Botanica applicata nei progetti di infrastrutture viarie

La progettazione di un’infrastruttura viaria è sottoposta come noto a procedura di Valutazione di Impatto Ambientale (VIA) nelle fasi di progetto preliminare e di progetto definitivo, in cui vengono principalmente: • messi a confronto i beni ambientali con le ipotesi di progetto dell’infrastruttura; • individuati i potenziali impatti e introdotte le opportune modifiche migliorative (tracciato, opere d’arte); • progettati gli interventi di mitigazione degli impatti residui. Di tutti i settori di analisi ambientale, risulta particolarmente importante quello botanico (flora e vegetazione) per le implicanze applicative negli interventi di mitigazione a verde e interventi di Ingegneria Naturalistica connesse con il progetto dell’infrastruttura

Floristic analysis of a high-speed railway embankment in a Mediterranean landscape

We analyzed the floristic composition of a 4.5 km-long segment of a high-speed railway in Lazio, central Italy, which travels on an artificial embankment through an intensively-farmed landscape. In total, 287 vascular plant species were recorded. The life-form distribution was found to be similar to that of the regional species pool, with high percentages of therophytes (38%) and phanerophytes (13%). In the chorological spectrum the Mediterranean floristic element prevailed (44%), while alien species were 8% of the flora. The phytosociological spectrum showed a high diversity of characteristic species from the class Stellarietea mediae or its subordinate syntaxa (26%), and in particular from the order Thero-Brometalia (Mediterranean, sub-nitrophilous annual communities). Species from forest syntaxa had a relatively high diversity (9%). These results suggest that the ecological filtering provided by the Mediterranean regional climate controlled species assemblage even in a completely artificial habitat, preventing floristic homogenization: the flora of the studied railway section is only partially »ruderalized«, while it keeps strong links with the regional (semi-) natural plant communities. However, in contrast to what is observed in central and north Europe, the railway sides studied in the present paper do not seem to represent a refugial habitat for rare species from grassland communities, mainly because in Italy semi-natural dry grasslands are still widely represented

Influence of bone density on implant stability parameters and implant success: a retrospective clinical study

<p>Abstract</p> <p>Background</p> <p>The aim of the present clinical study was to determine the local bone density in dental implant recipient sites using computerized tomography (CT) and to investigate the influence of local bone density on implant stability parameters and implant success.</p> <p>Methods</p> <p>A total of 300 implants were placed in 111 patients between 2003 and 2005. The bone density in each implant recipient site was determined using CT. Insertion torque and resonance frequency analysis were used as implant stability parameters. The peak insertion torque values were recorded with OsseoCare machine. The resonance frequency analysis measurements were performed with Osstell instrument immediately after implant placement, 6, and 12 months later.</p> <p>Results</p> <p>Of 300 implants placed, 20 were lost, meaning a survival rate of %. 93.3 after three years (average 3.7 ± 0.7 years). The mean bone density, insertion torque and RFA recordings of all 300 implants were 620 ± 251 HU, 36.1 ± 8 Ncm, and 65.7 ± 9 ISQ at implant placement respectively; which indicated statistically significant correlations between bone density and insertion torque values (p < 0.001), bone density and ISQ values (p < 0.001), and insertion torque and ISQ values (p < 0.001). The mean bone density, insertion torque and RFA values were 645 ± 240 HU, 37.2 ± 7 Ncm, and 67.1 ± 7 ISQ for 280 successful implants at implant placement, while corresponding values were 267 ± 47 HU, 21.8 ± 4 Ncm, and 46.5 ± 4 ISQ for 20 failed implants; which indicated statistically significant differences for each parameter (p < 0.001).</p> <p>Conclusion</p> <p>CT is a useful tool to determine the bone density in the implant recipient sites, and the local bone density has a prevailing influence on primary implant stability, which is an important determinant for implant success.</p

Field studies on the soil loss reduction effectiveness of three biodegradable geotextiles

Biodegradable geotextiles have the potential to significantly reduce soil loss and ensure slope stability in areas at risk. Here, we focus on three biodegradable textiles (namely, jute net, jute mat, and wool mat), and study their response in terms of soil loss to diverse precipitation events (average rainfall intensity from 3.7 mmh−1 to 70 mmh−1 and duration from 0.5 h to 11.6 h). Experiments are conducted in an ad hoc developed outdoor steep slope (more than 60%). Soil loss reduction from the treatments is found to be very remarkable (up to 98%), thus supporting the potential of natural materials for soil conservation. Also, experimental findings confirm that the maximum intensity of rainfall events plays an important role in driving soil erosion

Bone remodeling around implants placed in fresh extraction sockets.

Abstract: The aim of the present experimental study was to evaluate the physiologic bone remodeling in beagle dogs following the placement of small-diameter (3.25 mm) implants in fresh extraction sites. Five 1-year-old beagle dogs that weighed approximately 10 to 13 kg each were used in this study. The third and fourth premolars (P3, P4) were used as experimental teeth, which were hemisected using a fissure bur; the distal roots were removed carefully using forceps. Implants (3.25-mm wide, 10- or 11.5-mm long) were placed in the fresh extraction sockets with the neck of the implant at the level of the buccal bone crest. The dogs were subsequently put to sleep according to the following schedule: one dog 15 days after implant placement, two dogs after 1 month, and the remaining two dogs after 3 months. The distance from the implant shoulder to the bone wall crest was measured at both the buccal and lingual sites. The width of the buccolingual bone crest was measured using a caliper. Assessments were made immediately after root extraction and at 2, 4, and 12 weeks after implant placement. The mean width of the buccolingual bone crest was 4.5 +/- 0.5 mm at the time of root extraction. Subsequently, at 2, 4, and 12 weeks after implant placement, the buccolingual bone width was 4.1 +/- 0.5 mm, 3.7 +/- 0.3 mm, and 3.5 +/- 0.7 mm, respectively. Two weeks after implant placement, the lingual bone crest was measured at 0.2 +/- 0.3 mm from the implant shoulder, while the buccal bone crest was 0.3 +/- 0.3 mm. After 4 weeks of healing, the mean distance from the implant shoulder to the lingual bone crest was 0.1 +/- 0.9 mm, compared to 0.4 +/- 0.9 mm for the buccal bone crest. After 12 weeks of healing, the bone crest at the lingual sites was -0.3 +/- 0.5 mm from the implant shoulder, compared to 0.8 +/- 0.3 mm at the buccal sites. The findings from this study show that although vertical bone remodeling was indeed observed, the mean vertical buccal bone resorption was 0.5 mm. It might be suggested, therefore, that the implant position along the lingual wall and the use of implants with a narrow diameter in relation to the extraction socket width play a key role in reducing the rate of vertical bone resorption at the buccal aspect of implants placed in fresh extraction sockets. (Int J Periodontics Restorative Dent 2010;30:601-607.