The role of visual landmarks in the avian familiar area map - Commentary

The question of whether homing pigeons use visual landmarks for orientation from distant, familiar sites is an unresolved issue in the field of avian navigation. Where evidence has been found, the question still remains as to whether the landmarks are used independent of the map and compass mechanism for orientation that is so important to birds. Recent research has challenged the extent to which experiments that do not directly manipulate the visual sense can be used as evidence for compass-independent orientation. However, it is proposed that extending a new technique for research on vision in homing to include manipulation of the compasses used by birds might be able to resolve this issue. The effect of the structure of the visual sense of the homing pigeon on its use of visual landmarks is also considered.

Further evidence for visual landmark involvement in the pigeon's familiar area map

In previous experiments suggesting that previewing visual landscapes speeds homing from familiar release sites, restricted access to olfactory cues may have artefactually encouraged homing pigeons, Calumba livia, to resort to visual landmark orientation. Since evidence for the role of visual landmarks in wide-ranging avian orientation is still equivocal, Braithwaite & Guilford's (1991, Proc. R. Sec. Lond. Ser. B, 245, 183-186) 'previewing' experiments were replicated: birds were allowed or denied visual access to a familiar site prior to release, but allowed ample access to olfactory cues. In experiment 1, allowing birds to preview familiar sites for 5 min prior to release enhanced homing speeds by about 12%. In experiment 2, modified to reduce between-day effects on variation, previewing enhanced homing speeds by about 16%. These experiments support the conclusion that visual landmarks remote from sight of the loft are an important component of the familiar area map, although the nature of the landmarks and how they are encoded remain to be determined. (C) 1997 The Association for the Study of Animal Behaviour.

Local Area Plans: Best Practice Manual

This Manual has been prepared as a companion document for the Planning Guidelines, Local Area Plans: Creating Sustainable Communities - Guidelines for Planning Authorities (Hereafter referred to as ‘The Planning Guidelines’).

The aim of the Manual is to reinforce the key aspects of the Planning Guidelines by emphasising better and more consistent processes and highlighting examples of good practice.

The long-term impacts of fisheries on epifaunal assemblage function and structure, in a special area of conservation

Fisheries can have profound effects on epifaunal community function and structure. We analysed the results from five dive surveys (1975–1976, 1980, 1983, 2003 and 2007), taken in a Special Area of Conservation, Strangford Lough, Northern Ireland before and after a ten year period of increased trawling activity between 1985 and 1995. There were no detectable differences in the species richness or taxonomic distinctiveness before (1975–1983) and after (2003–2007) this period. However, there was a shift in the epifaunal assemblage between the surveys in 1975–1983 and 2003–2007. In general, the slow-moving, or sessile, erect, filterfeeders were replaced by highly mobile, swimming, scavengers and predators. There were declines in the frequency of the fished bivalve Aequipecten opercularis and the non-fished bivalves Modiolus modiolus and Chlamys varia and some erect sessile invertebrates between the surveys in 1975–1983 and 2003–2007. In contrast, there were increases in the frequency of the fished and reseeded bivalves Pecten maximus and Ostrea edulis, the fished crabs Cancer pagurus and Necora puber and the non-fished sea stars Asterias rubens, Crossaster papposus and Henricia oculata between the surveys in 1975–1983 and 2003–2007. We suggest that these shifts could be directly and indirectly attributed to the long-termimpacts of trawl fishing gear, although increases in the supply of discarded bait and influxes of sediment may also have contributed to changes in the frequency of some taxa. These results suggest that despite their limitations, historical surveys and repeat sampling over long periods can help to elucidate the inferred patterns in the epifaunal community. The use of commercial fishing gear was banned from two areas in Strangford Lough in 2011, making it a model ecosystem for assessing the long-term recovery of the epifaunal community from the impacts of mobile and pot fishing gear.

Average household income, crime, and smoking behaviour in a local area: The Finnish 10-Town study

Social environments, like neighbourhoods, are increasingly recognised as determinants of health. While several studies have reported an association of low neighbourhood socio-economic status with morbidity, mortality and health risk behaviour, little is known of the health effects of neighbourhood crime rates. Using the ongoing 10-Town study in Finland, we examined the relations of average household income and crime rate measured at the local area level, with smoking status and intensity by linking census data of local area characteristics from 181 postal zip codes to survey responses to smoking behaviour in a cohort of 23,008 municipal employees. Gender-stratified multilevel analyses adjusted for age and individual occupational status revealed an association between low local area income rate and current smoking. High local area crime rate was also associated with current smoking. Both local area characteristics were strongly associated with smoking intensity. Among ever-smokers, being an ex-smoker was less likely among residents in areas with low average household income and a high crime rate. In the fully adjusted model, the association between local area income and smoking behaviour among women was substantially explained by the area-level crime rate. This study extends our knowledge of potential pathways through which social environmental factors may affect health. (c) 2007 Elsevier Ltd. All rights reserved.

