The COST292 experimental framework for TRECVID 2007

In this paper, we give an overview of the four tasks submitted to TRECVID 2007 by COST292. In shot boundary (SB) detection task, four SB detectors have been developed and the results are merged using two merging algorithms. The framework developed for the high-level feature extraction task comprises four systems. The first system transforms a set of low-level descriptors into the semantic space using Latent Semantic Analysis and utilises neural networks for feature detection. The second system uses a Bayesian classifier trained with a “bag of subregions”. The third system uses a multi-modal classifier based on SVMs and several descriptors. The fourth system uses two image classifiers based on ant colony optimisation and particle swarm optimisation respectively. The system submitted to the search task is an interactive retrieval application combining retrieval functionalities in various modalities with a user interface supporting automatic and interactive search over all queries submitted. Finally, the rushes task submission is based on a video summarisation and browsing system comprising two different interest curve algorithms and three features

COST292 experimental framework for TRECVID 2008

In this paper, we give an overview of the four tasks submitted to TRECVID 2008 by COST292. The high-level feature extraction framework comprises four systems. The first system transforms a set of low-level descriptors into the semantic space using Latent Semantic Analysis and utilises neural networks for feature detection. The second system uses a multi-modal classifier based on SVMs and several descriptors. The third system uses three image classifiers based on ant colony optimisation, particle swarm optimisation and a multi-objective learning algorithm. The fourth system uses a Gaussian model for singing detection and a person detection algorithm. The search task is based on an interactive retrieval application combining retrieval functionalities in various modalities with a user interface supporting automatic and interactive search over all queries submitted. The rushes task submission is based on a spectral clustering approach for removing similar scenes based on eigenvalues of frame similarity matrix and and a redundancy removal strategy which depends on semantic features extraction such as camera motion and faces. Finally, the submission to the copy detection task is conducted by two different systems. The first system consists of a video module and an audio module. The second system is based on mid-level features that are related to the temporal structure of videos

The COST292 experimental framework for TRECVID 2007

In this paper, we give an overview of the four tasks submitted to TRECVID 2007 by COST292. In shot boundary (SB) detection task, four SB detectors have been developed and the results are merged using two merging algorithms. The framework developed for the high-level feature extraction task comprises four systems. The first system transforms a set of low-level descriptors into the semantic space using Latent Semantic Analysis and utilises neural networks for feature detection. The second system uses a Bayesian classifier trained with a "bag of subregions". The third system uses a multi-modal classifier based on SVMs and several descriptors. The fourth system uses two image classifiers based on ant colony optimisation and particle swarm optimisation respectively. The system submitted to the search task is an interactive retrieval application combining retrieval functionalities in various modalities with a user interface supporting automatic and interactive search over all queries submitted. Finally, the rushes task submission is based on a video summarisation and browsing system comprising two different interest curve algorithms and three features

Review of the herpetofauna of Attica, mainland Greece

Although the insular distribution of the rich herpetofauna of Greece has been studied more extensively, the mainland one is still underexplored. The region of Attica in central Greece represents one of these “black spots” in the mainland. Thus, in 2019 we surveyed for the first time the herpetofauna of Attica in a systematic way. We collected 794 field records of 31 species (4 amphibians, 27 reptiles); Testudo graeca and Trachemys elegans were documented for the first time for Attica. © 2021 Osterreichische Gesellschaft fur Herpetologie e.V.. All rights reserved

A rare case of saurophagy by scolopendra cingulata (Chilopoda: Scolopendridae) in the central aegean archipelago: A role for insularity?

Centipedes feed mainly on insects and other invertebrates. However, they may occasion-ally enhance their diet with small vertebrates. Lizard consumption by centipedes is rather rare. Here, we report an incident of saurophagy by the most common Mediterranean scolopendrid, Scolopendra cingulata, on the Aegean wall lizard, Podarcis erhardii. Island particularities may trigger such behaviours that could be more frequent than previously thought. © 2020, Lithuanian Nature Research Centre. All rights reserved

Living in sympatry: The effect of habitat partitioning on the thermoregulation of three Mediterranean lizards

The ability for effective, accurate and precise thermoregulation is of paramount importance for ectotherms. Sympatric lizards often partition their niche and select different microhabitats. These microhabitats, however, usually differ in their thermal conditions and lizards have to adapt their thermoregulation behavior accordingly. Here, we evaluated the impact of habitat partitioning on the thermal biology of three syntopic, congeneric lacertids (Podarcis peloponnesiacus, P. tauricus and P. muralis) from central Peloponnese, Greece. We assessed thermoregulation effectiveness (E) using the three standard thermal parameters: body (Tb), operative (Te) and preferred (Tpref) temperatures. We hypothesized that the microhabitats used by each species would differ in thermal quality. We also predicted that all species would effectively thermoregulate, as they inhabit a thermally challenging mountain habitat. As expected, the partition of the habitat had an effect on the thermoregulation of lizards since microhabitats had different thermal qualities. All three species were effective and accurate thermoregulators but one of them achieved smaller E values as a result of the lower Tb in the field. This discrepancy could be attributed to the cooler (but more benign) thermal microhabitats that this species occupies. © 2017 Elsevier Lt

