Methodological Approach to Reconstructing Lost Monuments from Archaeological Findings: The San Francesco di Castelletto Church in Genoa

Throughout history, natural hazards, wars, political changes and urban evolution have contributed to the obliteration of outstanding monuments. The study of their remains, frequently recovered as archaeological findings, can be the basis for a reconstruction of the lost structures, by way of their size, function, decoration and stylistic evolution. The present study developed a multidisciplinary approach to gather and interpret archaeological fragments and archive sources, in order to gain as much information as possible on \u201clost monuments\u201d. The approach was tested with remnants (i.e., several hundreds of marble fragments found during archaeological excavations) of the monastic complex of San Francesco di Castelletto (Genoa), which was demolished after the Napoleonic suppressions. A preliminary organisation of the sample set was attained through cataloguing shape, size, and decoration. After this, a comparison with similar complexes still existing in Genoa allowed the inference of the age and specific ornamental functions for the majority of the pieces. Surface analysis, carried out in situ (portable microscope) and on micro-samples (petrographic analysis and SEM-EDS), allowed the characterisation of the materials (e.g., assessing marble provenance and identifying pigments). As a whole, the method evolved into an operational protocol, which helped both the organisation of the archaeological findings and the reconstruction of unknown phases of the lost monument

Human cytomegalovirus glycoprotein complex gH/gL/gO uses PDGFR-alpha as a key for entry

Herpesvirus gH/gL envelope glycoprotein complexes are key players in virus entry as ligands for host cell receptors and by promoting fusion of viral envelopes with cellular membranes. Human cytomegalovirus ( HCMV) has two alternative gH/gL complexes, gH/gL/gO and gH/gL/UL128,130,131A which both shape the HCMV tropism. By studying binding of HCMV particles to fibroblasts, we could for the first time show that virion gH/gL/gO binds to platelet-derived growth factor-alpha (PDGFR-alpha) on the surface of fibroblasts and that gH/gL/gO either directly or indirectly recruits gB to this complex. PDGFR-alpha functions as an entry receptor for HCMV expressing gH/gL/gO, but not for HCMV mutants lacking the gH/gL/gO complex. PDGFR-alpha-dependent entry is not dependent on activation of PDGFR-alpha. We could also show that the gH/gL/gO-PDGFR-alpha interaction starts the predominant entry pathway for infection of fibroblasts with free virus. Cell-associated virus spread is either driven by gH/gL/gO interacting with PDGFR-alpha or by the gH/gL/UL128,130,131A complex. PDGFR-alpha-positive cells may thus be preferred first target cells for infections with free virus which might have implications for the design of future HCMV vaccines or anti-HCMV drugs

HCMV Spread and Cell Tropism are Determined by Distinct Virus Populations

Human cytomegalovirus (HCMV) can infect many different cell types in vivo. Two gH/gL complexes are used for entry into cells. gH/gL/pUL(128,130,131A) shows no selectivity for its host cell, whereas formation of a gH/gL/gO complex only restricts the tropism mainly to fibroblasts. Here, we describe that depending on the cell type in which virus replication takes place, virus carrying the gH/gL/pUL(128,130,131A) complex is either released or retained cell-associated. We observed that virus spread in fibroblast cultures was predominantly supernatant-driven, whereas spread in endothelial cell (EC) cultures was predominantly focal. This was due to properties of virus released from fibroblasts and EC. Fibroblasts released virus which could infect both fibroblasts and EC. In contrast, EC released virus which readily infected fibroblasts, but was barely able to infect EC. The EC infection capacities of virus released from fibroblasts or EC correlated with respectively high or low amounts of gH/gL/pUL(128,130,131A) in virus particles. Moreover, we found that focal spread in EC cultures could be attributed to EC-tropic virus tightly associated with EC and not released into the supernatant. Preincubation of fibroblast-derived virus progeny with EC or beads coated with pUL131A-specific antibodies depleted the fraction that could infect EC, and left a fraction that could predominantly infect fibroblasts. These data strongly suggest that HCMV progeny is composed of distinct virus populations. EC specifically retain the EC-tropic population, whereas fibroblasts release EC-tropic and non EC-tropic virus. Our findings offer completely new views on how HCMV spread may be controlled by its host cells

