Green infrastructure design for the containment of biological invasions. Insights from a peri-urban case study in Rome, Italy.

Secondary shrublands and transitional woodland/shrub formations are recognised to be particularly susceptible to plant invasions, one of the main global threats to biodiversity, especially in dynamic peri-urban landscapes. Urban fringes are in fact often the place for the sprawl of artificial surfaces, fragmentation of habitats, and complex land transitions (including both agriculture intensification and abandonment), which in turn increase propagule pressure of exotic species over residual semi-natural ecosystems. Within this framework, the present study was aimed at analysing i) how landscape composition and configuration affect the richness of woody exotic species in shrubland and transitional woodland/shrub patches, and ii) how this threat can be addressed by means of green infrastructure design in a peri-urban case study (Metropolitan City of Rome, Italy). Accordingly, the occurrence of exotic plants was recorded with field surveys and then integrated with landscape analyses, both at patch level and over a 250 m buffer area around each patch. Thus, the effect of landscape features on exotic plant richness was investigated with Generalised Linear Models, and the best model identified (pseudo R-square = 0.62) for inferring invasibility of shrublands throughout the study area. Finally, a Green Infrastructure (GI) to contain biological invasion was planned, based on inferred priority sites for intervention and respective, site-tailored, actions. The latter included not only the removal of invasive woody alien plants, but also reforestation and planting of native trees for containment of dispersal and subsequent establishment. Even though specifically developed for the study site, and consistent with local government needs, the proposed approach represents a pilot planning process that might be applied to other peri-urban regions for the combined containment of biological invasions and sustainable development of peripheral complex landscapes.

An unknown hotspot of plant diversity in the heart of the Central Apennine: flora and vegetation outline of Mt. Pozzoni-St. Rufo valley (Cittareale, Rieti).

Surprisingly enough, Italy still has some botanically unexplored areas; among these there are some territories between Lazio, Umbria and Abruzzo not included in any protected area. The study area, ranging for 340 ha, includes the mountainous area of Mt. Pozzoni-Mt. Prato-St. Rufo valley, which forms the upper part of the river Velino basin, located in the territory of the municipality of Cittareale (Rieti, Lazio), at an elevation from 1150 to 1903 m a.s.l. The substrate is mainly made of marly limestone of the Meso-Cenozoic Umbria-Marche sedimentary succession. The climate is Temperate and comprises vegetation belts from the montane to sub-alpine. Land cover is dominated by pastures and deciduous forests, with only a few hay meadows. 794 entities have been detected: 16% are considered rare or very rare for the regional territory with several floristic novelties for the regional flora, 6% of the total was found to be endemic to Italy and only eight taxa were aliens. Four taxa are new for the regional flora of Lazio: Arum cylindraceum, Alopecurus pratensis subsp. pratensis, Hieracium bupleuroides and Trinia glauca subsp. glauca. Forest vegetation is represented by beech forests, while dry grasslands are the most widespread vegetation type. The greatest phytocoenotic diversity was found within the secondary pastures. Particularly interesting is the plant community with Iris marsica, which suggests that limestone mountain ledges can represent a primary habitat for this endemic species of the Central Apennine. The presence of several habitats listed in the EU Habitat Directive indicates how the lack of detailed territorial knowledge can lead to the non-designation of conservation sites in areas of high naturalistic value. These findings showed that botanical explorations in territories which are still not known could contribute significantly to the identification of areas of high interest in conserving plant diversity.

Novel Nano-Liposome Formulation for Dry Eyes with Components Similar to the Preocular Tear Film.

Dry eye is commonly treated with artificial tears; however, developing artificial tears similar to natural tears is difficult due to the complex nature of tears. We characterized and evaluated a novel artificial tear formulation with components similar to the lipid and aqueous constituents of natural tears. Nano-liposomes, composed in part of phosphatidylcholine, were dispersed in an aqueous solution of bioadhesive sodium hyaluronate. Liposome size, zeta potential, and physicochemical properties of the fresh and stored (4 °C) liposomal formulation were analyzed. In vitro tolerance was tested using human corneal and conjunctival cell lines by exposures of 15 min to 4 h. The tolerance of the liposomal formulation was evaluated in animals (rabbits). The average liposome size was 186.3 ± 7.0 nm, and the zeta potential was negative. The osmolarity of the formulation was 198.6 ± 1.7 mOsm, with a surface tension of 36.5 ± 0.4 mN/m and viscosity of 3.05 ± 0.02 mPa·s. Viability values in the human corneal and conjunctival cell lines were always >80%, even after liposomal formulation storage for 8 weeks. Discomfort and clinical signs after instillation in rabbit eyes were absent. The new formulation, based on phosphatidylcholine-liposomes dispersed in sodium hyaluronate has suitable components and characteristics, including high in vitro cell viability and good in vivo tolerance, to serve as a tear substitute.

Design and characterization of an ocular topical liposomal preparation to replenish the lipids of the tear film.

