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The spread of the COVID-19 pandemic in 2020 had a huge impact on the life course of all of us. This rapid spread has also caused an increase in the research production in topics related to different aspects of COVID-19. Italy has been one of the first countries to be massively involved in the outbreak of the disease. In this paper, we present an extensive scientometric analysis of the research production both at global (entire literature produced in the first 2 years after the beginning of the pandemic) and local level (COVID-19 literature produced by authors with an Italian affiliation). Our results showed that US and China are the most active countries in terms of number of publications and that the number of collaborations between institutions varies depending on geographical distance. Moreover, we identified the medical-biological as the field with the greatest growth in terms of literature production. As regards the analysis focused on Italy, we have shown that most of the collaborations follow a geographical pattern, both externally (with a preference for European countries) and internally (two clusters of institutions, north versus center-south). Furthermore, we explored the relationship between the number of citations and variables obtained from the data set (e.g. number of authors). Using multiple correspondence analysis and quantile regression we shed light on the role of journal topics and impact factor, the type of article, the field of study and how these elements affect citations. [ABSTRACT FROM AUTHOR]

Our understanding of climate dynamics during millennial-scale events is incomplete, partially due to the lack of their precise phase analyses under various boundary conditions. Here we present nine speleothem oxygen-isotope records from mid-to-low-latitude monsoon regimes with sub-centennial age precision and multi-annual resolution, spanning the Heinrich Stadial 2 (HS2) — a millennial-scale event that occurred at the Last Glacial Maximum. Our data suggests that the Greenland and Antarctic ice-core chronologies require +320- and +400-year adjustments, respectively, supported by extant volcanic evidence and radiocarbon ages. Our chronological framework shows a synchronous HS2 onset globally. Our records precisely characterize a centennial-scale abrupt "tropical atmospheric seesaw" superimposed on the conventional "bipolar seesaw" at the beginning of HS2, implying a unique response/feedback from low-latitude hydroclimate. Together with our observation of an early South American monsoon shift at the HS2 termination, we suggest a more active role of low-latitude hydroclimate dynamics underlying millennial events than previously thought. New cave records from monsoon regions improve the Greenland ice core chronological framework around the Heinrich Stadial 2 by an order of magnitude, suggesting a more active role of low-latitude hydroclimate in millennial-scale climate oscillations. [ABSTRACT FROM AUTHOR]

Collapse is a common geomorphic process in karst areas, especially on the Yunnan-Guizhou Plateau, which has a tectonic background of integral uplift. The frequent occurrence of collapse processes in karst underground caves and canyons indicates that collapses play an important role in the formation of canyons. Through an analysis of the morphology of a semicircular cliff in the Huajiang Grand Canyon and an investigation of sediments at the bottom of the cliff, a large-scale collapse event was found to have occurred. U-series dating of secondary calcium carbonate cement in the collapse breccias indicates that collapse processes occurred approximately 200 ka. According to the geomorphological evolution of the Huajiang Grand Canyon, the following geomorphic evolutionary process is proposed: underground river—cave hall—collapse of a tiankeng—tiankeng degradation—canyon formation. These findings also show that the dating of collapsed breccia cement can be effectively used to determine the development times of karst canyons and the formation ages of tiankengs. [ABSTRACT FROM AUTHOR]

In this paper, we study the mobility choices of Italian students in their transition from a bachelor's to a master's degree level with an added emphasis on their overall mobility pathways. We consider individual data from the Italian National Student Archive on two cohorts of students who were enrolled in the academic years 2011–2012 and 2014–2015. We followed both cohorts in Italian universities for six academic years. This allowed us to depict five different profiles of students, categorise them as stayers vs. movers, and work at two different levels. Logit models were then adopted to study the probability to be in mobility at a master's level, given that a student had been a stayer at bachelor's degree, and to assess the effect of the field of study. Apart from individual characteristics, network centrality measures were encompassed in the model to assess the university attractiveness in influencing mobility choices. [ABSTRACT FROM AUTHOR]

