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46 results on '"Bartlett, D. J."'

1. Perturbations and the Future Conformal Boundary

Author

Lasenby, A. N., Handley, W. J., Bartlett, D. J., and Negreanu, C. S.

Subjects
General Relativity and Quantum Cosmology, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The concordance model of cosmology predicts a universe which finishes in a finite amount of conformal time at a future conformal boundary. We show that for particular cases we study, the background variables and perturbations may be analytically continued beyond this boundary and that the "end of the universe" is not necessarily the end of their physical development. Remarkably, these theoretical considerations of the end of the universe might have observable consequences today: perturbation modes consistent with these boundary conditions have a quantised power spectrum which may be relevant to features seen in the large scale cosmic microwave background. Mathematically these cosmological models may either be interpreted as a palindromic universe mirrored in time, a reflecting boundary condition, or a double cover, but are identical with respect to their observational predictions and stand in contrast to the predictions of conformal cyclic cosmologies., Comment: 29 pages, 32 figures

Published
2021
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2. Improved cosmological fits with quantized primordial power spectra

Author

Bartlett, D. J., Handley, W. J., and Lasenby, A. N.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, General Relativity and Quantum Cosmology
Abstract

We observationally examine cosmological models based on primordial power spectra with quantized wavevectors. Introducing a linearly quantized power spectrum with $k_0=3.225\times10^{-4}\mathrm{Mpc}^{-1}$ and spacing $\Delta k = 2.257 \times 10^{-4} \mathrm{Mpc}^{-1}$ provides a better fit to the Planck 2018 observations than the concordance baseline, with $\Delta \chi^2 = -8.55$. Extending the results of Lasenby et al [1], we show that the requirement for perturbations to remain finite beyond the future conformal boundary in a universe containing dark matter and a cosmological constant results in a linearly quantized primordial power spectrum. It is found that the infrared cutoffs for this future conformal boundary quantized cosmology do not provide cosmic microwave background power spectra compatible with observations, but future theories may predict more observationally consistent quantized spectra., Comment: 14 pages, 8 figures, prepared for submission to PRD

Published
2021
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8. Constraints on equivalence principle violation from gamma ray bursts

Author

Bartlett, D. J., Bergsdal, D., Desmond, H., Ferreira, P. G., Jasche, J., Bartlett, D. J., Bergsdal, D., Desmond, H., Ferreira, P. G., and Jasche, J.

Abstract

Theories of gravity that obey the weak equivalence principle have the same parametrized post-Newtonian parameter gamma for all particles at all energies. The large Shapiro time delays of extragalactic sources allow us to put tight constraints on differences in gamma between photons of different frequencies from spectral lag data, since a nonzero Delta gamma would result in a frequency-dependent arrival time. The majority of previous constraints have assumed that the Shapiro time delay is dominated by a few local massive objects, although this is a poor approximation for distant sources. In this work we consider the cosmological context of these sources by developing a source-by-source, Monte Carlo-based forward model for the Shapiro time delays by combining constrained realizations of the local density field using the Bayesian origin reconstruction from galaxies algorithm with unconstrained large-scale modes. Propagating uncertainties in the density field reconstruction and marginalizing over an empirical model describing other contributions to the time delay, we use spectral lag data of gamma ray bursts from the BATSE satellite to constrain Delta gamma < 2.1 x 10(-15) at 1 sigma confidence between photon energies of 25 keV and 325 keV., QC 20211110

Published
2021
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14. Poster presentations

