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The present study concerns the Phoenician-Punic site of Motya, a small island set in Western Sicily (Italy), in the Marsala Lagoon (Stagnone di Marsala), between Trapani and Marsala. A big disposal pit, datable to between the first half of the 8th and the mid-6th century bc, was identified in Area D. This context was sampled for plant macro-remains through bucket flotation. Palynological treatment and analysis were also performed on soil samples collected from each of the identified filling layers. The combination of the study of macro- and micro-remains has shown to be effective in answering questions concerning introduced food plants and agricultural practices, and native plants, including timber use. Here we investigate if a waste context can provide information about Phoenicians at Motya and their impact on the local plant communities. We found that human diet included cereals (mostly naked wheat), pulses and fruits. A focus was placed on weeds (including Lolium temulentum and Phalaris spp.) referable to different stages of crop processing. This aspect was enriched by the finding of cereal pollen, which suggests that threshing (if not even cultivation) was carried out on site. Palynology also indicates an open environment, with little to no forest cover, characterized by complex anthropogenic activities. Anthracology suggests the presence of typical Mediterranean plant taxa, including not only the shrubs Pistacia lentiscus and Erica multiflora, but also evergreen oaks. The presence of a stone pine nut and of Pinus pinea/pinaster in the pollen rain is noteworthy, suggesting the local occurrence of these Mediterranean pines outside their native distribution range. This represents the first such find in the central Mediterranean. Finally, the present study allows us to compare Motya’s past environment with the present one. The disappearance of Juniperus sp. and Erica arborea from the present-day surroundings of the Marsala lagoon appears to be related to land-overexploitation, aridification or a combination of both processes.

The risk of right ventricle (RV) failure remains a major contraindication for continuous-flow left ventricular assist device (CF-LVAD) implantation in patients with heart failure. It is therefore critical to identify the patients who will benefit from early intervention to avoid adverse outcomes. We sought to advance the computational modeling description of the mechanisms underlying RV failure in LVAD-supported patients. RV failure was studied by computational modeling of hemodynamic and cardiac mechanics using lumped-parameter and biventricular finite element (FE) analysis. Findings were validated by comparison of bi-dimensional speckle-tracking echocardiographic strain assessment of the RV free wall vs. patient-specific computational strain estimations, and by non-invasive lumped-based hemodynamic predictions vs. invasive right heart catheterization data. Correlation analysis revealed that lumped-derived RV cardiac output (R = 0.94) and RV stroke work index (R = 0.85) were in good agreement with catheterization data collected from 7 patients with CF-LVAD. Biventricular FE analysis showed abnormal motion of the interventricular septum towards the left ventricular free wall, suggesting impaired right heart mechanics. Good agreement between computationally predicted and echocardiographic measured longitudinal strains was found at basal (- 19.1 ± 3.0% for ECHO, and - 16.4 ± 3.2% for FEM), apical (- 20.0 ± 3.7% for ECHO, and - 17.4 ± 2.7% for FEM), and mid-level of the RV free wall (- 20.1 ± 5.9% for echo, and - 18.0 ± 5.4% for FEM). Simulation approach here presented could serve as a tool for less invasive and early diagnosis of the severity of RV failure in patients with LVAD, although future studies are needed to validate our findings against clinical outcomes.

The present study provides a critical review of the available historical data on the distribution of Abies nebrodensis, a fir tree endemic to Sicily. The only (somewhat ambiguous) references to its occurrence on Mount Etna date back to the 1st century bc and refer back to the 3rd century bc. Although the botanical and forestry literature and the very few surviving herbarium specimens do not prove that A. nebrodensis grew outside the Madonie mountain range, several indications suggest its past occurrence on other Sicilian mountain ranges such as the Erei, Nebrodi, and probably also Sicani mountains. The results of the most recent pollen investigations (still ongoing) point to the disappearance of Abies from most of Sicily by the 1st century bc, and at least since the Middle Ages A. nebrodensis had become extremely rare even on the Madonie mountains. Publications focused on the wooden artefacts from archaeological excavations and the restoration of architectural heritage have provided some information on the past use of fir wood in Sicily, but the species identity of the firs being used remain unresolved. The present review of the past occurrence and distribution of A. nebrodensis suggests that it may have previously occupied a wider ecological niche.

