Common bacterial blight

Common bacterial blight (Xanthomonas campestris pv. phaseoli) is the major bacterial disease of beans. The organism is present in numerous bean production regions of the world. High temp. and RH are favorable conditions for the development of the disease. The infection by the bacteria produces water-soaked spots on the leaves, stems, pods, and seeds. The disease can be controlled by cultural practices such as the use of disease-free seed, proper crop rotation with resistant crops, the use of various chemical products in seed treatment or as a foliage protectant before the infection becomes severe, the use of resistant var., and integrated control. The symptoms and damage caused by the disease are illustrated in color. (CIAT)La principal enfermedad bacteriana del frijol es el anublo bacteriano comun (Xanthomonas campestris pv. phaseoli). El organismo se encuentra presente en numerosas regiones productoras de frijol del mundo. La temp. y la HR alta son condiciones favorables para el desarrollo de la enfermedad; la infeccion por la bacteria produce manchas humedas en las hojas, tallos, vainas y semillas. El control de la enfermedad se puede hacer mediante practicas culturales como el uso de semilla libre de patogenos, la apropiada rotacion con cultivos resistentes, el uso de varios productos quimicos en el tratamiento de la semilla o para proteger el follaje antes de que la infeccion tome caracteristicas severas, la utilizacion de var. resistentes y el control integrado. Se ilustran a color los sintomas y danos causados por la enfermedad. (CIAT

Angular leaf spot

Angular leaf spot, caused by the fungus Isariopsis griseola in tropical and subtropical regions, can cause losses up to 50 percent. The pathogen infects the leaves by entering through the stomata or can be transmitted by the seed. Disease control can be carried out by cultural practices, use of disease-free seeds, planting in well-drained soils, the removal of infected harvest debris, and the utilization of chemical products and resistant var. Color illustrations are given of the symptoms and damage caused by the disease. (CIAT)La mancha foliar angular, causada por el hongo Isariopsis griseola en las regiones tropicales y subtropicales, puede ocasionar perdidas de hasta 50 por ciento. El patogeno infecta las hojas penetrando a traves de los estomas o puede transmitirse por la semilla. El control de la enfermedad se puede realizar mediante practicas culturales, utilizacion de semillas libres del patogeno, siembra en suelos bien drenados y eliminacion de residuos de cosecha infectados, y utilizacion de productos quimicos y de var. resistentes. Se dan ilustraciones a color de los sintomas y el dano causado por la enfermedad. (RA

Web-Based Training

Current Web-based training (WBT) is based upon systematic research and experience with strategies for improving learning and instruction, beginning in the early part of the 20th century and continuing to the present. Use of the World-Wide Web for delivery may improve access to training, but the effectiveness of the resulting training and the usefulness of the outcomes is chiefly dependent upon the quality of the instructional design and the completeness of the support package provided. Factors that impact WBT quality, and which must be addressed in design and implementation processes, include assessment and accommodation of trainees previous learning experiences, training expectations, and overall readiness for new training; availability and familiarity to trainees and trainers of appropriate delivery technologies; presence of technical support; opportunities for interaction with the trainer and other trainees; the preparation and practices of trainers; corporate support and recognition; trainees capacities and expectations for independent and self-directed learning; and the presence of relevant, quality online training materials. WBT creates changes and may thus produce stresses in the training environment, as well as efficiencies. Reduction in travel and subsistence requirements means cost savings, but may also be seen by trainees as depriving them of opportunities to meet with each other face-to-face; self-pacing means trainees may proceed independently and at their own rate, but also that group support may be reduced (unless a cohort model is adopted); use of the Internet for delivery of training materials may foster trainee independence, but may also result in confusion for some trainees used to print materials and a paced, group delivery model; trainers no longer have to lecture as materials (always high quality, and often multimedia-based) are prepared in advance, but some may resent the loss of their role at center-stage; trainees are more responsible for their own learning, which may reflect the autonomy of adult responsibility common in the other areas of their lives, but this may be different from the expectations of some for how training should be conducted. To achieve the efficiencies and advantages well-designed and -managed WBT may offer, adopting organizations must make adjustments. Managers may need to show concrete support for online training by permitting trainees to use corporate resources during company time, to assure access to adequate bandwidth. Trainers may need to master new skills and be willing to adopt new roles less concerned with information dissemination and more involved with meeting individual trainees expressed needs. Trainees themselves may also need new skills, and may need to exercise more independence and selfdirection in their learning. As technologies become more available to support WBT, and as more models of successful WBT are available, the commitment to this delivery model is predicted to continue to grow. The previous corporate experience of the productivity paradox in relation to computers, in which some succeeded in improving productivity while others did notand some even experienced productivity losseswill need to be avoided, especially in relation to promising innovations such as reusable learning objects. Similarly, arrival of the noncommercial new Internets in Canada and the United States constitute a fresh start, an opportunity to demonstrate the value of these resources for academic and research purposes. 2 Choices of the right technologies, effective use of these choices, attention to security and privacy concerns, adequate training and support of users at all levels, assurance of timely and convenient technology access, an

