Swimming speed alteration of larvae of Balanus Amphitrite as a behavioural end-point for laboratory toxicological bioassays

In this study, we investigate the feasibility of developing a new behavioural toxicity bioassay (Swimming Speed Alteration test—SSA test) with larvae of Balanus amphitrite (Crustacea Cirripedia). This organism was chosen as a model for different reasons: it is present all over the world, simple to be reared, easily available, and also because barnacles play an important role in the coastal ecosystem. In addition, all the operations related to the rearing and test execution are comparatively cheap. This bioassay was performed with several classes of chemical pollutants (antifouling biocides, neurotoxic pesticides, and heavy metals) and with environmental samples (sediment elutriates). The measurement of swimming speed, by means of video-graphic techniques, proved to be a valid instrument in highlighting the sub-lethal levels of toxicity caused by the different tested samples. In conclusion, the SSA test is able to provide in a biomonitoring program a good behavioural integrated output, which is also repeatable, sensitive, easily interpretable, and truly representative of a broad range of toxic compounds and environmental toxic matrices which are, generally, very complex and difficult to analyse. For all of these reasons, it could be proposed as a non-specific behavioural end-point. Physical and Chemical Impacts on Marine Organisms, a Bilateral Seminar Italy-Japan held in November 2004.     

Opposable spines facilitate fine and gross object manipulation in fire ants

Ants inhabit diverse terrestrial biomes from the Sahara Desert to the Arctic tundra. One factor contributing to the ants’ successful colonization of diverse geographical regions is their ability to manipulate objects when excavating nests, capturing, transporting and rendering prey or grooming, feeding and transporting helpless brood. This paper is the first to report the form and function of opposable spines on the foretarsi of queens and workers used during fine motor and gross motor object manipulation in the fire ant, Solenopsis invicta. In conjunction with their mandibles, queens and workers used their foretarsi to grasp and rotate eggs, push or pull thread-like objects out of their way or push excavated soil pellets behind them for disposal by other workers. Opposable spines were found on the foretarsi of workers from seven of eight other ant species suggesting that they might be a common feature in the Formicidae.     

A Comparative Study Between Bio-composites Obtained with Opuntia ficus indica Cladodes and Flax Fibers

This work is aimed to study the suitability of the wooden backbone of Opuntia ficus indica cladodes as reinforcement for the production of bio-composites. The wooden backbone can be extracted from O. ficus indica cladodes, which constitute a very relevant agricultural scrap, and is characterized by a thick walled cellular structure. In view of its potential in poly-lactic acid (PLA) matrix bio-composite production, two different possible applications were examined. In the first alternative, the wooden backbone was used in replacement of flax fibers for the production of fully consolidated bio-composites. Results obtained have shown that, though being characterized by lower properties compared to those of flax fiber composites, the opuntia actually works as an efficient reinforcement for PLA/wood flour matrix, increasing the flexural strength and elongation at break. In the second alternative, the cellular structure was used for the production of a sandwich bio-composite with a PLA/wood flour skin. In this case, the very high interlaminar adhesion strength between the skin and the core was considered as an indication of the potentiality of this material for the production of high strength sandwich structures. As a confirmation of this, no interlaminar debonding was observed during short beam tests.     

Fluorine in the rocks and sediments of volcanic areas in central Italy: total content, enrichment and leaching processes and a hypothesis on the vulnerability of the related aquifers

Rock, sediment and water samples from areas characterised by hydrothermal alterations in the Sabatini and Vico Volcanic Districts, near Rome and the large city of Viterbo, respectively, were collected and analysed to determine the total fluorine (F) content and to understand the F geochemical background level in the volcanic districts of central Italy. Leaching and alteration processes controlling the high concentration of F in water were also investigated. Fluorine concentrations were directly determined (potentiometrically) by an F selective electrode in water samples, while the procedure for rock samples included preliminary F dissolution through alkaline fusion. F concentrations higher than 800 mg kg(-1) were commonly found in the analysed rocks and sediments; the concentration depended on the lithology and on the distance from the alteration areas. A specific successive sampling campaign was conducted in three areas where the F content in sediments was particularly high; in the same areas, measurements of CO(2) flux were also performed to investigate the possible deep origin of F. To verify the relationships among the high F contents in rocks and sediments, the leaching processes involved and the presence of F in the aquifer, we also collected water samples in the western sector of the Sabatini Volcanic District, where hydrothermal manifestations and mineral springs are common. The data were processed using a GIS system in which the F distribution was combined with morphological and geological observations. The main results of our study are that (1) F concentrations are higher in volcanic and recently formed travertine (especially in hydrothermally altered sediments) than in sedimentary rocks and decrease with distance from hydrothermal alteration areas, (2) F is more easily leached from hydrothermally altered rocks and from travertine and (3) sediments enriched with F may indicate the presence of deep regional fractures that represent direct pathways of hydrothermal fluids from the crust to the surface.     

Psychological consequences of prenatal diagnosis in a case of familial Angelman Syndrome

Angelman Syndrome (AS), characterized by mental retardation, absence of speech, seizures and motor dysfunction, is caused by genetic defects leading to loss of expression of the maternal copy of the chromosome 15q11–13 imprinted region. Most cases are sporadic, being caused by de novo deletion of maternal chromosome 15q11–13 (75%) or by paternal uniparental disomy (3–4%). Familial cases can occur, due to mutations in the UBE3A gene or in the imprinting center. We describe the case of a pregnant woman having two nephews with AS caused by a UBE3A mutation; lack of communication within the family led the woman to be completely unaware of the risk of disease recurrence until 15 weeks of gestation. UBE3A genetic testing revealed she carried the familial mutation 892–893delCT. Prenatal diagnosis was performed on amniotic fluid and demonstrated that the fetus had inherited the mutation. The unexpected diagnosis and the subsequent termination of the pregnancy caused the woman to undergo acute psychological distress showing relevant psychopathological symptoms. Nevertheless, at 2-year follow-up, adverse consequences were minimized, and the couple was planning a new pregnancy. Factors affecting the psychological outcome of abortion and the role of psychological support in reducing the risk of long-term unfavorable consequences are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

The alternative Pharaoh approach: stingless bees mummify beetle parasites alive

Workers from social insect colonies use different defence strategies to combat invaders. Nevertheless, some parasitic species are able to bypass colony defences. In particular, some beetle nest invaders cannot be killed or removed by workers of social bees, thus creating the need for alternative social defence strategies to ensure colony survival. Here we show, using diagnostic radioentomology, that stingless bee workers (Trigona carbonaria) immediately mummify invading adult small hive beetles (Aethina tumida) alive by coating them with a mixture of resin, wax and mud, thereby preventing severe damage to the colony. In sharp contrast to the responses of honeybee and bumblebee colonies, the rapid live mummification strategy of T. carbonaria effectively prevents beetle advancements and removes their ability to reproduce. The convergent evolution of mummification in stingless bees and encapsulation in honeybees is another striking example of co-evolution between insect societies and their parasites.