Central-northern Italy Research Articles

Tomographic models and seismotectonics of the Reggio Emilia region, Italy

The aim of this study is to define the Vp and Vp/Vs structure of the fault zone ruptured by the M L 5.1 earthquake of October 15, 1996 which occurred near Reggio Emilia (central-northern Italy). A 1-month-long seismic sequence followed the mainshock and occurred in a small region along the outer border of the northern Apenninic belt, at depth ranging between 10 and 17 km. P- and S-wave arrival times from 304 aftershocks recorded by two local dense seismic arrays installed in the epicentral region have been inverted to obtain one- and three-dimensional velocity models by using state of the art local earthquake tomographic techniques. Velocity models and aftershock relocation help us to infer the seismotectonic of the region. Earthquakes originated along a NW-dipping backthrust of a NE-trending main thrust, composing the western part of the broad Ferrara Arc. A main high Vp and high Vp/Vs region delineates a pop-up structure in the center of the area. The high Vp/Vs within the pop-up structure supports the presence of a zone with increased pore pressure. The hypocentral depth of both mainshock and aftershocks is greater than those usually found for the main seismogenic regions of the Apenninic belt. P-wave velocity values in the seismogenic area, obtained by tomography, are compatible with rocks of the Mesozoic cover and suggest that seismicity occurred within the Mesozoic units stack at present by compressional tectonics.

Sensitive and Specific Detection of Pseudomonas avellanae using Primers based on 16S rRNA Gene Sequences

A rapid polymerase chain reaction (PCR)‐based procedure was developed for the detection of Pseudomonas avellanae, the causal agent of hazelnut (Corylus avellana) decline in northern Greece and central Italy. The partial sequence of the 16S rRNA gene of P. avellanae strain PD 2390, isolated in central Italy, was compared with the sequence coding for the same gene of P. syringae pv. syringae type‐strain LMG 1247t1. Primers PAV 1 and PAV 22 were chosen, and after the PCR, an amplification product of 762 base pairs was specifically produced only by 40 strains of P. avellanae isolated from northern Greece and central Italy. No other bacterial species among those tested showed an amplification product under optimized PCR conditions. The adding of 4% BLOTTO (10% skim milk powder and 0.2% NaN3) in the PCR mixture proved essential in order to avoid interference of hazelnut extracts during the amplification. The procedure proved more effective than repetitive PCR with ERIC primer sets in diagnosing apparently healthy hazelnut trees as infected. This technique could be of great help for screening the hazelnut propagative material as well as for monitoring the wild C. avellana trees growing in the woods near the infected hazelnut orchards.

Estimating the index flood using indirect methods

Three indirect techniques for index flood estimation are analysed in order to evaluate their applicability and effectiveness. These indirect techniques, based on both statistical and conceptual approaches, are applied to a set of 33 hydrometric stations, located in a large area in northern-central Italy. The results show that the statistical model, due to its flexible structure, has a better descriptive ability than the physically-based models, which are rigidly structured as they conceptualize the rainfall-runoff transformation. However, the rigid structure of the conceptual approaches reduces their dependence on the specific information of the single stations and therefore increases their robustness. Finally, the results highlight that direct estimation techniques could be advisable for catchments with peculiar geomorphoclimatic properties; that is to say properties which differ substantively from those of the majority of the basins considered in the identification of the indirect models. This conclusion seems to hold even when a very limited amount of hydrometric information is available.

GENETIC CHARACTERISATION OF ITALIAN WINE GRAPE CULTIVARS BY MICROSATELLITE DNA ANALYSIS

Fifty-three red and white Vitis vinifera wine grape accessions, chosen for similarities of growing district or morphological features from central northern Italy, were selected for genetic analysis employing the six microsatellite loci VVS1, VVS2, VVS5, VVS29, VVS 16 and VVMD7. The resulting data made it possible to characterise all the accessions and to evaluate the discriminating power of the 6 microsatellite markers, three of which appear to be sufficient to separate all the varieties. The data were also employed to assess the genetic relationships among the cultivars via two distinct approaches: δ μ (delta mu) and fuzzy set similarity. The cultivar clustering shown by the fuzzy set dendrogram appears to better match the geographical distribution of the varieties.