Author

Olds, T., Blunden, S., Petkov, J., Forchino, F., Teng, A., Bartle, A., Sadeh, A., Mindell, J., Thompson, K., Richdale, A., Schreck, K., Gibson, R., Gander, P., Elder, D., Levendowski, D., Rosen, C., Berka, C., Zavora, T., Olmstead, R., Popovic, D., Westbrook, P., Piteo, A., Roberts, R., Nettelbeck, T., Lushington, K., Van Den Heuvel, C., Kohler, M., Martin, J., Kennedy, D., Jackman, A., Davey, M., Nixon, G., Hope, S., Catroppa, C., O’Driscoll, D., Anderson, V., Trinder, J., Horne, R., Milte, C., Sinn, N., Quach, J., Hiscock, H., Wake, M., Fulton, M., Sciberras, E., Efron, D., Oberklaid, F., Jay, S., Eng, A., ’t Mannetje, A., Cheng, S., Douwes, J., Ellison-Loschmann, L., Mclean, D., Pearce, N., Zhou, X., Sargent, C., Darwent, D., Ferguson, S., Paech, G., Mattews, R., Williams, L., Roach, G., Martin, D., Lastella, A., Matthews, R., Wilsmore, N., Galante, R., Lee, J., Barnes, M., Kennedy, G., Howard, M., Smith, S., Doye, G., Mangie, J., Signal, L., Phipps-Nelson, J., Redman, J., Rajaratnam, S., Lamond, N., Dorrian, J., Whitwell, B., Rogers, N., Sutherland, K., Chan, A. S. L., Deane, S. A., Zeng, B., Lee, R. W. W., Darendeliler, M. A., Cistulli, P. A., Spong, J., Brown, D., Berlowitz, D., Keihani, S. M., Hillman, D., Collins, A., Jackson, M., Pierce, R., O’Donoghue, F., Bignold, J., Mercer, J., Gorman, M., Mcevoy, D., Antic, N., Catcheside, P., Verma, M., Wheatley, J., Amis, T., Marshall, N., Grunstein, R., Peltonen, M., Carlson, L., Hedner, J., Stenlof, K., Sjostrom, L., Williams, S., Kennerson, M., Liu, P., Little, C., Watson, A., Dunn, N., Beevers, A., Douglas, J., Ruehland, W., Singh, P., Thornton, A., Copland, J., Rochford, P., Perri, R., Ward, K., Palmer, L., Mukherjee, S., Cooper, M., Love, G., Fedson, A., Simpson, L., Edwards, C., Szegner, B., Wong, K., Cistulli, P., Marks, G., Zwar, N., Norman, M., Middleton, S., Sullivan, C., Terrill, P., Mason, D., Parsley, C., Dakin, C., Wilson, S., Khandoker, A., Palaniswami, M., Karunajeewa, A., Abeyratne, U., Hukins, C., Lee, S., Borodzicz, J., Amatoury, J., Robinson, T., Ip, T., Mackenzie, J., Scott, E., Hickie, I., Lovato, N., Lack, L., Wright, H., Muller, D., van Den Berg, M., van