Cytomegalovirus Replicon-Based Regulation of Gene Expression In Vitro and In Vivo

There is increasing evidence for a connection between DNA replication and the expression of adjacent genes. Therefore, this study addressed the question of whether a herpesvirus origin of replication can be used to activate or increase the expression of adjacent genes. Cell lines carrying an episomal vector, in which reporter genes are linked to the murine cytomegalovirus (MCMV) origin of lytic replication (oriLyt), were constructed. Reporter gene expression was silenced by a histone-deacetylase-dependent mechanism, but was resolved upon lytic infection with MCMV. Replication of the episome was observed subsequent to infection, leading to the induction of gene expression by more than 1000-fold. oriLyt-based regulation thus provided a unique opportunity for virus-induced conditional gene expression without the need for an additional induction mechanism. This principle was exploited to show effective late trans-complementation of the toxic viral protein M50 and the glycoprotein gO of MCMV. Moreover, the application of this principle for intracellular immunization against herpesvirus infection was demonstrated. The results of the present study show that viral infection specifically activated the expression of a dominant-negative transgene, which inhibited viral growth. This conditional system was operative in explant cultures of transgenic mice, but not in vivo. Several applications are discussed

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

Non-invasive analytical technique to address water uptake on stone surfaces: the implemented Contact Sponge Method (i-CSM)

The assessment of capillary rise rate is a recommended test in Cultural Heritage diagnostics to evaluate the evolution of stone textural properties and decay, and performances of conservation treatments. Beside laboratory tests, diverse non-invasive and non-destructive, in-situ methods were developed in order to establish the monitoring for monumental structures and decorative apparatus: Karsten tube, Mirowsky pipe and contact sponge methods (CSM). The comparison between the diverse techniques demonstrated high comparability between the datasets obtained with the CSM (UNI 11432:2011) and those recast with capillary absorption. However, the dataset collected with the conventional method is affected by high standard deviation due to several variables, mainly operator-dependent. The adoption of a pocket penetrometer, coupled with the use of a thicker sponge, aimed at parameterizing the load upon the surface. The implementations allowed a higher reproducibility of the measures, as well as the possibility of applying increasing pressures. In this study the i(mplemented)-CSM was adopted to test the adsorption behaviour of a set of ornamental stones (Macigno Sandstone, Breccia Aurora, Rosso Verona and Vicenza Stone) both un-weathered and weathered by freeze-thaw ageing and salt weathering. A correlation between the maximum open pore radius and an increase in water absorbance at higher loads was established. The preliminary promising results wait to be further validated on larger datasets

An experimental investigation into the salt-weathering susceptibility of building limestones

none2noDimension and ornamental stones used for built heritage are frequently affected, under all climates, by intense weathering induced by the transport of saline solutions. Accordingly, researchers addressed the weathering mechanisms induced by salts (primarily Na2SO4), the stresses generated in the host material, and the durability of ornamental and dimension stones. This study investigates the behaviour of four sedimentary lithotypes, differing in texture and structure (Breccia Aurora, Rosso Verona, and fine- and coarse-grained Vicenza Stone) exposed to a selection of saline solutions, aiming at evaluating their susceptibility to weathering and the influence of petrographic features on durability. The chosen Na2SO4, MgSO4, Na2CO3, NaCl, and KNO3 solutions include the anions characterizing the major saline sources affecting built heritage: capillary rise, acid rain, atmospheric particulate deposition, bird or other animal scat, and de-icing salt contamination. The petrophysical properties of unweathered and salt-weathered samples were characterized by relative mass variation estimation, capillary rise, and hygroscopic absorption-based porosimetry. Scanning Electron Microscopy coupled with microprobe allowed studying the morphological changes triggered by weathering and analysing the chemical composition of the efflorescence crust. The whole of data, consistently with literature, allowed inferring pore type and distribution as the main intrinsic parameters controlling salt weathering susceptibility. Moreover, Na2SO4 and Na2CO3 proved to be the most harmful, probably due to their ability to crystallize in different hydration stages at room temperature. The comparative analysis of the induced weathering can help to choose suitable dimension stones for new buildings or restoration replacements.openScrivano S.; Gaggero L.Scrivano, S.; Gaggero, L