At-site and regional assessment of the possible presence of non-stationarity in extreme rainfall in northern Italy

The possible presence of non-stationarity in long rainfall records, along with the related consequences in the estimation of the frequency distribution of the extreme events, was recently pointed out in several scientific studies. However, it is well known that the detection of the presence of non-stationarity may be affected by relevant uncertainties, which are mainly originated by the limited length of the available data samples. The present paper describes an analysis aimed at detecting the possible presence of non-stationarity in some long rainfall records observed in northern-central Italy. Firstly a regional analysis is performed in order to assess the possible presence of non-stationarity at regional scale. Secondly synthetic rainfall series are analysed in order to assess how much the sample variability of a short stationary series might induce effects which could be attributed to non-stationarity.

Assessing the effectiveness of hydrological similarity measures for flood frequency analysis

This paper evaluates the relative performance of four hydrological similarity measures that are used to form homogeneous pooling groups for regional frequency analysis. One pair of similarity measures is based on seasonality indexes that reflect the timing of extreme events. A further pair of measures considers a characterisation, at the basin scale, of the frequency distribution of rainfall extremes and the extent of the impervious portion of the catchment. The measures are applied to a case study encompassing a large area in Northern-Central Italy. The similarity measures are examined in the context of a pooling scheme that is designed to identify hierarchical, focused pooling groups. The performance of the similarity measures is quantified using a Monte Carlo experiment. The results demonstrate that similarity measures based on seasonality indexes are effective for estimating extreme flow quantiles for the study area. For ungauged catchments, a similarity measure incorporating both rainfall statistics and permeability information is most effective.

Architecture and seismotectonics of a regional low‐angle normal fault zone in central Italy

Information from surface geology, subsurface geology (boreholes, seismic reflection, and refraction profiles), and seismicity are used to depict the geometry and the possible seismogenic role of the Altotiberina Fault (AF), a low‐angle normal fault in central Italy. The AF extends along the inner Umbria region, for a length of ∼70 km, with an average dip of ∼30° and an horizontal displacement up to 5 km. It emerges west of the inner border of the Tiber basin and deepens beneath the Umbria‐Marche carbonate fold‐and‐thrust belt to a depth of 12–14 km. Close to the AF surface trace, low‐angle synthetic east dipping normal faults extensively outcrop, whereas high‐angle antithetic west dipping normal faults prevail farther east. Integrating geological and seismologic information, it can be stated that the AF behaves as an active extensional fault zone and represents the basal detachment of the west dipping seismogenic normal faults of the Umbria‐Marche region. The AF belongs to a regional NE dipping low‐angle normal fault system (Etrurian Fault System (EFS)), which extends for ∼350 km from northwestern Tuscany to southern Umbria. Early preliminary considerations suggest that the EFS may play an important role in controlling active extension and related seismicity in northern central Italy.

Fluid geochemical transect in the Northern Apennines (central-northern Italy): fluid genesis and migration and tectonic implications

