Confronto fra valutazioni del run-up fatte con un modello matematico e una formula empirica con misure di campo

La posizione planimetrica della linea di riva, soli tamente, viene determinata attraverso l\u2019uso di immagini aeree ed utilizzata pe r la ricostruzione dell\u2019evoluzione storica dei litorali. Tuttavia, le informazioni est ratte da tali immagini, descrivendo il confine istantaneo acqua-terra, consentono l\u2019indivi duazione della linea di riva esclusivamente come limite asciutto-bagnato proprio nel momento della ripresa. Per una pi\uf9 corretta localizzazione della linea di riva , \ue8 quindi necessario quantificare, oltre agli effetti di marea e di trasporto solido, gli effetti prodotti dal moto ondoso su tale posizione e in particolare il cosiddetto ru n-up. Nel presente lavoro si studia il run-up in una spia ggia naturale a debole pendenza ricadente nella Sicilia occidentale. Lo studio geom orfologico del sito precede lo studio idraulico, che partendo dalle misure di onde al largo, attraverso la loro trasposizione e la propagazione simulata con un mod ello matematico, porta alla stima delle onde sotto costa. Queste ultime sono ut ilizzate per valutare il run-up sia mediante una nota formula empirica sia utilizzando un modello numerico alla Boussinesq con una nuova condizione al contorno per la linea di riva. Il confronto dei risultati con le misure di campo mostra che i r isultati migliori si ottengono con la formula empirica, nella quale \ue8 tuttavia necessa rio calibrare i coefficienti con misure in situ

Strong contribution of diatom resting spores to deep-sea carbon transfer in naturally iron-fertilized waters downstream of South Georgia

Biogeochemical and diatom export fluxes are presented from two bathypelagic sediment trap deployments in the Antarctic Zone of the Southern Ocean. One of the sediment traps was deployed in very productive, naturally iron-fertilized waters downstream of South Georgia (P3, 2000 m) and compared to a deployment in moderately productive waters upstream of the island system (P2, 1500 m). At both sites significant diatom export events occurred in spring (November) and contained mostly empty cells that were associated with low particulate organic carbon (POC) fluxes. A summer export pulse occurred one month later at P2 (end February/March) compared to P3 (end January). Diatom fluxes at P3 were one order of magnitude higher than at P2, a difference mainly attributed to the short and intense export of resting spores from Chaetoceros Hyalochaete and Thalassiosira antarctica species. Aside from these resting spores, diatom export assemblages at both sites were dominated by empty Fragilariopsis kerguelensis frustules. The fraction of diatoms exported as empty frustules was considerably lower at P3 (52%) than P2 (91%). This difference was related to the flux of intact diatom resting spores at P3 and may partially explain the lower Si:C export stoichiometry observed at P3 (1.1) compared to P2 (1.5). Through the enumeration of full diatom frustules and subsequent biomass calculations we estimate that diatom resting spores account for 42% of annual POC flux in the productive waters downstream of South Georgia. At both sites the contribution of diatom vegetative stages to POC fluxes was considerably lower (<5%). From these analyses we conclude that resting spore export contributes towards the slightly higher bathypelagic (POC) flux at P3 (40.6 mmol m−2 y−1) compared to P2 (26.4 mmol m−2 y−1). We compared our sediment trap records with previously published diatom assemblage data from the mixed layer and surface sediments (3760 m) around South Georgia. The relative proportion of diatom resting spores within diatom assemblages increases as a function of depth and is explained by selective preservation of their robust frustules. Our study highlights the significance of diatom resting spore export as a carbon vector out of the mixed layer. Furthermore, the contribution or resting spores to POC flux in the bathypelagic ocean and sediments suggests they play a particularly important role in sequestering biologically fixed CO2 over climatically relevant timescales

Electrostatics promotes molecular crowding and selects the aggregation pathway in fibril-forming protein solutions

The role of intermolecular interaction in fibril-forming protein solutions and its relation with molecular conformation are crucial aspects for the control and inhibition of amyloid structures. Here, we study the fibril formation and the protein-protein interactions for two proteins at acidic pH, lysozyme and α-chymotrypsinogen. By using light scattering experiments and the Kirkwood-Buff integral approach, we show how concentration fluctuations are damped even at moderate protein concentrations by the dominant long-ranged electrostatic repulsion, which determines an effective crowded environment. In denaturing conditions, electrostatic repulsion keeps the monomeric solution in a thermodynamically metastable state, which is escaped through kinetically populated conformational sub-states. This explains how electrostatics acts as a gatekeeper in selecting a specific aggregation pathway

Ferulic acid-nlc with lavandula essential oil: A possible strategy for wound-healing?

