Browsing Research Articles (Statistics & Population Studies) by Title

Now showing items 41-60 of 162

    • Fitting power-law distributions to data with measurement errors 

      Koen, Chris; Kondlo, L (Oxford University Press, 2009)
      If X, which follows a power-law distribution, is observed subject to Gaussian measurement error e, thenX+e is distributed as the convolution of the power-lawand Gaussian distributions. Maximum-likelihood estimation of ...

    • Fitting sinusoids to observations of rotating spotted stars 

      Koen, Chris (Oxford University Press, 2007)
      It is assumed that K blocks (e.g. seasons) of observations are available, and the parameters characterizing a fixed-frequency sinusoidal variability (mean light level, amplitude, phase) are constant within each of the ...

    • The “four sigma” limit for significant periodicities 

      Koen, Chris (Springer Verlag, 2010)
      Most of the pulsations which have been observed in sdB stars have very low amplitudes. Detection of modes from photometric observations is usually performed by noting the most prominent peaks in a periodogram or, ...

    • Further observations of Hipparcos red stars and standards for UBV(RI)C photometry 

      Kilkenny, David; Koen, Chris; van Wyk, F.; Marang, F.; Cooper, D. (Oxford University Press, 2007)
      We present homogeneous and standardized UBV(RI)C JHK photometry for over 100 M stars selected from an earlier paper on the basis of apparent photometric constancy. L photometry has been obtained for stars brighter than ...

    • Global warming and psychotraumatology of natural disasters: the case of the deadly rains and floods of April 2022 in South Africa 

      Bouchard, Jean-Pierre; Pretorius, Tyrone B; Kramers-Olen, Anne L (Annales Médico-psychologiques, revue psychiatrique, 2023)
      Climate change and global warming have led to an increased incidence of flooding across the world. Against the backdrop of the recent devastating floods in the Kwazulu-Natal province of South Africa, this paper explores ...

    • HE 0230–4323: An unusual pulsating hot subdwarf star 

      Koen, Chris (Oxford University Press, 2007)
      HE 0230−4323 is a known binary, consisting of a subdwarf star and a companion which is not observable in the optical. Photometric measurements reported in this paper have shown it to be both a reflection-effect and a ...

    • HE 0230−4323 revisited: a new rapidly pulsating sdB star 

      Kilkenny, David; Koen, Chris; Worters, H. (Oxford University Press, 2010)
      HE 0230−4323 is a hot sdB star in a binary system. An earlier work demonstrated that the light curve of the system shows a strong (∼4 per cent) reflection effect and also appears to exhibit photometric variations of the ...

    • HE0230–4323: an unusual pulsating hot subdwarf star 

      Koen, Chris (Oxford University Press, 2007)
      HE 0230−4323 is a known binary, consisting of a subdwarf star and a companion which is not observable in the optical. Photometric measurements reported in this paper have shown it to be both a reflection-effect and a ...

    • Health trends, inequalities and opportunities in South Africa’s provinces, 1990–2019: Findings from the Global burden of disease 2019 Study 

      Achoki, Tom; Sartorius, Benn; Katoto, Patrick DMC (BMJ Publishing Group, 2022)
      Over the last 30 years, South Africa has experienced four ’colliding epidemics’ of HIV and tuberculosis, chronic illness and mental health, injury and violence, and maternal, neonatal, and child mortality, which have ...

    • HerMES: Candidate gravitationally lensed galaxies and lensing statistics at submillimeter wavelengths 

