Chemical, Natural, and Cultural Control of \u3ci\u3eHyadaphis Tataricae\u3c/i\u3e (Homoptera: Aphididae) on Honeysuckle

Hyadaphis tataricae is an aphid pest of honeysuckle relatively new to the Great Lakes and midwestern regions of North America. Feeding results in severly deformed terminals (witches\u27 brooms). Studies were conducted on natural, chemical, and cultural control. Foliar-applied systemic insecticides provided excellent knock-down and 3-4 weeks of residual control. Although diazinon also provided good knock-down, its residual activity was shorter. Malathion provided suppression but did not protect plants from injury. A tree and shrub soap wash did not provide control. Oxydemeton methyl provided best results of soil-applied systemics. Of 385 aphidophagous predators collected, 85% were syrphid larvae. The remainder were Coccinellidae and Chrysopidae. About 140,000 aphids were examined microscop- ically without visual evidence of insect pathogens and with only one mummified (parasitized) individual. Dormant pruning of previously broomed terminals resulted in increased vegetative growth of the plants and larger early season aphid populations. There was no visible difference in pruned vs. unpruned plants at the end of the growing season

Prediction Models for Flight Activity of the Cranberry Girdler (Lepidoptera: Pyralidae) in Wisconsin

Cranberry girdler, Chrysoteuchia topiaria, was monitored with pheromone traps in Wisconsin cranberry farms. Cumulative 50% capture was related to degree-days after first catch using air or soil temperature. An air temperature of O°C and soil temperature of 2°C were chosen as base temperatures for calculation of degree-days because they yielded estimates with the lowest coefficients of variation. Weibull functions were fitted to the relation- ship between cumulative percent capture and time or degree-days after first trap catch using air or soil temperatures. The models that predicted the date of 50% capture were evaluated with data from two other farms. Degree-days after first catch using soil temperatures predicted 50% catch with less variability than calendar date or degree-days after thaw of ice. but not significantly less variability than days after first catch or degree-days after first catch using air temperatures

Phenology of Oviposition of \u3ci\u3eDasyneura Oxycoccana\u3c/i\u3e (Diptera: Cecidomyiidae) in Relation to Cranberry Plant Growth and Flowering

Eggs of cranberry tipworm, Dasyneura oxycoccana (Diptera: Cecidomyiidae) were sampled in a Wisconsin cranberry marsh from 1990 through 1992. Oviposition began in May within one week after the first cranberry shoots elongated more than 5 mm. Oviposition fluctuated in June, then greatly decreased in July, after over 90% of cranberry flowers had opened. Some oviposition continued into August. Tipworm probably has greatly overlapping generations, as no distinct broods could be detected. Consequently, D. oxycoccana may be difficult to manage without control methods effective against multiple life stages

Parametrically excited surface waves in magnetic fluids: observation of domain structures

Observations of parametrically excited surface waves in a magnetic fluid are presented. Under the influence of a magnetic field these waves have a non--monotonic dispersion relation, which leads to a richer behavior than in ordinary liquids. We report observation of three novel effects, namely: i) domain structures, ii) oscillating defects and iii) relaxational phase oscillations.Comment: to be published in Physical Review Letter

Super-lattice, rhombus, square, and hexagonal standing waves in magnetically driven ferrofluid surface

Standing wave patterns that arise on the surface of ferrofluids by (single frequency) parametric forcing with an ac magnetic field are investigated experimentally. Depending on the frequency and amplitude of the forcing, the system exhibits various patterns including a superlattice and subharmonic rhombuses as well as conventional harmonic hexagons and subharmonic squares. The superlattice arises in a bicritical situation where harmonic and subharmonic modes collide. The rhombic pattern arises due to the non-monotonic dispersion relation of a ferrofluid

