14 research outputs found
Analisi del popolamento a Scarabaeoidea coprofagi del Parco Regionale della Maremma (GR)
Il presente studio, svolto all’interno del Parco Regionale della Maremma (Gr) dal Giugno 2003 al Maggio 2004, si è posto i seguenti obiettivi:
- verificare che il campione ottenuto fosse rappresentativo del popolamento analizzato;
- rilevare eventuali differenze significative tra i vari siti di campionamento;
- rilevare eventuali differenze nel funzionamento delle trappole quando esse fossero innescate con tipi diversi di sterco.
Si conclude che:
- un anno è un periodo di studio ottimale per ottenere buone indicazioni sul popolamento del gruppo sistematico studiato;
- risultati migliori si sono ottenuti nei siti in cui erano state posizionate sei trappole;
- il tipo di sterco usato per innescare le trappole non influenza significativamente la raccolta ;
- ciò che sembra influenzare maggiormente la struttura della popolazione raccolta sono invece le caratteristiche del sito di campionamento
Cumulative Annual Dung Beetle Diversity in Mediterranean Seasonal Environments
Species diversity assessments should consider the dynamic nature of ecological communities, especially in highly seasonal ecosystems. Here we provide a comprehensive framework for analysing seasonal changes in species composition, richness and diversity in two local dung beetle (Coleoptera: Scarabaeoidea: Aphodiidae, Geotrupidae, and Scarabaeidae) communities from Western Tuscany (Italy), in the Mediterranean ecoregion. We test whether, in this highly seasonal region, cumulative annual diversity is an oversimplification of well differentiated seasonal communities. Data were obtained through repeated standardised samples collected regularly over an entire year. We clearly identify different summer and winter communities at each site based on species composition and abundance. Seasonal richness and diversity values are different from the cumulative annual values, as a consequence of beta diversity between seasons, and some dung beetle species are identified as idiosyncratic of each particular season. Both ecological (niche partitioning) and biogeographical factors are suggested as drivers of these temporal variations. Thus, because local inventories of fauna that include records over long time periods actually reflect situations where coexistence and interactions are unlikely to occur, highly seasonal sites must be viewed as having temporally differentiated communities in order to reach feasible and reliable baselines for local diversity assessments. © 2011 The Ecological Society of Japan
Ossicular replacement prostheses from banked bone with ergonomic and functional geometry
This study shows the fabrication of innovative ossicular replacement prostheses (ORPs) based on banked cortical bone using computer numerically controlled ultraprecision micromilling, as a substantial improvement of "second generation" ORPs. Our aim is to combine optimal middle ear compatibility and surgical manageability in a single device, by releasing off-the-shelf homograft ORPs provided with the appealing features of synthetic ORPs, such as lightness, safety, measurement accuracy, surface decoration, and geometric plasticity. The new total ORP prototype was 13.1±0.1 mg, leading to 81% weight reduction with respect to the previous model. Surface motifs of the head plate were applied to prevent slipping and migration after surgery, as shown by finite element modeling analysis. In addition, bone ORPs were provided with holed head plates to facilitate their surgical positioning while reducing their mass. A comparative measurement of acoustic responses of bone against synthetic partial ORPs in the 250-8000 Hz frequency range demonstrated their superior behavior. This study showed that banked compact bone can be optimally manufactured, eventually enabling the fabrication of light, standardized, and highly performant ORPs. The new bone ORPs may represent the ideal combination of biocompatibility and technology which can ultimately accomplish unmet otosurgical needs