Mimicry and the eye of the beholder

Recent experiments (Dittrich et al. (Proc. R. Soc. Lond. B 251, 195 (1993))) suggest that pigeon perception of wasp mimicry by hoverflies is similar to that of humans and of computer-based image matching. However, the relations are nonlinear and may explain why some species are abundant despite their being poor mimics to the human eye. We suggest that these discrepancies between pigeon and human categorization may lie in the differences between avian and primate colour vision. As pigeon categorization and computer image analysis were both assessed by using colour slides designed for human vision, they lacked the natural colour information available to wild birds, in particular that from ultraviolet (uv) wavelengths.

Do clinicians know how to use pulse oximetry? A literature review and clinical implications

Pulse oximerry has become one of the most commonly used tools in the clinical environment for assessing patients' oxygenation status. It is employed almost continuously in critical care areas and frequently in the general ward environment. Although it is a much better tool for determining hypoxia than the human eye, its use is limited if clinicians do not understand relevant physiological principles, such as the oxyhaemoglobin dissociation curve and the inherent limitations of the device. Furthermore, the risk for compromised patient safety is significant if clinicians fail to recognise the potential for false or erroneous readings. This paper explores the research which has examined clinicians' comprehension of pulse oximetry. Fourteen studies examining clinicians' knowledge of pulse oximerry were reviewed. These studies revealed significant knowledge deficits about pulse oximerry amongst nurses, doctors and allied health professionals, all of whom used this technology frequently. Alarmingly, those lacking an adequate understanding of pulse oximerry included senior, experienced clinicians. The studies were limited by their use of convenience sampling and small sample sizes. Further research is needed to better understand the significance of this problem and to examine how principles of pulse oximerry are taught to nurses and other health professionals at the undergraduate and postgraduate levels. Educators and clinicians alike must ensure that a safe level of knowledge for the use of pulse oximerry is maintained in order to ensure that patient outcomes are not compromised.

Egg colour matching in an African cuckoo, as revealed by ultraviolet-visible reflectance spectrophotometry

Despite major differences between human and avian colour vision, previous studies of cuckoo egg mimicry have used human colour vision (or standards based thereon) to assess colour matching. Using ultraviolet-visible reflectance spectrophotometry (300-700 nm), we measured museum collections of eggs of the red-chested cuckoo and its hosts. The first three principal components explained more than 99% of the variance in spectra, and measures of cuckoo-host egg similarity derived from these transformations were compared with measures of cuckoo-host egg similarity estimated by human observers unaware of the hypotheses we were testing. Monte Carlo methods were used to simulate laying of cuckoo eggs at random in nests. Results showed that host and cuckoo eggs were very highly matched for an ultraviolet versus greenness component, which was not detected by humans. Furthermore, whereas cuckoo and host were dissimilar in achromatic brightness, humans did not detect this difference. Our study thus reveals aspects of cuckoo-host egg colour matching which have hitherto not been described. These results suggest subtleties and complexities in the evolution of host-cuckoo egg mimicry that were not previously suspected. Our results also have the potential to explain the longstanding paradox that some host species accept cuckoo eggs that are non-mimetic to the human eye.

Human saccadic eye movements and tracking by active foveation in log polar space

One of the possible models of the human visual system (HVS) in the computer vision literature has a high resolution fovea and exponentially decreasing resolution periphery. The high resolution fovea is used to extract necessary information in order to solve a vision task and the periphery may be used to detect motion. To obtain the desired information, the fovea is guided by the contents of the scene and other knowledge to position the fovea over areas of interest. These eye movements are called saccades and corrective saccades. A two stage process has been implemented as a mechanism for changing foveation in log polar space. Initially, the open loop stage roughly foveates on the best interest feature and then the closed loop stage is invoked to accurately iteratively converge onto the foveation point. The open loop stage developed for the foveation algorithm is applied to saccadic eye movements and a tracking system. Log polar space is preferred over Cartesian space as: (1) it simultaneously provides high resolution and a wide viewing angle; and (2) feature invariance occurs in the fovea which simplifies the foveation process.

Applications of aptamers in nanodelivery systems in cancer, eye and inflammatory diseases

Aptamers are an interesting class of molecules that have potential in many facets of human health. They are characterized by high affinity and specificity to their targets, are small in size, have similar properties to antibodies, but are made synthetically. All of these properties, among others, give aptamers the potential to diagnose, image and treat like no other molecules. By combining the unique properties of aptamers with the ever expanding field of nanotechnology and all it has to offer, we are entering a very promising new area of targeted nanodelivery treatments. These treatments have found success in the complex disease processes of cancer, eye and inflammatory diseases.

