107 research outputs found
Estimating total momentum at finite distances
We study the difficulties associated with the evaluation of the total Bondi
momentum at finite distances around the central source of a general
(asymptotically flat) spacetime. Since the total momentum is only rigorously
defined at future null infinity, both finite distance and gauge effects must be
taken into account for a correct computation of this quantity.
Our discussion is applicable in general contexts but is particularly relevant
in numerically constructed spacetimes for both extracting important physical
information and assessing the accuracy of additional quantities.Comment: 10 pages, 1 figure. Typos corrected. Comments added and a new
Appendix. To be published in PR
Recommended from our members
A near-optimal response-adaptive procedure randomisation for multi-armed clinical trials with normally distributed outcomes
We propose a novel response-adaptive randomisation procedure for multi-armed trials with normally
distributed outcomes which is non-myopic, thus is near-optimal in terms of patient bene t, yet maintains computa-
tional feasibility. We derive our response-adaptive algorithm based on the Gittins index for the multi-armed bandit
problem, as an extension of the method rst introduced in Villar et al (2015). We illustrate the proposed procedure
by simulations in the context of Phase II cancer trials. Our results show that there are e ciency and patient bene t
gains of using a response-adaptive allocation procedure with a continuous endpoint instead of a binary one. These
gains persist even if an anticipated low rate of missing data due to deaths, drop-outs or complete responses is imputed
online through a procedure introduced in this paper. Additionally, we discuss how there are response-adaptive designs
that outperform the traditional equal randomised design both in terms of e ciency and patient bene t measures in
the multi-armed trial context
Gravitational lens optical scalars in terms of energy-momentum distributions
This is a general work on gravitational lensing. We present new expressions
for the optical scalars and the deflection angle in terms of the
energy-momentum tensor components of matter distributions. Our work generalizes
standard references in the literature where normally stringent assumptions are
made on the sources. The new expressions are manifestly gauge invariant, since
they are presented in terms of curvature components. We also present a method
of approximation for solving the lens equations, that can be applied to any
order.Comment: 17 pages, 2 figures. Titled changed. Small improvements. References
added. Final version published in Phys.Rev.
Determinants of surgeon choice in cases of suspected implant rupture following mastectomy or aesthetic breast surgery: Clinical implications
Implant ruptures may be diagnosed by physical examination, ultrasound (US), and magnetic resonance imaging (MRI). The absence of standard guidelines to approach to implant ruptures may cause unnecessary surgical revisions in the absence of radiological confirmation of prosthetic damages.The purpose of this study was to analyze the diagnostic procedures applied to patients with suspected prosthetic rupture and surgeon choices to perform a revision or to plan a clinical and radiological follow-up.We conducted a retrospective study on 62 women submitted to revision surgery due to radiological diagnosis of suspected implant rupture, following mastectomy or aesthetic reconstruction, and admitted to a Plastic Surgery Department between 2008 and 2018.Seventy-three implants, believed to be ruptured, were explanted. One-third of these were intact and unnecessarily explanted. US associated with MRI evaluation resulted in the most helpful diagnostical method.A standardized clinical and radiological approach is essential to manage breast implant ruptures successfully. An innovative protocol is proposed in order to: ensure the appropriate management of implant ruptures and prevent unnecessary surgical revisions; reduce the risk of claims for medical malpractice in cases of unsatisfactory final aesthetic results or worse than before
On a class of 2-surface observables in general relativity
The boundary conditions for canonical vacuum general relativity is
investigated at the quasi-local level. It is shown that fixing the area element
on the 2- surface S (rather than the induced 2-metric) is enough to have a well
defined constraint algebra, and a well defined Poisson algebra of basic
Hamiltonians parameterized by shifts that are tangent to and divergence-free on
$. The evolution equations preserve these boundary conditions and the value of
the basic Hamiltonian gives 2+2 covariant, gauge-invariant 2-surface
observables. The meaning of these observables is also discussed.Comment: 11 pages, a discussion of the observables in stationary spacetimes is
included, new references are added, typos correcte
The AdS/CFT Correspondence and a New Positive Energy Conjecture for General Relativity
We examine the AdS/CFT correspondence when the gauge theory is considered on
a compactified space with supersymmetry breaking boundary conditions. We find
that the corresponding supergravity solution has a negative energy, in
agreement with the expected negative Casimir energy in the field theory.
