Effect of Symptomless Fungal Infection of Maize Seed on Germination in the Presence and Absence of Pythium debaryanum.

Seeds from ears of Zea mays infected by Gibberella zeae and Nigrospora oryzae frequently failed to show these fungi when germination took place in the absence of Pythium debaryanum. Diplodia zeae emerged from symptomless, infected seeds in both the presence and absence of P. debaryanum. Symptomless infection by Fusarium moniliforme evidently did not reduce germination in the absence of Pythium. The effect of F. moniliforme in the presence Pythium could not be tested because of inadequate controls. Symptomless infection by D. zeae, G. zeae, and N. oryzae always reduced the ability of seedlings to resist Pythium

Resistance to Pythium debaryanum in Zea mays Seedlings

Seedling resistance to Pythium was studied by placing maize kernels on or under a culture of Pythium growing on a semi synthetic medium. The main criteria were living plumules and roots after 14-days incubation at 12 C and 6 days at 23-27 C. Greater mortality occurred when inoculum was above the kernels than below. Surface-sterilization of kernels before exposure to Pythium increased seedling mortality, but moisture content of kernels at the start of exposure had only a slight effect on survival at 12 C. Maximum mortality occurred when the cold period was more than 8 days. Survival was greater after a short cold period of 1-2 days than if the kernels were not exposed to any cold-incubation period. Varying the length of the cold incubation introduces a genetic-incubation interaction. The critical period in exposure to Pythium at low temperatures was between 48 and 96 hours of exposure, by which time the fungus had become established in the kernels, and surface sterilization would not free them from infection. All kernels, from susceptible or resistant genotypes, were invaded in 4 days. A daily alternating incubation temperature (10-25 C) was highly variable in effect on survival. The expression of resistance was maximum in the plumule and scutellar node, which, if they survived the initial exposure to Pythium, showed near immunity. The radicle and seminal roots were never longer than 1 cm if exposed to Pythium, except in seedlings having a resistant plumule

SSME structural dynamic model development

A mathematical model of the Space Shuttle Main Engine (SSME) as a complete assembly, with detailed emphasis on LOX and High Fuel Turbopumps is developed. The advantages of both complete engine dynamics, and high fidelity modeling are incorporated. Development of this model, some results, and projected applications are discussed

The Power of Conferences: stories of serendipity, innovation and driving social change

A chance encounter at a conference sets up a series of unfolding events. In 1982, immunologist Ian Frazer attended his first international gastroenterology conference in Canberra, Australia. After his presentation on genital warts, a colleague, Dr Gabrielle Medley, discussed with him the potential link between the human papillomavirus and cancer. This meeting proved fateful, as it helped to put him on the path that would ultimately lead to the development of the HPV vaccine. This vaccine is now used across the globe, and may eradicate cervical cancer within a generation. This book seeks to explore and understand these long-term outcomes: what we loosely refer to as the ‘long tail’ of conference impact. By doing so, we hope to add to an increasingly complex picture of the value of conferences. For, despite the costs and effort involved in hosting and attending conferences, despite all the online communication options for the circulation of knowledge and commentary, many thousands of events, involving many thousands of people coming together, take place around the world each year. What makes them so worthwhile? How can we plan and design conferences to allow for the full range of potential benefits and outcomes

Business events and friendship: Leveraging the sociable legacies

© 2014 Cognizant Comm. Corp. Business events are celebrated for their contributions to community and industry. They are understood to be shared social contexts in which people meet to advance knowledge, sell products, and network. Less celebrated and, arguably, less understood is that business events provide a context for the development of friendships. In 2011 an online survey was conducted with the delegates of five international business events held in Sydney, Australia in the period 2009-2011. The survey was designed to investigate business legacies of the events (such as investment opportunities, research collaborations) rather than sociable legacies. However, a surprising number of references to friendship were made in the "additional comments" sections of the questionnaire. Reflecting on this finding, this article argues that friendships forged at business events contribute to, respectively: the well-being of delegates, association membership levels, conference attendance, retention of personnel in the profession, successful research and professional collaborations, and creativity and innovation in the sector. Business event planners can maximize opportunities for sociable outcomes among delegates by designing warm and inviting event spaces that facilitate interaction, and by providing social space for the development of relationships, optimal conditions for sociability, and opportunities for play to stimulate creativity and build community