Wave Number of Maximal Growth in Viscous Magnetic Fluids of Arbitrary Depth

An analytical method within the frame of linear stability theory is presented for the normal field instability in magnetic fluids. It allows to calculate the maximal growth rate and the corresponding wave number for any combination of thickness and viscosity of the fluid. Applying this method to magnetic fluids of finite depth, these results are quantitatively compared to the wave number of the transient pattern observed experimentally after a jump--like increase of the field. The wave number grows linearly with increasing induction where the theoretical and the experimental data agree well. Thereby a long-standing controversy about the behaviour of the wave number above the critical magnetic field is tackled.Comment: 19 pages, 15 figures, RevTex; revised version with a new figure and references added. submitted to Phys Rev

Take their word for it: The symbolic role of linguistic style matches in user communities

User communities are increasingly becoming an essential element of companies' business processes. However, reaping the benefits of such social systems does not always prove effective, often because companies fail to stimulate members' collaboration continuously or neglect their social integration. Following communication accommodation theory, the authors posit that members' communication style alignment symbolically reflects their community identification and affects subsequent participation behavior. This research uses text mining to extract the linguistic style properties of 74,246 members' posts across 37 user communities. Two mixed multilevel Poisson regression models show that when members' linguistic style matches with the conventional community style, it signals their community identification and affects their participation quantity and quality. Drawing on an expanded view of organizational identification, the authors consider dynamics in members' social identification by examining trends and reversals in linguistic style match developments. Whereas a stronger trend of alignment leads to greater participation quantity and quality, frequent reversals suggest lower participation quantity. At a community level, greater synchronicity in the linguistic style across all community members fosters individual members' participation behavior

Logics of Finite Hankel Rank

We discuss the Feferman-Vaught Theorem in the setting of abstract model theory for finite structures. We look at sum-like and product-like binary operations on finite structures and their Hankel matrices. We show the connection between Hankel matrices and the Feferman-Vaught Theorem. The largest logic known to satisfy a Feferman-Vaught Theorem for product-like operations is CFOL, first order logic with modular counting quantifiers. For sum-like operations it is CMSOL, the corresponding monadic second order logic. We discuss whether there are maximal logics satisfying Feferman-Vaught Theorems for finite structures.Comment: Appeared in YuriFest 2015, held in honor of Yuri Gurevich's 75th birthday. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-23534-9_1

Social Interactions vs Revisions, What is important for Promotion in Wikipedia?

In epistemic community, people are said to be selected on their knowledge contribution to the project (articles, codes, etc.) However, the socialization process is an important factor for inclusion, sustainability as a contributor, and promotion. Finally, what does matter to be promoted? being a good contributor? being a good animator? knowing the boss? We explore this question looking at the process of election for administrator in the English Wikipedia community. We modeled the candidates according to their revisions and/or social attributes. These attributes are used to construct a predictive model of promotion success, based on the candidates's past behavior, computed thanks to a random forest algorithm. Our model combining knowledge contribution variables and social networking variables successfully explain 78% of the results which is better than the former models. It also helps to refine the criterion for election. If the number of knowledge contributions is the most important element, social interactions come close second to explain the election. But being connected with the future peers (the admins) can make the difference between success and failure, making this epistemic community a very social community too

Retrograde semaphorin-plexin signalling drives homeostatic synaptic plasticity.

Homeostatic signalling systems ensure stable but flexible neural activity and animal behaviour. Presynaptic homeostatic plasticity is a conserved form of neuronal homeostatic signalling that is observed in organisms ranging from Drosophila to human. Defining the underlying molecular mechanisms of neuronal homeostatic signalling will be essential in order to establish clear connections to the causes and progression of neurological disease. During neural development, semaphorin-plexin signalling instructs axon guidance and neuronal morphogenesis. However, semaphorins and plexins are also expressed in the adult brain. Here we show that semaphorin 2b (Sema2b) is a target-derived signal that acts upon presynaptic plexin B (PlexB) receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the neuromuscular junction in Drosophila. Further, we show that Sema2b-PlexB signalling regulates presynaptic homeostatic plasticity through the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin. We propose that semaphorin-plexin signalling is an essential platform for the stabilization of synaptic transmission throughout the developing and mature nervous system. These findings may be relevant to the aetiology and treatment of diverse neurological and psychiatric diseases that are characterized by altered or inappropriate neural function and behaviour