First record of stellagama stellio (Squamata: Agamidae) from Karpathos Island, Greece

In this note we report for the first time the occurrence of the Roughtail Rock Agama (Stellagama stellio) from Kaprathos Island, Greece. Greece represents the westernmost range limit of the animal and hosts its only European populations. Although Karpathos is a relatively well-studied island in terms of its herpetofauna, this is the second remarkable herpetological finding within the past year, following the rediscovery of the Grass Snake more than 50 years after it was first described from the island. This report for S. stellio expands the range of the species and it is added to a long series of new records in the Greek herpetofauna that occurred during the last few years. © 2020 Folium Publishing Company

Diet composition of the Karpathos marsh frog (Pelophylax cerigensis): what does the most endangered frog in Europe eat?

Composición de la dieta de la rana de Kárpatos (Pelophylax cerigensis): ¿qué come la rana más amenazada de Europa? La rana de Kárpatos (Pelophylax cerigensis) es considerada la rana más amenazada de Europa. Aquí evaluamos su ecología alimentaria y examinamos 76 individuos de las dos poblaciones conocidas usando el método del lavado de estómago. También medimos el peso corporal, la longitud desde el hocico hasta la cloaca y el ancho de la boca de las ranas y el ancho y largo de las presas. La dieta de Pelophylax cerigensis, compuesta principalmente por Coleoptera, Aranean, Isopoda e Hymenoptera, es similar a la de otras especies de ranas verdes de las zonas adyacentes. Las dos poblaciones difieren en el tamaño corporal, pero presentan valores similares de abundancia y frecuencia de presas. Parece que P. cerigensis sigue una estricta estrategia de alimentación. El estudio de la disponibilidad de presas en sus hábitats aportará información valiosa.Composición de la dieta de la rana de Kárpatos (Pelophylax cerigensis): ¿qué come la rana más amenazada de Europa? La rana de Kárpatos (Pelophylax cerigensis) es considerada la rana más amenazada de Europa. Aquí evaluamos su ecología alimentaria y examinamos 76 individuos de las dos poblaciones conocidas usando el método del lavado de estómago. También medimos el peso corporal, la longitud desde el hocico hasta la cloaca y el ancho de la boca de las ranas y el ancho y largo de las presas. La dieta de Pelophylax cerigensis, compuesta principalmente por Coleoptera, Aranean, Isopoda e Hymenoptera, es similar a la de otras especies de ranas verdes de las zonas adyacentes. Las dos poblaciones difieren en el tamaño corporal, pero presentan valores similares de abundancia y frecuencia de presas. Parece que P. cerigensis sigue una estricta estrategia de alimentación. El estudio de la disponibilidad de presas en sus hábitats aportará información valiosa.The Karpathos marsh frog (Pelophylax cerigensis) is considered the most endangered frog in Europe. Here we assess its feeding ecology and examine 76 individuals from the two known populations using the stomach flushing method. We also measured body weight, snout–vent length, mouth width and prey width and length. Pelophylax cerigensis follows the feeding pattern of green frogs of the adjacent areas, with Coleoptera, Araneae, Isopoda and Hymenoptera being the main prey groups. The two populations differed in body size but had similar values of prey abundance and frequency. It seems that P. cerigensis follows a strict feeding strategy. Further research on prey availability in its habitats will provide valuable insight

Effective thermoregulation in a newly established population of Podarcis siculus in greece: A possible advantage for a successful invader

Temperature affects all aspects of reptilian biology. In order to colonize new habitats and support viable populations lizards have to successfully deal with their thermal environment. Podarcis siculus is a notorious example of a successful colonizer that has invaded numerous habitats outside its natural distribution range. Though certain features of its thermal biology have been assessed so far, the thermoregulatory abilities of the species remain poorly described. Here we investigated a recently discovered population in Greece and evaluated the effectiveness of thermoregulation measuring three main thermal parameters: set-point range, operative and field body temperatures. The Greek P. siculus appear to be accurate, precise and effective thermoregulators achieving E = 0.96. This effective thermoregulation may be used to explain, among other special characteristics, its spreading success. © Firenze University Press

Sex does not affect tail autotomy in lacertid lizards

Caudal autotomy is one of the most effective and widespread defensive mechanisms among lizards. When predators grasp the tail, lizards are able to shed it from the point of the attack and further. Numerous factors have been reported to affect tail-shedding performance such as temperature, age, predation pressure, intraspecific competition etc. Interestingly, the impact of sex on tail loss remains greatly understudied. Here, we analyzed tail autotomy performance, simulated in the lab, in 12 species of lacertid lizards belonging to five genera (Algyroides, Anatololacerta, Hellenolacerta, Ophisops, Podarcis). Our aim was to investigate whether sex affects caudal autotomy and/or the duration of post-autotomic tail movement. We failed to detect any effect of sex on tail loss in the species examined. Also, we did not find any sexual impact on the duration of tail movement after autotomy, with a single exception. Our findings suggest that autotomy serves as a defensive tactic equally in both sexes and is used in the same extent. © Firenze University Press