Chemical and isotopic characteristics of natural gas and thermal water discharges from the western back-arc Tyrrhenian Sea across the Apennine thrust-belt to the Po Valley and Adriatic coast foredeep basins in the Northern Apennines (central-northern Italy) reveal a large-scale fluid motion in the upper crust, both vertically and horizontally. On the basis of gas compositions, two different domains of rising fluids have been distinguished: (1) CO 2-rich, He-poor, 3He/ 4He-high domain in the western peri-Tyrrhenian extensional sector; (2) CH 4-rich, He-rich, 3He/ 4He-low domain in the eastern Adriatic compressional sector. Such gases, rising from various depths, are crossed by a huge lateral N 2-rich water flow, in the peri-Tyrrhenian sector, of Ca–SO 4(HCO 3) meteoric-derived waters that move in a regional wide aquifer hosted in a quite thick Mesozoic carbonate series. Morphologically, the CO 2 vents consist of mud basins with high gas-rate emission, where the rising fluids move upwards through diatremes. On the other hand, CH 4 emissions seep out from typical mud volcanoes with a reduced gas flow-rate, where the fluid motion is likely related to saline diapir extrusions, and the methane is mostly carried to the surface by the associated mud. The two rising mechanisms described locate southwest and northeast of the Apennine watershed respectively. From a seismic point of view the CH 4 domain in the thrust-belt and foredeep areas is characterized by a large number of earthquakes, indirectly pointing to a different rheological behavior of the terrains with respect to the more internal peri-Tyrrhenian area. Owing to the quite high thermal gradient of the latter, the boundary of the brittle–ductile crust in the peri-Tyrrhenian sector can be located at a <10 km shallow depth. Although the presence of several post-orogenic basins would suggest widespread extensional tectonics in all areas west of the Apennine watershed, those located in the easternmost part display gas vents with typical crustal 3He/ 4He ratios. As this ratio is very sensitive to deep fluids rising from the mantle, we hypothesize that such basins at the foot of the Apennines are not due to tensive stress, as suggested by their morphological shape. They are piggy-back (thrust-top) basins developed and evolved in a still acting compressive tectonic regime.

Genetic and Pathogenic Diversity of Pseudomonas avellanae Strains Isolated from Corylus avellana Trees in North-west of Italy, and Comparison with Strains from Other Regions

Forty strains of Pseudomonas avellanae isolated from hazelnut (Corylus avellana L.) trees in the Langhe district of Italy were compared with 15 strains collected from various geographic areas. All strains were assessed by rep-PCR genomic fingerprinting using ERIC, REP and BOX primer sets. Cluster analysis was performed by means of UPGMA. To check the possible differential virulence of the strains, pathogenicity tests were carried out by inoculating leaf scars of hazelnut trees in early autumn. Cluster analysis indicated that, during a four-year study, at least five groups of strains were isolated from different hazelnut orchards located in the small district of Langhe. Two groups were isolated from the same twig. Such strains showed around 20% similarity with other P. avellanae strains collected from northern Greece and central Italy. The strains from Langhe were less aggressive to hazelnut than strains from northern Greece and central Italy. These results and previous genomic characterizations indicate a possible correlation between genomic profile type and regional geographic distribution of P. avellanae strains. In addition, the genetic variability found in the strains from Langhe indicates that such populations are older than the more homogenous P. avellanae populations from other regions.

EFFECT OF DUST ON EPIPHYTIC LICHEN VEGETATION IN THE MEDITERRANEAN AREA (ITALY AND GREECE)

The epiphytic lichens around limestone and sandstone quarries were investigated in northern Greece and central Italy to study the effect of alkaline and acid dust on epiphytic lichen vegetation in the Mediterranean area. The results showed that the main factor influencing the diversity of the epiphytic lichen vegetation studied is the distance from quarries, and that the chemistry of dust is not an important parameter. The fact that all but a few resistant lichen species die when subjected to high dust concentrations suggests that epiphytic lichens could be usefully employed for monitoring dust fallout and the effects of dust contamination.

Plasma levels of antioxidant vitamins and cholesterol in a large population sample in central-northern Italy.

In a population-based multicenter case-control study of diet, life-style, and gastric cancer a large series of adults, aged 30-75 years (mean 58.9 years), were randomly sampled from the general population in 3 areas of Central-Northern Italy. To evaluate the relationship between plasma levels of antioxidant vitamins and cholesterol, and sociodemographic characteristics, life-style factors, and dietary intake of selected nutrients in a sample of the Italian population. A fasting blood sample was available for 945 subjects (553 men, 392 women). The plasma concentrations of ascorbic acid, carotene, retinol, alpha-tocopherol, and cholesterol were determined by a centralized laboratory. All participants answered to a detailed questionnaire collecting information on sociodemographic and anthropometric characteristics, smoking, alcohol drinking, and dietary habits. Covariance analysis models, with post hoc Dunnett tests, including terms for age, sex, study center, and period of blood drawing, were used for selected multiple-way comparisons of mean values of plasma nutrients. Mean plasma values of retinol were higher among men while women had higher levels of plasma carotene, ascorbic acid, alpha-tocopherol, and cholesterol. Plasma carotene levels showed an inverse association with body mass index, alcohol consumption, and smoking and a positive association with social class. Carotene concentrations were higher in plasma samples obtained in spring/summer, while ascorbic acid levels were higher in autumn/winter. Partial correlation co-efficients between plasma vitamin levels showed a strong correlation between carotene and ascorbic acid (0.69 in men; 0.74 in women), between carotene and alpha-tocopherol (0.44; 0.37), and between alpha-tocopherol and ascorbic acid (0.45; 0.41). Plasma alpha-tocopherol and retinol correlated with plasma cholesterol. On the other hand, plasma carotene and ascorbic acid were correlated with their estimated dietary intakes, while the intakes of other nutrients, as expected, correlated rather poorly with the respective plasma concentrations. Socio-economic factors, life-style, and specific nutrient intake, in addition to gender, are related to nutrient plasma levels in Italian adults and may provide specific suggestions for the prevention of chronic diseases.

