518 research outputs found
Mapping Moho depth variations in central Italy from PsMoho-P delay times: Evidence of an E-W transition in the Adriatic Moho at 42°N latitude
Along the Italian peninsula adjoin two crustal domains, peri-Tyrrhenian and Adriatic, whose
boundary is not univocal in central Italy. In this area, we attempt to map the extent of the Moho in the
two terrains from variations of the travel time difference between the direct P wave and the P-to-S wave
converted at the crust-mantle boundary, called PsMoho. We use teleseismic receiver functions computed
at 38 broad-band stations in this and previous studies, and assigned each of the recording sites to the
Adriatic or peri-Tyrrhenian terrains based on station location, geologic and geophysical data and
interpretation, and consistency of delays with the regional Moho trend. The results of the present study
show that the PsMoho arrival time varies from 2.3 to 4.1 s in the peri-Tyrrhenian domain and from 3.7 to
5.5 s in the Adriatic domain. As expected, the lowest time difference is observed along the Tyrrhenian
coastline and the largest values are observed in the axial zone of the Apennine chain. A key new result of
this study is a sharp E-W boundary in the Adriatic domain that separates a deeper Moho north of about
42 N latitude from a shallower Moho to the south. This feature is constrained for a length of about 40 km
by the observations available in this study. The E-W boundary requires a revision of prior mapping of the
Moho in central Italy and supports previous hypotheses of lithosphere segmentation
Potential rockfalls and analysis of slope dynamics in the palatine archaeological area (Rome, Italy)
The Palatine Hill is among the main archaeological sites of Roman antiquity. Today, this place requires continuous care for its safeguarding and conservation. Among the main problems, slope instabilities threaten the southwestern border of the hill flanked by the Velabrum Valley, as also testified by historical documents. The upper part of the investigated slope is characterized by Middle Pleistocene red-brownish tuffs known as "Tufo Lionato". The rock mass is affected by two jointing belts featuring the slope edge and its internal portion with different joint frequency and distribution. The analysis of the geometric relationship between the joint systems and the slope attitude evidenced possible planar sliding and toppling failure mechanisms on the exposed tuff cliffs. Potential rock block failures threatening the local cultural heritage were contrasted with preliminary works for site remediation. In addition, stress-strain numerical modelling verified the hypothesis of a tensile origin for the jointing belts, suggested by fracture characteristics and orientation. A first modelling was limited to the southwestern edge of the Palatine Hill and analysed the present stress-strain condition of the slope, proving the inconsistency with the observed deformation. A second modelling was extended to the Palatine-Velabrum slope-to-valley system to consider the role played by the geomorphological evolution of the area on the local slope dynamics during the late Pleistocene-Holocene. Results demonstrate how original conditions of slope instability, deformation and retreat along the Palatine western edge were determined by deep valley incision, and controlled by deformability contrasts within the slope. Slope instability influenced the site occupation and development during the Roman civilization, as also indicated by the remnants of retaining walls of different ages at the slope base
Stellar evolution confronts axion models
Axion production from astrophysical bodies is a topic in continuous development, because of theoretical progress in the estimate of stellar emission rates and, especially, because of improved stellar observations. We carry out a comprehensive analysis of the most informative astrophysics data, revisiting the bounds on axion couplings to photons, nucleons and electrons, and reassessing the significance of various hints of anomalous stellar energy losses. We confront the performance of various theoretical constructions in accounting for these hints, while complying with the observational limits on axion couplings. We identify the most favorable models, and the regions in the mass/couplings parameter space which are preferred by the global fit. Finally, we scrutinize the discovery potential for such models at upcoming helioscopes, namely IAXO and its scaled versions
Investigation of the Luco dei Marsi DSGSD revealing the first evidence of a basal shear zone in the central Apennine belt (Italy)
