179 research outputs found

    Paleosuoli tipo terra rossa al margine prealpino. Il caso di studio del Monte Casto (Val Sabbia -Brescia)

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    L\u2019area della Val Sabbia, nel suo tratto prealpino, \ue8 caratterizzata dalla presenza di una paleosuperficie su cui si sviluppano suoli di tipo Terra Rossa, spesso costituiti da coltri colluviate e, solo in particolari situazioni, conservati in posto. Il profilo in esame \ue8 stato identificato e descritto sulle pendici del Monte Casto, un piccolo rilievo calcareo che raggiunge i 400 m di quota. Il profilo \ue8 costituito da due unit\ue0 pedologiche distinte che vanno a formare un profilo composito: l\u2019unit\ue0 profonda \ue8 un paleosuolo fersiallitico in posto, tipo Terra Rossa, mentre quella superficiale mostra le caratteristiche di una successione di pi\uf9 coltri di loess pedogenizzate. Le due unit\ue0 sono state distinte in base alle loro caratteristiche micromorfologiche, chimiche e fisiche, e attraverso parametri e indici che ne hanno evidenziato il diverso grado di sviluppo morfologico e di espressione della pedogenesi: conseguenze, queste ultime, di un profondo cambiamento ambientale che ha interessato l\u2019area in esame durante la sua storia geologica pi\uf9 recente.The Prealpine reach of the Val Sabbia is characterised by the presence of a paleosurface strictly associated to the development of Terra Rossa type soils. They are often constituted by colluviated blankets of soil material and, only in particular situations, preserved in place. The described soil profile has been identified on the slopes of Mount Casto (a limestone plateau 400 m high). The profile is composed of two different pedologic units: the deeper one is a Terra Rossa fersiallitic paleosol in place, while the upper one is a soil developed from some loess blankets. The two units can be identified on the basis of their micromorphological, chemical and physical characteristics and, above all, using indexes and parameters enhancing their different degree of morphological development and of pedogenetic expression; the latter due to a paleoenvironmental change affecting the study area during its recent geological history

    Alpine gullies system evolution : erosion drivers and control factors. Two examples from the western Italian Alps

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    Denudation processes affecting mountain slopes may vary according to different factors (e.g., lithology and structural setting of bedrock, climate, relief features), which may be very diverse at the local scale. Gully complex systems, characterised by morphological features similar to those developing in other climate contexts (i.e., pseudo-badlands) are also becoming common at higher altitudes and latitudes. The selected study cases of Gran Gorgia (Susa Valley) and Saint Nicolas (Aosta Valley), in the Western Italian Alps, are sites of geomorphological interest as they are specifically relevant for their scientific features. The aims of this work are (i) reconstructing the morphometric evolution of gully systems and vegetation colonisation time by means of multitemporal spatial analysis on surface morphological changes under water erosion; (ii) reconstructing in detail, through dendrogeomorphological analysis, the progressive spatial surface denudation and changes in erosion rates, by analysing trees and exposed roots and using different indicators (i.e., compression wood, traumatic resin ducts); (iii) obtaining data on successive aggradation/degradation episodes along slopes surrounding such hotspots through geopedological investigations; and (iv) identifying which control factors exert a predominant role on denudation patterns in such contexts. Multidisciplinary analyses regarding the study sites allowed for detailing of erosional history of the studied slopes detecting the prevailing drivers of their evolution. According to the results and considering the common climate and bedrock conditions, the structural background seems to have more influence on slope evolution at the Saint Nicolas site, while superficial geomorphic processes seem to be more relevant at the Gran Gorgia site. Because the sites have already been recognised as part of geoheritage by local authorities, the data obtained in the present research on their genesis, evolution, and local drivers affecting the rates of denudation (i.e., scientific relevance of the site) suggests that description of the sites for dissemination purposes should include links to the entire slope history

    Geomorphology of the Mt. Cusna Ridge (Northern Apennines, Italy) : evolution of a Holocene landscape

