3,557 research outputs found
Evidence to Suggest That Teeth Act as Human Ornament Displays Signalling Mate Quality
Ornament displays seen in animals convey information about genetic quality, developmental history and current disease state to both prospective sexual partners and potential rivals. In this context, showing of teeth through smiles etc is a characteristic feature of human social interaction. Tooth development is influenced by genetic and environmental factors. Adult teeth record environmental and traumatic events, as well as the effects of disease and ageing. Teeth are therefore a rich source of information about individuals and their histories. This study examined the effects of digital manipulations of tooth colour and spacing. Results showed that deviation away from normal spacing and/or the presence of yellowed colouration had negative effects on ratings of attractiveness and that these effects were markedly stronger in female models. Whitening had no effect beyond that produced by natural colouration. This indicates that these colour induced alterations in ratings of attractiveness are mediated by increased/decreased yellowing rather than whitening per se. Teeth become yellower and darker with age. Therefore it is suggested that whilst the teeth of both sexes act as human ornament displays, the female display is more complex because it additionally signals residual reproductive value
Inspection report: The Oldham College
Dates of inspection: 23–27 February and 2–4 March 200
Do OB Runaway Stars Have Pulsar Companions?
We have conducted a VLA search for radio pulsars at the positions of 44
nearby OB runaway stars. The observations involved both searching images for
point sources of continuum emission and a time series analysis. Our mean flux
sensitivity to pulsars slower than 50 ms was 0.2 mJy. No new pulsars were found
in the survey. The size of the survey, combined with the high sensitivity of
the observations, sets a significant constraint on the probability, , of a
runaway OB star having an observable pulsar companion. We find \%
with 95\% confidence, if the general pulsar luminosity function is applicable
to OB star pulsar companions. If a pulsar beaming fraction of \onethird\ is
assumed, then we estimate that fewer than 20\% of runaway OB stars have neutron
star companions, unless pulsed radio emission is frequently obscured by the OB
stellar wind. Our result is consistent with the dynamical (or cluster) ejection
model for the formation of OB runaways. The supernova ejection model is not
ruled out, but is constrained by these observations to allow only a small
binary survival fraction, which may be accommodated if neutron stars acquire
significant natal kicks. According to Leonard, Hills and Dewey (1994), a 20\%
survival fraction corresponds to a 3-d kick velocity of 420 km s. This
value is in close agreement with recent revisions of the pulsar velocity
distribution.Comment: Submitted to the Astronomical Journal. 16 pages. Latex uses
aaspp4.sty. 3 postscript figures. Address correspondence to Colin Philp
([email protected]). Revision was to replace .ps file with latex fil
Modelling and Refinement in CODA
This paper provides an overview of the CODA framework for modelling and
refinement of component-based embedded systems. CODA is an extension of Event-B
and UML-B and is supported by a plug-in for the Rodin toolset. CODA augments
Event-B with constructs for component-based modelling including components,
communications ports, port connectors, timed communications and timing
triggers. Component behaviour is specified through a combination of UML-B state
machines and Event-B. CODA communications and timing are given an Event-B
semantics through translation rules. Refinement is based on Event-B refinement
and allows layered construction of CODA models in a consistent way.Comment: In Proceedings Refine 2013, arXiv:1305.563
The insulin-like growth factor system and its receptors: A potential novel anticancer target
The current generation of novel anticancer therapies that are in preclinical and clinical development are based on exploiting our increasing understanding of the molecular and cellular basis of cancer development and progression. Accelerated rates of cell division and proliferation have been postulated to predispose to the development of malignant disease. The insulin-like growth factor (IGF) signaling system has an important physiological role in regulating cellular proliferation and apoptosis. This function has led to considerable interest in its relevance to neoplasia over the last decade. In this review, we give an overview of the IGF system physiology, discuss the epidemiological significance of IGF signaling and neoplasia, and review the preclinical and clinical studies in targeting IGF receptors as cancer therapies
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Temperature dependent stiffness and visco-elastic behaviour of lipid coated microbubbles using atomic force microscopy.
yesThe compression stiffness of a phospholipid microbubble was determined using force-spectroscopy as a function of temperature. The stiffness was found to decrease by approximately a factor of three from 0.08 N m 1, at 10 C, down to 0.03 N m 1 at 37 C. This temperature dependence indicates that the surface tension of lipid coating is the dominant contribution to the microbubble stiffness. The timedependent material properties, e.g. creep, increased non-linearly with temperature, showing a factor of two increase in creep-displacement, from 24 nm, at 10 C, to 50 nm, at 37 C. The standard linear solid model was used to extract the visco-elastic parameters and their determination at different temperatures allowed the first determination of the activation energy for creep, for a microbubble, to be determined.EPSR
Effect of light filters on reading speed in normal and low vision due to age-related macular degeneration
Purpose: To investigate the effects of light filters on reading speed in normal and low vision due to age-related macular degeneration (AMD). Methods: Reading speed was determined for 12 subjects with normal vision and 12 subjects with non-exudative AMD using stationary lowercase nonsensical print in Times Roman font and four light filters; a yellow Corning Photochromic Filter (CPF) 450, a grey neural density (ND) filter, an individual filter obtained using the Intuitive Colorimeter® and a clear filter. Results: There was no statistically significant light filter effect on reading speed for the normal subjects. The AMD group demonstrated a statistically significant 5% average improvement in reading speed with the CPF450 compared with the other filters although some AMD subjects had improvements of 10-15%. Conclusions: Light filters obtained using the Intuitive Colorimeter® performed poorly when compared with the CPF450, ND and clear filters for both the study groups. For the AMD group, average reading speed was statistically greater with the CPF450 than the other filters, however it is questionable whether the improvement (5%) would be clinically significant. As some of the subjects with AMD had greater improvements with the CPF450 we advocate clinical assessment of light filters using existing protocols on an individual basis. © 2004 The College of Optometrists
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