Search

Abstract: Background: Sustained left ventricular (LV) dyssynchrony can lead to heart failure (HF) in the absence of coronary artery stenosis. We tested whether myocardial hibernation underlies the LV functional impairment caused by high-frequency pacing, an established model of nonischemic dilated cardiomyopathy. Methods and Results: Regional LV contractile and perfusion reserve were assessed by magnetic resonance imaging, respectively, as end-systolic wall thickening (LVESWT) and myocardial perfusion reserve index (MPRI) at rest and during low-dose dobutamine stress (LDDS, 10 μg·kg·min intravenously for 10minutes) in failing minipigs (n=8). LV tissue was analyzed for glycogen deposits and other molecular hallmarks of hibernation. LDDS caused a marked increase in LVESWT (27±2.98 vs. 7.15±3 %, P < .05) and MPRI (2.1±0.5 vs. 1.3±0.3 P < .05) in the region that was activated first (pacing site) compared with the opposite region. Myocardial glycogen content was markedly increased in the pacing site (P < .05 vs. opposite region). In addition, gene expression of glycogen phosphorylase was reduced in pacing site compared with opposite regions (0.71±0.1 vs. 1.03±0.3, P < .05), whereas that of hexokinase type II was globally reduced by 83%. Conclusions: The combination of high heart rate and sustained dyssynchronous LV contraction causes asymmetrical myocardial hibernation, in absence of coronary artery stenosis. [Copyright &y& Elsevier]

Abstract: This work stems from the results of a recent phylogenetic investigation on the Euscorpius carpathicus species complex from the Italian peninsula (Salomone et al. 2004. Phylogenetic relationships between the sibling species Euscorpius tergestinus and E. sicanus (Scorpiones, Euscorpiidae) as inferred from mitochondrial and nuclear sequence data. In: Proceedings of the16th Congress of Arachnology, August 2–7, 2004, Ghent University, Belgium, 268pp.; Salomone et al. in prep.). Molecular investigation produced interesting and unexpected findings on the scorpion Euscorpius tergestinus (C.L. Koch, 1837). Both nuclear and mitochondrial sequence data provided evidence of substantial genetic differentiation in specimens identified as Euscorpius tergestinus according to recent taxonomical changes (Fet and Soleglad 2002. Morphology analysis supports presence of more than one species in the “Euscorpius carpathicus” complex (Scorpiones: Euscorpiidae). Euscorpius 3, 51pp.). These specimens clearly belong to two well-differentiated evolutionary lineages. Molecular results highlighted the need for a new morphological investigation. The present study undertook the morphological analysis of specimens belonging to both genotypes with the aim of identifying morphological characteristics able to discriminate between the two taxa. The analysis of trichobothria patterns, morphometric ratios, granulation patterns and the observation of the pectinal sensilla confirm the difficulty in distinguishing these two genotypes and the high polymorphism of the subgenus Euscorpius Thorell, 1876. The length of pedipalp segments and dorsal patellar spurs (DPS), as well as femur leg granulation, are the main diagnostic characters; other ratios together with body color also help to distinguish the different genotypes. This study confirms the presence in Italy of two different cryptic species belonging to the “Euscorpius tergestinus” complex. Euscorpius tergestinus is a reddish, slender euscorpiid with a large dorsal patellar spine (DPS). A darker and generally squat phenotype with a short DPS, which corresponds to Euscorpius carpathicus concinnus sensu Caporiacco (1950), is elevated to the species level: Euscorpius concinnus (C.L. Koch, 1837). These two species are sympatric in several Italian regions, and their distribution pattern is possibly determined by intraguild predaction interaction. [Copyright &y& Elsevier]

Soils in clay pigeon shooting ranges can be seriously contaminated by heavy metals. The pellets contained in ammunition are composed of Pb, Sb, Ni, Zn, Mn and Cu. The total concentrations of these metals in soils, and the effects of their increasing levels on the arthropod community were investigated at seven sampling sites in a clay pigeon shooting range and compared with two controls. Research revealed that the spatial distribution of Pb and Sb contamination in the shot-fall area was strongly correlated with the flight path of the pellets. Ordination obtained through Redundance Analysis showed that Collembola, Protura and Diplura were positively correlated with major detected contaminants (Pb, Sb), while Symphyla showed a negative correlation with these pollutants. Determination of the soluble lead fraction in soil, and of its bioaccumulation in the saprophagous Armadillidium sordidum (Isopoda) and the predator Ocypus olens (Coleoptera), showed that a significant portion of metallic Pb from spent pellets is bioavailable in the soil and can be bioaccumulated by edaphic organisms, entering the soil trophic network, but without biomagnification. [Copyright &y& Elsevier]

