Architettura deposizionale dei depositi tardo-quaternari e sviluppo di sistemi di valli incise all'interno della porzione meridionale del bacino versiliese-pisano

I depositi caratterizzanti il sottosuolo delle pianure costiere, come nel caso della pianura pisana, costituiscono degli eccellenti archivi sedimentari utili per ricostruire in dettaglio gli scenari paleogeografici che si sono succeduti nel passato. Per ricostruire in dettaglio la geometria dei principali corpi sedimentari è necessaria un'attenta analisi di facies che si basi sull'osservazione diretta dei depositi tramite sondaggi a carotaggio continuo, insieme ad uno studio multidisciplinare. Questo studio di tesi si pone come obiettivo principale quello di ricostruire l'architettura deposizionale dei depositi tardo-quaternari del sottosuolo della porzione meridionale del bacino versiliese-pisano, tramite analisi di facies e correlazioni stratigrafiche lungo una griglia di sezioni

Genes and Aggressive Behavior: Epigenetic Mechanisms Underlying Individual Susceptibility to Aversive Environments

Over the last two decades, the study of the relationship between nature and nurture in shaping human behavior has encountered a renewed interest. Behavioral genetics showed that distinct polymorphisms of genes that code for proteins that control neurotransmitter metabolic and synaptic function are associated with individual vulnerability to aversive experiences, such as stressful and traumatic life events, and may result in an increased risk of developing psychopathologies associated with violence. On the other hand, recent studies indicate that experiencing aversive events modulates gene expression by introducing stable changes to DNA without modifying its sequence, a mechanism known as “epigenetics”. For example, experiencing adversities during periods of maximal sensitivity to the environment, such as prenatal life, infancy and early adolescence, may introduce lasting epigenetic marks in genes that affect maturational processes in brain, thus favoring the emergence of dysfunctional behaviors, including exaggerate aggression in adulthood. The present review discusses data from recent research, both in humans and animals, concerning the epigenetic regulation of four genes belonging to the neuroendocrine, serotonergic and oxytocinergic pathways—Nuclear receptor subfamily 3-group C-member 1 (NR3C1), oxytocin receptor (OXTR), solute carrier-family 6 member 4 (SLC6A4) and monoamine oxidase A (MAOA)—and their role in modulating vulnerability to proactive and reactive aggressive behavior. Behavioral genetics and epigenetics are shedding a new light on the fine interaction between genes and environment, by providing a novel tool to understand the molecular events that underlie aggression. Overall, the findings from these studies carry important implications not only for neuroscience, but also for social sciences, including ethics, philosophy and law

Iterleukin 1 alpha is a marker of endothelial cellular senescent

BACKGROUND: The functional changes associated with endothelial senescence may be involved in human aging and age-related vascular disorders. Since the inflammatory cytokine interleukin (IL-)1 inhibits endothelial growth, we evaluated the expression of IL-1α, IL-1β and their antagonist, the IL-1 receptor antagonist (IL-1ra), in endothelial in vitro senescence and quiescence. We also examined the expression of IL-1α in human senescent and progeric fibroblasts. RESULTS: We found that the overexpression of IL-1α specifically characterizes endothelial senescence. No modulation of this cytokine was observed in endothelial quiescence and in senescent or progeric human fibroblasts. The expression of IL-1β and IL-1ra was also assessed and found not to be affected by senescence. CONCLUSION: Our results indicate that a dysfunction of the cytokine network associates with aging and point to a specific role of IL-1α in endothelial senescence

Contribution of Benthic Processes to the Growth of Ooids on a Low-Energy Shore in Cat Island, The Bahamas

Ooids are typically found in frequently reworked coastal sediments, and are thought to accrete by inorganic chemical precipitation around moving grains. The high organic content and the presence of biosignatures, however, suggest that ooids interact with benthic microbial communities. Here, we investigate the role of benthic processes on ooid growth on a leeward shore of Cat Island, The Bahamas. Polished ooids are present in the surf zone, whereas dull ooids and grapestones are present in microbially colonized sediments seaward of the surf zone. Wave hydrodynamics and sediment transport modeling suggest that microbially colonized sediments are mobilized at monthly time scales. We propose a new conceptual model for both ooids and grapestone. Ooids rest and accrete in the area covered by microbial mats, but are periodically transported to the surf zone where wave abrasion polishes them within days. Ooids are then transported back to microbially colonized areas where the accretion cycle resumes. Ooids too large to be transported become trapped outside the surf zone, exit the “conveyor belt” and become grapestones. The benthic growth mechanism predicts petrographic characteristics that match observations: successive ooid laminae do not thin outward, laminae exhibit irregularities, and some ooids include multiple nuclei. Keywords: Pigeon Cay; grapestone; abrasion; carbonate precipitation; microbial matUnited States. National Aeronautics and Space Administration (Grant NNA13AA90A

Contribution of Benthic Processes to the Growth of Ooids on a Low-Energy Shore in Cat Island, The Bahamas

Ooids are typically found in frequently reworked coastal sediments, and are thought to accrete by inorganic chemical precipitation around moving grains. The high organic content and the presence of biosignatures, however, suggest that ooids interact with benthic microbial communities. Here, we investigate the role of benthic processes on ooid growth on a leeward shore of Cat Island, The Bahamas. Polished ooids are present in the surf zone, whereas dull ooids and grapestones are present in microbially colonized sediments seaward of the surf zone. Wave hydrodynamics and sediment transport modeling suggest that microbially colonized sediments are mobilized at monthly time scales. We propose a new conceptual model for both ooids and grapestone. Ooids rest and accrete in the area covered by microbial mats, but are periodically transported to the surf zone where wave abrasion polishes them within days. Ooids are then transported back to microbially colonized areas where the accretion cycle resumes. Ooids too large to be transported become trapped outside the surf zone, exit the “conveyor belt” and become grapestones. The benthic growth mechanism predicts petrographic characteristics that match observations: successive ooid laminae do not thin outward, laminae exhibit irregularities, and some ooids include multiple nuclei