      Wardlow, Julie L.; Cooray, Asantha; De Bernardis, Francesco; Amblard, A.; Arumugam, V.; Aussel, H.; Baker, A.J.; Bethermin, M.; Blundell, R.; Bock, J.; Boselli, A.; Bridge, C.; Buat, V.; Burgarella, D.; Bussmann, R.S.; Cabrera-Lavers, A.; Calanog, J.A.; Carpenter, J.M.; Casey, C.M.; Castro-Rodríguez, N.; Cava, A.; Chanial, P.; Chapin, E.; Chapman, S.C.; Clements, D.L.; Conley, A.; Cox, P.; Dowell, C.D.; Dye, S.; Eales, S.; Farrah, D.; Ferrero, P.; Franceschini, Alberto; Frayer, D.T.; Frazer, C.; Fu, Hai; Gavazzi, R.; Glenn, J.; González Solares, E.A.; Griffin, M.; Gurwell, M.A.; Harris, A.I.; Hatziminaoglou, Evanthia; Hopwood, R.; Hyde, A.; Ibar, Edo; Ivison, R.J.; Kim, S.; Lagache, G.; Levenson, L.; Marchetti, L.; Marsden, G.; Martinez-Navajas, P.; Negrello, M.; Neri, R.; Nguyen, H.T.; OHalloran, B.; Oliver, S.J.; Omont, A.; Page, Matthew J.; Panuzzo, P.; Papageorgiou, A.; Pearson, C.P.; Perez-Fournon, E.; Pohlen, M.; Riechers, D.; Rigopoulou, D.; Roseboom, I.G.; Rowan-Robinson, M.; Schulz, B.; Scott, Douglas; Scoville, N.; Seymour, N.; Shupe, D.L.; Smith, A.J.; Streblyanska, A.; Strom, A.; Symeonidis, Myrto; Trichas, M.; Vaccari, M.; Vieira, J.D.; Viero, M. P.; Wang, L.; Xu, C.K.; Zemcov, M.; Yan, L. (American Astronomical Society, 2013)
      Gravitational lensing increases the angular size and integrated flux of affected sources. It is exploited to investigate the mass distribution of the foreground lensing structures and the properties of the background lensed ...

    • Hermes: Cosmic infrared background anisotropies and the clustering of dusty star-forming galaxies 

      Viero, M. P.; Wang, L.; Zemcov, M.; Addison, G.; Amblard, A.; Arumugam, V.; Aussel, H.; Bethermin, M.; Bock, J.; Boselli, A.; Buat, V.; Burgarella, D.; Casey, C.M.; Clements, D.L.; Conley, A.; Conversi, L.; Cooray, Asantha; de Zotti, G.; Dowell, C.D.; Farrah, D.; Franceschini, Alberto; Glenn, J.; Griffin, M.; Hatziminaoglou, Evanthia; Heinis, S.; Ibar, Edo; Ivison, R.J.; Lagache, G.; Levenson, L.; Marchetti, L.; Marsden, G.; Nguyen, H.T.; OHalloran, B.; Oliver, S.J.; Omont, A.; Page, Matthew J.; Papageorgiou, A.; Pearson, C.P.; Perez-Fournon, I.; Pohlen, M.; Rigopoulou, D.; Roseboom, I.G.; Rowan-Robinson, M.; Schulz, B.; Scott, Douglas; Seymour, N.; Shupe, D.L.; Smith, A.J.; Symeonidis, Myrto; Vaccari, M.; Valtchanov, I.; Vieira, J.D.; Wardlow, Julie L.; Xu, C.K. (American Astronomical Society, 2013)
      Star formation is well traced by dust, which absorbs the UV/optical light produced by young stars in actively starforming regions and re-emits the energy in the far-infrared/ submillimeter (FIR/submm; e.g., Savage & ...

    • HerMES: The contribution to the cosmic infrared background from galaxies selected by mass and redshift 

      Viero, M. P.; Monclesi, L.; Quadri, L.F.; Arumugam, V.; Assef, R.J.; Bethermin, M.; Bock, J.; Bridge, C.; Casey, C.M.; Conley, A.; Cooray, Asantha; Farrah, D.; Glenn, J.; Heinis, S.; Ibar, Edo; Ikarashi, S.; Ivison, R.J.; Kohno, K.; Marsden, G.; Oliver, S.J.; Roseboom, I.G.; Schulz, B.; Scott, Douglas; Serra, P.; Vaccari, M.; Vieira, J.D.; Wang, L.; Wardlow, Julie L.; Wilson, G.W.; Yun, M.S.; Zemcov, M. (American Astronomical Society, 2013)
      The cosmic infrared background (CIB), discovered in Far Infrared Absolute Spectrophotometer (FIRAS) data from the Cosmic Background Explorer (COBE; Puget et al. 1996; Fixsen et al. 1998), originates from thermal ...

    • HerMES: The far-infrared emission from dust-obscured galaxies 

      Calanog, J.A.; Wardlow, Julie L.; Fu, Hai; Cooray, Asantha; Assef, R.J.; Bock, J.; Casey, C.M.; Conley, A.; Farrah, D.; Ibar, Edo; Kartaltepe, J.; Magdis, G.; Marchetti, L.; Oliver, S.J.; Perez-Fournon, I.; Riechers, D.; Rigopoulou, D.; Roseboom, I.G.; Schulz, B.; Scott, Douglas; Symeonidis, Myrto; Vaccari, M.; Viero, M. P.; Zemcov, M. (American Astronomical Society, 2013)
      The far-infrared (far-IR) luminosities of luminous infrared galaxies (LIRGs) and ultra-LIRGs (ULIRGs) are dominated by reprocessed thermal dust emission, due to a combination of star formation and active galactic nucleus ...

