19 research outputs found

    One year after on Tyrrhenian coasts: The ban of cotton buds does not reduce their dominance in beach litter composition

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    In January 2019, Italy banned the sale of plastic cotton buds, which is one of the most abundant litter items entering the sea and then washing ashore. However, since the ban came into force, no studies have been carried out to assess whether the measure has actually led to the reduction of plastic cotton buds accumulating on Italian coasts. Here we aim at evaluating the effectiveness of the ban in reducing the amount of cotton buds reaching sandy beaches of the Tyrrhenian coast. Specifically, we monitored the accumulation of beach litter for one year since the ban came into force. By surveying eight coastal sites from winter 2019 to winter 2020, we collected a total of 52,824 items mostly constituted by plastic debris (97.6%). We found that cotton buds were the most abundant item (42.3% of total litter), followed by plastic (28.5%) and polystyrene (5.43%) fragments. Our preliminary assessment suggests that the ban has so far not led to a sensible reduction in the amount of cotton buds entering the marine ecosystem. This was to be expected since implementation strategies are still lacking (i.e. no economic sanctions can be imposed in case of non-compliance) and bans are differently implemented among countries facing the Mediterranean Sea, calling for law enforcement and implementation at the national and international levels

    Excitotoxic lesion of the perirhinal cortex impairs spatial working memory in a delayed-alternation task.

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    The perirhinal cortex (PRh) is strategically located between the neocortex and memory-related structures such as the entorhinal cortex and the hippocampal formation. The pattern of strong reciprocal connections between these areas, together with experimental evidence that PRh damage induces specific memory deficits, has placed this cortical region at the center of a growing interest for its role in learning and memory mechanisms. The aim of the present study is to clarify the involvement of PRh in learning and retention in a novel experimental model of spatial working memory, the water T-maze. The data show that pre-acquisition neurotoxic PRh lesions caused task-learning deficits. This impairment was observed during the acquisition phase as well as the retrieval phase. On the other hand, a post-acquisition PRh neurotoxic lesion failed to impair the acquisition and the retrieval of the water T-maze task performed 32 day after lesion. These results suggest a possible key role of PRh in the acquisition but not in the retention of a working memory task. Furthermore, these results show that the water T-maze may be a suitable learning paradigm to study different components of learning and memory

    Excitotoxic lesion of the perirhinal cortex impairs spatial working memory in a delayed-alternation task.

    No full text
    The perirhinal cortex (PRh) is strategically located between the neocortex and memory-related structures such as the entorhinal cortex and the hippocampal formation. The pattern of strong reciprocal connections between these areas, together with experimental evidence that PRh damage induces specific memory deficits, has placed this cortical region at the center of a growing interest for its role in learning and memory mechanisms. The aim of the present study is to clarify the involvement of PRh in learning and retention in a novel experimental model of spatial working memory, the water T-maze. The data show that pre-acquisition neurotoxic PRh lesions caused task-learning deficits. This impairment was observed during the acquisition phase as well as the retrieval phase. On the other hand, a post-acquisition PRh neurotoxic lesion failed to impair the acquisition and the retrieval of the water T-maze task performed 32 day after lesion. These results suggest a possible key role of PRh in the acquisition but not in the retention of a working memory task. Furthermore, these results show that the water T-maze may be a suitable learning paradigm to study different components of learning and memory

    Rheological heterogeneities at the roots of the seismogenic zone

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    Although rheological heterogeneities are invoked to explain differences in fault-slip behavior, case studies where an interdisciplinary approach is adopted to capture their specific roles are still rare. In this work, we integrated geophysical, geological, and laboratory data to explain how rheological heterogeneities influence the earthquake activity at the roots of the seismogenic zone. During the 2016–2017 Central Italy sequence, following the major earthquakes, we observed a deepening of seismicity within the basement associated with a transient stress change. Part of this seismicity was organized in clusters of events, with similar sizes and waveforms. The structural study of exhumed basement rocks highlighted a heterogeneous fabric made of strong, quartz-rich lenses (up to 200 m) surrounded by a weak, interconnected phyllosilicate-rich matrix. Laboratory experiments simulating the main shock–induced increase in loading rate showed that the matrix lithology experienced an ac- celerating and self-decelerating aseismic creep, whereas the lens lithology showed dynamic instabilities. Our results suggest that the post–main shock loading rate increases favored accelerated creep within the matrix, which promoted, as a consequence, seismic instabilities within the lenses in the form of clustered seismicity. Our findings emphasize the strong connection between seismicity and the structural and frictional properties of the seismogenic zone

    The M. Tancia regional thrust: geometric, kinematic and mechanical characterization within the Structural Geology course at La Sapienza

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    Within the Structural Geology course of the BSC degree at La Sapienza University we have studied the geometry, kinematics and mechanics of a regional thrust fault exposed near Rieti (Lazio) and deformed during the Apenninic compressional phase. The fault is a km-scale displacement structure trending N-S and gently (10-20°) westward dipping. The thrust superposes the Maiolica (Early Cretaceous) over the Scaglia Variegata (Eocene) Formations and it is represented by a 6-8 m thick foliated (SCC’ tectonites) shear zone. Small displacement normal faults showing cataclastic fault rocks, cut the foliated fabric. We have used SCC’ tectonites to characterize the kinematic evolution of the fault zone. We have detected two sets of SCC’ fabric: one set shows a top to the east sense of shear that is consistent with the compressional phase, the second set overprints the first one and is characterized by a top the west kinematics likely due to the quaternary extensional phase of the area. The fault zone is characterized by two main types of fault rocks: principal slipping zones are affected by cataclastic processes, producing grain size reduction and localization; fluid assisted dissolution and precipitation processes promote the development of a distributed foliation within the entire fault zone. During the compressional phase the fault accumulated kilometers of displacement as a well-oriented structure within an Andersonian compressional regime. In the following Quaternary extension, some portions of the shear zone were reactivated via optimally oriented small normal faults, other portions of the fault zone were reactivated as misoriented structures (gently dipping planes) within the Andersonian extensional regime. This misoriented reactivation was likely promoted by clay concentration within the fault planes following pressure-solution processes
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