Prevalence of Helicobacter pylori infection in a cohort of Italian military students.

In 1990, to study regional prevalences and risk factors of Helicobacter pylori infection in healthy young adult males, sera were collected from a nationwide sample of 1659 males (mean age 20.7 years) at introduction into the Air Force School for military students in Caserta, Italy. An enzyme-linked immunosorbent assay was used to detect H. pylori specific immunoglobulin G antibodies. The observed overall seropositivity rate was 17.5% (95% CI 15.7-19.4). Prevalence was higher in southern Italy and in the Italian islands as compared with northern Italy and central Italy (21.3% vs. 9.5%). Multiple logistic regression analysis showed that residence in southern areas and islands was the strongest predictor of the likelihood of H. pylori seropositivity; number of siblings in the household was marginally associated; years of father's schooling was not a significant predictor. H. pylori positive subjects were more likely positive for antibodies to hepatitis A virus infection (anti-HAV) than those H. pylori negative (35.4% vs. 24.9%; Odds Ratio 1.7, 95% CI 1.3-2.2). Adjustment for the confounding effect of sociodemographic variables weakened this association (OR 1.3, 95% CI 1.0-1.7). These findings suggest that differences in environmental conditions rather than in socioeconomic status may have played the major role in the different spread of H. pylori infection across the country.

An outbreak of intrafamiliar hepatitis A associated with clam consumption: epidemic transmission to a school community.

An outbreak of hepatitis A is described involving thirteen cases in a town in central-northern Italy. The consumption of infected clams, caught in a polluted coastal area of the Adriatic Sea, caused hepatitis A in all five members of a family consisting of mother, father and children, two of whom attended primary school. The epidemic subsequently spread to the primary school with a secondary attack rate of 7.9%, 0 for female pupils and 18.9% for males. The epidemiological and environmental investigations showed that the critical exposure took place in the boys' toilet in the primary school (OR: 32.79, 95% CI: 6.83-157.45). To prevent the spreading of contagion, extra disinfection was carried out in the whole school and health education campaigns were mounted. The good basic hygienic conditions of the homes, together with the cooperation of school staff in surveillance and providing information, allowed the epidemic to be controlled.

A serological survey of bovine herpesvirus-1 infection in selected dairy herds in northern and central Italy

Serum samples from a total of 6979 dairy cattle from 55 herds in northern Italy (51 herds) and central Italy (4 herds), were examined by the serum neutralization test for the presence of antibody to bovine herpesvirus-1 (BHV-1). It was found that 84.31% of the farms selected in northern Italy and all the farms from central Italy had seropositive animals at titers of 1:4 or higher. The prevalence of infection was essentially the same among the cattle populations of the two selected areas of the country, being of 34.99% in the north and of 38.65% in central regions. A comparison of the data from the present study with those obtained in a serological survey conducted in Italy in 1966, shows that the rate of seropositive cattle to BHV-1 has increased by about 5.0% in the last 30 years.

Variations in the survival of adult cancer patients in Italy.

