56 research outputs found

    STRATIGRAPHIC AND STRUCTURAL ANALYSIS OF A HIGH RESOLUTION SEISMIC SURVEY PERFORMED IN THE BAY OF AUGUSTA (SE SICILY)

    Get PDF
    The Bay of Augusta is located along the NE margin of the Hyblean Plateau (SE Sicily). In this area a mostly bioclastic and terrigenous Quaternary succession outcrops. This area recorded a constant regional uplift rate of <1 mm/yr during the Late Pleistocene and recurrent, strong (up to 7.0 Md) historical earthquakes. Data for this study come from a recent nearshore geophysical survey performed by URS Corporation Ltd with the aim to evaluate the potential for seismic hazard. The collected data consist of: 1) a high resolution seismic survey (sparker source and sub-bottom profiling); 2) five soil borings to characterize and obtain age dates for shallow subsea sediments. Four main seismic units have been recognized inside the sedimentary infill: • Unit D is the oldest, seawards dipping, unit overlying the acoustic basement. Upwards this unit is bounded by a rough, erosional truncation (horizon H4). • Unit C shows sub-horizontal reflectors with variable seismic attributes, forming a prominent angular unconformity above H4; in the proximal sector of the Augusta Bay they lie seaward dipping. This unit shows valuable thickness change across the Bay and is bounded upwards by a very rough erosional truncation (horizon H3). • Unit B shows planar parallel reflectors with good lateral continuity. Its thickness change and it is very thin along the slope of the morphostructural highs formed by uplift of units D and C. Upwards it is bounded by a very prominent erosional truncation (H2 horizon). • Unit A is imaged by sub-horizontal, continuous reflectors, alternating with intervals of transparent seismic facies. The reflectors onlap the H2 horizon and, in a few places, display prograding geometry. On the collected samples biochronological and radiometric age-dating has been performed. The cores drilled the unit A and the uppermost part of the unit B, where the sediments have revealed absolute age > 50 kA. Two main groups of faults, referred to as the northwest and the southwest fault zones, are separated by a central zone where no evident fault planes have been imaged by seismic data. The faults in both groups strike from N30W to N52W and are also inferred to be steeply dipping. The faults pertaining to northwestern cluster show a very little offset, < 15 m. These faults have displaced mostly seismic unit C and have controlled two, NW-SE trending little structural lows in the central and in the northernmost sectors of the investigated area. These restricted basins have been filled by B and A seismic units deposits that don’t appear displaced by the fault cluster. The southeastern fault zone is long less than 700 m and show an offset of 1 to 5 m. These faults displaced the horizons of seismic Unit C in a sector where this unit outcrops at the sea bottom or it is draped by a very thin veneer of Unit A sediments. The faults pertaining to the northwestern zone post-date Unit C but they appear older than Units B and A.Radiocarbon age-dating have demonstrated that the most recent horizons involved in the northwestern fault zone displacement is > 50 kA. As concern the southeastern fault zone, results coming from radiocarbon age dating don’t have sufficient resolution to correlate deposits to seismic horizons involved in tectonic deformation. Nevertheless, there the seismic unit A also appears slightly involved by the latest faults activity. The analysis of the Bay of Augusta seismic grid has shown that very recent tectonic features have displaced the Late Quaternary sedimentary infill; interpretation of our results could better constrain the neotectonic setting of an area characterized by high seismic hazard

    VARIABILITY OF DEPOSITIONAL SETTING ALONG THE NORTH-WESTERN SICILY CONTINENTAL SHELF (ITALY) DURING LATE QUATERNARY: EFFECTS OF SEA LEVEL CHANGES AND TECTONIC EVOLUTION

