321 research outputs found

    The fate of the Volturno delta (northern Campania, Italy) among geological history and human influence

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    The present geomorphology of the Volturno River delta system (northern Campania, southern Italy) is largely a product of complex, long-lived relationships between geological evolution and human impacts. This presentation describes the evolution of the alluvial and coastal plain from the Holocene to the present time. The study was based on stratigraphic well log data analysis, cartographic sources from the last 150 years, bathymetric data acquired in 1887 and in 1987 and compared to extract seafloor changes in the delta offshore (Ruberti et al., 2022). The basis for the Holocene reconstruction was provided by the top of the Campania Grey Tuff (CGT) relief map, which evidences the incised valley excavation following the LGM sea level drop. The CGT is the product of a huge pyroclastic eruption of the Campi Flegrei volcanic district, occurred 39 ky BP, and thus represents both a major marker for the reconstruction of the subsurface stratigraphic record and a sturdy morphologic substrate engraved by river incision associated with the sea level fall that accompanied the last glacial period. The lowstand, transgressive and aggradation/highstand stacking of the Holocene facies were displayed. The present landscape appears largely inherited by the past MIS5 and LGM landscapes. A progressive increment of anthropic forcing took place after 2000 yr BP but the strongest modifications of the landscape occurred since the end of the XVII century. Until that time the landscape was largely covered by marshes and ponds. Human interventions started during the Spanish vice-Kingdom, at the end of the XVI century, when reclamation works were carried out with the aim to drain most of the marshy areas. The availability of reclaimed lands resulted in an intensive land transformation and the loss of most coastal wetland coupled with coastal erosion. Progradation of the delta ended during the early-middle XIX century. A peak of major alterations of the deltaic environment, and retreat of the coastline was attained between the 1960s and the 1990s. It is evident that the transformations of the landscape that have taken place over the last millennium are largely caused by anthropogenic impacts (i.e., reclamation, development of drainage network, land use changes). The sediment input of the river to the Tyrrhenian Sea sharply decreased, thus resulting in a dramatic change of the deltaic morphology and significant coastal land loss. The coastal zone, considered as a dissipative-type shoreline, evolved to an irreversible non-dissipative inshore profile characterized by mean erosional rates of 5 m/yr along the beaches and 24 m/yr on the delta mouth. The river delta changed from a cuspate, wave-dominate delta to arcuate and eventually delta-estuary type

    The response of a neutral atom to a strong laser field probed by transient absorption near the ionisation threshold

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    We present transient absorption spectra of an extreme ultraviolet attosecond pulse train in helium dressed by an 800 nm laser field with intensity ranging from 2times10122times10^{12} W/cm2^2 to 2times10142times10^{14} W/cm2^2. The energy range probed spans 16-42 eV, straddling the first ionisation energy of helium (24.59 eV). By changing the relative polarisation of the dressing field with respect to the attosecond pulse train polarisation we observe a large change in the modulation of the absorption reflecting the vectorial response to the dressing field. With parallel polarized dressing and probing fields, we observe significant modulations with periods of one half and one quarter of the dressing field period. With perpendicularly polarized dressing and probing fields, the modulations of the harmonics above the ionisation threshold are significantly suppressed. A full-dimensionality solution of the single-atom time-dependent Schr odinger equation obtained using the recently developed ab-initio time-dependent B-spline ADC method reproduce some of our observations

    Actual and forecasted vulnerability assessment to seawater intrusion via galdit-susi in the volturno river mouth (Italy)

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    Coastal areas have become increasingly vulnerable to groundwater salinization, especially in the last century, due to the combined effects of climate change and growing anthropization. In this study, a novel methodology named GALDIT-SUSI was applied in the floodplain of the Volturno River mouth for the current (2018) and future (2050) evaluation of seawater intrusion accounting for the expected subsidence and groundwater salinization rates. Several input variables such as digital surface model, land use classification, subsidence rate and drainage system have been mapped via remote sensing resources. The current assessment highlights how areas affected by salinization coincide with the semiperennial lagoons and inland depressed areas where paleosaline groundwaters are present. The future assessment (2050) shows a marked increase of salinization vulnerability in the coastal strip and in the most depressed areas. The results highlight that the main vulnerability driver is the Revelle index, while predicted subsidence and recharge rates will only slightly affect groundwater salinization. This case study indicates that GALDIT-SUSI is a reliable and easy-to-use tool for the assessment of groundwater salinization in many coastal regions of the world

    Brillouin microscopy, what is it really measuring?

