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.

Catching gender-Identity production in flight : making the commonplace visible

The purpose of this article is to develop and illustrate an approach for making the commonplace visible in a natural, as opposed to manipulated, social setting. The key research task was to find a way of capturing the ongoing production or enactment of the self that provides some insight into the way in which it is produced in a routine, matter of fact way. The article takes a number of steps to develop a research approach to the task. First, gender-identity was selected as a more specific aspect of self-production. Second, the concept of “flashpoints” was used to refer to a particular moment in the routine which achieves some significance or salience as a result of the participants seizing upon some otherwise unremarkable action or statement and twisting it to their purpose. In this study, the purpose was gender-identity creation. Primary school children in the classroom and their teachers were the participants of the study. Through the use of flashpoints, the article demonstrates how gender-identity production of these children can be caught in flight. The article concludes that this approach can be added to the researcher’s toolkit.

Visible transparent, UV-blocking polymer nanocomposite films containing nano-sized organic-LDH (Layered Double Hydroxide) hybrid

A nano-sized Mg2Al layered double hydroxide (LDH) was used for encapsulating an organic UV absorber, 2-hydroxy-4- methoxybenzeophenone-5-sulfonic acid (HMBS), to produce HMBS@LDH hybrid nano-platelets. Upon dispersing this organic-inorganic hybrid LDH into ethylene-vinyl alcohol copolymer (EVOH) for film casting, a thin polymer
nanocomposite film that is UV opaque but highly transparent to visible light (higher than 90%) was formed. Thermogravimetry (TG) analysis confirmed that the intercalation of HMBS into LDH considerably increased the thermal stability of HMBS. Such an improvement was attributed to the strong guest-host interaction between the HMBS anions and the LDH layers. Also, the nanocomposite films were flexible and had good mechanical properties.

An investigation into the use of physical modelling for the prediction of various feature types visible from different view points

This paper describes a general purpose flexible technique which uses physical modelling techniques for determining the features of a 3D object that are visible from any predefined view. Physical modelling techniques are used to determine which of many different types of features are visible from a complete set of viewpoints. The power of this technique lies in its ability to detect and parameterise object features, regardless of object complexity. Raytracing is used to simulate the physical process by which object features are visible so that surface properties (eg specularity, transparency) as well as object boundaries can be used in the recognition process. Using this technique occluding and non-occluding edge based features are extracted using image processing techniques and then parameterised. Features caused by specularity are also extracted and qualitative descriptions for these are defined.

Visible light activated TiO2/microcrystalline cellulose nanocatalyst to destroy organic contaminants in water

Hybrid TiO2/microcrystalline cellulose (MC) nanophotocatalyst was prepared in situ by a facile and simple synthesis utilizing benign precursors such as MC and TiCl4. The as-prepared nanocomposite was characterized by XRD, XPS, BET surface area analyzer, UV–vis DRS and TGA. Surface morphology was assessed by the means of SEM and HR-TEM. Statistics-based factorial design (FD) was adopted to investigate the effect of precursors concentrations and therefore to optimize the nanocomposite synthesis through catalytic adsorption of methylene blue (MB) from aqueous solutions. The results indicated that TiO₂/MC nanocomposites were photocatalytically active in diminishing 40–90% of MB in 4 h.

Ag/AgCl composite nanoparticles/polyacrylonitrile nanofiber films for visible-light photocatalysis

Ag/AgCl composite nanoparticles/polyacrylonitrile nanofiber films were prepared by electrospinning and subsequent in-situ reduction combining in-situ oxidation strategy. Electrospinning was firstly used to fabricate PAN/AgNO3 composite nanofibers; then the AgNO3 was reduced by in-situ reduction with glycol; finally, an in-situ oxidation between Ag nanoparticles and FeCl3 solution was carried on to prepare the compo-site nanofiber films. The as-prepared materials can be used as high-performance photocatalysts, taking the advantage of the visible-light activity, flexibility, and high photocatalytic kinetics. The present method is helpful for the development of the high-performance membrane based photocatalysts.

