Strujanje uzrokovano vjetrom u stratificiranom fluidu: numeričko istraživanje i primjena na Tršćanski zaljev u uvjetima jake bure

This study investigates the circulation driven by a severe bora wind event in the Gulf of Trieste during the stratification season. A preliminary numerical analysis of the wind driven transport in the surface boundary layer is carried out for an idealized, laterally unbounded, shallow domain. Then, the simulations are focused on the Gulf of Trieste, using a realistic bathymetry and assuming stably stratified initial conditions. First, the model is driven by constant wind forcing, then qualitative and quantitative estimations of the dynamics of the basin are made reproducing the strong Bora event of the 25 June 2002. Numerical results show good agreement with in situ measurements and remotely sensed images. The relevance of coastal upwelling and its persistence are also assessed. The results prove that mixing and coastal upwelling (both wind-driven) govern the circulation of the basin. When bora starts blowing, buoyant surface water is moved by EKMAN transport offshore inducing a bottom onshore current. Simultaneously, wind driven stirring breaks the initial stable stratification. The surface offshore current generates a sea surface level setup on the northern boundary. When bora decreases, this surface tilt is no longer sustained, and a reversal of the circulation is observed in the upper layer. The sensitivity to the wind forcing is also discussed. All of these issues are crucial to environmental problems such as pollutant dispersion or anoxia phenomena in the bottom layers of the Gulf.U ovom se radu analizira strujanje u Tršćanskom zaljevu uzrokovano jakom burom u vertikalno stratificiranom slučaju. Preliminarna numerička analiza strujnog polja uzrokovanog vjetrom urađena je za idealizirani slučaj horizontalno neograničene domene. Zatim su numeričke simulacije primijenjene na Tršćanski zaljev upotrebivši realnu batimetriju i uz pretpostavku vertikalno stabilne stratifikacije. 25. lipnja 2002. godine najprije je primjenijen stacionaran vjetar, a zatim realistična situacija jake bure. Rezultati numeričke integracije pokazuju dobro slaganje s in situ i daljinskim mjerenjima. Posebna je pažnja poklonjena intenzitetu obalnog “upwellinga” i njegovoj postojanosti. Rezultati ukazuju da su vertikalno miješanje i “upwelling” odgovorni za strujanje u bazenu. Bura uzrokuje EKMANOV transport i odnosi slatku vodu prema sredini zaljeva, te uzrokuje formiranje pridnene struje ka obali. Istovremeno vertikalno miješanje slabi vertikalnu stabilnost vodenog stupca. Površinska struja od obale prema sredini zaljeva uzrokuje nagib razine mora od sjeverne obale ka jugu. Kada prestane bura nagib razine mora se više ne može održati i javlja se površinska struja suprotnog smjera. U ovom je radu također istraživana osjetljivost numeričkih rješenja na utjecaj vjetra. Ovi su procesi važni za širenje otpadnih tvari kao i za eventualnu pojavu anoksije u pridnenom sloju zaljeva

Proteomic Analysis of a Nutritional Shift-up in Saccharomyces cerevisiae Identifies Gvp36 as a BAR-containing Protein Involved in Vesicular Traffic and Nutritional Adaptation

Yeast cells undergoing a nutritional shift-up from a poor to a rich carbon source take several hours to adapt to the novel, richer carbon source. The budding index is a physiologically relevant "global" parameter that reflects the complex links between cell growth and division that are both coordinately and deeply affected by nutritional conditions. We used changes in budding index as a guide to choose appropriate, relevant time points during an ethanol to glucose nutritional shift-up for preparation of samples for the analysis of proteome by two-dimensional electrophoresis/mass spectrometry. About 600 spots were detected. 90 spots, mostly comprising proteins involved in intermediary metabolism, protein synthesis, and response to stress, showed differential expression after glucose addition. Among modulated proteins we identified a protein of previously unknown function, Gvp36, showing a transitory increase corresponding to the drop of the fraction of budded cells. A gvp36Delta strain shares several phenotypes (including general growth defects, heat shock, and high salt sensitivity, defects in polarization of the actin cytoskeleton, in endocytosis and in vacuolar biogenesis, defects in entering stationary phase upon nutrient starvation) with secretory pathway mutants and with mutants in genes encoding the two previously known yeast BAR proteins (RSV161 and RSV167). We thus propose that Gvp36 represents a novel yeast BAR protein involved in vesicular traffic and in nutritional adaptation

Multi-Platform, High-Resolution Study of a Complex Coastal System: The TOSCA Experiment in the Gulf of Trieste

Although small in size, the Gulf of Trieste (GoT), a marginal coastal basin in the northern Adriatic Sea, is characterized by very complex dynamics and strong variability of its oceanographic conditions. In April–May 2012, a persistent, large-scale anticyclonic eddy was observed in the GoT. This event was captured by both High Frequency Radar (HFR) and Lagrangian drifter observations collected within the European MED TOSCA (Tracking Oil Spill and Coastal Awareness) project. The complexity of the system and the variety of forcing factors constitute major challenges from a numerical modeling perspective when it comes to simulating the observed features. In this study, we implemented a high-resolution hydrodynamic model in an attempt to reproduce and analyze the observed basin-wide eddy structure and determine its drivers. We adopted the Massachusetts Institute of Technology General Circulation Model (MITgcm), tailored for the GoT, nested into a large-scale simulation of the Adriatic Sea and driven by a tidal model, measured river freshwater discharge data and surface atmospheric forcing. Numerical results were qualitatively and quantitatively evaluated against HFR surface current maps, Lagrangian drifter trajectories and thermohaline data, showing good skills in reproducing the general circulation, but failing in accurately tracking the drifters. Model sensitivity to different forcing factors (wind, river and tides) was also assessed