Contribution of Benthic Processes to the Growth of Ooids on a Low-Energy Shore in Cat Island, The Bahamas

Ooids are typically found in frequently reworked coastal sediments, and are thought to accrete by inorganic chemical precipitation around moving grains. The high organic content and the presence of biosignatures, however, suggest that ooids interact with benthic microbial communities. Here, we investigate the role of benthic processes on ooid growth on a leeward shore of Cat Island, The Bahamas. Polished ooids are present in the surf zone, whereas dull ooids and grapestones are present in microbially colonized sediments seaward of the surf zone. Wave hydrodynamics and sediment transport modeling suggest that microbially colonized sediments are mobilized at monthly time scales. We propose a new conceptual model for both ooids and grapestone. Ooids rest and accrete in the area covered by microbial mats, but are periodically transported to the surf zone where wave abrasion polishes them within days. Ooids are then transported back to microbially colonized areas where the accretion cycle resumes. Ooids too large to be transported become trapped outside the surf zone, exit the “conveyor belt” and become grapestones. The benthic growth mechanism predicts petrographic characteristics that match observations: successive ooid laminae do not thin outward, laminae exhibit irregularities, and some ooids include multiple nuclei

Paraneoplastic lipase and amylase production in a patient with small-cell lung cancer: Case report

Background: Small-cell lung cancer (SCLC) is known to express antigens of both the neural crest and epithelium, and to secrete polypeptide hormones and enzymes. Anecdotal reports correlate lung cancer with marked hyperamylasemia, and a review of the literature reveals only one case of metastatic SCLC linked to high paraneoplastic lipase production. Case presentation: We present the case of a patient with metastatic SCLC who showed both lipase and pancreatic isoamylase elevation in the absence of acute pancreatitis. Chemotherapy resulted in a rapid reduction in serum lipase and in pancreatic isoamylase which was correlated with the radiological response of the tumor to therapy. Lipase and pancreatic isoamylase expression in tumor cells from the lung biopsy was confirmed by immunohistochemical staining. Conclusions: This is a very rare case of paraneoplastic syndrome linked to metastatic SCLC. The enzymes secreted could be used as markers of response to treatment until clonal selection mechanisms and intratumor heterogeneity induce changes in biochemical characteristics and consequently in tumor behavior

Too much tolerance for hyperoxemia in mechanically ventilated patients with SARS-CoV-2 pneumonia? Report from an Italian intensive care unit

Background: In COVID-19 patients requiring mechanical ventilation, the administration of high oxygen (O2) doses for prolonged time periods may be necessary. Although life-saving in most cases, O2 may exert deleterious effects if administered in excessive concentrations. We aimed to describe the prevalence of hyperoxemia and excessive O2 administration in mechanically ventilated patients with SARS-CoV-2 pneumonia and determine whether hyperoxemia is associated with mortality in the Intensive Care Unit (ICU) or the onset of ventilator-associated pneumonia (VAP). Materials and methods: Retrospective single-center study on adult patients with SARS-CoV-2 pneumonia requiring invasive mechanical ventilation for ≥48 h. Patients undergoing extracorporeal respiratory support were excluded. We calculated the excess O2 administered based on the ideal arterial O2 tension (PaO2) target of 55–80 mmHg. We defined hyperoxemia as PaO2 > 100 mmHg and hyperoxia + hyperoxemia as an inspired O2 fraction (FiO2) > 60% + PaO2 > 100 mmHg. Risk factors for ICU-mortality and VAP were assessed through multivariate analyses. Results: One hundred thirty-four patients were included. For each day of mechanical ventilation, each patient received a median excess O2 of 1,121 [829–1,449] L. Hyperoxemia was found in 38 [27–55]% of arterial blood gases, hyperoxia + hyperoxemia in 11 [5–18]% of cases. The FiO2 was not reduced in 69 [62–76]% of cases of hyperoxemia. Adjustments were made more frequently with higher PaO2 or initial FiO2 levels. ICU-mortality was 32%. VAP was diagnosed in 48.5% of patients. Hyperoxemia (OR 1.300 95% CI [1.097–1.542]), time of exposure to hyperoxemia (OR 2.758 [1.406–5.411]), hyperoxia + hyperoxemia (OR 1.144 [1.008–1.298]), and daily excess O2 (OR 1.003 [1.001–1.005]) were associated with higher risk for ICU-mortality, independently of age, Sequential Organ failure Assessment score at ICU-admission and mean PaO2/FiO2. Hyperoxemia (OR 1.033 [1.006–1.061]), time of exposure to hyperoxemia (OR 1.108 [1.018–1.206]), hyperoxia + hyperoxemia (OR 1.038 [1.003–1.075]), and daily excess O2 (OR 1.001 [1.000–1.001]) were identified as risk factors for VAP, independently of body mass index, blood transfusions, days of neuromuscular blocking agents (before VAP), prolonged prone positioning and mean PaO2/FiO2 before VAP. Conclusion: Excess O2 administration and hyperoxemia were common in mechanically ventilated patients with SARS-CoV-2 pneumonia. The exposure to hyperoxemia may be associated with ICU-mortality and greater risk for VAP