Nowadays, an increasing interest in combinatorial drug delivery systems is emerging, highlighting the possibility of exploiting essential oils (EO) for topical applications. This work aimed at developing nanostructured lipid carriers (NLC) for the combined delivery of ferulic acid and Lavandula EO, whose beneficial effects in wound-healing processes have been widely reported. Homogeneous (polydispersity index, PDI &lt; 0.2) nanoparticles with a small size ([removed]85%) were obtained. The co-presence of ferulic acid and Lavandula EO, as compared to synthetic isopropyl myristate-based NLC, increased nanoparticles’ stability, due to higher ordering chains, as confirmed by morphological and physicochemical studies. An enhanced cytocompatibility was observed when combining ferulic acid and Lavandula EO, as confirmed by in vitro studies on fibroblasts. Furthermore, the combined delivery of ferulic acid and Lavandula EO significantly promoted cell migration with higher effectiveness in respect to the free drug solution and the carrier without the EO. Taken all together, our results suggest a potential combined effect of the antioxidant ferulic acid and Lavandula EO co-delivered in lipid nanoparticles in promoting cell proliferation and migration, representing a promising strategy in the treatment of wounds

Tsunami Vulnerability Evaluation for a Small Ancient Village on Eastern Sicily Coast

The Ionian sea is prone to tsunamis due to its proximity to the Calabrian subduction zone, which is one of the major tsunamigenic areas of the Mediterranean. The tsunami disaster risk is, nowadays, significantly higher due to the increased exposure of buildings as a result of the economic and touristic growth of the Mediterranean coastal areas. This study focuses on Marzamemi, a small village in the western coast of Sicily, since its morphology and human presence amplify the need to assess its buildings’ vulnerability. The main objective of this research is to quantify the building vulnerability to tsunami hazards using a physical and realistic tsunami scenario. For this purpose, the relative vulnerability index of the buildings in Marzamemi was calculated by means of an improved Papathoma Tsunami Vulnerability Assessment (PTVA) model. The presented approach has three main improvements: (a) a probabilistic tsunami scenario was used; (b) a realistic signal of water surface linked with a specific focal mechanism was adopted; (c) a tsunami wave was propagated from offshore to nearshore using a nonlinear numerical model. The good results of the proposed methodology make it very useful for coastal risk planning conducted by decision makers and stakeholders

The sicilian rock partridge: latest data on genetic integrity from four different relict areas

Sicily (Italy) hosts a \u201crelict\u201d, endemic population of the birds Alectoris graeca whitakeri commonly known as Sicilian Rock Partridge. In the last decades, due to the risk of restocking with other European and Asiatic species for hunting purpose, a study was carried out to investigate the potential risk of hybridisation. The mtDNA control-region and nuclear microsatellites were genotyped. Due to the importance of the species, samples were mainly characterized by feather and stool samples, and rarely by carcasses found in the environment, from year 2011 to 2012. A panel of 7 microsatellite loci was validated. Three multiplexes that allowed the simultaneous amplification of 3 microsatellites, and 2 for other two microsatellites, for a total of 7 markers, were utilized. Results showed the occurrence of hybridization both towards the Middle Eastern species, A. chukar and the Northern European species, A. rufa. A total of 18.5% of the samples were collected from the wild environment showed a high degree of hybridization. This fact, even if linked to a small number of samples, highlights a potential risk of hybridization in 4 Sicilian provinces and underlines the importance of further investigations to understand the entity of the problem

Early Stage Alterations in White Matter and Decreased Functional Interhemispheric Hippocampal Connectivity in the 3xTg Mouse Model of Alzheimer’s Disease

Alzheimer’s disease (AD) is characterized in the late stages by amyloid-β (Aβ) plaques and neurofibrillary tangles. Nevertheless, recent evidence has indicated that early changes in cerebral connectivity could compromise cognitive functions even before the appearance of the classical neuropathological features. Diffusion tensor imaging (DTI), resting-state functional magnetic resonance imaging (rs-fMRI) and volumetry were performed in the triple transgenic mouse model of AD (3xTg-AD) at 2 months of age, prior to the development of intraneuronal plaque accumulation. We found the 3xTg-AD had significant fractional anisotropy (FA) increase and radial diffusivity (RD) decrease in the cortex compared with wild-type controls, while axial diffusivity (AD) and mean diffusivity (MD) were similar. Interhemispheric hippocampal connectivity was decreased in the 3xTg-AD while connectivity in the caudate putamen (CPu) was similar to controls. Most surprising, ventricular volume in the 3xTg-AD was four times larger than controls. The results obtained in this study characterize the early stage changes in interhemispheric hippocampal connectivity in the 3xTg-AD mouse that could represent a translational biomarker to human models in preclinical stages of the AD

Synergistic effect induced by gold nanoparticles with polyphenols shell during thermal therapy: Macrophage inflammatory response and cancer cell death assessment