The wollastonite–garnet–diopside-bearing marbles cropping out in the Migmatite Complex west to the Tamarispa and San Lorenzo villages share a common metamorphic and deformational history with the surrounding migmatite, with metamorphic peak conditions between 650 and 850 °C. Within the marble, there is an interesting and rare garnet mineralization. The peculiar characteristic and geological–cultural and touristic attraction of this geosite is the presence of large garnet crystals (up to 20 cm). The whitish rock matrix is characterized by coarse-grained rock-forming minerals (mainly wollastonite, calcite, diopside and subordinately pectolite, quartz, plagioclase, epidote, apatite, titanite) with a compositional layering and a weak foliation (S2 schistosity), parallel to that of the surrounding gneiss and migmatites. At the outcrop scale, the giant garnet crystals often show a brown core in high relief surrounded by a darker rim with less relief. Under conservation state, the wollastonite–garnet–diopside-bearing marbles show an evident differential alteration with dissolution processes of the matrix and an increasingly pronounced enucleation of the garnet crystals. The Tamarispa outcrop with spectacular giant garnet crystals is here proposed as a new, potential geosite relevant for didactic, cultural, and touristic purposes. Conservation and valorization aspects are discussed within the more general framework of the geological, natural, and environmental resources of the local territory. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the prevalence of less severe hypercortisolism (LSH) in fractured patients, and its association with hypertension, hyperglicemia, dyslipidemia, and obesity. Method: From July 2015 to October 2018 we enrolled all fractured patients admitted in our outpatient center for metabolic bone diseases, after exclusion of patients with secondary osteoporosis apart from diabetes and taking drugs known to affect bone metabolism. In all enrolled patients we collected data regarding gonadal status, history of diabetes, high blood pressure, dyslipidemia, and measured blood pressure, lipid profile, fasting glycaemia. Bone mass was measured with DXA at lumbar spine and femoral neck and the presence of fractures was evaluated with X-ray of thoracic and lumbar spine. All patients performed twice, 1 mg overnight dexametasone suppression test (DST) and, as confirmatory, 2day low-dose DST for diagnosing hypercortisolism. Results: We enrolled 101 fractured patients (75 females, 26 males), aged 65 ± 10.3 years. Five out of 101 (5.0%) patients were diagnosed as LSH. Fifty-five (54.5%) out of 101 were hypertensive, 57 (56.4%) dyslipidemic, 17 (16.8%) hyperglicaemic, 28(27.7%) obese patients. LSH tended to be associated to blood hypertension [5/5 vs 50/96 (Fisher exact test, p = 0.06) hypertensive patients]. Four out five LSH patients were hypogonadic. Conclusions: Our study confirms that a nonnegligible percentage of fractured subjects actually presents an unrecognized hypercortisolism. Accordingly, regardless of age, we suggest to screen for hypercortisolism all patients with established osteoporosis and in particular hypertensive subjects. [ABSTRACT FROM AUTHOR]

The concept of geoheritage is related to places of geological interest, generally of aesthetic, cultural, socio-economic and/or scientific value. Many geosites are of karstic nature, because of their intrinsic beauty, their singularity and high geodiversity. Caves are among the most visited and economically exploited geological landforms. They constitute geosites as a whole, with their scenic landscapes, hydrogeological importance and the presence of bewildering natural rock and mineral formations including stalactites, stalagmites, flowstones and many other bizarre speleothem shapes. In some cases, a single speleothem, and the palaeoclimate record it contains, can be on its own of extraordinary importance to science. Once studied, these samples are often stored in research institution collections, rarely accessible to the wide public. In this paper, we report on the museumization of a stalagmite that has delivered a unique and exceptionally long glacial climate record from southern Italy, shedding light on the causes that led to the Neanderthal contraction and Modern Human expansion in this mild Mediterranean climate between 45 and 42 thousands years ago. The proposed museumization aims to demonstrate the potential of speleothems, after scientific application, in terms of educational and tourist resources. This approach allows to highlight the scientific importance of karst and cave geosites to the wide public, promoting their conservation and the valorisation of the studied cave-material. [ABSTRACT FROM AUTHOR]

The orthoquartzite Imawarì Yeuta cave hosts exceptional silica speleothems and represents a unique model system to study the geomicrobiology associated to silica amorphization processes under aphotic and stable physical–chemical conditions. In this study, three consecutive evolution steps in the formation of a peculiar blackish coralloid silica speleothem were studied using a combination of morphological, mineralogical/elemental and microbiological analyses. Microbial communities were characterized using Illumina sequencing of 16S rRNA gene and clone library analysis of carbon monoxide dehydrogenase (coxL) and hydrogenase (hypD) genes involved in atmospheric trace gases utilization. The first stage of the silica amorphization process was dominated by members of a still undescribed microbial lineage belonging to the Ktedonobacterales order, probably involved in the pioneering colonization of quartzitic environments. Actinobacteria of the Pseudonocardiaceae and Acidothermaceae families dominated the intermediate amorphous silica speleothem and the final coralloid silica speleothem, respectively. The atmospheric trace gases oxidizers mostly corresponded to the main bacterial taxa present in each speleothem stage. These results provide novel understanding of the microbial community structure accompanying amorphization processes and of coxL and hypD gene expression possibly driving atmospheric trace gases metabolism in dark oligotrophic caves. [ABSTRACT FROM AUTHOR]