Stability of the gauge theory would imply that this supergravity solution has
minimum energy among all solutions with the same boundary conditions. Hence we
are lead to conjecture a new positive energy theorem for asymptotically locally
Anti-de Sitter spacetimes. We show that the candidate minimum energy solution
is stable against all quadratic fluctuations of the metric.Comment: 25 pages, harvma
Crop Updates 2001 - Lupins
This session covers twenty six papers from different authors:
INTRODUCTION,
1. Introduction, Dr Mark Sweetingham LUPIN RESEARCH AND INDUSTRY DEVELOPMENT, Agriculture Western Australia
VARIETIES
2. Lupin variety performance: Are you making the most of it? Bevan J. Buirchell, Agriculture Western Australia
3. Adaption of restricted-branching lupins in Western Australia, Bob French and Laurie Wahlsten, Agriculture Western Australia
4. Isolated microspore culture of lupin for production of doubled haploids, Dr Janet Wroth, Dr Kirsty Bayliss and A/Prof. Wallace Cowling, Plant Sciences, Faculty of Agriculture, The University of Western Australia
NUTRITION
5. Banding manganese fertiliser below the seed increases seed yields of narrow-leafed lupins, R.F. Brennan, Agriculture Western Australia
6. Residual value of manganese fertiliser for lupin grain production, R.F. Brennan, Agriculture Western Australia
AGRONOMY
7. Lupin seeding density, Miles Dracup, Agriculture Western Australia, Nick Galwey, University of Western Australia and Bob Thomson, University of Western AustraliaPESTS AND DISEASES
8. Anthracnose in lupins – understanding the risk, Moin Salam, Art Diggle, Geoff Thomas, Mark Sweetinghamand Bill O’Neill, Agriculture Western Australia
9. Implications of the ‘green bridge’ for viral and fungal disease carry-over between seasons, Debbie Thackray, Agriculture Western Australia and Centre for Legumes in Mediterranean Agriculture
10. Insect pest development in WA via the ‘green bridge’, Kevin Walden, Agriculture Western Australia
11. Lupin anthracnose – seed infection thresholds, Geoff Thomas, Agriculture Western Australia
12. Identification and characterisation of resistance genes to Phomopsis blight in narrow-leafed lupin, M. Shankar1, M.W. Sweetingham1&2 and W.A. Cowling1&3 , 1Co-operative Research Centre for Legumes in Mediterranean Agriculture, 2Agriculture Western Australia, 3Plant Sciences
13. Plant disease diagnostics, Dominie Wright and Nichole Burges, Agriculture Western Australia
14. Detection of strains of Phomopsis exhibiting species preference in lupins, M. Shankar, 1Co-operative Research Centre for Legumes in Mediterranean Agriculture and M.W. Sweetingham, Agriculture Western Australia
15. Potential alternate host for the lupin anthracnose pathogen, Geoff Thomasa, Hu’aan Yangb, Mark Sweetinghamab and Ming Pei Youa, aAgriculture Western Australia, bCooperative Research Centre for Legumes in Mediterranean Agriculture
WEEDS
16. Wild radish – the implications for our rotations, Dr David Bowran, Centre for Cropping Systems
17. Competitiveness of wild radish in a wheat – lupin rotation, Abul Hashem, Nerys Wilkins, and Terry Piper, Agriculture Western Australia
18. Population explosion and persistence of wild radish in a wheat-lupin rotation, Abul Hashem, Nerys Wilkins, Aik Cheam and Terry Piper, Agriculture Western Australia
19. Inter-row knockdowns for profitable lupins, Paul Blackwell, Agriculture Western Australia, Miles Obst, Mingenew
20. Is it safe to use 2,4-D Ester 80% pre-sowing when furrow sowing lupins? Andrew Sandison, Elders Ltd
QUALITY AND MARKET DEVELOPMENT
21. Lupin protein – what we know, Bill O’Neill, Agriculture Western Australia
22. Foliar N application increases grain protein in lupins, Bob French and Laurie Wahlsten, Agriculture Western Australia
23. Can lupin grain protein be increased with Flexi-N? Cameron Weeks, Erin Hasson, Mingenew-Irwin Group and Luigi Moreschi, CSBP futurefarm
24. Putting a value on lupin use in the aquaculture industry: a fishy business? Brett D. Glencross, Fisheries WA, Fremantle Maritime Centre, Fremantle
25. Selection for thinner seed coats and pod walls in lupins, Jon Clements, Centre for Legumes in Mediterranean Agriculture and Miles Dracup, Agriculture Western Australia
26. Assessing the nutritional benefit of Australian sweet lupin (Lupinus angustifolius) in human foods, Ramon Hall (SPIRT PhD scholar), Stuart Johnson, Madeleine Ball, Deakin University, Melbourne, Sofia Sipsas and David Petterson, Agriculture Western Australi
Activation of the P2X7 ion channel by soluble and covalently bound ligands
The homotrimeric P2X7 purinergic receptor has sparked interest because of its capacity to sense adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide (NAD) released from cells and to induce calcium signaling and cell death. Here, we examine the response of arginine mutants of P2X7 to soluble and covalently bound ligands. High concentrations of ecto-ATP gate P2X7 by acting as a soluble ligand and low concentrations of ecto-NAD gate P2X7 following ADP-ribosylation at R125 catalyzed by toxin-related ecto-ADP-ribosyltransferase ART2.2. R125 lies on a prominent cysteine-rich finger at the interface of adjacent receptor subunits, and ADP-ribosylation at this site likely places the common adenine nucleotide moiety into the ligand-binding pocket of P2X7
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