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The construction of an instruction manual in carry-over value athletics.
Thesis (M.S.
Scientific Standards and the Regulation of Genetically Modified Insects
Experimental releases of genetically modified (GM) insects are reportedly being evaluated in various countries, including Brazil, the Cayman Islands (United Kingdom), France, Guatemala, India, Malaysia, Mexico, Panama, Philippines, Singapore, Thailand, the United States of America, and Vietnam. GM mosquitoes (Aedes aegypti) have already been released for field trials into inhabited areas in the Cayman Islands (2009–?), Malaysia (2010–2011), and Brazil (2011–2012). Here, we assess the regulatory process in the first three countries permitting releases (Malaysia, US, and the Cayman Islands) in terms of pre-release transparency and scientific quality. We find that, despite 14 US government–funded field trials over the last 9 years (on a moth pest of cotton), there has been no scientific publication of experimental data, and in only two instances have permit applications been published. The world's first environmental impact statement (EIS) on GM insects, produced by US authorities in 2008, is found to be scientifically deficient on the basis that (1) most consideration of environmental risk is too generic to be scientifically meaningful; (2) it relies on unpublished data to establish central scientific points; and (3) of the approximately 170 scientific publications cited, the endorsement of the majority of novel transgenic approaches is based on just two laboratory studies in only one of the four species covered by the document. We find that it is not possible to determine from documents publically available prior to the start of releases if obvious hazards of the particular GM mosquitoes released in Malaysia, the Cayman Islands, and Brazil received expert examination. Simple regulatory measures are proposed that would build public confidence and stimulate the independent experimental studies that environmental risk assessments require. Finally, a checklist is provided to assist the general public, journalists, and lawmakers in determining, from documents issued by regulators prior to the start of releases, whether permit approval is likely to have a scientifically high quality basi
Attractive and repulsive cracks in a heterogeneous material
We study experimentally the paths of an assembly of cracks growing in
interaction in a heterogeneous two-dimensional elastic brittle material
submitted to uniaxial stress. For a given initial crack assembly geometry, we
observe two types of crack path. The first one corresponds to a repulsion
followed by an attraction on one end of the crack and a tip to tip attraction
on the other end. The second one corresponds to a pure attraction. Only one of
the crack path type is observed in a given sample. Thus, selection between the
two types appears as a statistical collective process.Comment: soumis \`a JSTA
Fracture Surfaces as Multiscaling Graphs
Fracture paths in quasi-two-dimenisonal (2D) media (e.g thin layers of
materials, paper) are analyzed as self-affine graphs of height as a
function of length . We show that these are multiscaling, in the sense that
order moments of the height fluctuations across any distance
scale with a characteristic exponent that depends nonlinearly on the order of
the moment. Having demonstrated this, one rules out a widely held conjecture
that fracture in 2D belongs to the universality class of directed polymers in
random media. In fact, 2D fracture does not belong to any of the known kinetic
roughening models. The presence of multiscaling offers a stringent test for any
theoretical model; we show that a recently introduced model of quasi-static
fracture passes this test.Comment: 4 pages, 5 figure
Roughness of tensile crack fronts in heterogenous materials
The dynamics of planar crack fronts in heterogeneous media is studied using a
recently proposed stochastic equation of motion that takes into account
nonlinear effects. The analysis is carried for a moving front in the
quasi-static regime using the Self Consistent Expansion. A continuous dynamical
phase transition between a flat phase and a dynamically rough phase, with a
roughness exponent , is found. The rough phase becomes possible due
to the destabilization of the linear modes by the nonlinear terms. Taking into
account the irreversibility of the crack propagation, we infer that the
roughness exponent found in experiments might become history-dependent, and so
our result gives a lower bound for .Comment: 7 page
Roughness and multiscaling of planar crack fronts
We consider numerically the roughness of a planar crack front within the
long-range elastic string model, with a tunable disorder correlation length
. The problem is shown to have two important length scales, and the
Larkin length . Multiscaling of the crack front is observed for scales
below , provided that the disorder is strong enough. The asymptotic
scaling with a roughness exponent is recovered for scales
larger than both and . If , these regimes are separated
by a third regime characterized by the Larkin exponent .
We discuss the experimental implications of our results.Comment: 8 pages, two figure
Initial beam-profiling tests with the NML prototype station at the Fermilab A0 Photoinjector
The beam-profile diagnostics station prototype for the superconducting rf
electron linac being constructed at Fermilab at the New Muon Lab has been
tested. The station uses intercepting radiation converter screens for the
low-power beam mode: either a 100-\mu m thick YAG:Ce single crystal
scintillator or a 1-\mu m thin Al optical transition radiation (OTR) foil. The
screens are oriented with the surface perpendicular to the beam direction. A
downstream mirror with its surface at 45 degrees to the beam direction is used
to direct the radiation into the optical transport. The optical system has
better than 20 (10) \mu m rms spatial resolution when covering a vertical field
of view of 18 (5) mm. The initial tests were performed at the A0 Photoinjector
at a beam energy of ~15 MeV and with micropulse charges from 25 to 500 pC for
beam sizes of 45 to 250 microns. Example results will be presented.Comment: 3 pp. Particle Accelerator, 24th Conference (PAC'11) 2011. 28 Mar - 1
Apr 2011. New York, US
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