1,721,038 research outputs found
Distribution of benthic foraminiferal assemblages in the Ombrone River Basin (Tuscany Continental Shelf, Tyrrhenian Sea, Italy). Relationships with fluvial run-off
No full textHyalinea balthica (Schröter): the ecological significance of inflated and compact phenotypes in circalittoral environment.
No full textValvulineria bradyana (Fornasini) in organic matter-enriched environment (Ombrone River mouth, Central Italy).
No full textOpportunistic benthic foraminfera as indicators of eutrophicated environments. Actualistic study and comparison with the Santernian middle Tiber Valley (Central Italy).
No full textDistribution of recent benthic foraminifers in the Ombrone River Basin (Tuscany Continental shelf, Tyrrhenian Sea, Italy). Relations with fluvial run-off.
No full textOpportunistic benthic foraminifera as indicators of eutrophicated environments. Actualistic study and comparison with the Santernian middle Tiber Valley (Central Italy)
No full textThe study of extant organisms is the base of the environmental micropaleontology, since the knowledge of natural mechanisms, which regulate their distribution in present environments, is the necessary base for the reconstruction of fossil environments. Since most shallow-water taxa well tolerate a wide range of environmental conditions, the organic flux, which determines trophic levels, appears the most important factor that regulates the distribution of benthic foraminifera. On the contrary, other variables like substrate, temperature and salinity are less important for their occurrence. Since the end of the 90s, many studies have been performed on recent benthic foraminifera from a small marine basin located along the southern Tuscan shelf, characterized by the sedimentary contribution of the Ombrone River. The geographical features of this basin, named Ombrone River Basin (ORB), are unfavourable to the organic matter dispersion, determining a particularly suitable environment for the study of eutrophicated sea-bottoms. Researches evidenced the correlation between a typical assemblage, dominated by the opportunistic Valvulineria bradyana and the organic flux of fluvial origin. Particularly, the statistical multivariate analysis performed on 127 samples from the ORB helped to determine the distribution of such assemblage. In this work, the quantitative parameters describing the structure of the V. bradyana assemblage (species richness, heterogeneity,
dominance) are evidenced and discussed, defining an actualistic model for assemblages that could be used to evidence the organic paleo-flux in coastal marine areas influenced by river contributions. During the Early Pleistocene, the coast of Latium was located in eastern position with respect to the present one. In front to the coast, some structural highs emerged, forming an island lineage parallel to the coast and delimiting a narrow inner basin. In this basin, the Tiber River and other minor rivers built their delta systems. This paleogegraphic setting has been evaluated as favourable to the development of eutrophicated environments, and consequently many tens of available samples from the clayey terms of the Chiani-Tevere Formation have been considered for a comparison with the actualistic model. The foraminiferal assemblages from three sites, Civita di Bagnoregio, Orte, and Nazzano, are dominated by V. bradyana and show quantitative parameters coinciding with the recent model utilized as marker of the organic flux. These episodes of eutrophication in the inner Tyrrhenian basin may be considered coeval, because all the three successions are ascribed to the Santernian (Globigerina cariacoensis Zone). Considering the paleogeography of the region, it may be supposed that the Civita di Bagnoregio site was probably influenced by the contribution of a small river which flowed
into the Tyrrhenian Sea near this locality. In addition, the Orte and the Nazzano sites corresponded to the Nera and Farfa delta systems, respectively. These preliminary results are encouraging for the development of the research aimed to the reconstruction of the organic paleo-flux along the coast of Latium, with useful implications for a detailed paleogeographic reconstruction of the Santernian middle Tiber Valley. In addition, the good accordance between a paleogeographic reconstruction based on geological evidences and the preliminary results obtained by paleoecological proxies, validate the utility of the actualistic model considered as typical marker of the river organic flux
Benthic Foraminifera as Environmental Indicators in Mediterranean Marine Caves: A Review
Full text linkMarine caves are characterized by wide environmental variability for the interaction between marine and continental processes. Their conditions may be defined as extreme for inhabiting organisms due to the enclosed morphology, lack of light, and scarcity of nutrients. Therefore, it is necessary to identify reliable ecological indicators for describing and assessing environmental conditions in these habitats even more than elsewhere. This review aims to provide the state of art related to the application of benthic foraminifera as proxies in the (paleo)ecological characterization of different habitats of marine caves. Special attention was addressed to a research project focused on Mediterranean marine caves with different characteristics, such as extent, morphology, freshwater influence, salinity, sediment type, oxygenation, and organic matter supply. This review aims to illustrate the reliability of foraminifera as an ecological and paleoecological indicator in these habitats. They respond to various environmental conditions with different assemblages corresponding to a very detailed habitat partitioning. Because marine caves may be considered natural laboratories for environmental variability, the results of these studies may be interpreted in the perspective of the global variability to understand the environmental drivers of future changes in marine systems
Benthic foraminifera in sediment core of Augusta Harbour (Sicily, Italy) as proxies for environmental assessment
No full text
Addressing Challenges in Image Translation for Contrast-Enhanced Mammography using Generative Advesarial Networks
No full textMedical imaging is a cornerstone of modern healthcare, facilitating early diagnosis and the development of efficient treatment plans. Breast imaging includes different imaging modalities, including mammography and MRI, each encompassing unique information. Unfortunately, improving diagnostic performance can be accompanied by an increase in patient-related risks. Specifically, Contrast-enhanced mammography (CEM) offers better performance while exposing women to the risk of adverse reactions from the contrast agents used for it. To reduce these risks, deep learning solutions have become one of the promising research frontiers in recent years. In image-to-image translation, a mapping function is learned to transform a given image from a source domain to a target domain. In medical imaging, the most common solutions are based on GANs, such as pix2pix. When applied to CEM, we found that pix2pix encounters specific challenges due to low data quality, insufficient model capacity, and domain-derived requirements. Thus, these models have low performance out-of-the-box. In this paper, we highlight these specific challenges, propose tailored evaluation strategies, and present preliminary results on a novel dataset, showcasing the need for specialized approaches in medical imaging translation
- …