This paper focuses on the study of different Roman mortars (renders, finishing coats), used in the construction and restoration of the Forum Traiani thermal baths (Central Sardinia, Italy), a significant example of the Roman-style architecture in Sardinia. The archaeological site is located in a high hydrogeological risk area, due to the cyclical flooding of nearby Tirso river. Moreover, the presence of thermal saline (NaCl-bearing) water spring directly in contact with mortars and building stones, also contributed to structure degradation. An analytical approach, comprising mineralogical-petrographic characterization, physical analysis and particle-size distribution of aggregate, was used for mortars characterization. In addition, pXRD analysis on mortars defined the presence of alteration minerals while the thermal characterization (TGA) gave information about binder hydraulicity degree. Further μ-XRD-associated μ-Raman spectroscopy and μ-FTIR were utilized for pigments identification on frescos. Interesting results came from two wall stratigraphic series of mortars, highlighting construction stages, ancient restoring interventions and waterproofing methods. The main pigments used on red, yellow and black frescoes were red ochre, goethite and wood charcoal respectively. [ABSTRACT FROM AUTHOR]

Combining historical, archaeological and experimental data, traditional and archaeological ceramics, from the Santarém district, with different chronology and functions have been studied. Our aim is to understand ancient pottery technology and to evaluate whether ceramic production followed similar principles in the Middle Ages (from the Islamic to the Christian domination) and Modern times. Moreover, traditional ceramics, knowing the productive process, have been used as a tool to interpret ancient pottery technology. We considered different utilitarian ceramic groups, namely fire, table and food-liquid container wares. Through the combination of optical microscopy (OM), X-ray powder diffraction (XRPD), X-ray fluorescence spectroscopy (XRF) with physical and mechanical tests, it has been possible to collect valuable information regarding pottery manufacturing, considering the age and the object function. Moreover, it is also considered the effect of raw materials mixing and ceramic paste preparation on ceramics final characteristics. Our results indicate that both during the Middle Ages and in Modern times, technical expertise played, and still play, a fundamental role in the creation of a specific object. In this specific case, behavioural and socio-cultural factor drove ceramists' decision when selecting between different technological solutions, and every decision or technical choice is/was taken depending on the functional and performance characteristics desired for a specific artefact. This happened during the Middle Ages, and is still happening nowadays for the production of traditional ceramics in the district of Santarém, Portugal. [ABSTRACT FROM AUTHOR]

In the present work, the mineralogical-petrographic and physical features of Middle Jurassic sandstones with macrofossil plant remains belonging to the Domenico Lovisato collection, housed at the Geological and Palaeontological Museum of the Cagliari University (Sardinia, Italy), have been studied to define the alteration processes and the consolidating treatment. These sandstones, coming from the Genna Selole formation (central Sardinia), show evident problems of physical decay, due to petrophysical and compositional characteristics such as high porosity, low cementing degree, and presence of clay minerals (e.g., phyllosilicates). This latter leads to subsequent cyclic mechanisms of hydration/dehydration, which affect these sedimentary rocks. For this purpose, five main different sandstone specimens with evident crystalline matrix decohesion have been selected and analyzed. To define their mineralogical-petrographic (composition, microstructure) and physical characteristics (real and bulk densities, helium porosity, water absorption, mechanical strength, etc.), the optical microscope (OM) in polarized light, X-ray powder diffraction analysis (XRPD), helium and water pycnometer, and point load test were used. Testing the most suitable and compatible products for consolidation and time-saving of the palaeobotanical remains, several experimental treatment tests have been performed using four chemical products (i.e., alkoxysilane ethyl silicates and Na/K-silicate). [ABSTRACT FROM AUTHOR]

