Low faunal diversity on Maltese sandy beaches : fact or artefact?

Eight sandy beaches on Malta and two on Gozo were sampled for macrofauna to test the hypothesis that Maltese beaches have an intrinsically low diversity. Stations distributed in the supralittoral (dry zone), mediolittoral (wet zone) and upper infralittoral (submerged zone to 1m water depth) were sampled by sieving core samples and standardised searching during daytime, and pitfall trapping and standardised sweeping of the water column using a hand-net at night, as appropriate. Physical parameters of the sediment were measured and human occupancy of the beaches was estimated. From the supralittoral and mediolittoral, 39 species represented by 1584 individuals were collected by the combined techniques of pitfall trapping, sieving and standard searching. For Ramla beach, which had the highest diversity, 267 individuals representing 25 infaunal species were collected by sieving from a combined volume of 1.175m3 of sand, and 149 individuals representing 28 epifaunal species were collected by standardised searching from a combined area of 700m2 of sand during two winter and two summer sampling sessions between 1992 and 1993. For nine other beaches sampled during the summer of 2000, only six macrofaunal species were collected from core samples, with overall population densities ranging from 4.13 to 45.45 individualsm 2. Only 92 individuals belonging to 12 species were collected by hand-net from the uppermost infralittoral of five beaches sampled using this method during the summer of 2000. Taxa of gastropods, bivalves, decapods, mysids and staphylinid beetles generally abundant on Mediterranean sandy beaches, were entirely absent from the beaches sampled. Few correlations that could explain the impoverishment of Maltese sandy beaches were found between physical parameters and faunal abundances, and other factors such as inadequate sampling effort, human disturbance and marine pollution were also excluded; however, seasonally biased sampling may partly explain the results obtained. One factor that may explain why certain species are missing could be lack of recruitment, due to Malta’s geographical isolation from the European and African mainlands. 2003 Elsevier Ltd. All rights reserved.peer-reviewe

Shedding light on a living lab: the CLEF NEWSREEL open recommendation platform

In the CLEF NEWSREEL lab, participants are invited to evaluate news recommendation techniques in real-time by providing news recommendations to actual users that visit commercial news portals to satisfy their information needs. A central role within this lab is the communication between participants and the users. This is enabled by The Open Recommendation Platform (ORP), a web-based platform which distributes users' impressions of news articles to the participants and returns their recommendations to the readers. In this demo, we illustrate the platform and show how requests are handled to provide relevant news articles in real-time

Changes in the macroalgal assemblage of the uppermost infralittoral fringe following a point oil spill in the Grand Harbour, Malta

The uppermost infralittoral rocky shore macrophyte assemblage at Rinella Creek in the Grand Harbour, Malta was sampled in June 2002. Two days later, approximately 3.5 tonnes of oil were accidentally released at this site and the oil on the shore was cleaned up with steam. The site was visited 16 times over a period of 14 months to record the recolonization process. Multivariate community analysis showed that the community had recovered within a year from the incident.peer-reviewe

The concept of audit materiality and attitudes towards materiality threshold disclosure among Maltese audit practitioners

Materiality permeates the audit process and is a term often used to describe the scope of the auditor’s responsibility to the general public. This paper attempts to evaluate the Maltese auditing profession’s perceptions and use of the concept of materiality in the performance of an audit as well as attitudes towards disclosure of materiality thresholds. Results from personal in-depth interviews with twenty-four practitioners show that although considerable importance is attached to qualitative aspects of materiality, professional judgment is applied to establish quantitative materiality thresholds. Practitioners in Malta do not seem to treat materiality uniformly, with various materiality thresholds applied in practice. Nevertheless, prescriptive guidelines are not advisable. The proposal of disclosing materiality thresholds to reduce the omnipresent expectations gap was strongly rejected. It is the authors’ view that such disclosures, need to be adequately regulated and users would need a proper understanding of materiality and audit methodologies.peer-reviewe

Assessment of the ecological status of Maltese coastal waters using the Rhodophyta/Phaeophyta Mean Ratio Index (R/P Rt. I.)

Macroalgae from seven sites along the rocky upper infralittoral of Malta and Gozo were sampled in the spring, summer and winter seasons of 2003 and 2004. The aim was to apply the hodophyta/Phaeophyta mean ratio index (R/P rt. I.), a biological index which makes use of macroalgae, to discriminate between the sites, which are subject to different degrees of anthropogenic stress and which were therefore expected to have a different ecological status as defined by the EU’s Water Framework Directive. The R/P rt. I. generally discriminated between sites, however, two sites gave anomalous results.peer-reviewe

Can functional groups be used to discriminate between sites along a water quality gradient in Maltese coastal waters?

This study investigates whether macroalgal functional groups can be used to distinguish between rocky shores subject to different degrees of anthropogenic stress. Macroalgae from seven sites situated along the rocky upper infralittoral (0-50 cm depth) of Malta and Gozo were seasonally sampled in 2003 and 2004. A total of 86 macroalgal species belonging to the following functional types were found: 6 articulated, 23 corticated-terete, 6 crustose, 35 filamentous and 16 foliose. The ANOSIM procedure applied to the percentage cover of each functional group detected significant differences between years, sites and seasons. The SIMPER procedure showed that the functional groups foliose, crustose and corticated-terete mostly contributed to determine the observed patterns in hierarchical groupaverage linkage cluster analysis and nMDS ordination. On the basis of the multivariate analyses made, it may be concluded that functional groups discriminated among sites.peer-reviewe

A Search for Wolf-Rayet Stars in the Small Magellanic Cloud

We conducted an extensive search for Wolf-Rayet stars (W-Rs) in the SMC, using the same interference filter imaging techniques that have proved successful in finding W-Rs in more distant members of the Local Group. Photometry of some 1.6 million stellar images resulted in some 20 good candidates, which we then examined spectroscopically. Two of these indeed proved to be newly found W-Rs, bringing the total known in the SMC from 9 to 11. Other finds included previously unknown Of-type stars (one as early as O5f?p)),the recovery of the Luminous Blue Variable S18, and the discovery of a previously unknown SMC symbiotic star. More important, however, is the fact that there does not exist a significant number of W-Rs waiting to be discovered in the SMC. The number of W-Rs in the SMC is a factor of 3 lower than in the LMC (per unit luminosity), and we argue this is the result of the SMC's low metallicity on the evolution of the most massive stars.Comment: Accepted by Astrophysical Journal. Postscript version available via ftp.lowell.edu/pub/massey/smcwr.ps.gz Revised version contains slightly revised spectral types for the Of stars but is otherwise unchange

Detection of curved lines with B-COSFIRE filters: A case study on crack delineation

The detection of curvilinear structures is an important step for various computer vision applications, ranging from medical image analysis for segmentation of blood vessels, to remote sensing for the identification of roads and rivers, and to biometrics and robotics, among others. %The visual system of the brain has remarkable abilities to detect curvilinear structures in noisy images. This is a nontrivial task especially for the detection of thin or incomplete curvilinear structures surrounded with noise. We propose a general purpose curvilinear structure detector that uses the brain-inspired trainable B-COSFIRE filters. It consists of four main steps, namely nonlinear filtering with B-COSFIRE, thinning with non-maximum suppression, hysteresis thresholding and morphological closing. We demonstrate its effectiveness on a data set of noisy images with cracked pavements, where we achieve state-of-the-art results (F-measure=0.865). The proposed method can be employed in any computer vision methodology that requires the delineation of curvilinear and elongated structures.Comment: Accepted at Computer Analysis of Images and Patterns (CAIP) 201