As part of the ITACARE project, the present study analyzed and compared population-based data on the survival of adult cancer patients in Italy, according to sex, age, period of diagnosis and geographical area. Nine Italian population-based cancer registries provided data on all their cancer patients (total 90,431 cases) followed for at least 5 years and diagnosed during the period 1978-1989. About 10% of the Italian population is covered by these registries. The data was analyzed by means of a multivariate model. The major findings were that there was a general improvement in 5-year relative survival over the study period (from 33% to 39%) and that there were significant differences in survival between different areas of the country, particularly for cancer sites which respond well to treatment. In general, the area covered by the Ragusa (Sicily) registry was characterized by significantly worse survival than other registry populations. Other important findings were that for all malignant cancer sites 5-year relative survival decreased with age from 50% for the youngest age class (15-44 years) to 27% for the oldest age class (75+ years) and that women have a better prognosis for most cancer sites (overall 5-year relative survival in women 48% vs 32% in men). The significant regional differences in survival may reflect unequal provision of care, particularly between northern-central Italy and the south. The reasons for the general survival improvement with time are not completely understood, whereas the marked overall sex difference is related to the fact that the commonest cancer in women (breast cancer) is eminently more treatable than the commonest malignancy in men (lung cancer). The unfavorable trend with increasing age may be due to increasing difficulty in applying complete therapy protocols as general health declines, sometimes in relation to an advanced cancer stage at diagnosis.

Lichens as bioindicators of air quality in Montecatini Terme (central northern Italy)

Epiphytic lichens were used as bioindicators of air quality in the town of Montecatini Terme in central northern Italy. By means of 26 Index of Atmospheric Purity (LAP) relevés, a zone-map was drawn by automatic mapping programmes and the area was divided into 4 air quality zones. These zones were not concentric with respect to the city centre, suggesting that they are determined by air pollution and not by urban drought. The worst air quality occurred in urban areas with heavy motorized traffic and along a highway, while higher LAP values were found in areas free of traffic. These results are in agreement with data on the incidence of motorized traffic and air pollutants measured by recording gauges, which showed that SO2 levels were very low, NOx being the main pollutant. This allowed to conclude that in the area the main source of air pollution is from motorized traffic and that changes in lichen frequencies are largely determined by nitrogen oxides. Furthermore, the results underlined the fact that sulphur dioxide is no longer the main pollutant affecting lichen presence.

Interferon-Alpha Is Effective in the Treatment of HIV-1–Related, Severe, Zidovudine-Resistant Thrombocytopenia: A Prospective, Placebo-controlled, Double-Blind Trial

To determine the effect of interferon-alpha for severe, zidovudine-resistant, HIV-1-related thrombocytopenia. Prospective, randomized, double-blind, placebo-controlled, multicenter, crossover trial. Outpatient clinics in Central Northern Italy. 15 sequential patients positive for HIV-1 with platelet counts less than 25 x 10(9)/L who were refractory to 1 month of full-dose (1000 mg/d) zidovudine. Interferon-alpha (3 million units) or placebo (1 mL saline) three times a week subcutaneously for 4 weeks, followed by a 4-week washout period. Patients were then switched to the alternative treatment for the next 4 weeks, followed by another 4 weeks of washout, and they were randomly assigned to either sequence of treatment. Patients received zidovudine (200 mg three times daily) throughout the study. The primary end point was the platelet count (measured weekly). Secondary end points were qualitative assessment of the platelet response; bleeding time; p24 antigen in serum; CD4/CD8 counts; beta 2-microglobulin in serum; and platelet-associated IgG. Interferon-alpha significantly increased platelet counts in the 12 patients who completed the study (baseline level, 15.6 +/- 7.1 x 10(9)/L; after 4 weeks of interferon-alpha therapy, 82.2 +/- 52.2 x 10(9)/L). The estimated increase in the platelet count after interferon-alpha compared with placebo was 60.0 x 10(9)/L (95% CI, 23.2 to 96.8 x 10(9)/L). The increase was already statistically significant after 3 weeks (66.6 +/- 49.7 x 10(9)/L) and remained significantly increased 1 week after discontinuing interferon-alpha therapy (58.2 +/- 45.0 x 10(9)/L). Placebo did not modify the platelet count. The bleeding time was significantly shortened by interferon-alpha. Four of 12 patients who had more serious alterations of some measures reflecting disease severity did not respond to interferon-alpha. No relevant side effects were observed. Interferon-alpha is a safe and effective treatment for zidovudine-resistant, HIV-related thrombocytopenia.

