Annotated world bibliography of host fruits of Bactrocera latifrons (Hendel) (Diptera: Tephritidae)

Bactrocera latifrons (Hendel) (Diptera: Tephritidae) infests fruits and vegetables of a number of different plant species, with host plants primarily found in the plant families Solanaceae and Cucurbitaceae. Although B. latifrons is of primarily Asian distribution (e.g., Pakistan, India, Sri Lanka, Burma, China [Fujian, Yunnan, Hong Kong, Hainan], Thailand, Laos, Vietnam, Malaysia, Singapore, Taiwan, and Brunei), its range has expanded through introductions into Hawaii, Okinawa, Tanzania, and Kenya, and poses a threat of introduction into other countries where it does not presently occur. As with other tephritid fruit fly species, establishment of B. latifrons can have significant economic consequences, including damage and loss of food production, as well as requirements for implementation of costly quarantine treatments to permit export of commodities susceptible to infestation by B. latifrons. In order to avoid these adverse economic consequences, one needs to prevent the entry, establishment and spread of B. latifrons into a new habitat. To successfully achieve this, an accurate knowledge of the fly’s host plants is essential. Cognizant of this need, we prepared, and present here, a worldwide list of host plants for B. latifrons, with annotations on reported laboratory and field infestation data. Overall, a total of 59 plant species from 14 plant families are identified as hosts of B. latifrons, based on reported field infestation data

Bounds for the discrete correlation of infinite sequences on k symbols and generalized Rudin-Shapiro sequences

Motivated by the known autocorrelation properties of the Rudin-Shapiro sequence, we study the discrete correlation among infinite sequences over a finite alphabet, where we just take into account whether two symbols are identical. We show by combinatorial means that sequences cannot be "too" different, and by an explicit construction generalizing the Rudin-Shapiro sequence, we show that we can achieve the maximum possible difference.Comment: Improved Introduction and new Section 6 (Lovasz local lemma

Flight data analysis of power subsystem degradation at near synchronous altitude Quarterly report

Flight data analysis of spacecraft power subsystem degradation at near synchronous altitud

Planet formation around stars of various masses: The snow line and the frequency of giant planets

We use a semi-analytic circumstellar disk model that considers movement of the snow line through evolution of accretion and the central star to investigate how gas giant frequency changes with stellar mass. The snow line distance changes weakly with stellar mass; thus giant planets form over a wide range of spectral types. The probability that a given star has at least one gas giant increases linearly with stellar mass from 0.4 M_sun to 3 M_sun. Stars more massive than 3 M_sun evolve quickly to the main-sequence, which pushes the snow line to 10-15 AU before protoplanets form and limits the range of disk masses that form giant planet cores. If the frequency of gas giants around solar-mass stars is 6%, we predict occurrence rates of 1% for 0.4 M_sun stars and 10% for 1.5 M_sun stars. This result is largely insensitive to our assumed model parameters. Finally, the movement of the snow line as stars >2.5 M_sun move to the main-sequence may allow the ocean planets suggested by Leger et. al. to form without migration.Comment: Accepted to ApJ. 12 pages of emulateap

Integrating payload design, planning, and control in the Dutch Utilisation Centre

Spacecraft payload design, experiment planning and scheduling, and payload control are traditionally separate areas of activity. This paper describes the development of a prototype software tool--the Activity Scheduling System (ASS)--which integrates these activity areas. ASS is part of a larger project to build a Dutch Utilisation Centre (DUC), intended eventually to support all space utilization activities in The Netherlands. ASS has been tested on the High Performance Capillary Electrophoresis payload. The paper outlines the integrated preparation and operations concept embodied in ASS. It describes the ASS prototype, including a typical session. The results of testing are summarized. Possible enhancement of ASS, including integration into DUC, is sketched

Numerical and physical simulation of rapid microstructural evolution of gas atomised Ni superalloy powders

The rapid microstructural evolution of gas atomised Ni superalloy powder compacts over timescales of a few seconds was studied using a Gleeble 3500 thermomechanical simulator, finite element based numerical model and electron microscopy. The study found that the microstructural changes were governed by the characteristic temperatures of the alloy. At a temperature below the γ' solvus, the powders maintained dendritic structures. Above the γ' solvus temperature but in the solid-state, rapid grain spheroidisation and coarsening occurred, although the fine-scale microstructures were largely retained. Once the incipient melting temperature of the alloy was exceeded, microstructural change was rapid, and when the temperature was increased into the solid + liquid state, the powder compact partially melted and then re-solidified with no trace of the original structures, despite the fast timescales. The study reveals the relationship between short, severe thermal excursions and microstructural evolution in powder processed components, and gives guidance on the upper limit of temperature and time for powder-based processes if desirable fine-scale features of powders are to be preserved