Biotechnology provides valuable tools to support conservation of plant species, especially in case of threatened taxa or when dealing with seed unavailability, low viability or sterility. However, plant cell culture methods have often to face problems associated with tissue recalcitrance to in vitro systems. Recalcitrance can be related to a variety of triggering factors, involving many efforts and manipulations within one or more of the micropropagation stages before obtaining successful results. An in vitro propagation protocol was developed for Zelkova sicula, a very rare and endangered relict tree, endemic to Sicily (Southern Italy). The species revealed extremely recalcitrant to in vitro culture approaches, but after many trials throughout a number of years an effective micropropagation protocol was completed. The rooting rate was about 84% of the treated explants, 8% of which were successfully acclimatized outdoor and reintroduced in the wild within a comprehensive conservation project. The technique allowed to overcome the problems of sexual sterility of this species, hence contributing concretely to contrast the problems connected with its conservation. However, additional efforts need to be carried out in order to refine the acclimatization step and further improve the whole process effectiveness. A micropropagation protocol was developed for the rare and endangered tree species Zelkova sicula. The in vitro procedure allowed to overcome seed sterility providing a plant stock successfully reintroduced in the wild.

Calendula maritima Guss. is a plant endemic to the coastline of W Sicily, whose distribution range experienced a dramatic shrinkage during the last centuries along with the degradation and fragmentation of the associated plant assemblages. According to that, it can represent an effective target species to test the response of coastal biota to anthropogenic disturbance. In order to better understand the niche width of C. maritima, the coastal plant communities in which it is still found have been investigated through vegetation relevés carried out on different size plots. Although the sea marigold has been considered as a pioneer species typical of shifting dunes, field investigations highlighted that it also occurs in different plant assemblages. Data concerning the smaller plots allowed the identification of three groups of relevés: one showing the highest number of trivial ruderal plants, another hosting some psammophilous species, and a third linked with rocky surfaces. These three groups do not cluster with the relevés issuing from literature, carried out some 40 years ago, that mostly focused on dune ecosystems. It is assumed that the strong floristic differences between these two different types of relevés may be linked with the destruction of shifting dunes occurred over the last decades, and which also caused the local extinction of many other plants related with this habitat. However, this could also reflect a lack of historical relevés concerning C. maritima populations growing on coastal rocky sites. Interestingly, a gradual expansion of the niche of C. maritima was highlighted, likely depending on the ability of the species to colonize new plant communities in response to increasing anthropogenic disturbance. Our results also confirm that hybridization with the contiguous congener species Calendula fulgida Raf. may represent a major threat for conservation of the remnant populations of C. maritima.

No abstract available]

Although Type B aortic dissection (AoD) has better in-hospital survival than Type A AoD, the short- and long term outcome for patients remains challenging, with 50–80% deaths at 5-years. Dissection-related complications include rapid aortic expansion, impending rupture, and malperfusion syndromes. We aimed to assess hemodynamic implications of patients with patent false lumen (FL) of dissected aorta. Computational fluid dynamic analyses were performed on patient-specific aortic geometries reconstructed from computed tomography scans of 25 patients with AoDs, who were admitted in our hospital from 2007 to 2013. We used the development of acute complications and chronic aneurysmal evolution as patient endpoints. Anatomical variables were correlated with hemodynamic variables, and regression was then performed to show independent determinants of FL flow. Velocity streamlines revealed helical, slower-moving flow in the FL of AoDs. Blood pressure and wall shear stress varied markedly between subjects, depending on AoD geometry. Lastly, linear regression shown that the height of entry tears was a significant predictor of blood flow through the patent FL. The greater the entry tear is, the greater the flow in the patent FL and thus the risk of dissection-related complications. Computational flow analysis may lead to more confident predictions of which patients will suffer adverse events and facilitate the clinical decision-making process related to the treatment of Type B AoDs.

Fatigue life of fastener holes can be enhanced via a cold-expansion process to introduce a compressive residual stress field around the hole edge and to reduce crack growth propagation. Considering that aerospace components contain multiple rows of holes, the present investigation focuses on the evaluation of the three-dimensional residual stress distribution in adjacent cold-expanded (CE) holes. The redistribution of residual stresses caused by a cut introduced between two adjacent holes was also investigated. Finite element (FE) analysis and experimental technique were used to assess the residual stress distribution in a 6082-T6 aluminum plate with two adjacent holes expanded sequentially at 4 % nominal interference. The influence of center-to-center distance between holes was explored to assess the optimal level of separation between adjacent holes. Results suggested that residual stresses near second CE hole are markedly lower than those of first CE hole and that a cutting process does not affect the beneficial compressive residual stress around CE holes. These effects may delay fatigue crack propagation from CE holes or cut-out holes.