A comprehensive aerosol spray method for the rapid photocatalytic grid area analysis of semiconductor photocatalyst thin films

Indicator inks, previously shown to be capable of rapidly assessing photocatalytic activity via a novel photo-reductive mechanism, were simply applied via an aerosol spray onto commercially available pieces of Activ (TM) self-cleaning glass. Ink layers could be applied with high evenness of spread, with as little deviation as 5% upon UV-visible spectroscopic assessment of 25 equally distributed positions over a 10 cm x 10 cm glass cut. The inks were comprised of either a resazurin (Rz) or dichloroindophenol (DCIP) redox dye with a glycerol sacrificial electron donor in an aqueous hydroxyethyl cellulose (HEC) polymer media. The photo-reduction reaction under UVA light of a single spot was monitored by UV-vis spectroscopy and digital images attained from a flat-bed scanner in tandem for both inks. The photo-reduction of Rz ink underwent a two-step kinetic process, whereby the blue redox dye was initially reduced to a pink intermediate resorufin (Rf) and subsequently reduced to a bleached form of the dye. In contrast, a simple one-step kinetic process was observed for the reduction of the light blue redox dye DCIP to its bleached intermediates. Changes in red-green-blue colour extracted from digital images of the inks were inversely proportional to the changes seen at corresponding wavelengths via UV-visible absorption spectroscopy and wholly indicative of the reaction kinetics. The photocatalytic activity areas of cuts of Activ (TM) glass, 10 cm x 10 cm in size, were assessed using both Rz and DCIP indicator inks evenly sprayed over the films: firstly using UVA lamp light to activate the underlying Activ (TM) film (1.75 mW cm(-2)) and secondly under solar conditions (2.06 +/- 0.14 mW cm(-2)). The photo-reduction reactions were monitored solely by flat-bed digital scanning. Red-green-blue values of a generated 14 x 14 grid (196 positions) that covered the entire area of each film image were extracted using a Custom-built program entitled RGB Extractor(C). A homogenous degradation over the 196 positions analysed for both Rz (Red colour deviation = 19% UVA, 8% Solar: Green colour deviation = 17% UVA, 12% Solar) and DCIP (Red colour deviation = 22% UVA, 16% Solar) inks was seen in both UVA and solar experiments, demonstrating the consistency of the self-cleaning titania layer on Activ (TM). The method presented provides a good solution for the high-throughput photocatalytic screening of a number of homogenous photocatalytically active materials simultaneously or numerous positions on a single film; both useful in assessing the homogeneity of a film or determining the best combination of reaction components to produce the optimum performance photocatalytic film. (C) 2010 Elsevier B.V. All rights reserved.

POINT-AGAPE pixel lensing survey of M31 - Evidence for a MACHO contribution to galactic halos

The POINT-AGAPE collaboration is carrying out a search for gravitational microlensing toward M31 to reveal galactic dark matter in the form of MACHOs (Massive Astrophysical Compact Halo Objects) in the halos of the Milky Way and M31. A high-threshold analysis of 3 years of data yields 6 bright, short- duration microlensing events, which are confronted to a simulation of the observations and the analysis. The observed signal is much larger than expected from self lensing alone and we conclude, at the 95% confidence level, that at least 20% of the halo mass in the direction of M31 must be in the form of MACHOs if their average mass lies in the range 0.5-1 M-circle dot. This lower bound drops to 8% for MACHOs with masses similar to 0.01 M-circle dot. In addition, we discuss a likely binary microlensing candidate with caustic crossing. Its location, some 32' away from the centre of M31, supports our conclusion that we are detecting a MACHO signal in the direction of M31.

Classical novae from the POINT-AGAPE microlensing survey of M31 - I. The nova catalogue

The POINT-AGAPE (Pixel-lensing Observations with the Isaac Newton Telescope-Andromeda Galaxy Amplified Pixels Experiment) survey is an optical search for gravitational microlensing events towards the Andromeda galaxy (M31). As well as microlensing, the survey is sensitive to many different classes of variable stars and transients. Here we describe the automated detection and selection pipeline used to identify M31 classical novae (CNe) and we present the resulting catalogue of 20 CN candidates observed over three seasons. CNe are observed both in the bulge region as well as over a wide area of the M31 disc. Nine of the CNe are caught during the final rise phase and all are well sampled in at least two colours. The excellent light-curve coverage has allowed us to detect and classify CNe over a wide range of speed class, from very fast to very slow. Among the light curves is a moderately fast CN exhibiting entry into a deep transition minimum, followed by its final decline. We have also observed in detail a very slow CN which faded by only 0.01 mag d(-1) over a 150-d period. We detect other interesting variable objects, including one of the longest period and most luminous Mira variables. The CN catalogue constitutes a uniquely well-sampled and objectively-selected data set with which to study the statistical properties of CNe in M31, such as the global nova rate, the reliability of novae as standard-candle distance indicators and the dependence of the nova population on stellar environment. The findings of this statistical study will be reported in a follow-up paper.