Abstract: The oribatid mite Carabodes reticulatus Berlese, 1913 is redescribed from typical and topotypical material. A new species, C. tyrrhenicus, widespread in Sardinia and other Tyrrhenian islands, is also described on the basis of morphological evidence. Scanning electron microscopy was used to study intra- and inter-specific variation, in order to determine diagnostic characters. The morphology-based taxonomy was tested through allozyme analysis of the two species and of two closely related species, namely C. coriaceus C. L. Koch, 1836 and C. arduinii Valle, 1955. Allozyme data are largely congruent with morphological evidence, indicating that the four entities represent well-differentiated evolutionary lineages. Molecular results show large inter-specific genetic differentiation, suggesting that these taxa arose from ancient cladogenetic events. [Copyright &y& Elsevier]

Abstract: The effects of spatial scale on the assessment of soil biodiversity were investigated through a field study conducted in the Pelagian Islands, Sicilian Channel, southern Mediterranean. The oribatid mite community in this archipelago was investigated from both an ecological and a biogeographical point of view. The following hierarchically nested spatial scales were considered: 1—archipelago (γ-diversity); 2—island (α- and β-diversity between the islands); 3—sites (α- and β-diversity within each island). Quantitative and semi-quantitative soil sample replicates were collected during the wet season (autumn, 1999) in Lampedusa and Linosa, the two major islands of the archipelago. Data revealed that the sample α-diversity of the two islands is similar. The density of species followed a geometrical trend (a few dominant species with the remainder fairly uncommon) typical of communities in which a single environmental factor dominates species ecology. Community structure differed significantly between the two islands. Species turnover (β-diversity) was very high at every spatial scale, from the sites to the archipelago. Biogeographical results highlighted great differences between faunas in the two islands. The formulation of hypotheses for biodiversity patterns is strongly scale dependent: the heuristic and conservation value of the biogeographical approach increases from local to regional scales, because the importance of historical factors increases while that of ecological factors decreases. [Copyright &y& Elsevier]

Oribatid mite and Carabid beetle communities were investigated at five sites in the ‘Pietraporciana’ and ‘Lucciolabella’ Nature Reserves (central Italy). In this part of southern Tuscany many attempts have been made to encourage the regeneration of native habitats and to preserve existing ones. Human-induced changes in the original forest landscape have had a direct impact on mite and carabid populations. Significant differences in species diversity and abundance among different sites were revealed throughout the sampling period. Species richness, abundance and diversity of oribatid mites decrease from woodland sites to open habitats where evenness was high. There is an inverse trend between the number of species and richness of carabid beetles and those of oribatid mites. Canonical correspondence analysis (CCA) of oribatid and carabid beetle compositions discriminated the sites, demonstrating how even small areas with different vegetation, composition, structure, environment and microclimate were characterised by distinct edaphic populations. [Copyright &y& Elsevier]

Abstract: This paper presents a multiple channel, bidirectional and implantable biotelemetric platform, suitable for real time in vivo monitoring of several physiological parameters. This system consists of an implantable unit, an external host and a user terminal. The ZigBee wireless technology, functioning as telemetric link, enables long battery lifetime and offers the opportunity to build up complex wireless networks of implantable and wearable sensors. A smart Analog Front End, that allows a real time optimization of the signals output dynamics, is also described. Different kinds of sensors, ranging from resistive to current or voltage output sensors, can be directly connected to the front end. The firmware code of the implanted unit can be reprogrammed through the telemetric link, thus enabling active interactions between the system and the end user. For the code development, particular attention was devoted to reducing power consumption: a theoretical maximum battery life of several years, suitable for chronic implants, can be achieved. In order to validate the platform, a ZigBee point to point wireless connection between the implant and the external unit was implemented. Two different sensors were used, i.e. a temperature sensor and a pressure transducer. The system performances were assessed through several in vivo tests. In particular, aortic and ventricular real time pressure and temperature monitoring are reported with the system implanted in farm pigs. Data acquisition was validated by comparison with medical golden standard for pressure monitoring. Finally, the lowest level of transmission power required to establish a reliable communication by using a ZigBee compliant hardware implanted under skin has been quantified as 13.33μW during an in vivo experiment in an anesthetized pig. This value is fully compliant with the reference level for general public exposure to time varying electric and magnetic fields. [Copyright &y& Elsevier]

Summary: Clay pigeon shooting ranges can be an important source of heavy metal contamination in terrestrial ecosystems. The pellets contained in spent ammunition are mainly composed of lead (Pb) and antimony (Sb). Total concentrations of these metals were measured in soils from seven sampling sites within a clay pigeon shooting range and compared with two controls to investigate the effects of their increased levels on the oribatid mites and Collembola community. We found that the spatial distribution of Pb and Sb contamination in the fall-out area is strongly related to the flight path of pellets. Oribatid and Collembola communities are able to survive at levels of heavy metals far higher than the lethal concentration for the most tolerant plants but oribatid mites seem to be affected by heavy metals more than springtails. Collembola and oribatid mites exhibit a wide range of responses to disturbance and many species are more strongly influenced by microhabitat characteristics than levels of pollution. The effects of annual cultivations conducted in the shooting range and those of heavy metal pollution result in a simplification and homogeneity of community composition. Among arthropods, oribatid mites and springtails have a great potential as bioindicators of environmental conditions; the issue remains as to whether differences in population structure can be used to determine the type of disturbance. [Copyright &y& Elsevier]