Background: In recent decades, gold nanoparticle (Au NP)-based cancer therapy has been heavily debated. The physico-chemical properties of AuNPs can be exploited in photothermal therapy, making them a powerful tool for selectively killing cancer cells. However, the synthetic side products and capping agents often induce a strong activation of the inflammatory pathways of macrophages, thus limiting their further applications in vivo. Methods: Here, we described a green method to obtain stable polyphenol-capped AuNPs (Au NPs@polyphenols), as polyphenols are known for their anti-inflammatory and anticancer properties. These NPs were used in human macrophages to test key inflammation-related markers, such as NF-κB, TNF-α, and interleukins-6 and 8. The results were compared with similar NPs obtained by a traditional chemical route (without the polyphenol coating), proving the potential of Au NPs@polyphenols to strongly promote the shutdown of inflammation. This was useful in developing them for use as heat-synergized tools in the thermal treatment of two types of cancer cells, namely, breast cancer (MCF-7) and neuroblastoma (SH-SY5Y) cells. The cell viability, calcium release, oxidative stress, HSP-70 expression, mitochondrial, and DNA damage, as well as cytoskeleton alteration, were evaluated. Results: Our results clearly demonstrate that the combined strategy markedly exerts anticancer effects against the tested cancer cell, while neither of the single treatments (only heat or only NPs) induced significant changes. Conclusions: Au NP@polyphenols may be powerful agents in cancer treatment

The role of diatom resting spores in pelagic–benthic coupling in the Southern Ocean

Natural iron fertilization downstream of Southern Ocean island plateaus supports large phytoplankton blooms and promotes carbon export from the mixed layer. In addition to sequestering atmospheric CO2, the biological carbon pump also supplies organic matter (OM) to deep-ocean ecosystems. Although the total flux of OM arriving at the seafloor sets the energy input to the system, the chemical nature of OM is also of significance. However, a quantitative framework linking ecological flux vectors to OM composition is currently lacking. In the present study we report the lipid composition of export fluxes collected by five moored sediment traps deployed in contrasting productivity regimes of Southern Ocean island systems (Kerguelen, Crozet and South Georgia) and compile them with quantitative data on diatom and faecal pellet fluxes. At the three naturally iron-fertilized sites, the relative contribution of labile lipids (mono- and polyunsaturated fatty acids, unsaturated fatty alcohols) is 2–4 times higher than at low productivity sites. There is a strong attenuation of labile components as a function of depth, irrespective of productivity. The three island systems also display regional characteristics in lipid export. An enrichment of zooplankton dietary sterols, such as C27Δ5, at South Georgia is consistent with high zooplankton and krill biomass in the region and the importance of faecal pellets to particulate organic carbon (POC) flux. There is a strong association of diatom resting spore fluxes that dominate productive flux regimes with energy-rich unsaturated fatty acids. At the Kerguelen Plateau we provide a statistical framework to link seasonal variation in ecological flux vectors and lipid composition over a complete annual cycle. Our analyses demonstrate that ecological processes in the upper ocean, e.g. resting spore formation and grazing, not only impact the magnitude and stoichiometry of the Southern Ocean biological pump, but also regulate the composition of exported OM and the nature of pelagic–benthic coupling

Efficient spin transport through native oxides of nickel and permalloy with platinum and gold overlayers

We present measurements of spin pumping detected by the inverse spin Hall effect voltage and ferromagnetic resonance spectroscopy in a series of metallic ferromagnet/normal metal thin film stacks. We compare heterostructures grown in situ to those where either a magnetic or nonmagnetic oxide is introduced between the two metals. The heterostructures, either nickel with a platinum overlayer (Ni/Pt) or the nickel-iron alloy permalloy (Py) with a gold overlayer (Py/Au), were also characterized in detail using grazing-incidence x-ray reflectivity, Auger electron spectroscopy, and both SQUID and alternating-gradient magnetometry. We verify the presence of oxide layers, characterize layer thickness, composition, and roughness, and probe saturation magnetization, coercivity, and anisotropy. The results show that while the presence of a nonmagnetic oxide at the interface suppresses spin transport from the ferromagnet to the nonmagnetic metal, a thin magnetic oxide (here the native oxide formed on both Py and Ni) somewhat enhances the product of the spin-mixing conductance and the spin Hall angle. We also observe clear evidence of an out-of-plane component of magnetic anisotropy in Ni/Pt samples that is enhanced in the presence of the native oxide, resulting in perpendicular exchange bias. Finally, the dc inverse spin Hall voltages generated at ferromagnetic resonance in our Py/Au samples are large, and suggest values for the spin Hall angle in gold of 0.04<αSH<0.22, in line with the highest values reported for Au. This is interpreted as resulting from Fe impurities. We present indirect evidence that the Au films described here indeed have significant impurity levels.B.L.Z. and D.B. gratefully acknowledge support from the NSF (Grants No. DMR-0847796 and No. DMR-1410247). B.L.Z. also thanks the University of Minnesota Chemical Engineering and Materials Science Department, as a portion of this work benefited from support of the George T. Piercy Distinguished Visiting Professorship. Work at the University of Minnesota was supported primarily by the NSF under Grant No. DMR-1507048, with additional support from the NSF MRSEC under Grant No. DMR-1420013. The work at WMI is supported by Deutsche Forschungsgemeinschaft via SPP 1538 Spin-Caloric Transport (Project No. GO 944/4-1). Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by Los Alamos National Laboratory (Contract No. DE-AC52-06NA25396) and Sandia National Laboratories (Contract No. DE-AC04-94AL85000)