    • Herschel PEP/HerMES: the redshift evolution of dust attenuation and of the total (UV+IR) star formation rate density 

      Burgarella, D.; Buat, V.; Gruppioni, C.; Cucciati, O.; Heinis, S.; Berta, S.; Bethermin, M.; Bock, J.; Cooray, Asantha; Dunlop, J.S.; Farrah, D.; Franceschini, Alberto; Le Floch, E.; Lutz, D.; Magnelli, B.; Nordon, R.; Oliver, S.J.; Page, Matthew J.; Popesso, P.; Pozzi, F.; Riguccini, L.; Vaccari, M.; Viero, M. P. (EDP Sciences, 2013)
      Using new homogeneous luminosity functions (LFs) in the far-ultraviolet (FUV) from VVDS and in the far-infrared (FIR) from Herschel/PEP and Herschel/HerMES, we studied the evolution of the dust attenuation with redshift. ...

    • The Herschel* view of the environment of the radio galaxy 4C+41.17 at z = 3.8 

      Wylezalek, D.; Vernet, J.; De Breuck, C.; Stern, D.; Galametz, A.; Seymour, N.; Jarvis, Matt; Barthel, P.; Drouart, G.; Rottgering, H.J.A.; Greve, T.R.; Haas, M.; Hatch, N.; Ivison, R.J.; Lehnert, M.; Meisenheimer, K.; Miley, G.; Nesvadba, N.; Stevens, J.A. (Oxford University Press, 2013)
      We present Herschel observations at 70, 160, 250, 350 and 500 μm of the environment of the radio galaxy 4C+41.17 at z = 3.792. About 65 per cent of the extracted sources are securely identified with mid-infrared sources ...

    • Herschel*-ATLAS: correlations between dust and gas in local submm-selected galaxies 

      Dunne, L.; Bourne, N.; Bendo, G.J.; Smith, M.W.L.; Clark, C.J.R.; Smith, Daniel J.B.; Rigby, E.E.; Baes, M.; Leeuw, L.L.; Maddox, S.J.; Thompson, M.A.; Bremer, M.N.; Cooray, Asantha; Dariush, A.; de Zotti, G.; Dye, S.; Eales, S.; Hopwood, R.; Ibar, Edo; Ivison, R.J.; Jarvis, Matt; Michalowski, M.J.; Rowlands, K.; Valiante, E. (2013)
      We present an analysis of CO molecular gas tracers in a sample of 500 μ m-selected Herschel -ATLAS galaxies at z < 0 . 05 ( cz < 14990 km s − 1 ). Using 22 − 500 μ m photom- etry from WISE , IRAS an ...

    • Herschel-ATLAS: A binary HyLIRG pinpointing a cluster of starbursting protoellipticals 

      Ivison, R.J.; Swinbank, A.M.; Jarvis, Matt (American Astronomical Society, 2013)
      Panchromatic observations of the best candidate hyperluminous infrared galaxies from the widest Herschel extragalactic imaging survey have led to the discovery of at least four intrinsically luminous z = 2.41 galaxies across ...

    • High Concussion Rate in Student Community Rugby Union Players During the 2018 Season: Implications for Future Research Directions 

      Surmon, S (UWC, 2019)
      Collision sports, such as Rugby Union (“Rugby”) have a particularly high risk of injury. Of all injuries common to collision sports, concussions have received the most attention due to the potentially negative cognitive ...

    • History of chronic disease is a novel intrinsic risk factor associated with gradual onset injuries in recreational road cyclists: A cross-sectional study in 21,824 cyclists - SAFER XIV 

      Du Toit, François; Sonja, Swanevelder; Schwellnus, MP (Elsevier, 2020)
      Objectives: Risk factors related to Gradual onset injuries (GOIs) in cyclists need to be identified to enable effective injury prevention strategies. We aim to determine risk factors related to GOIs in cyclists participating ...

    • Housing ownership among female migrants in South Africa: The case of metropolitan and non-metropolitan areas 

      Nsengiyumva, Philomene; Tati, Gabriel (SUN Journals, 2017)
      In the study of female migration and housing acquisition, little has been elaborated about the magnitude and the direction of female migrants in South African context. Furthermore, housing tenure status is still under ...