369 research outputs found
Evidence of slope instability in the Southwestern Adriatic Margin
International audienceThe Southwestern Adriatic Margin (SAM) shows evidence of widespread failure events that generated slide scars up to 10 km wide and extensive slide deposits with run out distances greater than 50 km. Chirp-sonar profiles, side-scan sonar mosaics, multibeam bathymetry and sediment cores document that the entire slope area underwent repeated failures along a stretch of 150 km and that mass-transport deposits, covering an area of 3320 km2, are highly variable ranging from blocky slides to turbidites, and lay on the lower slope and in the basin. The SAM slope between 300?700 m is impacted by southward bottom currents shaping sediment drifts (partly affected by failure) and areas of dominant erosion of the seafloor. When slide deposits occur in areas swept by bottom currents their fresh appearence and their location at seafloor may give the misleading impression of a very young age. Seismic-stratigraphic correlation of these deposits to the basin floor, however, allow a more reliable age estimate through sediment coring of the post-slide unit. Multiple buried failed masses overlap each other in the lower slope and below the basin floor; the most widespread of these mass-transport deposits occurred during the MIS 2-glacial interval on a combined area of 2670 km2. Displacements affecting Holocene deposits suggest recent failure events during or after the last phases of the last post-glacial eustatic rise. Differences in sediment accumulation rates at the base or within the sediment drifts and presence of downlap surfaces along the slope and further in the basin may provide one or multiple potential weak layers above which widespread collapses take place. Neotectonic activity and seismicity, together with the presence of a steep slope, represent additional elements conducive to sediment instability and failure along the SAM. Evidence of large areas still prone to failure provides elements of tsunamogenic hazard
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Comparison of rating-based and choice-based conjoint analysis models. A case study based on preferences for iced coffee in Norway
The authors compare two conjoint analysis approaches eliciting consumer preferences among different product profiles of iced coffees in Norway: rating-based and choice-based conjoint experiments. In the conjoint experiments, stimuli were presented in the form of mock-up pictures of iced coffees varying in coffee type, production origin, calorie content and price, following an orthogonal design. One group of participants (n = 101) performed a rating task of 12 iced coffees whereas another group (n = 102) performed a choice task on 20 iced coffees presented in eight triads. Then, all participants performed self-explicated rating and ranking evaluations of the iced coffee attributes. The rating data were analyzed by a Mixed Model ANOVA while the choice data were analyzed by a Mixed Logit Model. Both models include conjoint factors, demographic variables and their interactions. Results show that the two approaches share similar main results, where consumers prefer low calorie and low price iced coffee products. However, additional effects are detected within each of the two approaches. Further, self-explicated measures indicate that coffee type is the primary attribute for consumers’ selection of iced coffee. The two conjoint approaches are compared and discussed in terms of experimental designs, data analysis methodologies, outcomes, user-friendliness of the results interpretation, estimation power and practical issues
Bilateral antererior circulation stroke: A rare but threatening consequence of pituitary apoplexy. Case report and systematic literature review
Background: Brain stroke is a rare, life-threatening condition associated with pituitary apoplexy (PA), resulting from direct arterial occlusion due to mechanical compression secondary to the sudden enlargement of the pituitary adenoma, or to vessel vasospasm, induced by tumor hemorrhage. Case report: We report the case of a 64-year-old woman with PA complicated by bilateral anterior circulation stroke due to critical stenosis of both anterior cerebral arteries (ACA). Despite the quick surgical decompression and consequent blood flow restoration, the neurological conditions of the patient did not improve and she died 18 days later. Ten other cases of anterior circulation stroke due to PA were retrieved in a systematic review of literature. Clinical and neuroradiological features of these patients and treatment outcome were assessed to suggest the most proper management. Conclusion: The onset of neurological symptoms suggestive for brain stroke in patients with PA requires performing an emergency Magnetic Resonance Imaging (MRI), including Diffusion-weighted and angiographic MR-sequences. The role of surgery in these cases is debated, however, transsphenoidal adenomectomy would permit us to decompress the ACA and restore blood flow in their territories. Although the prognosis of PA-induced anterior circulation stroke is generally poor, a timely diagnosis and treatment would be paramount for improving patient outcome
Germano Sartelli
Libro-catalogo della mostra sugli artisti imolesi che hanno partecipato alle Biennali Internazionali d'arte di Venezia. Capitolo dedicato all'opera dello scultore Germano Sartelli, tra i principali esponenti dell'informale italiano
Intron 4–5 hTERT DNA Hypermethylation in Merkel Cell Carcinoma: Frequency, Association with Other Clinico-pathological Features and Prognostic Relevance