    Get PDF
    The geological, geomorphological and sedimentological features of the north-western Sicily continental shelf are here illustrated with the aim to propose a geological model able to explain the Neogene-Quaternary evolution of the Sicilian continental margin in the context of the central Mediterranean region. Above the continental shelf and upper slope the sedimentary succession, showing along the different sectors of the margin considerably variable internal geometry and stratigraphic relationships with the underlying units, is interpreted as a IV order depositional sequence (Late Quaternary Depositional Sequence, LQDS) deposited during the last eustatic change (last 125 ky). The lower boundary of the LQDS is represented by a subaerial erosional surface formed during the last eustatic sea level fall ended in the LGM (20-18 ka). This unconformity lies above a seaward dipping Pleistocene succession whose depositional architecture is in turn controlled by Quaternary eustatic sea-level fluctuations. A dense dataset of morphobathymetric and high resolution seismic data allowed to recognize along the continental shelf to bathyal plain system different types of continental shelf with different stratigraphic and morphostructural settings, associated to both large-scale processes and specific factors related to more local control: a) predominantly rocky shelves, both accompanied by a moderate frontal sedimentary prism and with a structural edge, in the structural highs of the Monti di Palermo offshore and around the main rocky headlands (Capo San Vito, Monte Catalfano); b), depositional shelves, in the Castellammare, Palermo and Termini Imerese gulfs, both with a regular seaward deepening of the substrate and with a substrate uplift at the shelf break. We confirm that depositional sequences in this margin are the result of the interaction between sea level changes and sedimentation, but demonstrate that the tectonic activity has played a key role, not only in the creation of different types of continental shelves, but also to determine the different characters of each sequence in different areas. The general tectonic uplift during the Pleistocene, together with the episodic alternation of extensional and compressional events, often with strike-slip component, is responsible for the thickness and facies variation both onland, where residual Pleistocene marine deposits today outcrops, and in the continental shelf, where most of the depositional sequences developed and are now recognized. As well tectonic activity exerted a control on the geomorphological features (e.g. pockmarks and mounds) of the present day coastal areas and shelf-slope system, as well as for the submarine canyons and the mass failure processes

    Exploration and learning in capuchin monkeys (Sapajus spp.): the role of action-outcome contingencies

    Get PDF
    Animals have a strong propensity to explore the environment. Spontaneous exploration has a great biological significance since it allows animals to discover and learn the relation between specific behaviours and their consequences. The role of the contingency between action and outcome for learning has been mainly investigated in instrumental learning settings and much less in free exploration contexts. We tested 16 capuchin monkeys (Sapajus spp.) with a mechatronic platform that allowed complex modules to be manipulated and to produce different outcomes. Experimental subjects could manipulate the modules and discover the contingencies between their own specific actions and the outcomes produced (i.e., the opening and lighting of a box). By contrast, Control subjects could operate on the modules, but the outcomes experienced were those performed by their paired Experimental subjects (\u27\u27yoked-control\u27\u27 paradigm). In the exploration phase, in which no food reward was present, Experimental subjects spent more time on the board and manipulated the modules more than Yoked subjects. Experimental subjects outperformed Yoked subjects in the following test phase, where success required recalling the effective action so to open the box, now baited with food. These findings demonstrate that the opportunity to experience action-outcome contingencies in the absence of extrinsic rewards promotes capuchins\u27 exploration and facilitates learning processes. Thus, this intrinsically motivated learning represents a powerful mechanism allowing the acquisition of skills and cognitive competence that the individual can later exploit for adaptive purposes

    Empirical experiments on intrinsic motivations and action acquisition: results, evaluation, and redefinition

    Get PDF
    This document presents Deliverable D3.2 of the EU-funded Integrated Project "IM-CLeVeR - Intrinsically Motivated Cumulative Learning Versatile Robots", contract n. FP7-ICT-IP-231722.The aims of the deliverable, as given in the original IM-CLEVER proposal were to identify new key empirical phenomena and processes, allowing the design of a second set of experiments. This report covers: (1) novelty detection and discovery of when/what/how of agency in experiments with humans ("joystick experiment") and Parkinson patients. (2) how object properties that stimulate intrinsically motivated interaction and facilitate the acquisition of adaptive knowledge and skills in monkeys and children ("board experiment")

    Exploration and learning in capuchin monkeys (Sapajus spp.): the role of action-outcome contingencies