Residual stresses play a key role on the mechanics underlying the fatigue crack growth propagation of welded joints. Indeed, compressive residual stresses may induce a beneficial enhancement of the fatigue life under loading condition whereas tensile residual stresses may act to increase the stress distribution at crack tip, resulting in a life-threatening condition of the welded structure. In-process distortion and final geometry of welded joints are also affected by residual stresses. In this paper, the longitudinal residual stress distributions in friction stir welding (FSW) joints were investigated for butt and skin–stringer geometries, including lap and T configurations. To measure residual stresses, the cut-compliance and the inverse weight-function methodologies were adapted for skin–stringer FSW geometries via finite element analysis. AA2024-T4 and AA7075-T6 aluminum alloys were used to weld dissimilar skin–stringer joints whereas butt joints were made of AA2024. The effect of most relevant process parameters as well as the cooling during welding process was also investigated for a better understanding of welding residual stresses. Our findings suggest that FSW of complex skin–stringer geometries produces higher residual stresses than those of butt joints, and that the cooling water flux further reduces residual stresses. Changes of process parameters did not affect markedly residual stress distribution.

Experimental measurements of the out-of-plane displacement surrounding cold-expanded holes in a 6082-T6 aluminum alloy were made with a 3D optical scanner using the technique of the encoded light-pattern projection in white light. The measured surface profiles have shown the thickness discontinuity along the hole edge due to the effect of the split in the sleeve. An analytical–numerical solution of the out-of-plane displacement is presented based on existing analytical models. Thus, the results given by the analytical model were then compared with the experimental data and with a finite element (FE) model that simulates the cold-expansion process. The location of the elastic–plastic boundary was estimated as the point at which no change in thickness was observed; a good agreement was found in the comparison of measured, FE and analytical results. The measured surface profiles agreed with those predicted by the FE model and analytical solution. The proposed experimental approach can be used together with FE analysis for predicting the radial and circumferential residual stresses in cold-expanded hole. It is quite versatile and can also be used as quality-control technique in the manufacturing processes of cold-expanded holes.

The vegetation and fire history of few coastal sites has been investigated in the Mediterranean region so far. We present the first paleoecological reconstruction from coastal Sicily, the largest island in the Mediterranean Sea. We analysed pollen and charcoal in the sediments of Biviere di Gela, a lake (lagoon) on the south coast of Sicily. Our data suggest that the area became afforested after a marine transgression at ca. 7200 cal b.p. (5250 b.c.). Build-up of forest and shrublands took ca. 200–300 years, mainly with the deciduous trees Quercus, Ostrya and Fraxinus. Juniperus expanded ca. 6900 cal b.p. (4950 b.c.), but declined again 6600 cal b.p. (4650 b.c.). Afterwards, evergreen trees (Q. ilex-type and Olea) became dominant in the forest and Pistacia shrublands were established. Forest and shrubland reached a maximum ca. 7000–5000 cal b.p. (5050–3050 b.c.); subsequently forest declined in response to human impact, which was probably exacerbated by a general trend towards a more arid climate. During the Neolithic, fire was used to open the landscape, significantly reducing several arboreal taxa (Q. ilex, Fraxinus, Juniperus) and promoting herbs and shrubs (Achillea, Cichorioideae, Brassicaceae, Ephedra). Final forest disruption occurred around 2600 cal b.p. (650 b.c.) with the onset of the historically documented Greek colonization. We conclude that the open maquis and garrigue vegetation of today is primarily the consequence of intensive land-use over millennia. Under natural or near-natural conditions arboreal taxa such as Q. ilex, Olea and Pistacia would be far more important than they are today, even under the hot and rather dry coastal conditions of southern Sicily.

Carpobrotus spp. are amongst the most impactful and widespread plant invaders of Mediterranean habitats. Despite the negative ecological impacts on soil and vegetation that have been documented, information is still limited about the effect by Carpobrotus on soil microbial communities. We aimed to assess the changes in the floristic, soil and microbial parameters following the invasion by Carpobrotus cfr. acinaciformis within an insular Mediterranean ecosystem. Within three study areas a paired-site approach, comparing an invaded vs. a non-invaded plot, was established. Within each plot biodiversity indexes, C and N soil content, pH and microbial biomass and structure (bacterial and fungal) were assessed. Invaded plots showed a decrease of α-species richness and diversity. The least represented plant species in invaded plots were those related to grassland habitats. In all invaded soils, a significant increase of carbon and nitrogen content and a significant decrease of pH were registered. Carpobrotus significantly increased bacterial and fungal biomass and altered soil microbial structure, particularly favoring fungal growth. Carpobrotus may deeply impact edaphic properties and microbial communities and, in turn, these strong modifications probably increase its invasive potential and its ability to overcome native species, by preventing their natural regeneration.