Radiative Muon Capture on Hydrogen and the Induced Pseudoscalar Coupling

The first measurement of the elementary process $\mu^- p \rightarrow \nu_{\mu} n \gamma$ is reported. A photon pair spectrometer was used to measure the partial branching ratio ($2.10 \pm 0.22) \times 10^{-8}$ for photons of k > 60 MeV. The value of the weak pseudoscalar coupling constant determined from the partial branching ratio is $g_p(q^{2}=-0.88m_{\mu}^2) = (9.8 \pm 0.7 \pm 0.3) \cdot g_a(0)$, where the first error is the quadrature sum of statistical and systematic uncertainties and the second error is due to the uncertainty in $\lambda_{op}$, the decay rate of the ortho to para $p \mu p$ molecule. This value of g_p is $\sim$1.5 times the prediction of PCAC and pion-pole dominance.Comment: 13 pages, RevTeX type, 3 figures (encapsulated postscript), submitted to Phys. Rev. Let

First Neutrino Observations from the Sudbury Neutrino Observatory

The first neutrino observations from the Sudbury Neutrino Observatory are presented from preliminary analyses. Based on energy, direction and location, the data in the region of interest appear to be dominated by 8B solar neutrinos, detected by the charged current reaction on deuterium and elastic scattering from electrons, with very little background. Measurements of radioactive backgrounds indicate that the measurement of all active neutrino types via the neutral current reaction on deuterium will be possible with small systematic uncertainties. Quantitative results for the fluxes observed with these reactions will be provided when further calibrations have been completed.Comment: Latex, 7 pages, 10 figures, Invited paper at Neutrino 2000 Conference, Sudbury, Canada, June 16-21, 2000 to be published in the Proceeding

Measurement of the rate of nu_e + d --> p + p + e^- interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory

Solar neutrinos from the decay of $^8$B have been detected at the Sudbury Neutrino Observatory (SNO) via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to nu_e's, while the ES reaction also has a small sensitivity to nu_mu's and nu_tau's. The flux of nu_e's from ^8B decay measured by the CC reaction rate is \phi^CC(nu_e) = 1.75 +/- 0.07 (stat)+0.12/-0.11 (sys.) +/- 0.05(theor) x 10^6 /cm^2 s. Assuming no flavor transformation, the flux inferred from the ES reaction rate is \phi^ES(nu_x) = 2.39+/-0.34 (stat.)+0.16}/-0.14 (sys) x 10^6 /cm^2 s. Comparison of \phi^CC(nu_e) to the Super-Kamiokande Collaboration's precision value of \phi^ES(\nu_x) yields a 3.3 sigma difference, providing evidence that there is a non-electron flavor active neutrino component in the solar flux. The total flux of active ^8B neutrinos is thus determined to be 5.44 +/-0.99 x 10^6/cm^2 s, in close agreement with the predictions of solar models.Comment: 6 pages (LaTex), 3 figures, submitted to Phys. Rev. Letter