Dongen, H. P. A., Miller, B., Orr, R., O’Connor, H., Chow, C. M., Litchfield, C., Glozier, N., Ogeil, R., Broadbear, J., Bakar, R. A., Denotti, A., Rae, C., Bartlett, D. J., Wong, K. K. H., Yang, Q., Walton, D., Sachinwalla, T., Grunstein, R. R., Dang, D., Cunnington, D., Swieca, J., Chen, Y., Young, A., Jakobson, A., Fitzgerald, P., Conduit, R., Smith, D., Jorgensen, G., Lee, H. L., Simpson, G., Ferns, J., Shepherd, K., James, A., Musk, A., Hunter, M., Eastwood, P., Duce, B., Al-Abri, M., Al-Hashmi, K., Jaju, D., Al-Rawas, O., Hassan, M., Ngan, A., Marshall, M. J., Dawson, A. D. G., Bucks, R. S., Walker, A., Hensley, R., Machaalani, R., Waters, K., Harrison, H., Tai, A., Raju, S., Williamson, B., Richardson, H. L., Walker, A. M., Horne, R. S. C., Yuill, M., Harris, M. A., Griffiths, A., Trang, L., Paramalingam, N., Davis, E., Jones, T., Stick, S., Wilson, A., Suresh, S., Cooper, D., Walsh, J., Maddison, K., Hoegh, T., Daulatzai, M., Karmakar, C., Khan, N., Bei, B., Nicholas, C., Worsnop, C., Jordan, A., Saboisky, J., White, D., Malhotra, A., Stadler, D., Mcevoy, R. D., Paul, D., Bradley, J., Maclean, J., Fitzgerald, D., Witcombe, N., Yiallourou, S., Sands, S., Ratnavadivel, R., George, K., Ryan, M., Thompson, C., Catcheside, P. G., Harmer, L., Deacon, N., Wang, D., Piper, A., Yee, B., Mihai, R., Davey, M. J., Nixon, G. M., Tyler, L., Vidal, A., Lambert, S., Tolson, J., Henderson, M., Maree, B., Campbell, A., Neill, A., Heraganahally, S., Bowden, J., Carney, S., Robinson, S., Sajkov, D., Bakker, J., Rixon, K., Hanssen, K., Chia, C., Sather, T., Keir, G., Chikazaza, M., Shirlaw, T., Jones, D., West, J., Dooney, N., Teo, M. Y., Falland, K., Phung, S., Cullen, S., Kevin, G., Mcardle, N., Joosten, S., Turton, A., Hamilton, G., Lavercombe, M., Hocking, V., Clarence, M., Thien, F., Senin, S. R., Ong, T. H., Ong, G., Roebuck, T., Ho, S., Langan-Fox, J., Davis, S., Van, E., Paul, E., Naughton, M., Iqbal, S. M., Gray, P., Urquhart, D., Williams, G., Verginis, N., Boynton, A., Gradinger, F., Partinen, M., Stucki, G., Cooper, P., Biggs, S., Dollman, J., Sweeney, B., Jones, L., Milgrom, J., Ericksen, J., Parry, B., Meliska, C., Sorenson, D., Lopez, A., Martinez, F., Nowakowski, S., Hauger, R., Elliott, J., Kripke, D., Duncan, S., Larsson, E., Fuller, J., Krass, I., Saini, B., and Junge, M.

