Regional gravity anomaly map and crustal model of the Central-Southern Apennines (Italy)

The deep structures of the Central–Southern Apennines are analysed on the basis of the regional component of gravity anomalies, obtained applying a stripping technique. This procedure allows the accurate removal of the gravimetric effect of the three-dimensional shallow (within the first 10 km) geological bodies from the observed Bouguer anomaly. The resulting anomaly map differs quite significantly from the Bouguer anomaly map, providing new constraints on the nature of the deeper part of the crust and on the upper mantle. The stripping reveals that the regional gravity lows are shifted westward in comparison with Bouguer anomaly lows. Moreover, the gravimetric pattern indicates a lack of cylindrism for the deep structures of the Apennine Chain, which in the study area can be roughly divided into three main segments. The observed differences between the gravity anomalies pattern of the Central Apennines and that of the Southern Apennines are marked. The integration of gravimetric results with other geophysical data suggests that: (i) a ramp-dominated style for the buried Apulia (Adria) units and part of the underlying basement is compatible with gravimetric data and (ii) most of the regional gravity anomalies in the Central Apennines seem to originate within the lower crust

Ocular surface analysis in patients affected with rheumatic diseases

Objective. The international criteria for primary Sjogren's Syndrome (SS I) diagnosis (Vitali et al. 2002) include the Schirmer test I and vital dye staining as tests for ocular surface involvement, but diagnosis can be reached also when the item for ocular signs is not satisfied. The purpose of our study was to evaluate the ocular surface in patients with Sjogren's Syndrome, non- Sjogren's autoimmune diseases and Sicca Syndrome, to understand whether the SS I diagnosis can be targeted also on other tests related to the ocular surface status. Methods. Clinical and cytological data were collected from 122 patients: 40 patients had diagnosis of Primary Sjogren's Syndrome, 51 a non Sjogren's autoimmune disease and 31 had symptoms of dry eye. A validated questionnaire on symptoms was filled by each patient; clinical tests included: Schirmer test I, Jones test, Ferning test, Break Up Time, corneal aesthesiometry, tear clearance test, vital dye staining of the ocular surface, scraping and impression conjunctival cytology. Data were statistically evaluated by using SPSS software and Mann-Whitney analysis on unpaired data. Results. Data show that the subjective symptoms score, tear production, tear turnover, corneal sensitivity and ocular surface integrity are affected in SS I patients, with a statistically significant difference when matched to the other two groups. Conclusions. Our results suggest to enlarge the spectrum of ocular surface analysis, to support and orient a differential diagnosis among the autoimmune diseases

Sulla correzione topografica nei Rilievi gravimetrici geominerari

Si inette in evidenza che, in certi casi, l'estendere a zone<br />lontane (oltre 20 km) la sola correzione per la calotta o piastra, può introdurre<br />errori notevoli nelle differenze tra le anomalie, anche nel caso di rilevamenti su<br />piccole aree; l'errore è funzione crescente delle differenze tra le quote delle<br />stazioni. Si propone uii criterio per determinare le distanze cui conviene limitare<br />la correzione per la calotta (o piastra) e la topografica in senso stretto.<br />Si riporta, come esempio, il caso di un rilevamento (regione del M.<br />Amiata) in cui i limiti comunemente adottati (calotta fino alla zona 02 di<br />Hayford e topografica fino alla M) avrebbero introdotto errori superiori a<br />quelli che si sarebbero ottenuti scegliendo, in base all'analisi preventiva<br />proposta, limiti più ristretti per le correzioni

Rilievo magnetometrico del giacimento di Fornovolasco

Sono descritte le operazioni di campagna ed i metodiusati nell'interpretazione di un rilievo magnetometrico eseguito nella zonadel giacimento di pirite e magnetite di Fornovolasco (Lucca), sito sulle pendicidella Pania Secca (Alpi Apuane). Mediante le determinazioni di AH,AZ e AD è stato possibile ricavare in ogni stazione il vettore anomalo totale.L'interpretazione è stata basata sull'uso di modelli costituiti da elettrocalamiteprismatiche. I risultati dell'interpretazione sono discussi sulla basedelle conoscenze geominerarie sul giacimento

Osservazioni sul comportamento di una apparecchiatura geoelettrica a corrente commutata per misure di resistività

Si descrive un'apparecchiatura a corrente commutataa 10 Hz per misure di resistività. Vengono riportate le varie prove effettuatesull'apparecchiatura per determinarne sia le approssimazioni di misura chele caratteristiche di impiego. Vengono valutati alcuni effetti induttivi legatiall'impiego della corrente alternata, con un metodo per successive approssimazioni;si dimostra che nei casi interessanti le misure fatte con l'apparecchiaturein esame, tali effetti sono trascurabili

Geoelectrical survey of structures closed in depth by two dipping discontinuities

Alfano's integral equation method, previously used to calculate VES theoretical curves in parallel or diverging dipping planes including an indefinite conductive medium (open structures), was applied to calculate VES theoretical curves in closed structures, i.e. when the conductive medium is limited in depth. The theoretical curves, as calculated for various cases, show slopes steeper than the corresponding two-layers curves and resistivity asymptotic values equal to those of the resistive layer; their trends can be used to evaluate the dips of contacts. Two surveys, carried out on similar superficial situations in the Appennines area, have been interpreted by means of the new theoretical curves, and have shown different structural situations in depth