Making a visible difference : overcoming barriers using arts-based learning

This paper reports on a small-scale action research project conducted by two university-based researchers using a visual arts method. The seven-week drawing programme was the second cycle of an action research project. The participants were nine boys of primary school age variously identified by their teachers as reluctant readers and/or as struggling with print literacy. The thematic concerns addressed in the paper fall into two broad categories: motivating learners by drawing on their popular cultural capital and interests, as well as tracing the construction of visual texts as data in action research. Findings are presented in response to the following research questions: What happens to those students who do not or cannot meet the required standards in literacy? What kind of research approach can be utilised or adapted to respond to the literacy practices and behaviours of young people?

Making things visible

A screendance artist response to the essay "Falling into the surface (toward a materiality of affect)" 1999 by Pia Ednie-Brown curated by Simon Ellis.

Making visible the invisible act of doping

This paper describes the construction of the visual space of surveillance by the global anti-doping apparatus, it is a space inhabited daily by professional cyclists. Two principal mechanisms of this apparatus will be discussed—the Whereabouts System and the Biological Passport; in order to illustrate how this space is constructed and how it visualises the invisible act of doping. These mechanisms act to supervise and govern the professional cyclist and work to classify them as either clean or dirty in terms of the use of prohibited doping substances or methods. Contrary to the analysis of liberal anti-doping scholars such as Hanstad, Loland and Møller this paper argues that Foucault’s Panopticon paradigm is a useful tool for the analysis of this apparatus. The Whereabouts System and Biological Passport are the instruments by which the anti-doping apparatus intensifies the construction of the space of surveillance in professional sport. This space of surveillance not only locates and makes visible the physical location of each individual cyclist, but it also makes visible their internal bodily functions, in this case the composition and the fluctuations of the composition of their blood. In making the cyclist visible the instruments do not allow the cause of doping, or the event of doping to be known or observed. Rather what they do is cast the body in terms of abnormalities of time, place or blood. In the case of an abnormality of the cyclist’s blood, the cause itself cannot be identified with any certainty, all that is made visible is a suggestion, or a probability, that doping may have occurred. The ultimate effects are twofold—an internalisation and continual monitoring of one’s self as well as by the authorities, and a radical change in the nature and the definition of the offence of doping. No longer is it positive evidence of doping that is punishable, but what becomes punishable is an abnormality, in the cyclist’s location, or their body, which suggests a probability that the invisible act of doping may have occurred. In the course of this process accepted manners of proving an offence by the use of scientific evidence and expert commentary are transformed. The Whereabouts System and the Biological Passport open up a new manner in which the invisible can be visualised. Through the discourse and the attendant commentary of the expert a new alliance between doping and the law is constructed. The result is a redistribution of the way in which the law visualises and treats the symptoms (the signifier) and the signified act of doping. The Whereabouts System and Biological Passport are the instruments by which the anti-doping apparatus intensifies the construction of the space of surveillance in professional sport. This space of surveillance not only locates and makes visible the physical location of each individual cyclist, but it also makes visible their internal bodily functions, in this case the composition and the fluctuations of the composition of their blood. In making the cyclist visible the instruments do not allow the cause of doping, or the event of doping to be known or observed. Rather what they do is cast the body in terms of abnormalities of time, place or blood. In the case of an abnormality of the cyclists’s blood, the cause itself cannot be identified with any certainty, all that is made visible is a suggestion, or a probability, that doping may have occurred. The ultimate effects are twofold—an internalisation and continual monitoring of one’s self as well as by the authorities, and a radical change in the nature and the definition of the offence of doping. No longer is it positive evidence of doping that is punishable, but what becomes punishable is an abnormality, in the cyclist’s location, or their body, which suggests a probability that the invisible act of doping may have occurred. In the course of this process accepted manners of proving an offence by the use of scientific evidence and expert commentary are transformed. The Whereabouts System and the Biological Passport open up a new manner in which the invisible can be visualised. Through the discourse and the attendant commentary of the expert a new alliance between doping and the law is constructed. The result is a redistribution of the way in which the law visualises and treats the symptoms (the signifier) and the signified act of doping.