Estimating Distributional Impacts of an Innovation Across Sectors in an Industry: A case study of the Australian wool industry

In this paper an approach that can be used to determine the distribution of a productivity gain on an industry is detailed. In particular, the model developed in this paper extends earlier evaluations by emphasising the crucial role of substitution between inputs across different participants in the supply chain. Crucial to any analysis of an industry are the estimates of the elasticity's of derived demand at each stage and how it changes, as the product is further refined. The wool industry is used to illustrate the effects of an innovation across sectors.Agribusiness, Production Economics,

All-Orders Singular Emission in Gauge Theories

I present a class of functions unifying all singular limits for the emission of soft or collinear gluons in gauge-theory amplitudes at any order in perturbation theory. Each function is a generalization of the antenna functions of ref. [1]. The helicity-summed interferences these functions are thereby also generalizations to higher orders of the Catani--Seymour dipole factorization function.Comment: 5 pages, 1 figur

Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils

Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability

Computational Identification of Four Spliceosomal snRNAs from the Deep-Branching Eukaryote Giardia intestinalis

Funding: Marsden Fund New Zealand Allan Wilson Centre The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.RNAs processing other RNAs is very general in eukaryotes, but is not clear to what extent it is ancestral to eukaryotes. Here we focus on pre-mRNA splicing, one of the most important RNA-processing mechanisms in eukaryotes. In most eukaryotes splicing is predominantly catalysed by the major spliceosome complex, which consists of five uridine-rich small nuclear RNAs (U-snRNAs) and over 200 proteins in humans. Three major spliceosomal introns have been found experimentally in Giardia; one Giardia U-snRNA (U5) and a number of spliceosomal proteins have also been identified. However, because of the low sequence similarity between the Giardia ncRNAs and those of other eukaryotes, the other U-snRNAs of Giardia had not been found. Using two computational methods, candidates for Giardia U1, U2, U4 and U6 snRNAs were identified in this study and shown by RT-PCR to be expressed. We found that identifying a U2 candidate helped identify U6 and U4 based on interactions between them. Secondary structural modelling of the Giardia U-snRNA candidates revealed typical features of eukaryotic U-snRNAs. We demonstrate a successful approach to combine computational and experimental methods to identify expected ncRNAs in a highly divergent protist genome. Our findings reinforce the conclusion that spliceosomal small-nuclear RNAs existed in the last common ancestor of eukaryotes

X-ray observations of cataclysmic variables

Cataclysmic variables are close binary systems where mass is accreted onto a white dwarf through an accretion disc. Approximately half the gravitational energy in the disc is released in a boundary layer as X-rays. X-rays originate from matter under the extreme and energetic conditions and provide a unique view of high energy processes. X-ray luminosities are sensitive to the accretion rate through the disc and to the conditions in the inner accretion zone. Accretion discs are wide spread throughout astronomy. The extraction of potential energy from accreted material is known to be the principal source of power in several types of system; quasars, galactic nuclei, binary X-ray sources, cataclysmic variables (CVs) and proto-planetary discs. CVs provide probably the best opportunity to study the accretion process in isolation. Previous X-ray analysis of dwarf novae relied upon relatively short snap shot observations, which are unable to provide a full picture of the outburst cycle evolution. Multiple outbursts with far greater temporal accuracy and coverage than has ever been observed before are presented in this thesis. Pointed observations using the proportional counter array on the Rossi X-ray Timing Explorer of SS Cygni, U Gem and SU UMa are analysed. The behaviour in the optical band is similar for the three systems in this thesis, however, a large distinction is seen in the X-ray band. The hard X-ray outburst flux in SS Cygni and SU UMa are quenched below the quiescent flux, while in U Gem it is unusually faint in quiescence brightening in outburst. The hard quiescent X-ray spectrum is replaced by an intense soft X-ray component in outburst for all dwarf novae. Analysis of U Gem suggests that X-rays originate from the inner accretion disc with a scale height not much greater than the disc thickness. The start of the hard X-ray outburst is delayed behind the optical rise, this delay is roughly consistent for the three systems presented. This indicates that the origin of the heating wave in the accretion disc and the time it takes to propagate to the boundary layer are similar for these systems. The hard X-ray recovery also has a range of times, with the peak occurring as the optical flux reaches quiescence suggesting the cooling front reaches the boundary layer at the same time in relation to the end of the optical outburst. The spectra for all three systems presented in this thesis are well described by a thermal plasma model with sub-solar abundances and are consistent with higher reflection during the hard X-ray suppression. This indicates that the disc is likely to be truncated in quiescence. SS Cygni has a wide range of quiescent accretion rates. However, the X-ray flux in SS Cygni and U Gem always increases when the boundary layer transitions from both optically thick to thin, into outburst, and optically thin to thick, out of outburst. This is surprising, the flux is expected to decrease when the critical accretion rate is reached suggesting that the critical accretion rate when the boundary layer transitions is not fixed. The quiescent X-ray flux in SU UMa decreases and, with SS Cygni, is between 2 − 3 orders of magnitude higher than predictions by the disc instability model

Design and implementation of robust decentralized control laws for the ACES structure at Marshall Space Flight Center

Many large space system concepts will require active vibration control to satisfy critical performance requirements such as line-of-sight accuracy. In order for these concepts to become operational it is imperative that the benefits of active vibration control be practically demonstrated in ground based experiments. The results of the experiment successfully demonstrate active vibration control for a flexible structure. The testbed is the Active Control Technique Evaluation for Spacecraft (ACES) structure at NASA Marshall Space Flight Center. The ACES structure is dynamically traceable to future space systems and especially allows the study of line-of-sight control issues