Biosynthesized silver nanoparticles to control fungal infections in indoor environments

Fungi grow especially in dark and moist areas, deteriorating the indoor environment and causing infections that particularly affect immunosuppressed individuals. Antimicrobial coatings have as principal objective to prevent biofilm formation and infections by incorporation of bioactive additives. In this sense, metallic nanoparticles, such as silver, have proven to be active against different microorganisms specially bacteria. Biosynthesized method is a promising environmentally friendly option to obtain nanoparticles. The aim of this research was assess the employment of plants extracts of Aloysia triphylla (cedrón), Laurelia sempervirens (laurel) and Ruta chalepensis (ruda) to obtain silver nanoparticles to be used as an antimicrobial additive to a waterborne coating formulation. The products obtained were assessed against fungal isolates from biodeteriorated indoor coatings. The fungi were identified by conventional and molecular techniques as Chaetomium globosum and Alternaria alternate. The results revealed that the coating with silver nanoparticles obtained with L. sempervirens extract at 60°C with a size of 9.8 nm was the most efficient against fungal biofilm development.Fil: Deya, Marta Cecilia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Bellotti, Natalia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentin

Landsscape diachronic reconstruction in the Tiber Delta during historical time. A holistic approach

The sensitivity of deltas in response to evolutionary factors makes them important archives of the events that occurred in the entire river basin. Detailed knowledge of the stratigraphy and morphology, combined with a set of archaeological, palaeobotanical and historical information, make possible to reconstruct the diachronic changes of the landscape in the Tiber delta plain over the past 3000 years taking into account natural and anthropic forcing. The main factors that contributed to the delta landscape change are considered following a temporal scansion. Among the natural factors, we considered climate, sea level rise, tectonic and local subsidence. Among the human factors we considered the population density and several human activities, such as farming and breeding practices, reclamation, construction of ports, canals and salt works. To evaluate the amount of sediment involved in the delta evolution during different periods, the BQART model was used. Prior to Roman times anthropogenic forcing had a lower influence than natural forcing on the landscape evolution. During the Roman period (between third century BC-fourth century AD), the delta landscape was severely conditioned by the human activity. Throughout the Middle Ages and until the first half of the nineteenth century, a more natural landscape evolved in the delta, gradually and partially replacing the previous landscape. With the arrival of the new Italian State a new and impressive landscape change occurred. The evolution of the Tiber delta landscape appear particularly affected by anthropogenic forcing when socio-political organization allowed the control and planning of policy actions

Natural and anthropogenic forcing during the last two centuries in Ombrone Delta (Southern Tuscany - Central Italy)

This study describes advances in understanding of the recent evolution of the Ombrone River delta. Several aspects have been studied and updated: the stages of progradation and retreat of the shoreline from the Middle Ages, with particular reference to the last 200 years, have been reconstructed and the natural and/or human forcing responsible for the area’s evolution have been hypothesized. The processes that led to the formation and evolution of some small coastal lakes and the more recent evolution of the shoreline are defi ned. Monitoring of shoreline variations in the Ombrone Delta apex has been achieved by comparing aerial photos acquired in 1995, 1998, 2004, 2006 and 2010. The progressive landward migration of the shoreline has resulted in a realignment of the coast. Comparison with older erosion and progradation rates shows decreasing erosion rates along the delta apex with time: the erosion rate of the northern wing has reached peaks of around 14 m/yr (2004-2006), and then fallen to 4.5 m/yr in the latest period (2006-2010). The Ombrone River delta is characterized by the presence of beach ridges, ponds and, in the past, of a coastal lake. Morpho- bathymetric analysis and comparison with historical maps shows that during the XIX century, the historical lake preserved its geometry; only in the 1883 map seaward side presents an irregular geometry, while in the 1929 map the ponds have been represented for the fi rst time and are located seaward with respectto the XIX century beach ridge. Comparing morpho-bathymetric data of Chiaro Grande pond and submerged apical mouth, this study confi rmed the hypothesisabout Chiaro Grande pond genesis in which its formation is based on the closure of a narrow sea stretch consequent to the emergence of a bar. The independence between the genesis of ponds and lake evolution, highlighting the importance of mouth bar growth as a recurrent mechanism for confi ning narrow sea stretches. The orientation of morphological features and the prevailing wave climate suggest a sediment transport from south to north