The Staglieno Monumental Cemetery (Genoa, Italy): microenvironment characterization through weathering indicators

The site of the Monumental Cemetery of Staglieno (Genoa, Northern Italy, about 0.33 km2 wide) was addressed by a systematic analysis of decay factors for monuments, to identify potential management concerns. Geologic (structural and stratigraphic), geomorphologic, hydrogeological, hydrologic, meteorological (between 1947 and 2007), botanic and urbanistic (land use) analyses were addressed, and thematic cartography edited for each issue. The decay was observed on ten monuments in white Carrara marble placed in four different areas of the Cemetery (highly vegetated alluvial plain, mildly steep hill slope, south-facing hill slopes, humid creek banks, sheltered galleries, etc.). At the mesoscale, the monuments were addressed for detailed survey, rendered as a weathering map, coupled with decay quantification by the Fitzner indexes. The large- and mesoscale analysis was associated with in situ observation and microinvasive ablation of the surface deposits. These were then analysed by plane polarized light optical microscopy and scanning electron microscope with microprobe (SEM + EDS). Finally, to enhance field observations, all decay evidences were gathered into a protocol inspired to the UNI 11182 weathering descriptions grouped in (1) chromatic alteration (2) ablation weathering (3) accretional weathering. By calibrating the influence of each factor and agent, we attained a weathering zonation into subareas (e.g. Cimitero Protestante, Porticato Inferiore, Boschetto Irregolare, Galleria Pontasso)

Micro-porosity and minero-petrographic features influences on decay: Experimental data from four dimension stones

Sedimentary stones have been used since long as dimension stones, constituting the primary building material of several monumental structures all over the world. The understanding of their behaviour when exposed to weathering factors is crucial for preservation, replacement and restoration intervention. Although not directly involved with decay mechanisms, micro-pores (i.e. open pores with radius <0.1 \uc2\ub5m) and their interconnection to the wider ones are important for air and water flow inside rocks. In fact, micro-pores are not directly the site of ice or salt crystallization, nor of oil and gas entrapment, but are the main pathway for fluids during both adsorption and evaporation processes. The study of narrow pores is therefore crucial to predict e.g. stone durability and physical properties. This study presents the study on four different sedimentary lithotypes vastly employed as dimension or ornamental stones in Italy, both sound and artificially weathered. In particular, coupled MIP and hygroscopic sorption based micro-porosimetry were used to uncover liability to relative humidity variation, in association with a thorough mineralogical characterization. The MIP intrusion pattern attained pore shapes and typology description for the different rock types; but only the hygroscopic sorption helped deciphering the on-going processes. Moreover, the coupling of petrography and petro-physical analyses (i.e. MIP and hygroscopic sorption based micro-porosimetry) pointed out that phyllosilicates have a role in decay processes of rocks due to swelling and/or suturing of the adjacent voids

Paint Relics on Middle Age Building Stones as Proxies of Commercial Routes and Artistic Exchanges: A Multi-Analytical Investigation

Fifty-four pieces out of 356 marble pieces deriving from the decorative and architectonic apparatus of the medieval monastic complex of S. Francesco of Castelletto (Genoa, Italy) preserve traces of varicolored paint layers. Microscopic samples of green, blue, red, pink, white, and yellow paint relics were collected by scalpel and analyzed by means of Scanning Electron Microscope coupled with Energy Dispersive Spectroscopy (SEM-EDS), µ-Raman, and Fourier Transform Infra-Red Spectroscopy with Attenuated Total Reflection (FTIR-ATR), to characterize pigments and binders. The combined results from the different techniques allowed verification that stone decoration in Genoa during the Middle Ages encompassed a calcite groundwork and the use of a mixture of oils and proteins (probably egg) to apply pigments. The assemblage of impurities within the pigment has been correlated with the provenance sites along the commercial continental (Hungary and France) and maritime (Sardinia, Cyprus, or Veneto) routes between the 13th and 15th centuries. Moreover, the investigation of the painted layer improved the characterization of the decorative techniques in use in Genoa during the Middle Ages