Lichen biomonitoring of trace metals in the Pistoia area (central northern Italy)

The epiphytic lichen Parmelia caperata (L.) Ach. was used as bioaccumulator of the heavy metals Cd, Cr, Cu, Hg, Ni, Pb and Zn in the environs of the town of Pistoia (central northern Italy). The concentrations of Cd, Cr, Ni, Hg and Pb were comparable with those found in areas not subject to atmospheric pollution. Copper and especially Zn were found in rather high concentrations. Fertilizers and pesticides were the main source of atmospheric contamination.

Genomic DNA fingerprints and phenotypic characteristics of serotype B Haemophilus influenzae isolates from Italy

Three different restriction enzymes (PstI, EcoRI, SspI) were used to analyze the total genomic DNA fingerprints of 52 Haemophilus influenzae type b (Hib) isolates collected between 1982 and 1992 from patients and carriers in central-northern Italy. The same isolates were also characterized by biotyping and antimicrobial agent susceptibility typing. In addition, 13 Hib reference strains from Sweden and the Netherlands were subjected to DNA fingerprinting and compared to Italian isolates. Both genotypic and phenotypic analysis revealed low variability among the Italian study isolates. Most were biotype I and all study isolates but one were susceptible to ampicillin, chloramphenicol, rifampin, third-generation cephalosporins and cotrimoxazole. Among the 52 Italian isolates, 3 distinct DNA patterns were identified, and 88.5% of study strains belonged to the same DNA group. There was sharing of the predominant DNA profile among isolates cultured in different years from different geographical areas and different invasive, respiratory and surface infections. However, another DNA pattern was only found in carrier isolates and in one surface infection isolate. Comparison by DNA fingerprinting showed that the majority of Italian isolates were closely related to most of the analyzed Swedish and Dutch reference strains, previously shown by other techniques to be predominant in those areas. This finding provides additional support for the hypothesis that there may be a dominant European Hib clone. The results show that DNA fingerprinting is a reliable method for Hib characterization and may be a useful additional epidemiological tool for this microorganism.

Exposure to agricultural treatment residues: Some simple statistical considerations based on monitoring data for ethoxyquin on apples

The data examined here concern ethoxyquin levels, mainly measured in apple samples from the retail market. In this study about three hundred measurements, carried out on apples in Northern-Central Italy and recently published, are examined, with the purpose of defining the main characteristics of value statistical distribution and variability and to optimize sampling criteria. The analysis did not indicate the presence of significantly high levels or consequently significantly high risks; nevertheless, it pointed out some important aspects in data collection and evaluation. First, it appeared that the statistical distribution of data is typically nonsymmetrical, non-Gaussian, and characterized by a tail extending toward the high values. The logarithmic transformation of data appeared useful in order to obtain a Gaussian distribution. As a rule, the data variability appeared to be high. The frequency and distribution of values above the analytical threshold resulted in significant change, both in time and in space. The percentage of positive values (above the analytical threshold) appeared to vary up to a factor of 2–3, as analogously did their geometric mean. The analysis of statistical distributions of such values indicated that (i) the geometric mean of data may be considered the best indicator of their central tendency; (ii) the standard deviation of measurement carried out in the same place and in the same year may range from 0.7 to 1 for log-transformed data, which means approximately a factor of 2–3 for original data (two standard deviations correspond to a factor of 4–9); (iii) 95% of the residue level population, under conditions similar to those examined here, may be reasonably expected to fall within a value 5- to 15-fold higher than the geometric mean of data (with a 95% confidence level); (iv) this last aspect is due to lognormal distribution features which imply the possible presence of a slight number of high values together with a large number of much lower values. This preliminary study indicates that a risk of possible sporadic significant exposure levels may exist; it is, however, very important to identify whether highest exposure levels are randomly distributed in space and time or rather affect a specific group of subjects in a specific period.