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    Brillouin microscopy measures compressibility, but is being increasingly used to assess stiffness of cells and tissues. Using hydrogels with tunable properties, we demonstrate that Brillouin microscopy is insensitive to stiffness of hydrated materials, but depends strongly on water content, consistent with a theoretical model of biphasic compressibility. Empirical correlations between Brillouin measurements and stiffness arise due to their mutual dependence on water content, but correlations vanish once hydration is controlled

    Involvement of MAF/SPP1 axis in the development of bone marrow fibrosis in PMF patients

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    Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by hyperplastic megakaryopoiesis and myelofibrosis. We recently described the upregulation of MAF (v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog) in PMF CD34+ hematopoietic progenitor cells (HPCs) compared to healthy donor. Here we demonstrated that MAF is also upregulated in PMF compared with the essential thrombocytemia (ET) and polycytemia vera (PV) HPCs. MAF overexpression and knockdown experiments shed some light into the role of MAF in PMF pathogenesis, by demonstrating that MAF favors the megakaryocyte and monocyte/macrophage commitment of HPCs and leads to the increased expression of proinflammatory and profibrotic mediators. Among them, we focused our further studies on SPP1 and LGALS3. We assessed SPP1 and LGALS3 protein levels in 115 PMF, 47 ET and 24 PV patients plasma samples and we found that SPP1 plasma levels are significantly higher in PMF compared with ET and PV patients. Furthermore, in vitro assays demonstrated that SPP1 promotes fibroblasts and mesenchymal stromal cells proliferation and collagen production. Strikingly, clinical correlation analyses uncovered that higher SPP1 plasma levels in PMF patients correlate with a more severe fibrosis degree and a shorter overall survival. Collectively our data unveil that MAF overexpression contributes to PMF pathogenesis by driving the deranged production of the profibrotic mediator SPP1

    Cultivation of Human Corneal Endothelial Cells Isolated from Paired Donor Corneas

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    Consistent expansion of human corneal endothelial cells (hCECs) is critical in the development of tissue engineered endothelial constructs. However, a wide range of complex culture media, developed from different basal media have been reported in the propagation of hCECs, some with more success than others. These results are further confounded by donor-to-donor variability. The aim of this study is to evaluate four culture media in the isolation and propagation of hCECs isolated from a series of paired donor corneas in order to negate donor variability

    Correlation-Driven Transient Hole Dynamics Resolved in Space and Time in the Isopropanol Molecule

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    The possibility of suddenly ionized molecules undergoing extremely fast electron hole (or hole) dynamics prior to significant structural change was first recognized more than 20 years ago and termed charge migration. The accurate probing of ultrafast electron hole dynamics requires measurements that have both sufficient temporal resolution and can detect the localization of a specific hole within the molecule. We report an investigation of the dynamics of inner valence hole states in isopropanol where we use an x-ray pump–x-ray probe experiment, with site and state-specific probing of a transient hole state localized near the oxygen atom in the molecule, together with an ab initio theoretical treatment. We record the signature of transient hole dynamics and make the first tentative observation of dynamics driven by frustrated Auger-Meitner transitions. We verify that the effective hole lifetime is consistent with our theoretical prediction. This state-specific measurement paves the way to widespread application for observations of transient hole dynamics localized in space and time in molecules and thus to charge transfer phenomena that are fundamental in chemical and material physics

    Controlling the 3D architecture of Self-Lifting Auto-generated Tissue Equivalents (SLATEs) for optimized corneal graft composition and stability

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    Ideally, biomaterials designed to play specific physical and physiological roles in vivo should comprise components and microarchitectures analogous to those of the native tissues they intend to replace. For that, implantable biomaterials need to be carefully designed to have the correct structural and compositional properties, which consequently impart their bio-function. In this study, we showed that the control of such properties can be defined from the bottom-up, using smart surface templates to modulate the structure, composition, and bio-mechanics of human transplantable tissues. Using multi-functional peptide amphiphile-coated surfaces with different anisotropies, we were able to control the phenotype of corneal stromal cells and instruct them to fabricate self-lifting tissues that closely emulated the native stromal lamellae of the human cornea. The type and arrangement of the extracellular matrix comprising these corneal stromal Self-Lifting Analogous Tissue Equivalents (SLATEs) were then evaluated in detail, and was shown to correlate with tissue function. Specifically, SLATEs comprising aligned collagen fibrils were shown to be significantly thicker, denser, and more resistant to proteolytic degradation compared to SLATEs formed with randomly-oriented constituents. In addition, SLATEs were highly transparent while providing increased absorption to near-UV radiation. Importantly, corneal stromal SLATEs were capable of constituting tissues with a higher-order complexity, either by creating thicker tissues through stacking or by serving as substrate to support a fully-differentiated, stratified corneal epithelium. SLATEs were also deemed safe as implants in a rabbit corneal model, being capable of integrating with the surrounding host tissue without provoking inflammation, neo-vascularization, or any other signs of rejection after a 9-months follow-up. This work thus paves the way for the de novo biofabrication of easy-retrievable, scaffold-free human tissues with controlled structural, compositional, and functional properties to replace corneal, as well as other, tissuesThis study was supported by the Medical Research Council grant MR/ K017217/1, the Biotechnology and Biological Sciences Research Council, grant BB/I008187/1 and the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I + D + I) from the Spanish Ministry of Economy and Competitiveness (Instituto de Salud Carlos III), grant FIS PI14/0955 (cofinanced by FEDER funds, European Union)
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