An analysis on human personality and hotel web design : a Kohonen network approach

Having an eye catching and attractive website could help hotels to compete in the vigorous online market. This study attempts to examine the relationship between human personality and the web design preferences. Kohonen Networks were adopted to cluster people with similar personality characteristics and identify their differences on web design preferences. Empirical results indicated people with similar personality traits have similar design preferences. For example, to attract those who got high scores in agreeableness, conscientiousness and openness but low score in neuroticism, a web page should start with a language selection page with introductory movie, one large image on the web page showing hotel interior design with hotel guest in the photo, and with background music.

Non-invasive collection and examination of human corneal epithelial cells

Purpose. To report the development of a new apparatus for non-invasive collection of human corneal epithelial cells.

Methods. Previous methods of non-invasive, irrigative corneal cell collection resulted in low cell yields limiting potential analysis. A new ocular surface cell collection apparatus (OSCCA) was designed to collect more epithelial cells from direct irrigation of the corneal surface to allow for clinical comparisons. Forty-five samples were obtained (unilateral or bilateral over seven visits) from five human participants. Cell yield, size, phenotype, and corneal staining (prior and post eye wash) were examined.

Results. On average 364 ± 230 epithelial cells were collected from the cornea per eye. Epithelial cell sizes ranged from 8.21 to 51.69 μm in diameter, and 67.30 to 2098.85 μm2 area. The proportion of corneal specific cells collected per sample was 75 ± 14% as determined by positive K3 expression with AE5. On average, 77 ± 0.2% of epithelial cells harvested were nucleated, the remainder were non-nucleated ghost cells. Corneal staining was reduced in the OSCCA-washed vs. contralateral non-washed eyes (p = 0.02).

Conclusions. The OSCCA allows collection of human corneal epithelial cells with significantly higher yields, and greater specificity than previously reported. Reduced corneal staining observed post eye-wash demonstrated the safety of the technique, and its ability to remove cells directly from the corneal surface. The OSCCA could provide an objective non-invasive method of investigating pathological changes, effects of topical therapeutics, and impact of contact lenses and care-solutions of the cells of the ocular surface.

Human corneal epithelial cell shedding and fluorescein staining in response to silicone hydrogel lenses and contact lens disinfecting solutions

A pilot study was conducted to evaluate human corneal epithelial cell shedding in response to wearing a silicone hydrogel contact lens/solution combination inducing corneal staining. The nature of ex vivo collected cells staining with fluorescein was also examined. A contralateral eye study was conducted in which up to eight participants were unilaterally exposed to a multipurpose contact lens solution/silicone hydrogel lens combination previously shown to induce corneal staining (renu® fresh™ and balafilcon A; test eye), with the other eye using a combination of balafilcon A soaked in a hydrogen peroxide care system (Clear Care®; control eye). Lenses were worn for 2, 4 or 6 hours. Corneal staining was graded after lens removal. The Ocular Surface Cell Collection Apparatus was used to collect cells from the cornea and the contact lens. In the test eye, maximum solution-induced corneal staining (SICS) was observed after 2 hours of lens wear (reducing significantly by 4 hours; p < 0.001). There were significantly more cells collected from the test eye after 4 hours of lens wear when compared to the control eye and the collection from the test eye after 2 hours (for both; n = 5; p < 0.001). The total cell yield at 4 hours was 813 ± 333 and 455 ± 218 for the test and control eyes, respectively (N = 5, triplicate, p = 0.003). A number of cells were observed to have taken up the fluorescein dye from the initial fluorescein instillation. Confocal microscopy of fluorescein-stained cells revealed that fluorescein was present throughout the cell cytoplasm and was retained in the cells for many hours after recovery from the corneal surface. This pilot study indicates that increased epithelial cell shedding was associated with a lens-solution combination which induces SICS. Our data provides insight into the transient nature of the SICS reaction and the nature of fluorescein staining observed in SICS.

