Kettle holes are relatively common features of glaciated landscapes and have been widely reported in the literature. The work reported here documents the presence of kettle holes at high altitude and ...low latitude in the Central Apennines (Italy) and describes the geomorphic and pedogenic processes that originated the soils infilling these depressions. The areas selected for this study were located on three of the main massifs of the Central Apennines (Italy): Gran Sasso, Majella, and Sibillini. The kettle holes on these massifs formed at the end of the Würm glaciation, appear smaller and shallower than those reported from elsewhere in the northern hemisphere, are roughly circular in form and do not contain bogs or lakes. In each area the dimensions of 40 kettle holes were measured and three kettle holes were excavated to examine the soils developed inside them. The size of the kettle holes was highest in the Sibillini massif, where the glaciers reached altitudes as low as 1700m in the very narrow, low-lying valleys. It is hypothesised that at lower elevations the glacier receded more rapidly generating larger blocks of ice and consequently larger kettle holes. Once formed, the kettle hole depressions were very effective as sediment traps and acted as sink for materials washed in from the surrounding slopes or from more distant wind-blown sources. In the kettle holes from Gran Sasso and Majella massifs, small fragments of woody charcoal were found. The material filling the kettle holes accumulated inside them in the form of layers. Soils formed inside the kettle holes showed horizons whose thickness and properties appeared mostly inherited from the amassed layers. The only pedogenic process common to the kettle holes of the three massifs was the incorporation of organic matter that, as expected from the rather cold climatic conditions, was subjected to slow dynamics. In the kettle holes of the Majella massif, the horizons developed from layers rich of materials of volcanic origin, and the formation of short-range order minerals occurred. We conclude that the soils inside the kettle holes are a repository of geomorphic, pedogenic and, in reference to the source of the charcoal, paleo-environmental information.
► For the first time is reported the presence of kettle holes at low latitudes. ► For the first time pedogenic processes into kettle holes are reported. ► Geomorphic, pedogenic and paleo-environmental information are stored on kettle holes.
This work dealt with two groups of vineyard soils developed from a thinly layered limestone in central Italy so as to evaluate the evolution of the rock fragments and their capability to release ...nutrients. One group consisted of five soils at 1–2 years after plantation of vines (renewed soils), while the other group was represented by five soils at 20–29 years from plantation (aged soils). Soils were sampled by horizons on a volume basis. Fine earth, rock fragments classed according to the degree of alteration, and fresh rock were analyzed for mineralogy, porosity, pH, total NH
4
+-N, and extractable Ca, Mg and K. Results indicated that the rock fragments of the aged soils were less and appeared more altered than those of the renewed soils. This fact was ascribed to weathering processes that progressively transformed rock fragments into fine earth. Weathering of rock fragments was promoted by the calcite dissolution and the mechanical works made to break up the soil and for routine soil management. Because of this, rock fragments increased porosity and exposed new mineral surfaces to soil solution, with consequent reduction of their size and increasing of their friability and release of NH
4
+-N, Ca, Mg and K.
Magma emplacement in the upper crust is often associated with crustal extension, whereby space for intrusions is made by dilation along transtensive and strike‐slip faults. The lenticular shape of ...several intrusions indicates that a further mechanism for magma intrusion is laccolith emplacement with roof uplift of the overburden. Additionally, melts exploit rheological discontinuities (e.g., sedimentary layering) during their ascent. We present an emplacement model for intrusion of the shallow level Gavorrano Granite (northern Apennine, Italy), which is located at the core of an open anticline. The shape of the intrusion and structural features of the host rocks are indicative of a synkinematic emplacement in a growing thrust anticline. Space was provided by the opening of dilatation zones at the core of anticline as a consequence of different amounts of translation between hanging wall and footwall units which were separated by evaporitic rocks. These evaporitic units acted as major décollement layers. Analog models provide results in good agreement with the structural setting of the anticline and emphasize the possibility that melts filled the dilatation zone, with the décollement layers further facilitating intrusion.