Deep-seated gravitational slope deformations (DSGSDs) show a wide range of geomorphological characteristics and kinematic behaviours. In many cases, deforming rock masses move on a continuous surface or a thick basal shear zone (BSZ) overlying the stable bedrock. The nature of this boundary is a significant issue in scientific debates since examples of BSZs have been observed or inferred in some DSGSDs worldwide. In the central Apennines, although several cases of DSGSDs have been described in recent decades, no evidence of BSZs has been documented thus far. This work presents the first case of a BSZ found in the region at the bottom of a large-scale gravitational deformation that affects the Mesozoic-Cenozoic carbonate ridge overhanging the Luco dei Marsi village (Abruzzi region). The BSZ consists of several metres-thick, cataclastic breccia developed within middle-Upper Cretaceous biodetritic limestone. The breccia level is exposed for approximately 200 m with a subhorizontal geometry and shows severe rock damage and weathering. The DSGSD hosting the BSZ affects an NNW-SSE-oriented and wide Miocene anticline whose eastern limb is dismembered by Pliocene-Quaternary normal faults delimiting the edge of a large Quaternary intermontane basin (the Fucino Basin). Field survey, aerial photointerpretation, and remote sensing (DInSAR technique) analyses outline an active gravity-driven process. This is characterized by several kinds of geomorphological features, including downhill- and uphill-facing scarps, ridge-top depressions, gravitational grabens and trenches in the upper and middle parts of the ridge, and bulging at the toe of the slope. These features, which can be distinguished from tectonic elements due to their shape and extension, are an indication of a high degree of internal deformation and a compound sagging geometry for the Luco dei Marsi DSGSD. The short-term activity of the process was revealed by DInSAR time series covering almost thirty years of satellite datasets, including ERS1/2, ENVISAT, COSMO-SkyMed, and SENTINEL 1 constellations. Strain rates on the order of a few mm/yr were inferred, with a marked difference between different sectors of the DSGSD area. The long-term (y > 102) lifespan of the DSGSD was framed into a multiple-step conceptual model summarizing the Early Pleistocene-Holocene geological evolution of the area. The model results outline the control exercised by extensional tectonics on DSGSD development, as progressive displacements along normal faults in the latest Pleistocene were the cause of lateral unconfinement at the toe of the slope. This work further contributes to the increasing knowledge on DSGSDs in the central Apennines and the understanding of the relationship between deformation features induced by slope morphogenesis, such as the BSZ, and Quaternary tectonics within the mountain belt
Macroseismic effects highlight site response in Rome and its geological signature
A detailed analysis of the earthquake effects on the urban area of Rome has been conducted for the L’Aquila sequence, which occurred in April 2009, by using an on-line macroseismic questionnaire. Intensity residuals calculated using the mainshock and four aftershocks are analyzed in the light of a very accurate and original geological reconstruction of the subsoil of Rome based on a large amount of wells. The aim of this work is to highlight ground motion amplification areas and to find a correlation with the geological settings at a sub-regional scale, putting in evidence the extreme complexity of the phenomenon and the difficulty of making a simplified model. Correlations between amplification areas and both near-surface and deep geology were found. Moreover, the detailed scale of investigation has permitted us to find a correlation between seismic amplification in recent alluvial settings and subsiding zones, and between heard seismic sound and Tiber alluvial sediments
Double Heterozygous Mutations Involving Both HNF1A/MODY3 and HNF4A/MODY1 Genes: A case report
none9Abstract
We describe the first MODY case with mutations involving both HNF4A and HNF1A genes.
History and Examination. A male patient was diagnosed with diabetes at age 17; the metabolic control rapidly worsened to insulin requirement. At that time no relatives were known to be affected by diabetes, which was diagnosed years later in both parents (father at age 50, mother at age 54) and the sister (age 32 during pregnancy).
Investigations. The genetic screening showed a double heterozygosity for the mutation p.E508K in HNF1A/MODY3 gene and the novel variant p.R80Q in HNF4A/MODY1 gene. The genetic testing of the family showed that the father carried the MODY3 mutation while the mother, the sister and her two children carried the MODY1 mutation.
Conclusions. MODY1 and MODY3 mutations may interact by chance to give a more severe form of diabetes (younger age at presentation, early need of insulin therapy to control hyperglycemia).mixedG. Forlani; S. Zucchini; A. Di Rocco; R. Di Luzio; M. Scipione; E. Marasco; G. Romeo; G. Marchesini Reggiani; V. MantovaniG. Forlani; S. Zucchini; A. Di Rocco; R. Di Luzio; M. Scipione; E. Marasco; G. Romeo; G. Marchesini Reggiani; V. Mantovan
First results from the CROP-11 deep seismic profile, central Apennines, Italy: evidence of mid-crustal folding
The CROP-11 deep seismic profile across the central Apennines, Italy, reveals a previously unknown, mid-crustal antiform here interpreted as a fault-bend fold-like structure. The seismic facies and gravity signature suggest that this structure consists of low-grade metamorphic rocks. Geomorphological, stratigraphic and tectonic evidence in the overlying shallow thrusts suggests that this structure developed in early to mid-Messinian time and grew out of sequence in late Messinian–
Pliocene time. The out-of-sequence growth may reflect a taper subcriticality stage of the Apenninic thrust wedge, which
induced renewed contraction in the rear.Published583–586ope
First results from CROP-11 deep seismic profile, central Apennines, Italy:evidence of mid-crustal folding.
Geophysical and geological data used to reconstruct the deep structures of central Ital
- …