Published
2009
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16. Poster abstracts

Author

Marshall, N. S., Almqvist, C., Grunstein, R. R., Marks, G. B., Nixon, G. M., Wawruszak, M., Verginis, N., Horne, R. S. C., Davey, M. J., Blunden, S. L., Chervin, R. D., Ng, M. L., O’Driscoll, D. M., Yang, J. S. C., Noa, A. M., Lushington, K., Camfferman, D., Gold, M., Kennedy, D., Galland, B. C., Taylor, B. J., Tripp, E. G., Phillips, A. M., Lrichardson, H., Verbeek, M., Parslow, P., Scott, S., Walker, A. M., Harding, R., Richards, H., Lack, L., Gradisar, M., Harris, J., Vu, T., Mitchell, P. I., Toth, K. A., Mcculloch, B. J., Campbell, A., Signal, T. L., O’Keeffe, K., Kanbayashi, T., Kondo, H., Satoh, S., Takemura, T., Kaneko, Y., Kanayama, H., Abe, M., Nishino, S., Ishikawa, H., Shimizu, T., Stadler, D., Catcheside, P., George, K., Thompson, C., Ryan, M., Mcevoy, R. D., Wilkinson, V., Nicholas, C., Worsnop, C., Jordan, A., Malhotra, A., Steiner, K., White, D., Trinder, J., Hellgren, J., Lee, Y., O’Brien, D., Yee, B., Rimmer, J., Grunstein, R., Hilditch, C. J., Catcheside, P. G., Rischmueller, M., Kirkness, J. P., Schneider, H., Patil, S. P., Mcginley, B. M., Smith, P. L., Schwartz, A. R., Maddison, K. J., Walsh, J. H., Philippe, D. L., Platt, P. R., Hillman, D. R., Eastwood, P. R., Yeo, A., Thomson, K., Melehan, K. L., Bartlett, D. J., Wong, K. K., Car, G., Feenstra, J. F. E., Eckert, B., Rixon, K., Hukins, C., Crummy, F., Kossmann, T., Cameron, P., Naughton, M. T., Larby, J. R., Curtin, D., Semple, K., Douglas, J., Lee, Y. H., Edwards, N., Sullivan, C. E., Lehman, S., Antic, N. A., Mcevoy, D., Mukherjee, S., Fedson, A., Palmer, L. J., Love, G., Singh, B., James, A., Cullen, S. C., Mcardle, N., Hillman, D., Clarke, P. F., Van Eps, C., Hawley, C., Lee, R. W., Chan, A. S., Cistulli, P. A., Abdul Latif, H., Stick, S., Maul, J., Wilson, A., Suresh, S., James, J., Byrne, S., Doull, I., Evans, H., Parsley, C. L., Williams, G., Dakin, C., Harris, M., Cooper, D. M., Heussler, H., Chan, E. Y.-T., Hyde, M. L., Yuill, M., Harris, M. A., Schibler, A., Wilson, S., Cooper, D., Maclean, J. E., Fitzsimons, D., Waters, K., Fitzgerald, D., Coussens, S., Berryman, M., Parsons, D., Saint, D., Pamula, Y., Martin, A. J., Abbot, D., Piper, A. J., Wang, D., Yee, B. J., Willson, G. N., Flunt, D., Bassin, D., Bateman, P., Ratnavadivel, R., Lester, S., Huang, Q. R., He, H. X., Chow, C. M., Jones, A. C., Visvalingam, V. V., Lui, P., Buchanan, P., Duce, B. L., Bliss, R. A., Bruck, D., Afaghi, A., O’Connor, H., Smith, S. S., Kilby, S., Jorgensen, G., Douglas, J. A., Johns, M. W., Tucker, A. J., Chapman, R. J., Michael, N. J., Beale, C. A., Stephens, M. N., Ferguson, S. A., Lamond, N., Jay, S. M., Dorrian, J., Jones, C. B., Roach, G. D., Dawson, D., Jackson, M. L., Howard, M. E., Kennedy, G., Swann, P., Pierce, R. J., Loughran, S. P., Wood, A. W., Croft, R. J., Barton, J. M., Thompson, B., Stough, C., Kandelaars, K., Warman, G. R., Bolton, C. A., Fernando, III, A. T., Cheeseman, J. F., Inglis, C., Huang, H.-C. C., Wlee, R., Richards, D., Turton, A., Copland, J., Ho, M., Rochford, P. D., Brazzale, D. J., Zubrinich, C., Roebuck, T. J., Toman, P., Ho, S., Szollosi, I., Naughton, M., Ruehland, W., Churchward, T., Ruehland, W. R., Churchward, T. J., Barnes, M., Lakey, T., Denotti, A. L., Dungan, G. C., Wong, K. K. H., Gilholme, J. W., Cunnington, D., Cherry, G., Teichtahl, H., Mietus, J. E., Goldberger, A. L., Thomas, R. J., Linklater, S., Martin, J., Galilogadr, S., Mihai, R., Gulliver, T., Wales, P., Salvini, A., Whitehead, B., Laybutt, N., Latham-Smith, F., Shine, N. P., Coates, H. L., Lannigan, F. J., Ng, A. T., Darendeliler, M. A., Zeng, B., Ng, A., Darendeliler, A., Cistulli, P., Qian, J., Hanssen, K., Schnider, H., Lewis, R. H., De Fazio, D., Pierce, R., Pretto, J., Mcdonald, C., Howard, M., Baulk, S. D., Biggs, S. N., Van Den Heuvel, C. J., Reid, K., Vakulin, A., Anderson, R., Banks, S., Davies, A. N., Williams, A. D., Almond, J., Beard, D., Peisker, C., Ball, M., Taylor, A., Wright, H., Clark, R., Hensley, M., Rowland, S., Windler, S., Kennedy, G. A., Gullo, M., Clarke, C., Gain, K., Murphy, M., Rebus, C., Saunders, K., Imazu, M., Morgan, H., Kwan, M., Nicholls, G., Tolson, J., Worsnop, C. J., Navin, C., Baker, G., and Van Der Touw, T.