Analogue models investigating the emplacement of granitic magmas at upper crustal levels during strike-slip deformation are presented in this paper. Variations in parameters such as ratio between ...horizontal displacement (
D
v) and vertical magma upraising (
I
v), and the number of feeding points were considered during the experiments. Model results show that a strong interaction between surface faulting and granite intrusions develops during deformation. On one side, magma intrusion influences the sequence of structures development and the final fault pattern. On the other side, magma emplacement is strongly influenced by the syn-intrusion lateral displacement (
D
t), which in turn reflects variations in
D
v and
I
v. For high
D
t values (i.e. high displacement velocity or low injection rate), the importance of the horizontal displacement with respect to the vertical magma upraising results in asymmetric and drop-shaped plutons, with a sheared tail elongating in the sense of the strike-slip displacement. In this case, the intrusion long-axis tracks the long-axis of the strain ellipsoid. For low
D
t values (i.e. low displacement velocity or high injection rate), the strike-slip displacement is strongly subordinated to the vertical magma upraising and pluton emplacement is controlled by development of tensional shears at the surface. In these conditions, the long-axis of the magmatic bodies lies in the quadrants of compression of the strike-slip deformation and intrusions are apparently dragged in an opposite sense to that imposed by the transcurrent deformation.
Experimental design was utilized to simultaneously investigate the effect of varying the type of diluent (insoluble Calcium phosphate or water-soluble arabic gum) and the diluent/matrix ratio on the ...drug release behaviour from both lipophilic (glyceryl behenate, Compritol
®) or hydrophilic (hydroxypropylmethylcellulose) matrix tablets. Ketoprofen, theophylline and sodium sulphadiazine were selected as model drugs on the basis of their respectively very low, medium and high water-solubility, in order to evaluate the influence of this parameter as well. The selected response variables were the dissolution efficiency (i.e. the area under the dissolution curve) after one and six hours and the time necessary to dissolve 10% drug. Tablets obtained by direct compression of drug-diluent-matrix ternary mixtures prepared according to the experimental plan provided for by an asymmetric screening matrix, were tested for drug release properties using a USP paddle apparatus. Graphic analysis of the effects allowed identification, for each examined drug, of the formulation factors active on the selected responses and determination of the proper level of the variables to be selected for the response improvement. The different results obtained with the three examined drugs pointed out the role of the drug solubility in determining the influence of formulation parameters on drug release rate from matrix tablets.
The soil skeleton (larger than 2
mm fraction) can provide a source of organic carbon which may represent an unexplored possibility of adsorbing and degrading pesticides.
The present paper reports a ...laboratory experiment on the adsorption of metobromuron and terbuthylazine on the skeleton and fine earth of two Italian soils derived from two parent rocks, a calcareous marl and a sandstone.
K
F values of 1.30 and 2.22 for metobromuron and 1.24 and 2.21 for terbuthylazine were found in the fine earth of sandstone and calcareous marl, respectively. Surprisingly, the soil skeleton, intended as the 2–10
mm fraction, showed a good adsorption capacity of about 40% and 20% with respect to the fine earth fraction for sandstone and calcareous marl soils, respectively. The derived
K
oc values for the skeleton turned out to be much higher than those of the fine earth indicating an adsorption activity of organic carbon in the skeleton higher than that of the fine earth.
Pesticide degradation followed first order kinetics in all samples and half-life values in the skeleton were in the same range as those in the fine earth demonstrating a biodegradation activity of this substrate. A degradation trial in sterilized skeleton of the two soils supports the previous statement, since degradation was almost absent.
The experiment performed indicated a possible contribution of the soil coarse fraction to pesticide adsorption and degradation, helping in their disappearance from the environment.
