EC07-1780 Lady Beetles of Nebraska

Extension Circular 07-1780 discusses lady beetles of Nebraska

Oscillations and velocity structure of a long-lived cyclonic spot

Dark brown cyclonic spots ('barges') at 14°N were studied by using Voyager 1 and 2 images of Jupiter. Movie sequences were made to study the spots' behavior over intervals of 50 days and longer. These movies revealed that the length and width vary by ±9% with a period of about 15 days, while the area remains approximately constant. The horizontal velocity field was investigated for an interval of about 1 day. Flow around the largest barge (feature 6) occurs as a ring current. The vorticity inferred is about 2½ times that of the ambient cyclonic zonal circulation, and about one-half the value of the local planetary vorticity. Length and width variations appear to be associated with a nonzero horizontal divergence field. If the oscillations are a natural mode of the system, the 15-day period will provide an important datum for testing models of stable closed vortices

Cross-Resistance and Resistance Longevity as Induced by Bean Leaf Beetle, Cerotoma trifurcata and Soybean Looper, Pseudoplusia includens herbivory on Soybean

Cross-resistance, and longevity of resistance, induced by the bean leaf beetle, Cerotoma trifurcata, was studied IN the soybean PI 227687 that exhibited induced response in earlier studies. Bean leaf beetle adults and soybean looper, Pseudoplusia includens, larvae were used to induce resistance and to determine beetle feeding preference. Beetles were collected from soybean fields 2 to 5 days prior to the feeding preference test. The level of cross-resistance induced by soybean looper herbivory to subsequent bean leaf beetle feeding was higher when compared to cross-resistance induced by bean leaf beetle herbivory against subsequent feeding by soybean looper. Further, herbivory by the bean leaf beetle also induced resistance against soybean looper feeding. In the longevity study, leaflets from treated plants were collected 5, 10, 12, 14, 16, 20 and 25 days after initiation of feeding. Pairwise comparisons of leaflets from plants treated by bean leaf beetle herbivory with untreated plants revealed that induced responses were highest 14 and lowest 25 days after initiation of feeding. On other sampling days, levels of induced response varied with the sampling day

Molecular Differentiation of Alfalfa Weevil Strains (Coleoptera: Curculionidae)

Mitochondrial DNA was amplified and sequenced from eastern, western, and Egyptian strains of alfalfa weevil, Hypera postica (Gyllenhal). Eastern and Egyptian weevils differed at only 2 nucleotide sites in 1,031 base pairs sequenced; western weevils differed by 5% sequence divergence. Three restriction sites were identified which separated eastern and western haplotypes. No intrastrain polymorphism was detected in 150 weevils from Nebraska. Collections from Lincoln in eastern Nebraska and Scottsbluff in western Nebraska were fixed for the eastern and western haplotypes, respectively. Eastern and western haplotypes were found together in the same fields in a broad overlap region in central Nebraska

The so-called dry laser cleaning governed by humidity at the nanometer scale

Illumination with single nanosecond pulses leads to the detachment of silica particles with 250nm radii from siliconsurfaces. We identify two laser-energy dependent cleaning regimes by time-of-flight particle-scattering diagnostics. For the higher energies, the ejection of particles is produced by nanoscale ablation due to the laser field enhancement at the particle-surface interface. The damage-free regime at lower energy is shown to be governed by the residual water molecules, which are inevitably trapped on the materials. We discuss the great importance that the humidity plays on the cleaning force and on the adhesion in the experiments.Peer reviewe

Library Design in Combinatorial Chemistry by Monte Carlo Methods

Strategies for searching the space of variables in combinatorial chemistry experiments are presented, and a random energy model of combinatorial chemistry experiments is introduced. The search strategies, derived by analogy with the computer modeling technique of Monte Carlo, effectively search the variable space even in combinatorial chemistry experiments of modest size. Efficient implementations of the library design and redesign strategies are feasible with current experimental capabilities.Comment: 5 pages, 3 figure

Designing the EMBeRS summer school: Connecting stakeholders in learning, teaching and research

© 2017 Asia-Pacific Society for Computers in Education. All rights reserved. In this paper, we describe our research investigating design, teaching and learning aspects of the EMBeRS Summer School. In 2016, thirteen graduate Environmental Science students participated in a ten-day Summer School to learn about interdisciplinary approaches to researching socio-environmental systems. Using the Employing Model-Based Reasoning in Socio-Environmental Synthesis (EMBeRS) approach, students learned about wicked problems, team composition, systems thinking and modelling, stakeholder management, and communication. They applied this approach to their own research, as well as to a case study, in order to, ultimately, further the EMBeRS approach in their own institutions. Learning sciences researchers, environmental science instructors and learners collaborated in design, teaching, and learning during the 2016 Summer School in order to co-create and co-configure the tasks, social arrangements, and tools for learning, teaching and design. This paper identifies four examples of connections between the stakeholders (researchers, instructors and learners), the tools that facilitated the connection, and the implications for learning, teaching and design

Density of Superfluid Helium Droplets

The classical integral cross sections of large superfluid 4He_N droplets and the number of atoms in the droplets (N=10^3-10^4) have been measured in molecular beam scattering experiments. These measurements are found to be in good agreement with the cross sections predicted from density functional calculations of the radial density distributions with a 10-90 % surface thickness of 5.7\AA. By using a simple model for the density profile of the droplets a thickness of about 6-8\AA is extracted directly from the data.Comment: 27 pages, REVTeX, 5 postscript figure

Dynamics of liquid 4He in Vycor

We have measured the dynamic structure factor of liquid 4He in Vycor using neutron inelastic scattering. Well-defined phonon-roton (p-r) excitations are observed in the superfluid phase for all wave vectors 0.3 < Q < 2.15. The p-r energies and lifetimes at low temperature (T = 0.5 K) and their temperature dependence are the same as in bulk liquid 4He. However, the weight of the single p-r component does not scale with the superfluid fraction (SF) as it does in the bulk. In particular, we observe a p-r excitation between T_c = 1.952 K, where SF = 0, and T_(lambda)=2.172 K of the bulk. This suggests, if the p-r excitation intensity scales with the Bose condensate, that there is a separation of the Bose-Einstein condensation temperature and the superfluid transition temperature T_c of 4He in Vycor. We also observe a two-dimensional layer mode near the roton wave vector. Its dispersion is consistent with specific heat and SF measurements and with layer modes observed on graphite surfaces.Comment: 3 pages, 4 figure