6,069 research outputs found
Spatially Explicit Estimates of Crop Rotation Responses
Crop Production/Industries, Environmental Economics and Policy, Land Economics/Use,
Impact of a New Introductory Mathematical Modeling Course on Student Confidence in Mathematical Ability and Skills
Interdisciplinary mathematics and science courses are increasing in popularity. Faculty teaching these courses are given the opportunity to show how mathematics plays an important role in science and how it can be used to improve our understanding of mathematics and science. This paper discusses a new course in mathematical modeling that focuses on environmental issues. Course content and format are presented, as well as the results of a study on the changes in students’ perceptions of their mathematical abilities as a result of taking this new course
Characterising and Testing Deep UV LEDs for Use in Space Applications
Deep ultraviolet (DUV) light sources are used to neutralise isolated test
masses in highly sensitive space-based gravitational experiments. An example is
the LISA Pathfinder charge management system, which uses low-pressure mercury
lamps. A future gravitational-wave observatory such as eLISA will use UV
light-emitting diodes (UV LEDs), which offer numerous advantages over
traditional discharge lamps. Such devices have limited space heritage but are
are now available from a number of commercial suppliers. Here we report on a
test campaign that was carried out to quantify the general properties of three
types of commercially available UV LEDs and demonstrate their suitability for
use in space. Testing included general electrical and UV output measurements,
spectral stability, pulsed performance, temperature dependence as well as
thermal vacuum, radiation and vibration survivability
Adventures in Invariant Theory
We provide an introduction to enumerating and constructing invariants of
group representations via character methods. The problem is contextualised via
two case studies arising from our recent work: entanglement measures, for
characterising the structure of state spaces for composite quantum systems; and
Markov invariants, a robust alternative to parameter-estimation intensive
methods of statistical inference in molecular phylogenetics.Comment: 12 pp, includes supplementary discussion of example
Malathion Resistance in Larvae of Some Southern Minnesota Populations of the Indianmeal Moth,\u3ci\u3e Plodia Interpunctella\u3c/i\u3e (Lepidoptera: Pyralidae), Infesting Bulk-Stored Shelled Corn
Larvae of 21 field collected populations of the Indianmeal moth, Plodia interpunctella, infesting stored shelled corn in southern Minnesota were tested for their susceptibility to malathion in the laboratory. A population that was a composite of the 21 populations and a malathion susceptible population were also tested for their susceptibility to malathion, pirimiphos-methyl and chlorpyrifos-methyl. Comparison of the LDso values of the field populations with the malathion susceptible population indicated that the field populations were ca. 33- to 625-fold resistant to malathion. The composite field population was ca. 243-fold resistant to malathion, and this population was 3.2-fold cross-resistant to pirimiphos-methyl, but was highly susceptible to chlorpyrifos-methyl
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