PURPOSE: Dry eye (DE) includes a group of diseases related to tear film disorders. Current trends for DE therapy focus on providing lipid components to replace the damaged lipid layer. Formulations that contain aqueous and mucin-like compounds may have additional therapeutic benefits for DE patients. The aim of this work was to design and evaluate novel formulations having the potential to become topical treatment for DE. METHODS: Unpreserved liposomal formulations composed of phosphatidylcholine (PC), cholesterol, and α-tocopherol (vit E) were prepared by the thin-film hydration technique. Formulations were characterized in terms of liposome size, pH, surface tension, osmolarity, and viscosity. In vitro tolerance assays were performed on macrophage, human corneal, and conjunctival cell lines at short- and long-term exposures. In vivo ocular tolerance was studied after instillation of the formulation. RESULTS: The mean liposome size was less than 1 µm and surface tension < 30 mN/m for all formulations. The final liposomal formulation (PC-cholesterol-vit E in a ratio of 8:1:0.8) had physiological values of pH (6.45 ± 0.09), osmolarity (289.43 ± 3.28 mOsm), and viscosity (1.82 ± 0.02 mPa · s). Cell viability was greater than 80% in the corneal and conjunctival cells. This formulation was well tolerated by experimental animals. CONCLUSIONS: The unpreserved liposomal formulation has suitable properties to be administered by a topical ophthalmic route. The liposome-based artificial tear had good in vitro and in vivo tolerance responses. This formulation, composed of a combination of liposomes and bioadhesive polymers, may be used successfully as a tear film substitute in DE therapy.

Effect of corneal thickness on dynamic contour, rebound, and goldmann tonometry.

PURPOSE: To identify correlations among intraocular pressure (IOP) measurements obtained using the rebound tonometer (RBT), the dynamic contour tonometer (DCT), and the Goldmann applanation tonometer (GAT). The effects of corneal thickness on the measures obtained using each of the 3 tonometers also were examined. DESIGN: Cross-sectional study. PARTICIPANTS: One hundred forty-six eyes of 90 patients with ocular hypertension or glaucoma. METHODS: Intraocular pressure measurements were obtained in all patients using RBT, DCT, and GAT. Central corneal thickness was determined by ultrasound pachymetry. Patients were divided randomly into 6 groups to vary the order in which the tonometers were used. All IOP measurements were made by the same examiner, who was masked to the readings obtained. MAIN OUTCOME MEASURES: Intraocular pressure and central corneal thickness. RESULTS: There was good correlation between IOP readings obtained using the RBT and GAT (r = 0.864; P<0.0001), between DCT and GAT (r = 0.871; P<0.0001), and between RBT and DCT (r = 0.804; P<0.0001). Rebound tonometer and DCT readings consistently were higher than GAT measurements (RBT-GAT median difference, 1.4+/-2.7 mmHg; DCT-GAT median difference, 4.4+/-2.6 mmHg). A Bland-Altman plot indicated that the 95% limits of agreement between RBT and GAT were -4.3 to 6.4 mmHg (slope = 0.056; P = 0.218), those between DCT and GAT were -0.7 to 9.5 mmHg (slope = 0.016; P = 0.717), and those between RBT and DCT were -3.1 to 9.8 mmHg (slope = -0.041; P = 0.457). Using RBT, the point that best discriminated between patients with an IOP 21 mmHg or less and more than 21 mmHg as determined by GAT was >23.3 mmHg (sensitivity, 66.7%; specificity, 92.1%); using DCT, this point was >22.7 mmHg (sensitivity, 95.6%; specificity, 71.3%). In terms of pachymetry, GAT and RBT behaved similarly. Using these instruments, differences of approximately 3 mmHg were detected between the groups of patients with the thinnest (<531 mum) and thickest (>565 mum) corneas, whereas a significantly lower difference (0.5 mmHg) was noted for the DCT. CONCLUSIONS: Measurements obtained both with the RBT and DCT show excellent correlation with those provided by applanation tonometry. Both tonometers tend to overestimate the IOP measured with the GAT, particularly the DCT. This last tonometer seems to be less affected by the corneal thickness.

Contrast sensitivity and disability glare in patients with dry eye.

PURPOSE: To evaluate contrast sensitivity and disability glare in patients with dry eye using the Contrast Glaretester 1000. METHODS: Contrast sensitivity and disability glare were determined in 33 eyes of 33 patients with dry eye and 30 eyes of 30 healthy control subjects for six target sizes with a visual angle of 6.3-0.7 degrees using the Contrast Glaretester 1000, whose working mechanism is similar to that of the conventional perimetry instrument. RESULTS: Contrast sensitivity was significantly worse in dry eye group when viewing all target sizes (reduction of 0.10-0.25 log contrast units, p < 0.01) except at 6.3 degrees. In the presence of glare, differences in log contrast sensitivity between the groups (0.10-0.25 units) were significant (p < 0.01) for all target sizes, with the dry eye group showing worse results. The reduction in contrast sensitivity induced by glare (disability glare) was significantly worse in the dry eye group versus the control group but only for the 2.5-degree size target, where 0.14 log contrast units were lost. CONCLUSIONS: Contrast sensitivity with and without glare was significantly reduced in patients with dry eye compared with control subjects, but the number of log contrast units lost with glare (disability glare) was similar in the two groups, except for the 2.5-degree size target.