Have Population Increases of Large Birds Outpaced Airworthiness Standards for Civil Aircraft?

Bird-aircraft collisions (bird strikes) are an increasing safety and economic concern to the USA civil aviation industry, costing over $400 million each year. One approach to reducing risks associated with strikes is to require commercial aircraft components to meet certain standards of safe performance in the event of a bird strike. The Federal Aviation Administration has developed airworthiness standards for airframes, windshields and engines using a single 4-lb (1.82-kg) bird mass as the maximum that must be tested (with the exception of a single 8-lb bird for the empennage, 6-lb bird for certain mid-sized engines that may be developed in the future, and an 8-lb bird for certain large-intake engines on aircraft such as the Boeing 777). Because of concern within the aviation industry that populations of certain flocking bird species weighing more than 4 lbs, such as Canada geese (Branta canadensis), have increased dramatically, discussions are underway in the USA and Europe regarding the need to revise 4- and 8-lb test standards to heavier body masses or to include multiple strikes. To help clarify this issue, we surveyed the avian literature and determined that 36 and 14 of the approximately 650 bud species that nest in North America (north of Mexico) have average body masses (for at least 1 gender) greater than 4 and 8 lbs, respectively. Of the 31 species for which population trend data were available, 24 (77%) showed population increases over the past 2040 years, 2 showed declines, and the other 5 were stable. Thirteen of the 14 species with mean body masses over 8 lbs showed population increases. At least 261 strikes with \u3e4-lb birds caused substantial damage to civil aircraft in the US4 1990-2001. Furthermore, multiple buds were involved in 31% of the strikes with \u3e4-lb buds and 40% of the strikes with \u3e8-lb buds. Therefore, we conclude that airframe, windshield, and engine standards, as well as proposals to allow high-speed (\u3e250 knot) operations below 10,000 feet, should be reevaluated to address the threat posed by increased populations of large flocking buds. Finally, because most critical aircraft components are not designed to withstand strikes by birds greater than 4 lhs, wildlife biologists who work at airports should increase efforts to detect, remove and disperse these large buds from airport environments

Bouncing localized structures in a liquid-crystal light-valve experiment

Experimental evidence of bouncing localized structures in a nonlinear optical system is reported.Comment: 4 page

Comparing use terms in a Spanish and US research university e-journal licenses: recent trends

This paper describes the results of a study to compare contemporary e-journal licenses from two research universities in the United States and Spain in terms of e-reserves, interlibrary loan, text and data mining, authors´ rights and treatment of copyright exceptions, usage statistics, governing law, data privacy, and obligations entailing security. The data include a higher proportion of scholarly society and academic press publishers than earlier license analyses. This analysis compares license terms over time, across publisher types and between the two libraries, and it compares findings with recommendations from model licenses. The results show progress toward model license goals in some areas, but deficiencies in others including self-archiving, usage statistics clauses, and clauses related to e-resource data privacy and library security and disciplinary obligations. Our findings also raise questions about international ILL and governing venue clauses in library licenses outside the North American context

Comparing use terms in a Spanish and US research university e-journal licenses: recent trends

This paper describes the results of a study to compare contemporary e-journal licenses from two research universities in the United States and Spain in terms of e-reserves, interlibrary loan, text and data mining, authors´ rights and treatment of copyright exceptions, usage statistics, governing law, data privacy, and obligations entailing security. The data include a higher proportion of scholarly society and academic press publishers than earlier license analyses. This analysis compares license terms over time, across publisher types and between the two libraries, and it compares findings with recommendations from model licenses. The results show progress toward model license goals in some areas, but deficiencies in others including self-archiving, usage statistics clauses, and clauses related to e-resource data privacy and library security and disciplinary obligations. Our findings also raise questions about international ILL and governing venue clauses in library licenses outside the North American context

Expressive Art to Facilitate the Development of the Occupational Profile: A Scoping Review

Background. The American Occupational Therapy Association and the American Medical Association have changed CPT codes to require a completed occupational profile at every evaluation and re-evaluation session for reimbursement as of January 1, 2017. A revitalization of art in occupational therapy has led to a recent increase in the evidence supporting the use of expressive art in practice. The benefits of expressive art can directly enhance the occupational profile required by these changing reimbursement requirements. Methods. A scoping review method was applied in the current study. Out of 347 initial articles, 12 met the inclusion criteria and were analyzed through critical appraisal of topics and use of a matrix. Results. Analysis of the data elucidated emergent themes of expressive art’s positive effects on verbal communication, the client’s therapeutic reflection, the accuracy of information, the clinician’s use of prompting, the therapeutic relationship, and client engagement. Conclusion. Expressive art can strengthen the occupational profile and information-gathering process. The benefits related to using art in occupational therapy may enhance the complexity of the overall evaluation process, as described by newly changing CPT codes. Expressive art techniques can facilitate the development of client-centered goals and individualized intervention planning, creating an overall positive service delivery process

Exploring the vicinity of the Bogomol'nyi-Prasad-Sommerfield bound

We investigate systems of real scalar fields in bidimensional spacetime, dealing with potentials that are small modifications of potentials that admit supersymmetric extensions. The modifications are controlled by a real parameter, which allows implementing a perturbation procedure when such parameter is small. The approach allows obtaining the energy and topological charge in closed forms, up to first order in the parameter. We illustrate the procedure with some examples. In particular, we show how to remove the degeneracy in energy for the one-field and the two-field solutions that appear in a model of two real scalar fields.Comment: Revtex, 9 pages, To be published in J. Phys.

Bloch Brane

We investigate a system described by two real scalar fields coupled with gravity in (4, 1) dimensions in warped spacetime involving one extra dimension. The results show that the parameter which controls the way the two scalar fields interact induces the appearence of thick brane which engenders internal structure, driving the energy density to localize inside the brane in a very specific way.Comment: 13 pages, 6 figures; some misprints corrected, to appear in JHE

Tiling the plane without supersymmetry

We present a way of tiling the plane with a regular hexagonal network of defects. The network is stable and follows in consequence of the three-junctions that appear in a model of two real scalar fields that presents $Z_3$ symmetry. The $Z_3$ symmetry is effective in both the vacuum and defect sectors, and no supersymmetry is required to build the network.Comment: Revtex, 4 pages, 1 ps figure; version to appear in Phys. Rev. Let

Bags, junctions, and networks of BPS and non-BPS defects

We investigate several models of coupled scalar fields that present discrete Z_2, Z_2 x Z_2, Z_3 and other symmetries. These models support topological domain wall solutions of the BPS and non-BPS type. The BPS solutions are stable, but the stability of the non-BPS solutions may depend on the parameters that specify the models. The BPS and non-BPS states give rise to bags, and also to three-junctions that may allow the presence of networks of topological defects. In particular, we show that the non-BPS defects of a specific model that engenders the Z_3 symmetry give rise to a stable regular hexagonal network of domain walls.Comment: Revtex, 16 pages, 6 ps figures; Shorter version to be published in Phys. Rev.

New Lump-like Structures in Scalar-field Models

In this work we investigate lump-like solutions in models described by a single real scalar field. We start considering non-topological solutions with the usual lump-like form, and then we study other models, where the bell-shape profile may have varying amplitude and width, or develop a flat plateau at its top, or even induce a lump on top of another lump. We suggest possible applications where these exotic solutions might be used in several distinct branches of physics.Comment: REvTex4, twocolumn, 10 pages, 9 figures; new reference added, to appear in EPJ