Thermochronometric evidence of far-field stress transfer in continental collisions

In this dissertation, two low-temperature thermochronometers [fission-track analysis on apatite and (U-Th)/He analyses on zircons] are applied on various tectonostratigraphic units from three collisional settings: (i) the Bitlis-Pütürge Massif (SE Turkey), (ii) the Lesser Caucasus (Georgia, Armenia, Azerbaijan), and (iii) the Strandja Massif (SE Bulgaria and NW Turkey). The aim of the study is to better understand the syn- and post-collisional thermochronological evolution of collisional orogens, thus elucidating the dynamics of stress partitioning and transmission during continental collisions. Another focal point of this study is to constrain better the timing of the Arabia-Eurasia collision in the area of its maximum indentation and clarify the overall evolution of the area. From a general viewpoint, our dataset for the Eurasian foreland north of the Arabia-Eurasia collision (the Bitlis-Pütürge Massif and the Lesser Caucasus region) suggest that the tectonic stresses related to the collision during mid-Miocene time were transmitted efficiently over large distances, focusing preferentially at rheological discontinuities located as far as the Lesser Caucasus and the Eastern Pontides. Since the late Middle Miocene a new tectonic regime is active as the westward translation of Anatolia is accommodating most of the Arabia-Eurasia convergence, thus decoupling the foreland from the orogenic wedge and precluding efficient northward stress transfer. In the Strandja Massif the mechanism of stress transmission was very different. The bulk of the massif has escaped significant Alpine-age deformation, which is recorded only in the northern sector. We argue that in the Strandja orogen the stress mostly bypassed the orogenic prism and focused on the Srednogorie rift basin to the north, rheologically weakened by previous Late Cretaceous back-arc extension

A simple and reliable methodology to detect egg white in art samples

A protocol for a simple and reliable dot-blot immunoassay was developed and optimized to test work of art samples for the presence of specific proteinaceus material (i.e. ovalbumin-based). The analytical protocol has been extensively set up with respect, among the other, to protein extraction conditions, to densitometric analysis and to the colorimetric reaction conditions. Feasibility evaluation demonstrated that a commercial scanner and a free image analysis software can be used for the data acquisition and elaboration, thus facilitating the application of the proposed protocol to commonly equipped laboratories and to laboratories of museums and conservation centres. The introduction of method of standard additions in the analysis of fresh and artificially aged laboratory-prepared samples, containing egg white and various pigments, allowed us to evaluate the matrix effect and the effect of sample aging and to generate threshold density values useful for the detection of ovalbumin in samples from ancient works of art. The efficacy of the developed dot-blot immunoassay was proved testing microsamples from 13th–16th century mural paintings of Saint Francesco Church in Lodi (Italy). Despite the aging, the altered conditions of conservation, the complex matrix, and the micro-size of samples, the presence of ovalbumin was detected in all those mural painting samples where mass-spectrometry-based proteomic analysis unambiguously detected ovalbumin peptides

Implicazioni medico-legali delle linee guida cliniche

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Implicazioni medico-legali delle linee guida cliniche

Clinical guidelines are defined as «systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances». Their aim is to help the physician in making clinical decisions, improving the quality of patient care, and promoting efficient use of economic resources. The paper explores legal, deontological and ethical aspects of guidelines in the Italian context. In Italy, adherence to the guidelines is not considered legally binding for the physician. Anyway guidelines can be used by the Court in medical malpractice litigation. In fact, assuming that clinical guidelines express the reasonable standard of care, they can be considered a tool for assessment of the questionable conduct. To avoid that guidelines might be considered merely as an instrument of defensive medicine, it is essential that clinicians become aware of their importance in improving clinical practice

Testing Anti-Biofilm Polymeric Surfaces: Where to Start?