Merkel cell carcinoma (MCC) is an aggressive skin tumor with neuroendocrine differentiation, mainly affecting elderly population or immunocompromised individuals. As methylation of the human telomerase reverse transcriptase (mhTERT) has been shown to be a prognostic factor in different tumors, we investigated its role in MCC, in particular in intron 4–5 where rs10069690 has been mapped and recognized as a cancer susceptibility locus. DNA methylation analysis of hTERT gene was assessed retrospectively in a cohort of 69 MCC patients from the University of Bologna, University of Turin and University of Insubria. Overall mortality was evaluated with Kaplan-Meier curves and multivariable Royston-Parmar models. High levels of mhTERT (mhTERThigh) (HR = 2.500, p = 0.015) and p63 (HR = 2.659, p = 0.016) were the only two clinico-pathological features significantly associated with a higher overall mortality at the multivariate analysis. We did not find different levels of mhTERT between MCPyV (+) and (−) cases (21 vs 14, p = 0.554); furthermore, mhTERThigh was strongly associated with older age (80.5 vs 72 years, p = 0.026), no angioinvasion (40.7% vs 71.0%, p = 0.015), lower Ki67 (50 vs 70%, p = 0.005), and PD-L1 expressions in both tumor (0 vs 3%, p = 0.021) and immune cells (0 vs 10%, p = 0.002). mhTERT is a frequently involved epigenetic mechanism and a relevant prognostic factor in MCC. In addition, it belongs to the shared oncogenic pathways of MCC (MCPyV and UV-radiations) and it could be crucial, together with other epigenetic and genetic mechanisms as gene amplification, in determining the final levels of hTERT mRNA and telomerase activity in these patients
How to make a 350-m-thick lowstand systems tract in 17,000 years: The Late Pleistocene Po River (Italy) lowstand wedge
The 350-m-thick succession of the Po River lowstand wedge (Italy) associated with the Last
Glacial Maximum (deposited over ~17 k.y) contains stratal architecture at a physical scale
commonly attributed to much longer time scales, with complex, systematically varying internal
clinothem characteristics. This study investigated clinothem stacking patterns and controls
through the integration of seismic reflection data with sediment attributes, micropaleontology, regional climate, eustacy, and high-resolution age control possible only in Quaternary
sequences. Three clinothem types are differentiated based on topset geometry, shelf-edge
and onlap-point trajectory, internal seismic facies, and interpreted bottomset deposits: type
A has moderate topset aggradation, ascending shelf-edge trajectory, and mass-transport bottomset deposits; type B has eroded topset, descending shelf-edge trajectory, and bottomset
distributary channel-lobe complexes; and type C has maximal topset aggradation, ascending
shelf-edge trajectory, and concordant bottomsets. Type A and C clinothems exhibit reduced
sediment bypass and delivery to the basin, whereas type B clinothems are associated with
short intervals of increased sediment export from the shelf to deeper water. Clinothems individually span a range of 0.4–4.7 k.y., contemporaneous with significant eustatic and climate
changes, but their stacking patterns resemble those found in ancient successions and ascribed
to significantly longer durations, indicating that (1) the response time of ancient continental
margin–scale systems to high-frequency variations in accommodation and sediment supply
could be as short as centuries, (2) even millennial- to centennial-scale stratal units can record
substantial influence of allogenic controls, and (3) sandy deposits can be compartmentalized
even in a short-duration lowstand systems tract
Large-scale response of the Eastern Mediterranean thermohaline circulation to African monsoon intensification during sapropel S1 formation
This study was supported by Shell International Exploration and Production Inc. We thank the R/V URANIA crew for at sea assistance. This is the ISMAR contribution n. 1914. We thank Dr. L. Capotondi and Dr. L. Vigliotti for their constructive comments on the first draft of the manuscript. We also thank Dr. Daria Pasqual (University of Padova, Dept. of Geosciences) for her assistance in XRF analyses. We thank two anonymous reviewers and the Editor H. Bauch for their constructive comments. We also acknowledge Prof. Gerhard Schmiedl (Universität Hamburg) and Associate Prof. Syee Weldeab (Earth Science, UC Santa Barbara) for providing published data used in this study.Peer reviewedPostprin
Large-scale response of the Eastern Mediterranean thermohaline circulation to African monsoon intensification during sapropel S1 formation
The formation of Eastern Mediterranean sapropels has periodically occurred during intensification of northern hemisphere monsoon precipitation over North Africa. However, the large-scale response of the Eastern Mediterranean thermohaline circulation during these monsoon-fuelled freshening episodes is poorly constrained. Here, we investigate the formation of the youngest sapropel (S1) along an across-slope transect in the Adriatic Sea. Foraminifera-based oxygen index, redox-sensitive elements and biogeochemical parameters reveal – for the first time – that the Adriatic S1 was synchronous with the deposition of south-eastern Mediterranean S1 beds. Proxies of paleo thermohaline currents indicate that the bottom-hugging North Adriatic Dense Water (NAdDW) suddenly decreased at the sapropel onset simultaneously with the maximum freshening of the Levantine Sea during the African Humid Period. We conclude that the lack of the “salty” Levantine Intermediate Water hampered the preconditioning of the northern Adriatic waters necessary for the NAdDW formation prior to the winter cooling. Consequently, a weak NAdDW limited in turn the Eastern Mediterranean Deep Water (EMDWAdriatic) formation with important consequences for the ventilation of the Ionian basin as well. Our results highlight the importance of the Adriatic for the deep water ventilation and the interdependence among the major eastern Mediterranean water masses whose destabilization exerted first-order control on S1 deposition
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