’s Ninth New Collegiate Dictionary, 1987)

A role for microRNAs in the Drosophila circadian clock

Little is known about the contribution of translational control to circadian rhythms. To address this issue and in particular translational control by microRNAs (miRNAs), we knocked down the miRNA biogenesis pathway in Drosophila circadian tissues. In combination with an increase in circadian-mediated transcription, this severely affected Drosophila behavioral rhythms, indicating that miRNAs function in circadian timekeeping. To identify miRNA–mRNA pairs important for this regulation, immunoprecipitation of AGO1 followed by microarray analysis identified mRNAs under miRNA-mediated control. They included three core clock mRNAs—clock (clk), vrille (vri), and clockworkorange (cwo). To identify miRNAs involved in circadian timekeeping, we exploited circadian cell-specific inhibition of the miRNA biogenesis pathway followed by tiling array analysis. This approach identified miRNAs expressed in fly head circadian tissue. Behavioral and molecular experiments show that one of these miRNAs, the developmental regulator bantam, has a role in the core circadian pacemaker. S2 cell biochemical experiments indicate that bantam regulates the translation of clk through an association with three target sites located within the clk 3′ untranslated region (UTR). Moreover, clk transgenes harboring mutated bantam sites in their 3′ UTRs rescue rhythms of clk mutant flies much less well than wild-type CLK transgenes