The study focused on the volcanic glass used in the production of bedding mortars and concrete of the Roman theatre (I cent. AD) of the Nora site. The volcanic glasses were frequently used as aggregate and with pozzolanic function in all hydraulic mortars of the different sectors of the building (e.g., concretes of tribunalia vaults and external niches, jointing and foundation mortars of cavea tier ashlars, brick bedding), together with mainly quartz-feldspar sands, local Oligo-Miocenic andesitic-dacitic volcanics and Palaeozoic and Tyrrhenian sedimentary rocks. These volcanic glasses show characteristics closer to obsidian than to natural pozzolan normally used in the Roman period. They have definitely not sourced locally, unlike the other components that make up the aggregate. To identify their provenance, a petrochemical comparison between several samples taken from the theatre mortars and the volcanic outcrops of some probable Sardinian source areas is made. The use of the not local pozzolanic glass is a technical innovation in the mortars of the Nora archaeological site, and considering the wide use of obsidians in the prehistoric periods for the production of tools, significant considerations about its origin, procurement and use are made. [ABSTRACT FROM AUTHOR]

The aim of this work is the physical and mineralogical-petrographic characterization of the mortars from the Baths with Heliocaminus, a special and unique architectural building in the complex of the Hadrian's Villa in Tivoli. Thirty samples were investigated for composition and physical properties (density, porosity, water absorption, mechanical strength, particle size distribution of aggregate, etc.), representative of eight mortar groups: cubilia bedding mortar, brick bedding mortars, floor-coating and wall-coating bedding mortars, floor ( rudus) and wall conglomerates ( trullisatio), vault concretes, and lime plasters ( arriccio). Physical parameters, together with the microscopic analysis and binder/aggregate ratio determined in three ways using image analysis (on thin sections and on specimens) and weight-data from dissolution of binder, have shown an interesting relationship between the physical-compositional characteristics and the function of mortars within the structure of the Heliocaminus baths. To identify the minerals and the reactant phases between binder and aggregate, as well as the hydraulic degree, selected samples were analyzed with x-ray powder diffraction, thermogravimetry, and differential scanning calorimetry techniques. The obtained results provide a close relation between pozzolanic characteristics and physical-mechanical properties of the mortars (i.e., punching strength index). [ABSTRACT FROM AUTHOR]

The pyroclastic rocks, belonging to the calcalkaline volcanic activity occurred in Sardinia between 32 and 11 Ma ago, were widely used as construction material in several Romanesque Churches of the easternmost Logudoro, as well as in the Sardinia territory. In this work was taken as a case study the Church of Nostra Signora di Otti (12th cent.). There are no historical or archaeological evidences of the ancient quarries. Based on the geochemical, petrographic and volcanological characters of several samples from an extensive field area (approximately 150 kmq), a geographical zoning of the Oligo-Miocenic volcanics has been recognised. Internally to the Oschiri sector, according to TiO vs Differentiation Index diagram, there are three different sub-zones with pyroclastics: less fractionated (D.I. ~70 ÷ 78); intermediate fractionated (D.I. ~76 ÷ 79); more fractionated (D.I. ~77 ÷ 82). To identify the origin of the ignimbrites of the Church, two statistical methods have been used: stepwise linear discriminant and canonical analysis. Moreover, to define the geochemical transformation processes induced by the alteration, by XRD analysis and XRF, SEM-EDS data, a comparative study of concentrations of major and trace elements measured between the surface portion and the innermost of the stone has been made. [ABSTRACT FROM AUTHOR]

The present work aims to study the consolidating and protective chemical treatments of the Pietra Cantone, a Miocenic (lower Tortonian) limestone widely used in important monuments and historical buildings of Cagliari (southern Sardinia, Italy). Similar limestones of the same geological period have also been used in several important monuments of Mediterranean area, i.e., Malta and Gozo Islands, Matera (central Basilicata, Italy), Lecce (southern Puglia, Italy) and Balearic Islands (Spain). The Pietra Cantone limestone shows problems of chemical-physical decay, due to their petrophysical and compositional characteristics: high porosity (on average 28-36 vol%), low cemented muddy-carbonate matrix, presence of phyllosilicates and sindepositional sea salts (<3%). So, after placed in the monument, this stone is easily alterable by weathering chemical processes (e.g., carbonate dissolution and sulfation) and also by cyclic mechanisms of crystallization/solubilization of salts and hydration/dehydration of hygroscopic phases of the clay component. To define the mineralogical-petrographic features (composition, texture) of limestone, the clay and salt crystalline phases, the optical microscope in polarized light and diffraction analysis were used. To define the petrophysical characteristics (i.e., shape and size distribution of porosity, surface area (SBET), matrix microstructures, rock composition) and interactions of chemical treatments with rock, SEM-EDS analysis and N2 porosimetry with BET and BJH methods were used. To evaluate the efficacy of Na/K-silicates, ethyl silicate consolidants and protective nano-molecular silane monomer water repellent, the mechanical strengths (uniaxial compressive strength, point load and flexural resistance), water/helium open porosity, water absorption and vapour permeability data determined before and after the chemical treatments of the Pietra Cantone samples from monument were compared. [ABSTRACT FROM AUTHOR]