Eye tracking the sublime in spectacular moments of science fiction film

In this chapter I will explore science fiction film spectacle as a particular type of endangering sensorial experience. Employing eye-tracking technology to assess where a small group of viewers look, I will contend that through its spectacular set pieces, science fiction film creates two distinct gazing regimes. First, such spectacular scenes create an experience of sublime contemplation where the viewer is (haptically) lost in the wondrous images liquefying before them. These moments of sublime contemplation create the condition where the viewer feels as if they have had an outer-body experience; one that has been cut free from the borders of the linguistic-led self of everyday life. Second, I will argue that certain scenes of science fiction spectacle work to commodify the viewing experience, creating a gazing pattern that is ‘driven’ by the mechanics of the event moment, by the theme park ride aesthetic and the logic of late capitalism. Set in this sensible, empirical context, the sublime dangers of science fiction film can be considered in two distinct ways. On the one hand, when the viewer is caught gazing in a moment of sublime contemplation there is embodied transgression and transcendence: here I will postulate that the viewer exists purely as a carnal being, or are newly if momentarily constituted as post-human, in the impossible present or possible future world that has been spectacularly imagined for them. On the other hand, when the viewer is presented with a spectacle that demands attention to the mechanics and drivers of the scene as it unfolds, a viewing position is created where the very rhythms of the theme park ride is created, where capitalist life is simply being re-engineered. Sublime and spectacular science fiction endangerment, then, liberates and destroys, and it is the encounter between these two vexing poles that is of central concern in this chapter. My focus will predominately be on the eyes, on vision. Undertaking a small-scale empirical study that uniquely utilizes eye tracking technology, this chapter will concentrate on what viewers attend to, gaze at and ‘contemplate’ when viewing two differently constituted ‘spectacle’ sequences: the sun explodes scene from Sunshine (Boyle, 2007) and the Godzilla enters Manhattan scene from Godzilla (Emmerich, 1998).

Effect of retinal image defocus on the thickness of the human choroid

PURPOSE: To describe the time-course and amplitude of changes to sub-foveal choroidal thickness (SFCT) induced by imposed hyperopic and myopic retinal defocus and to compare the responses in emmetropic and myopic subjects. METHODS: Twelve East Asian subjects (age: 18-34 years; six were emmetropic and six had myopia between -2.00 and -5.00 dioptres (D)) viewed a distant target (video movie at 6 m) for 60 min on two separate occasions while optical coherence tomography (OCT) images of the choroid were taken in both eyes every 5 min to monitor SFCT. On each occasion, one eye was optimally corrected for distance with a contact lens while the other eye wore a contact lens imposing either 2.00 D hyperopic or 2.00 D myopic retinal defocus. RESULTS: Baseline SFCT in myopic eyes (mean ± S.D.): 256 ± 42 μm was significantly less than in emmetropic eyes (423 ± 62 μm; p < 0.01) and was correlated with magnitude of myopia (-39 μm per dioptre of myopia, R(2) = 0.67: p < 0.01). Repeated measures anova (General Linear Model) analysis revealed that in both subject groups, 2.00 D of myopic defocus caused a rapid increase in SFCT in the defocussed eye (significant by 10 min, increasing to approximately 20 μm within 60 min: p < 0.01), with little change in the control eye. In contrast, 2.00 D of hyperopic defocus caused a decrease in SFCT in the experimental eye (significant by 20-35 min. SFCT decreased by approximately 20 μm within 60 min: p < 0.01) with little change in the control eye. CONCLUSIONS: Small but significant changes in SFCT (5-8%) were caused by retinal defocus. SFCT increased within 10 min of exposure to 2.00 D of monocular myopic defocus, but decreased more slowly in response to 2.00 D of monocular hyperopic defocus. In our relatively small sample we could detect no difference in the magnitude of changes to SFCT caused by defocus in myopic eyes compared to emmetropic eyes.

Secrecy and human rights abuse in Australia’s offshore immigration detention centres

All asylum seekers who arrive in Australia’s territorial waters by boat are subject to mandatory, indefinite and unreviewable detention on Nauru and Papua New Guinea. This offshore detention regime is characterised by a high degree of secrecy, low levels of transparency and accountability, and few opportunities for external oversight. This has created a closed, controlled environment, in which people are routinely neglected and harmed. To better understand the human impact of Australia’s offshore detention regime, this article draws on research from social psychology regarding human behaviour in closed institutions. This research – which has substantially informed prison policies throughout the Western world – demonstrates the critical importance of external oversight, openness and transparency for the protection of human rights of people in closed institutions. This knowledge has not been applied to Australia’s offshore immigration detention regime. To the contrary: creating a closed, opaque system of detention has been an explicit policy goal of the Australian government. By actively restricting transparency, this research demonstrates that not only are the abuses of detainees’ human rights hidden from the public eye, they are inevitable.