Lethal Temperatures of Diapausing \u3ci\u3eBathyplectes Curculionis\u3c/i\u3e (Hymenoptera: Ichneumonidae) a Parasite of the Alfalfa Weevil (Coleoptera: Curculionidae)

Seasonally acclimatized diapausing larvae of Bathyplectes curculionis (Thomson) were exposed to extreme hxgh and low temperatu~es to determine lethal temperatures for this stage of the parasite. The possible effects of relative humidity on high temperature mortality, mortality induced by repetitive exposures to sublethal temperatures, and differential survival between sexes, were also measured. The upper lethal temperature for summer larvae was 60°C (LDSo from 2 to 4 h), and the lower lethal temperature for winter larvae was -25°C (LDSo from 0 to % h). Summer larvae showed significantly increased mortality with repetitive exposures to sublethal temperatures (55OC) whereas winter larval mortality did not increase significantly with repetitive exposures to sublethal temperatures (-20°C). In winter experiments in which the sex of the emerging adult could be measured, no significant difference in survival was found between the sexes. Our results, in conjunction with published field data, strongly suggest that heat kill in the summer may be a significant mortality factor in warmer areas of the parasite\u27s range

Energy efficient engine. Low pressure turbine test hardware detailed design report

The low pressure turbine for the energy efficient engine is a five-stage configuration with moderate aerodynamic loading incorporating advanced features of decambered airfoils and extended blade overlaps at platforms and shrouds. Mechanical integrity of 18,000 hours on flowpath components and 36,000 hours on all other components is achieved along with no aeromechanical instabilities within the steady-state operating range. Selection of a large number (156) of stage 4 blades, together with an increased stage 4 vane-to-blade gap, assists in achieving FAR 36 acoustic goals. Active clearance control (ACC) of gaps at blade tips and interstage seals is achieved by fan air cooling judiciously applied at responsive locations on the casing. This ACC system is a major improvement in preventing deterioration of the 0.0381 cm (0.015 in.) clearances required to meet the integrated-core/low-spool turbine efficiency goal of 91.1% and the light propulsion system efficiency goal of 91.7%

Multiple mechanisms of spiral wave breakup in a model of cardiac electrical activity

It has become widely accepted that the most dangerous cardiac arrhythmias are due to re- entrant waves, i.e., electrical wave(s) that re-circulate repeatedly throughout the tissue at a higher frequency than the waves produced by the heart's natural pacemaker (sinoatrial node). However, the complicated structure of cardiac tissue, as well as the complex ionic currents in the cell, has made it extremely difficult to pinpoint the detailed mechanisms of these life-threatening reentrant arrhythmias. A simplified ionic model of the cardiac action potential (AP), which can be fitted to a wide variety of experimentally and numerically obtained mesoscopic characteristics of cardiac tissue such as AP shape and restitution of AP duration and conduction velocity, is used to explain many different mechanisms of spiral wave breakup which in principle can occur in cardiac tissue. Some, but not all, of these mechanisms have been observed before using other models; therefore, the purpose of this paper is to demonstrate them using just one framework model and to explain the different parameter regimes or physiological properties necessary for each mechanism (such as high or low excitability, corresponding to normal or ischemic tissue, spiral tip trajectory types, and tissue structures such as rotational anisotropy and periodic boundary conditions). Each mechanism is compared with data from other ionic models or experiments to illustrate that they are not model-specific phenomena. The fact that many different breakup mechanisms exist has important implications for antiarrhythmic drug design and for comparisons of fibrillation experiments using different species, electromechanical uncoupling drugs, and initiation protocols.Comment: 128 pages, 42 figures (29 color, 13 b&w

Eyespray Vaccination: Infectivity and Development of Immunity to Eimeria acervulina and Eimeria tenella

The infectivity of a coccidiosis vaccine and its ability to immunize chickens against two species of Eimeria was examined. The vaccine was administered to newly-hatched chicks by spraying directly onto the eye. The method resulted in a high proportion of chicks infected with E. acervulina and E. tenella. Vaccinated birds reared in cages in the absence of reinfection did not develop immunity to either species by 4 wk of age, but birds reared in floor pens developed immunity to both E. acervulina and E. tenella

Radiography Faculty Engaged in Online Education: Perceptions of Effectiveness, Satisfaction, and Technological Self-Efficacy

Purpose To assess radiography faculty perceptions of the effectiveness of online courses. Methods An original survey instrument was created by selecting items from 3 instruments used in prior research and adding unique questions designed to elicit demographic data from faculty. The sample included a national dataset of radiography faculty members employed in Joint Review Committee on Education in Radiologic Technology–accredited programs in the United States. Results Findings showed that faculty perceptions of online course effectiveness are not affected significantly by faculty position, type of institution, faculty age, or years of teaching experience. Positive perceptions of the effectiveness of online courses moderately increased with years of teaching online courses, number of online courses taught in the past 5 years, and perceived competence with the use of technology. Faculty satisfaction with interaction in online courses moderately increased as the years of teaching online courses increased. However, the number of years of teaching online courses was not related to faculty satisfaction with teaching online courses or faculty satisfaction with institutional support. Online technology acceptance had a moderately positive relationship with perceived ease of use and a strong positive relationship with perceived usefulness of online technology. In addition, the use of technology-enhanced learning methods had a strong positive relationship with technological self-efficacy. Conclusion Radiography faculty perceptions of the effectiveness of online courses improved with experience in teaching online courses and competence with use of technology. Perceived ease of use and perceived usefulness of online technology were related directly to online technology acceptance. Furthermore, faculty members with technological self-efficacy were more likely to use technology-enhanced learning methods in the online environment