23,989 research outputs found
Comparative Biology of Temperate and Subtropical Bark and Ambrosia Beetles (Coleoptera: Scolytidae, Platypodidae) in Indiana and Florida
Bark and ambrosia beetles were compared from two intensively studied sites. The Indiana site produced 58 species, the Florida site 57 species; 17 species occurred at both sites. Much greater plant host diversity at the Indiana site seems balanced by more favorable climate at the Florida site. There are more exotic species at the Florida site. Different patterns in feeding habits and mating habits of the beetles are related to the climate and history of the sites in complex ways. A list of the and their habits is included
New Distribution Records of Scolytidae From Indiana and Florida
Twenty-three new state records are provided for Florida and Indiana Scolytidae; 92 species are now known from Indiana, 112 from Florida
Issues in the development of advance directives in mental health care
<i>Background</i>: Interest in advance directives in mental health care is growing internationally. There is no clear universal agreement as to what such an advance directive is or how it should function. <i>Aim</i>: To describe the range of issues embodied in the development of advance directives in mental health care. <i>Method</i>: The literature on advance directives is examined to highlight the pros and cons of different versions of advance directive. <i>Results</i>: Themes emerged around issues of terminology, competency and consent, the legal status of advance directives independent or collaborative directives and their content. Opinions vary between a unilateral legally enforceable instrument to a care plan agreed between patient and clinician. <i>Conclusion</i>: There is immediate appeal in a liberal democracy that values individual freedom and autonomy in giving weight to advance directives in mental health care. They do not, however, solve all the problems of enforced treatment and early access to treatment. They also raise new issues and highlight persistent problems. <i>Declaration</i> <i>of</i> <i>interest</i>: The research was funded by the Nuffield Foundation grant number
MNH/00015G
Permutation Classes of Polynomial Growth
A pattern class is a set of permutations closed under the formation of
subpermutations. Such classes can be characterised as those permutations not
involving a particular set of forbidden permutations. A simple collection of
necessary and sufficient conditions on sets of forbidden permutations which
ensure that the associated pattern class is of polynomial growth is determined.
A catalogue of all such sets of forbidden permutations having three or fewer
elements is provided together with bounds on the degrees of the associated
enumerating polynomials.Comment: 17 pages, 4 figure
Development of heat flux sensors in turbine airfoils
The objective is to develop heat flux sensors suitable for use on turbine airfoils and to verify the operation of the heat flux measurement techniques through laboratory experiments. The requirements for a program to investigate the measurement of heat flux on airfoils in areas of strong non-one-dimensional flow were also identified
Advanced Solar Power Systems
The Advanced Solar Power System (ASPS) concentrator uses a technically sophisticated design and extensive tooling to produce very efficient (80 to 90%) and versatile energy supply equipment which is inexpensive to manufacture and requires little maintenance. The advanced optical design has two 10th order, generalized aspheric surfaces in a Cassegrainian configuration which gives outstanding performance and is relatively insensitive to temperature changes and wind loading. Manufacturing tolerances also have been achieved. The key to the ASPS is the direct absorption of concentrated sunlight in the working fluid by radiative transfers in a black body cavity. The basic ASPS design concepts, efficiency, optical system, and tracking and focusing controls are described
The EMC of satellite power systems and DoD C-E systems
The solar power satellite (SPS) technical parameters that are needed to accurately assess the electromagnetic compatibility (EMC) between SPS systems and DoD communications-electronics (C-E) systems are identified and assessed. The type of electromagnetic interactions that could degrade the performance of C-E systems are described and the major military installations in the southwestern portions of CONUS where specially sensitive C-E systems are being used for combat training and evaluation are identified. Classes of C-E systems that are generally in the vicinity of these military installations are considered. The Technical parameters that govern the degree of compatibility of the SPS with these C-E systems, and some technical requirements that are necessary to ensure short-term and long-term EMC are identified
Atlas and checklist of the bark and ambrosia beetles of Texas and Oklahoma (Curculionidae: Scolytinae and Platypodinae)
180 species of bark and ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) are known to occur in Texas and Oklahoma. 175 species are known from Texas, 35 of which are reported here for the first time. 78 species are known from Oklahoma, 47 of which are new records for the state. Based on overall distribution patterns the largest group of species found in Texas and virtually all known from Oklahoma are widely distributed in eastern and southeastern North America, reaching their southwestern limits here. In the case of Texas other large elements include Neotropical elements shared with Mexico and a large number found in southwestern North America. New distribution and significant new host records are discussed. Distribution maps are included for most species and a checklist is provided as an appendix
Sorting with a forklift
A fork stack is a generalised stack which allows pushes and pops of several
items at a time. We consider the problem of determining which input streams can
be sorted using a single forkstack, or dually, which permutations of a fixed
input stream can be produced using a single forkstack. An algorithm is given to
solve the sorting problem and the minimal unsortable sequences are found. The
results are extended to fork stacks where there are bounds on how many items
can be pushed and popped at one time. In this context we also establish how to
enumerate the collection of sortable sequences.Comment: 24 pages, 2 figure
Static Structural Signatures of Nearly Jammed Disordered and Ordered Hard-Sphere Packings: Direct Correlation Function
Dynamical signatures are known to precede jamming in hard-particle systems,
but static structural signatures have proven more elusive. The observation that
compressing hard-particle packings towards jamming causes growing
hyperuniformity has paved the way for the analysis of jamming as an "inverted
critical point" in which the direct correlation function diverges. We
establish quantitative relationships between various singularities in
and the total correlation function that provide a concrete means of
identifying features that must be expressed in if one hopes to reproduce
details in the pair correlation function accurately. We also analyze systems of
three-dimensional monodisperse hard-spheres of diameter as they approach
ordered and disordered jammed configurations. For the latter, we use the
Lubachevsky-Stillinger (LS) and Torquato-Jiao (TJ) packing algorithms, which
both generate disordered packings, but can show perceptible structural
differences. We identify a short-ranged scaling as and show that this, along with the developing delta function at
, is a consequence of the growing long-rangedness in . Near the
freezing density, we identify qualitative differences in the structure factor
as well as between TJ- and LS-generated configurations and link
them to differences in the protocols' packing dynamics. Configurations from
both algorithms have structure factors that approach zero in the low-wavenumber
limit as jamming is approached and are shown to exhibit a corresponding
power-law decay in for large as a consequence. Our work advances the
notion that static signatures are exhibited by hard-particle packings as they
approach jamming and underscores the utility of the direct correlation function
as a means of monitoring for an incipient rigid network
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