This work studies the Heliocaminus Baths. From an architectural point of view, this is a special and unique building in the complex of the Hadrian's Villa in Tivoli. This research is carried out with a multidisciplinary approach combining petrophysical, petrographic and mineralogical characterization with the techniques of digital survey. The purpose of the research is to contribute to the understanding of Roman construction through the study of materials and from architectural aspects. Using mineral-petrographic and physical analysis, a set of samples (mortars and stones) was investigated for composition and physical properties (density, porosity, water absorption, mechanical strength, etc.). In the case of mortars, these parameters, together with the particle size distribution and the binder/aggregate ratio determined in two ways using image analysis (on thin sections and on specimens), have shown a relationship between the physical and compositional characteristics and the function of mortars within the structure of the Heliocaminus Baths. However, in some cases, different characteristics were detected between the mortars belonging to the same masonry and with same function in the building, showing a slight inhomogeneity in the production of mortars. Furthermore, some relationships between compositional, physical aspects (i.e. porosity, sorting and size of aggregate) and mechanical strength have been found. All the gathered data, linked to the point cloud 3D model, allowed an accurate location of the traces from the construction story of this structure. [ABSTRACT FROM AUTHOR]

The Roman municipium of Forum Sempronii (Fossombrone, Marche) was located along the 'Via Consolare Flaminia', in the stretch of road where it ran along the final sector of the valley of the River Metauro ( Mataurus). The ancient colony of Forum Sempronii, which is cited by Strabo, Pliny, and Ptolemy, was found in the second century BC, probably on the site of an earlier community and its activity continued until the end of the fifth century AD. During ancient and more recent archaeological excavations, many fragments of coloured stones and marbles, and some white marble sculptures have been unearthed. In this paper, we report the results of the provenance identification of the white marbles used for the sculptures found in the archaeological site of Forum Sempronii and now displayed at the local archaeological museum. The determination of the source origin of the white marbles used for the sculptures has been established by mineralogical-petrographic and geochemical analyses. Microscopic study of thin sections together with carbon and oxygen stable isotope ratios indicate that more than one type of white marbles was used: Pentelikon, Lunense, and Thasian. [ABSTRACT FROM AUTHOR]

Chemical mobility of crystalline and amorphous SiO2 plays a fundamental role in several geochemical and biological processes, with silicate minerals being the most abundant components of the Earth's crust. Although the oldest evidences of life on Earth are fossilized in microcrystalline silica deposits, little is known about the functional role that bacteria can exert on silica mobility at non-thermal and neutral pH conditions. Here, a microbial influence on silica mobilization event occurring in the Earth's largest orthoquartzite cave is described. Transition from the pristine orthoquartzite to amorphous silica opaline precipitates in the form of stromatolite-like structures is documented through mineralogical, microscopic and geochemical analyses showing an increase of metals and other bioessential elements accompanied by permineralized bacterial cells and ultrastructures. Illumina sequencing of the 16S rRNA gene describes the bacterial diversity characterizing the consecutive amorphization steps to provide clues on the biogeochemical factors playing a role in the silica solubilization and precipitation processes. These results show that both quartz weathering and silica mobility are affected by chemotrophic bacterial communities, providing insights for the understanding of the silica cycle in the subsurface. [ABSTRACT FROM AUTHOR]

The research focuses on the geochemical and petrographic characterisation of volcanics that were used in the Roman city of Nora archaeological site. These rocks formed during the Late Eocene-Miocene orogenic Sardinian magmatic activity (38-15 Ma), were used as construction materials (ashlars, decorative frame, etc.) and as aggregate in the ancient mortars of some important buildings of Nora (e.g. Roman theatre, first century AD). Several samples coming from the Roman theatre (taken as study cases) and other ancient buildings and artefacts of Nora village were studied and chemically petrographically analysed. To define their provenance, analytical data of major and trace elements by XRF method were compared with those of several volcanics coming from the sector around the Nora archaeological site and from Sulcis area, frequented in ancient times by Romans. To highlight the geochemical discriminant markers or affinities between the sample populations of volcanics, factorial analysis was used, taking some significant variables: SiO2, Na2O, K2O, L.o.I, Al2O3, Rb, Ba, Sr. The results of this research allow also defining the aspects of stone quarry extraction and construction technologies used in the Roman period. [ABSTRACT FROM AUTHOR]