Published
2006
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19. 0669 The Effects Of Continuous Positive Airway Pressure Therapy In Moderate To Severe Obstructive Sleep Apnea: A High-density EEG Study

Author

D’Rozario, A L, primary, Kao, C, primary, Mullins, A E, primary, Memarian, N, primary, Yee, B, primary, Duffy, S, primary, Banerjee, D, primary, Cho, G, primary, Wong, K K, primary, Kremerskothen, K, primary, Chapman, J, primary, Haroutonian, C, primary, Bartlett, D J, primary, Naismith, S L, primary, and Grunstein, R R, primary

Published
2020
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37. STUDIES ON DOG SEMEN

Author

BARTLETT, D. J.

Abstract

Semen was collected by artificial vagina from three adult dogs of mixed breed twice weekly during the 1st year, once weekly during the 2nd year, and twice monthly during the 3rd year. Ejaculates were collected entire, or in separate fractions—the first or pre-sperm, the second or sperm-rich, and the third or post-sperm fractions. The average total duration of ejaculation was 11 min, the greater part of this time, 8 min, consisting of ejaculation of the third fraction. The average total ejaculate volume was 12·0 ml, the values for the first, second, and third fractions being 0·9, 2·6, and 9·2 ml, respectively. The average sperm concentration of the total ejaculate was 53 × 106cells per ml, the values for the second and third fractions being 247 × 106and 10 × 106cells per ml, respectively. In nigrosin-eosin stained preparations, the average percentage of 'dead' (eosin-stained) spermatozoa per ejaculate at room temperature varied from fifteen in second-fraction samples to twenty in total-ejaculate samples. The dimensions of normal unstained spermatozoa in these preparations were: total length 68 μ, head length 7 μ, head width 5 μ, midpiece length 11 μ, and tail length 50 μ. The average percentage of abnormal spermatozoa per ejaculate was fifteen. The head and tail regions of spermatozoa were affected by the highest percentage of abnormalities. Alteration in semen quality with seasonal variation or change in collection frequency was only significant (P<0·01) for the total ejaculate volume of individual dogs. Dog spermatozoa retained their motility for a greater length of time in phosphate buffered sperm suspensions than in undiluted semen, and motility was adversely affected at body temperature. The longest preservation of progressive motility at room temperature, 32 hr, was associated with the spermatozoa in a second-fraction semen sample diluted with egg-yolk citrate.

Published
1962
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38. Coastal adaptation

Author

Klein, R. J. T., Buckley, E. N., Nicholls, R. J., Ragoonaden, S., Aston, J., Michele Capobianco, Mizutani, N., Nunn, P. D., Bartlett, D. J., Boyd, J. G., Lecomte, E. L., Loizidou, X. I., Volonté, C. R., and Niang-Diop, I.

43. A multivariate model of determinants of motor change for children with cerebral palsy.

Author

Bartlett DJ and Palisano RJ

Subjects
Cerebral Palsy complications, Child, Child, Preschool, Cognition Disorders etiology, Humans, Models, Theoretical, Motivation, Multivariate Analysis, Nuclear Family psychology, Patient-Centered Care, Physical Endurance, Prognosis, Range of Motion, Articular, Sensation Disorders etiology, Temperament, Activities of Daily Living, Cerebral Palsy diagnosis, Cerebral Palsy rehabilitation, Disability Evaluation, Motor Skills, Patient Care Planning
Abstract

The purpose of this article is to describe the development of a theory- and data-based model of determinants of motor change for children with cerebral palsy. The dimensions of human functioning proposed by the World Health Organization, general systems theory, theories of human ecology, and a philosophical approach incorporating family-centered care provide the conceptual framework for the model. The model focuses on relationships among child characteristics (eg, primary and secondary impairments, personality), family ecology (eg, dynamics of family function), and health care services (eg, availability, access, intervention options). Clarification of the complex multivariate and interactive relationships among the multiple child and family determinants, using statistical methods such as structural equation modeling, is necessary before determining how physical therapy intervention can optimize motor outcomes of children with cerebral palsy. We propose that the development and testing of multivariate models is also useful in physical therapy research and in the management of complex chronic conditions other than cerebral palsy. Testing of similar models could provide physical therapists with support for: (1) prognostic discussions with clients and their families, (2) establishment of realistic and attainable goals, and (3) interventions to enhance outcomes for individual clients with a variety of prognostic attributes.

Published
2000

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