Present day awareness of biofilm colonization on polymeric surfaces has prompted the scientific community to develop an ever-increasing number of new materials with anti-biofilm features. However, compared to the large amount of work put into discovering potent biofilm inhibitors, only a small number of papers deal with their validation, a critical step in the translation of research into practical applications. This is due to the lack of standardized testing methods and/or of well-controlled in vivo studies that show biofilm prevention on polymeric surfaces; furthermore, there has been little correlation with the reduced incidence of material deterioration. Here an overview of the most common methods for studying biofilms and for testing the anti-biofilm properties of new surfaces is provided

Non-Lethal Effects of N-Acetylcysteine on Xylella fastidiosa Strain De Donno Biofilm Formation and Detachment

This study investigated in-vitro the non-lethal effects of N-acetylcysteine (NAC) on Xylella fastidiosa subspecies pauca strain De Donno (Xf-DD) biofilm. This strain was isolated from the olive trees affected by the olive quick decline syndrome in southern Italy. Xf-DD was first exposed to non-lethal concentrations of NAC from 0.05 to 1000 µM. Cell surface adhesion was dramatically reduced at 500 µM NAC (−47%), hence, this concentration was selected for investigating the effects of pre-, post- and co-treatments on biofilm physiology and structural development, oxidative homeostasis, and biofilm detachment. Even though 500 µM NAC reduced bacterial attachment to surfaces, compared to the control samples, it promoted Xf-DD biofilm formation by increasing: (i) biofilm biomass by up to 78% in the co-treatment, (ii) matrix polysaccharides production by up to 72% in the pre-treatment, and (iii) reactive oxygen species levels by 3.5-fold in the co-treatment. Xf-DD biofilm detachment without and with NAC was also investigated. The NAC treatment did not increase biofilm detachment, compared to the control samples. All these findings suggested that, at 500 µM, NAC diversified the phenotypes in Xf-DD biofilm, promoting biofilm formation (hyper-biofilm-forming phenotype) and discouraging biofilm detachment (hyper-attachment phenotype), while increasing oxidative stress level in the biofilm

Il paese senza incroci. Racconti di strade ed emozioni

Folletti, cappelli e segnali stradali sono al centro di brevi storie immaginifiche, dove i luoghi reali diventano luoghi del cuore e svelano sentimenti ed emozioni nascosti. Solo i bambini – e coloro che lo sono rimasti almeno un po’ – possono capire quanto gli occhi del cuore possono vedere profondamente, al di là della realtà che ci viene data. I cinque racconti formano un piccolo libro di lettura, per distrarsi e immaginare, adatto anche a percorsi didattici nella scuola primaria e nella scuola secondaria di primo grado

Understanding the Role of the Antioxidant Drug Erdosteine and Its Active Metabolite on <i>Staphylococcus aureus</i> Methicillin Resistant Biofilm Formation

Increasing numbers of researches have suggested that some drugs with reactive oxygen species (ROS)-mediated mechanisms of action modulate biofilm formation of some pathogenic strains. However, the full contribution of ROS to biofilm development is still an open question. In this paper, the correlations between the antioxidant drug Erdosteine (Er) and its active Metabolite I (Met I), ROS and biofilm development of two strains of methicillin resistant Staphylococcus aureus are presented. Experiments revealed that Er and Met I at 2 and 5 mg/L increased up to three orders of magnitude the number of biofilm-dwelling cells, while the content of ROS within the biofilms was reduced above the 87%, with a major effect of Met I in comparison to Er. Comparative proteomics showed that, 5 mg/L Met I modified the expression of 30% and 65% of total proteins in the two strains respectively. Some proteins involved in cell replication were upregulated, and a nitric oxide-based mechanism is assumed to modulate the biofilm development by changing quorum sensitive pathways. Additionally, several proteins involved in virulence were downregulated in the presence of Met I, suggesting that treated cells, despite being greater in number, might have lost part of their virulence

Increased erosion of high-elevation land during late Cenozoic: evidence from detrital thermochronology off-shore Greenland

Mountain regions at high altitudes show deeply incised glacial valleys that coexist with a high-standing low-relief landscape, whose origin is largely debated. Whether the plateaus contributed to sediment production during the late Cenozoic is a currently debated issue in glacial geomorphology and paleoclimatology. In this study, we used detrital apatite fission-track dating of marine sediments to trace provenance and spatial variation in focused erosion over the last 7 million years. The decomposition of age distributions into populations reveals that, moving upwards through the sections, two young populations get younger, while two older populations get progressively older. We interpreted these trends as the effect of glacial erosion on the valley floors and an increased sediment contribution from the high elevations. To test this hypothesis, we compared the measured ages with synthetic age distributions, which represented a change in the elevation of focused erosion. We conclude that the central-eastern Greenland region is the main source of sediments, and in addition to enhanced valley incision, sediments have also been sourced from progressively higher elevations since 7 Ma. The ageing trend provides an unusual case in detrital thermochronology and a strong evidence that intensified Quaternary glaciations amplify the erosional process both in valley bottoms and at high elevations