    Get PDF
    Abstract Animals have a strong propensity to explore the environment. Spontaneous exploration has a great biological significance since it allows animals to discover and learn the relation between specific behaviours and their consequences. The role of the contingency between action and outcome for learning has been mainly investigated in instrumental learning settings and much less in free exploration contexts. We tested 16 capuchin monkeys (Sapajus spp.) with a mechatronic platform that allowed complex modules to be manipulated and to produce different outcomes. Experimental subjects could manipulate the modules and discover the contingencies between their own specific actions and the outcomes produced (i.e., the opening and lighting of a box). By contrast, Control subjects could operate on the modules but the outcomes experienced were those performed by their paired Experimental subjects (&quot;yoked-control&quot; paradigm). In the Exploration Phase, in which no food reward was present, Experimental subjects spent more time on the board and manipulated the modules more than Yoked subjects. Experimental subjects outperformed Yoked subjects in the following Test phase, where success required recalling the effective action so to open the box, now baited with food. These findings demonstrate that the opportunity to experience action-outcome contingencies in the absence of extrinsic rewards promotes capuchins&apos; exploration and facilitates learning processes. Thus, this intrinsically motivated learning represents a powerful mechanism allowing the acquisition of skills and cognitive competence that the individual can later exploit for adaptive purposes

    Psychological dimensions associated with youth engagement in climate change issues: a person-centered approach

    Get PDF
    Climate change is one of the greatest global threats that has ecological, economic, social, and psychological consequences. Nowadays, young people are the target of political agenda since they represent potential future policymakers. Consequently, it is crucial to identify the psychological features that contribute to engagement of young people in climate change issue. This study aimed at identifying and describing different configurations of youth perceiving and experiencing climate change. A sample of 224 participants (61% females; Mage = 21.04, SD = 1.65) were involved in study. From a cluster analysis emerged three distinct profiles, Eco-Disengaged, Eco-Engaged/Oriented and Eco-Engaged/Disoriented, which differ in levels of climate change awareness, worry and anxiety. Findings suggest that institutions might develop green education programs based on young people’s individual difference

    Synthesis and characterization of CdS nanoparticles embedded in a polymethylmethacrylate matrix

    Get PDF
    CdS nanopowder capped with sodium bis(2-ethylhexyl)sulfosuccinate was synthesized by using water-in-oil microemulsions. The CdS nanoparticles of about 5 nm obtained were embedded in polymethylmethacrylate matrix by a photocuring process. The transparent yellow solid compound was characterized by optical absorption and emission spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The properties of this compound were compared with those of the nanopowder dispersed in heptane and in methylmethacrylate. The results obtained indicate that the nanoparticles are homogeneously dispersed in the matrix and do not change in size during the embedding process. Even if the surface slightly changes its luminescence properties, as a consequence of the different new chemical environment, the final product seems to be suitable for practical applications

    Does Presentation Format Influence Visual Size Discrimination in Tufted Capuchin Monkeys (Sapajus spp.)?

    Get PDF
    Most experimental paradigms to study visual cognition in humans and non-human species are based on discrimination tasks involving the choice between two or more visual stimuli. To this end, different types of stimuli and procedures for stimuli presentation are used, which highlights the necessity to compare data obtained with different methods. The present study assessed whether, and to what extent, capuchin monkeys\u27 ability to solve a size discrimination problem is influenced by the type of procedure used to present the problem. Capuchins\u27 ability to generalise knowledge across different tasks was also evaluated. We trained eight adult tufted capuchin monkeys to select the larger of two stimuli of the same shape and different sizes by using pairs of food items (Experiment 1), computer images (Experiment 1) and objects (Experiment 2). Our results indicated that monkeys achieved the learning criterion faster with food stimuli compared to both images and objects. They also required consistently fewer trials with objects than with images. Moreover, female capuchins had higher levels of acquisition accuracy with food stimuli than with images. Finally, capuchins did not immediately transfer the solution of the problem acquired in one task condition to the other conditions. Overall, these findings suggest that - even in relatively simple visual discrimination problems where a single perceptual dimension (i.e., size) has to be judged - learning speed strongly depends on the mode of presentation

    The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

    Get PDF
    The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article
    • …
    corecore