The effect of chitosan and of different concentrations of β- or hydroxypropyl-β-cyclodextrins, separately or in various (w/w) combinations, on the dissolution characteristics of glyburide (an oral ...hypoglycemic agent subject to incomplete and variable bioavailability) and on its permeability through Caco-2 cells has been investigated. Cyclodextrins (and particularly the hydroxypropyl-derivative, in virtue of its higher water solubility) were clearly more effective than chitosan in enhancing the drug dissolution properties: the aqueous glyburide solubility was improved 40-fold in the presence of 25
mM hydroxypropyl-β-cyclodextrin, 25-fold in the presence of 13
mM β-cyclodextrin (saturation solubility) and only 3-fold in the presence of chitosan at its saturation concentration (0.5% w/v). When chitosan and cyclodextrin were simultaneously present, a strong reduction of the cyclodextrin solubilizing efficiency towards the drug was observed, and it was attributed to a possible competition effect of polymer and glyburide for the interaction with the macrocycle. By contrast, permeation studies revealed that chitosan was more powerful than cyclodextrins in enhancing the glyburide permeability through Caco-2 cells. This was probably in virtue of the polymer's favourable effect on the tight junctions opening, as demonstrated by the significant decrease in the transepithelial electrical resistance recorded in its presence. Moreover, interestingly, when using the carriers together, conversely from solubility studies, a significant (
P<0.05) synergistic effect in enhancing glyburide apparent permeability was revealed in permeation experiments.
IntroductionClinical effectiveness of targeted therapies is often transitory and virtually all patients develop secondary resistance. The heterogeneous mechanisms of resistance and the sub-clonal ...evolution pattern of cell populations that emerge upon pharmacological selection limit disease control with subsequent lines of therapy. We used colorectal cancer (CRC) to test the hypothesis that ancestral oncogenic event (such as WNT pathway alterations) shared by every cell sub-clone might be better suited as therapeutic targets than heterogeneous events in the branches, as the former remain present in each drug-resistant cell independently from its genetic drift.Material and methodsExome analysis was performed on a panel of CRC cells that became resistant to commonly used targeted agents to uncover genetic alterations acquired under drug selective pressure. Tumour evolution of resistant cell population was then inferred through EXPANDs software. β-catenin activity, cell growth and death were measured upon functional and pharmacological modulation of WNT pathway in resistant cells and preclinical models established from tissues biopsy obtained from CRC patients who relapsed during treatment with targeted therapies.Results and discussionsExome sequencing and phylogenetic tracking unveiled a complex sub-clonal architecture in CRC resistance cell populations, indicating parallel evolution of multiple independent cellular lineages, each associated with distinct genomic landscapes. Functional and pharmacological inhibition of WNT signalling induces cell death in CRC preclinical models, regardless of drug type or resistance mechanisms. Pharmacological blockade of WNT pathway resulted in translocation of β-catenin to the plasma membrane, decreased of β-catenin dependent Tcf/LEF transcriptional activity, and cell growth impairment despite massive molecular drift of resistant derivatives. Concomitant blockade of WNT and MAPK signalling restrained evolution of drug-resistant clones and prevent onset of secondary resistance.ConclusionIn summary, reliance of CRC on the WNT pathway is preserved in later phases of colorectal carcinogenesis when tumours face genomic bottlenecks and sub-clonal evolution driven by administration of target therapies; thus offering the possibility of a common therapeutic strategy to overcome secondary resistance to treatments.
Abstract The fibrogenic evolution of chronic viral hepatitis B and C towards cirrhosis represents a key issue in clinical Hepatology whose monitoring still relies on liver biopsy and consequent ...histopathological staging. In the last decade, non-invasive methodologies have been proposed to predict the presence of fibrosis in chronic liver disease. Most of these methods are based on algorithms, including biochemical parameters, which have demonstrated an acceptable diagnostic accuracy towards the two extremities of the fibrogenetic process. The introduction of transient elastography has represented a further advancement in clinical Hepatology and it seems that the combination of different non-invasive methodologies will provide an improvement in the clinical management of disease progression in viral chronic hepatitis. Studies, conducted especially in chronic viral hepatitis C, suggest that transient elastography is a useful technique for the detection of severe fibrosis-cirrhosis and for the exclusion of significant fibrosis (≥F2), that could be employed as “diagnostic discriminator” for establishing clinical priorities and reducing the number of liver biopsies. This review article will focus on the clinical utility of this novel methodology for the assessment of liver fibrosis in chronic viral hepatitis and will highlight potential further advantages.
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