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    The Mt. Cusna ridge, located in the Northern Apennines (North Italy), is a mountain area of relevant geological interest for the interaction through time of distinct geomorphic processes, acting since the end of the Last Glacial Maximum. A geomorphological map at the 1:10,000 scale was produced to characterise the main landforms and processes identifiable on the ridge. From this, a detailed reconstruction of the Holocene landscape history of the area is drawn. After deglaciation, at the end of the Pleistocene, glacial and periglacial processes left wide deposits and barren surfaces. Slope and running water processes acted cyclically on the landscape through phases of stronger slope denudation and landslide activation followed by stability periods. These processes are related to the main climatic changes recorded for the N Apennines during the Holocene. Since the Late Holocene, the impact of human communities may have played a prominent role as an agent of landscape modification

    The Dlx5 homeodomain gene is essential for normal olfactory development and connectivity in the mouse.

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    Towards a map of the Upper Pleistocene loess of the Po Plain Loess Basin (Northern Italy)

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    Upper Pleistocene (MIS 4-2) loess sequences occur in most of continental Europe and in Northern Italy along the Po Plain Loess Basin. Loess is distributed along the flanks of the Po Plain and was deposited on glacial deposits, fluvial terraces, uplifted isolated hills, karst plateaus, slopes and basins of secondary valleys. Loess bodies are generally tiny and affected by pedogenesis, being locally slightly reworked by slope processes and bioturbation. Notwithstanding, loess in the Po Plain is an important archive of paleoenviron-mental record and its mapping provides new insights in paleoenvironmental and palaeoseismic reconstructions of Northern Italy

    Characterization of MCF mammary epithelial cells overexpressing the Arylhydrocarbon receptor (AhR)

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    <p>Abstract</p> <p>Background</p> <p>Recent reports indicate the existence of breast cancer cells expressing very high levels of the Arylhydrocarbon receptor (AhR), a ubiquitous intracellular receptor best known for mediating toxic action of dioxin and related pollutants. Positive correlation between the degree of AhR overexpression and states of increasing transformation of mammary epithelial cells appears to occur in the absence of any exogenous AhR ligands. These observations have raised many questions such as why and how AhR is overexpressed in breast cancer and its physiological roles in the progression to advanced carcinogenic transformation. To address those questions, we hypothesized that AhR overexpression occurs in cells experiencing deficiencies in normally required estrogen receptor (ER) signaling, and the basic role of AhR in such cases is to guide the affected cells to develop orchestrated cellular changes aimed at substituting the normal functions of ER. At the same time, the AhR serves as the mediator of the cell survival program in the absence of ER signaling.</p> <p>Methods</p> <p>We subjected two lines of Michigan Cancer Foundation (MCF) mammary epithelial cells to 3 different types ER interacting agents for a number of passages and followed the changes in the expression of AhR mRNA. The resulting sublines were analyzed for phenotypical changes and unique molecular characteristics.</p> <p>Results</p> <p>MCF10AT1 cells continuously exposed to 17-beta-estradiol (E2) developed sub-lines that show AhR overexpression with the characteristic phenotype of increased proliferation, and distinct resistance to apoptosis. When these chemically selected cell lines were treated with a specific AhR antagonist, 3-methoxy-4-nitroflavone (MNF), both of the above abnormal cellular characteristics disappeared, indicating the pivotal role of AhR in expressing those cellular phenotypes. The most prominent molecular characteristics of these AhR overexpressing MCF cells were found to be overexpression of ErbB2 and COX-2. Furthermore, we could demonstrate that suppression of AhR functions through anti-AhR siRNA or MNF causes the recovery of ERalpha functions.</p> <p>Conclusion</p> <p>One of the main causes for AhR overexpression in these MCF breast cancer cells appears to be the loss of ERalpha functions. This phenomenon is likely to be based on the mutually antagonistic relationship between ER and AhR.</p
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