|Home||<< 1 2 3 4 5 6 7 8 9 >>|
Muheim, R., Phillips, J. B., & Akesson, S. (2006). Polarized light cues underlie compass calibration in migratory songbirds. Science, 313(5788), 837–839.
Abstract: Migratory songbirds use the geomagnetic field, stars, the Sun, and polarized light patterns to determine their migratory direction. To prevent navigational errors, it is necessary to calibrate all of these compass systems to a common reference. We show that migratory Savannah sparrows use polarized light cues from the region of sky near the horizon to recalibrate the magnetic compass at both sunrise and sunset. We suggest that skylight polarization patterns are used to derive an absolute (i.e., geographic) directional system that provides the primary calibration reference for all of the compasses of migratory songbirds.
Marchant, P. R. (2006). Investigating whether a crime reduction measure works. Radical Statistics, 91.
Abstract: Crime is a serious business. It causes great distress and fear. It costs a lot
to deal with its consequences. In these regards crime shares much with
the problem of ill-health and disease. The application of sound science and
statistics has allowed great strides to be made in dealing with problems of
ill health. Medical statistics is one of the recognised, established
disciplines involved in researching healthcare.
The parallels between research in crime reduction and in healthcare do
appear to differ in terms of quality. Although there is still room for
considerable improvement in researching health-care, an investigation
into the underpinning of statistical methods used indicates that the
problems are substantially worse in the study of crime. The consideration
given to statistics in crime studies seems rather flimsy, yet important
claims are made which are statistical at source and may affect policy, and
so can have considerable costs attached. Therefore, for example, it is
important to know whether the underlying crime level has really changed,
rather than just being the result of perhaps sampling variation or some
artefact giving rise to statistical bias or systematic error. This is necessary
when trying to determine whether a Crime Reduction Intervention (CRI)
has actually worked.
I started examining the scientific basis of the claim for the effectiveness for
one particular CRI, basically because I was concerned about negative side
effects and I thought the claim implausible. I remain concerned and
unconvinced. The statistical issues and concerns I raise apply also to
investigating other CRIs and to existing published analyses.
This piece extends work presented in Marchant (2006); earlier work on the
statistical issues involved can be found in Marchant (2005a, b; 2004).
Gardner, C. (2006). The use and misuse of coloured light in the urban environment. Optics & Laser Technology, 38(4-6), 366–376.
Abstract: The last few years have seen a huge increase in the transfer of coloured architectural lighting, derived from entertainment and theatre, into the urban and exterior environment. Part of the reason for this is that in the last 15 yr or so, there have been a number of important introductions in coloured lighting technology. These have transformed lighting practice, and while their widespread introduction is seen by some as an enrichment of the urban fabric, others see it as presenting considerable dangers, in terms of aesthetics, perception and in terms of civic identity. Its negative effects on the urban environment have been termed ‘colour blight’.
In this paper, the range of coloured lighting technologies is surveyed and other causes for the increase in coloured lighting are also discussed, together with the problems and benefits involved. Finally, some tentative means are put forward for resolving the problems caused by ‘colour blight’. Current good practice is illustrated by the author's own experience, including his consultancy's participation in a number of urban lighting strategies in the UK and elsewhere. This work involves implementation of a comprehensive lighting plan for the historic city of York, as part of the Urban Lighting Group consortium of three lighting design practices.
Anisimov, V. N. (2006). Light pollution, reproductive function and cancer risk. Neuroendocrinology Letters, 27(1-2), 35–52.
Abstract: At present, light pollution (exposure to light-at-night) both in the form of occupational exposure during night work and as a personal choice and life style, is experienced by numerous night-active members of our society. Disruption of the circadian rhythms induced by light pollution has been associated with cancer in humans. There are epidemiological evidences of increased breast and colon cancer risk in shift workers. An inhibition of the pineal gland function with exposure to the constant light (LL) regimen promoted carcinogenesis whereas the light deprivation inhibits the carcinogenesis. Treatment with pineal indole hormone melatonin inhibits carcinogenesis in pinealectomized rats or animals kept at the standard light/dark regimen (LD) or at the LL regimen. These observations might lead to use melatonin for cancer prevention in groups of humans at risk of light pollution.
Xavier Kerola, D. (2006). Modelling artificial night-sky brightness with a polarized multiple scattering radiative transfer computer code: Modelling artificial night-sky brightness. Monthly Notices of the Royal Astronomical Society, 365(4), 1295–1299.
Abstract: As part of an ongoing investigation of radiative effects produced by hazy atmospheres, computational procedures have been developed for use in determining the brightening of the night sky as a result of urban illumination. The downwardly and upwardly directed radiances of multiply scattered light from an offending metropolitan source are computed by a straightforward Gauss-Seidel (G-S) iterative technique applied directly to the integrated form of Chandrasekhar's vectorized radiative transfer equation. Initial benchmark night-sky brightness tests of the present G-S model using fully consistent optical emission and extinction input parameters yield very encouraging results when compared with the double scattering treatment of Garstang, the only full-fledged previously available model.