Nephrops norvegicus in the Adriatic Sea: Connectivity modeling essential fish habitats and management area network

AbstractKnowledge of connectivity among subpopulations is fundamental in the identification of the appropriate geographical scales for stock status evaluation and management, the identification of areas with greater retention rates, and space‐based fisheries management. Here, an integration of hydrodynamic, biological, and habitat models results is used to assess connectivity and support the definition of essential fish habitats (EFH) in the Adriatic Sea, with reference to Nephrops norvegicus, an important benthic commercial resource, the recruitment of which is strongly related to larval dispersal from spawning to recruitment areas. We explored oceanographic and biological connectivity in the Adriatic Sea under a wide and representative variety of oceanographic conditions (winters 2006–2012) by tracking 3D trajectories of larvae released from different areas. We used a Lagrangian model that features a specific larval behavior module with explicit dependence on environmental parameters (i.e., temperature and sediment type) and that is driven by high‐resolution hydrodynamic and meteorological data. The results were used to partition the area in which Nephrops was observed into 20 homogenous management subareas; to assess the connection between spawning, recruitment, and harvesting grounds; and to identify potential subpopulation boundaries as well as the connectivity among the potential subpopulations. The results suggest the presence of at least three distinct subpopulations, which need to be independently managed and conserved, and confirms that the Jabuka‐Pomo pit is the most important spawning area, but alone it cannot sustain Nephrops populations throughout the Adriatic Sea. The results also show the importance to move from particle‐tracking to approaches based on integrated models

Spatial patterns and drivers of benthic community structure on the northern Adriatic biogenic reefs

The northern Adriatic Sea (NAS) hosts numerous biogenic subtidal reefs that are considered biodiversity hotspots. Several studies have already investigated the origin and biodiversity of these reefs. However, many of them are still unexplored and further knowledge is needed for their conservation. Here, the spatial variability, epibenthic community structure, and environmental features that characterize these habitats were investigated. Fifteen randomly selected reefs were sampled between 2013 and 2017, including some remote sites that have never been studied before. A fuzzy k-means clustering method and redundancy analysis were used to find similarities among sites in terms of epibenthic assemblages and to model relationships with abiotic variables. The results showed that these reefs are highly heterogeneous in terms of species composition and geomorphological features. The results were also consistent with previous studies and highlighted three main types of benthic assemblages defined by the dominance of different organisms, mainly reflecting the coastal-offshore gradient: nearshore reefs, generally dominated by stress-tolerant species; reefs at a middle distance from the coast, characterized by sponges, non-calcareous encrusting algae and ascidians; offshore reefs, dominated by reef builders. However, distance from the coast was not the only factor affecting species distribution, as other local factors and environmental characteristics also played a role. This kind of biogenic reefs in temperate seas are still poorly known. The present work contributed to shed further light on these habitats, by complementing the results of previous studies on their natural diversity, highlighting the specificity of the epibenthic communities of NAS reefs and the need to improve current, still inadequate, conservation measures

Human neural stem cell transplantation in ALS: initial results from a phase I trial

We report the initial results from a phase I clinical trial for ALS. We transplanted GMP-grade, fetal human neural stem cells from natural in utero death (hNSCs) into the anterior horns of the spinal cord to test for the safety of both cells and neurosurgical procedures in these patients. The trial was approved by the Istituto Superiore di Sanit\ue0 and the competent Ethics Committees and was monitored by an external Safety Board

Exome-wide Rare Variant Analysis Identifies TUBA4A Mutations Associated with Familial ALS

Exome sequencing is an effective strategy for identifying human disease genes. However, this methodology is difficult in late-onset diseases where limited availability of DNA from informative family members prohibits comprehensive segregation analysis. To overcome this limitation, we performed an exome-wide rare variant burden analysis of 363 index cases with familial ALS (FALS). The results revealed an excess of patient variants within TUBA4A, the gene encoding the Tubulin, Alpha 4A protein. Analysis of a further 272 FALS cases and 5,510 internal controls confirmed the overrepresentation as statistically significant and replicable. Functional analyses revealed that TUBA4A mutants destabilize the microtubule network, diminishing its repolymerization capability. These results further emphasize the role of cytoskeletal defects in ALS and demonstrate the power of gene-based rare variant analyses in situations where causal genes cannot be identified through traditional segregation analysis

Analysis of shared common genetic risk between amyotrophic lateral sclerosis and epilepsy

Because hyper-excitability has been shown to be a shared pathophysiological mechanism, we used the latest and largest genome-wide studies in amyotrophic lateral sclerosis (n = 36,052) and epilepsy (n = 38,349) to determine genetic overlap between these conditions. First, we showed no significant genetic correlation, also when binned on minor allele frequency. Second, we confirmed the absence of polygenic overlap using genomic risk score analysis. Finally, we did not identify pleiotropic variants in meta-analyses of the 2 diseases. Our findings indicate that amyotrophic lateral sclerosis and epilepsy do not share common genetic risk, showing that hyper-excitability in both disorders has distinct origins

Association of Variants in the SPTLC1 Gene With Juvenile Amyotrophic Lateral Sclerosis

Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation.Objective: To identify the genetic variants associated with juvenile ALS.Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism.Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members.Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway.Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.</p

ON THE APPLICATION OF A HYDRODYNAMIC NUMERICAL MODEL TO THE GULF OF TRIESTE FOR OPERATIONAL PURPOSES

2005/2006XIX Ciclo1977Versione digitalizzata della tesi di dottorato cartacea. Nell'originale cartaceo errata numerazione delle pagin