411 research outputs found

    Geomorphic hazards and intense rainfall: the case study of the Recco Stream catchment (Eastern Liguria, Italy)

    Get PDF
    Abstract. A critical pluviometric event occurred in the central-eastern Ligurian Riviera, 15 km from Genoa, on 1 June 2007. This event caused landslides and hydraulic problems between Sori and Camogli and in the inland area of the Recco Valley. An analysis of the heavy rainfall was conducted. Hourly precipitation data revealed a critical event between 04:00 a.m. and 07:00 a.m. local time, with more than 220 mm of precipitation over three hours. Slope movements were mainly debris flows that detached from the lateral valleys of the Recco Stream catchment and from well-maintained, wooded slopes that were also characterised by cultivated terraces. Numerous slide planes corresponded to the interface between the surface cover and the underlying bedrock, which presents an unfavourable geologic structure in terms of stability assessment. In most cases, the displaced material had a limited thickness. Debris cover was rapidly channelled along small valleys, which controlled the critical hydraulic conditions in the secondary drainage network. Man-made drainage systems were partially or totally blocked in a very short time and, like the natural watercourses, accumulated thick and extensive alluvial fans. Most of the instability phenomena occurred in areas that had been designated medium or low-risk areas during land planning, and in sectors that were defined as stable, because they lacked geomorphic indicators connected to landslide risks. The above considerations highlight some gaps of the Recco Stream Master Plan. Therefore, to update this land planning tool, it is necessary to extensively investigate local geomorphological characteristics and to adopt a different method for assigning weights to the geohazard maps

    Man-made activities and morphological changes of Ligurian floodplains (Italy) since modern history to nowadays: an approach through old maps comparison

    Get PDF
    The Tyrrhenian slope of Liguria extends along the coast, from West to East, for nearly 300 km between Ventimiglia to Marinella di Sarzana: this stretch of territory presents more than a hundred catchments mainly characterized by small-size floodplains, usually less than 1 km2. Ligurian catchments, except for the Roja and the Magra rivers, have common features: by the area they can be distinguished in small basins (less than 15 km2), medium (15-150 km2) and large (150-500 km2). The slopes of the catchment areas are very steep, while the flat alluvial plains are typically narrow and elongated: the largest one are referred to the Entella stream (approximately 4 km long) and the Centa stream (about 7 km in length). On these floodplains are located almost Ligurian urban areas, which represent the expansion of the historical settlements and road connections. Through a comparative mapping it was rebuilt the morphological evolution of Ligurian floodplains in historical times, witnessing the land-use and riverbed changes in the modern era until today, by using: 1) Historical maps of the eighteenth century by Matteo Vinzoni (\u201cPianta delle due riviere della serenissima Repubblica di Genova divise nei commissariati di sanit\ue0\u201d e \u201cIl Dominio della Serenissima Repubblica di Genova in terraferma\u201d); 2) historical topographic maps of the first half of the nineteenth century (\u201cStati Sardi di Terraferma), in different topographic scales: a) 1:50.000, b) 1:20.000 and c) 1:9.450; 3) historical topographic maps of the second half of the nineteenth century until the first half of the twentieth century (\u201cTavolette dell\u2019Istituto Geografico Militare Italiano, Firenze, 1878-1940, 1:25.000); 4) regional maps for the second half of the twentieth century, 1: 10.000 and 1: 25.000, while the current status was assessed with Google Earth Pro platforms; 5) important information was taken by the Map of the historical evolution of urban fabric, 1: 50.000 produced by Liguria Region and obtained by the overlap of urbanized areas in different periods (1855, 1936, 1964 and 1986). The secular human activities have therefore modified the natural landscape through land use changes, either for catchment or for the floodplain. The main channel, and even the minor hydrographic network, have showed major transformations over time. The anthropic action has deeply modified the morphology of Ligurian floodplains, except for the two largest: Albenga (Centa stream) and Chiavari-Lavagna (Entella stream), which still have a portion of soil for agricultural purposes. In many cases it has detected a river-bed covering, especially in the medium-terminal portion, for the purpose of building needs and the road link. Other very widespread changes finally concern: a) deviations and displacements of the riverbed, b) the progradation of the coastline due to fills and embankments

    The recent abrupt increase in the precipitation rate, as seen in a ultra-centennial series of precipitation

    Get PDF
    The authors analyse the ultra-centennial series (1833- 1995) of daily total amounts of precipitation recorded in the Genoa University’s Meteorological Observatory and the precipitation annual rates, investigating any relationship with the recent occurrences of exceptional rainfall. Among the principal results there is a constant decrease in the number of rainy days since the first records and a significative jump of precipitation rate since 1950. The application of the Gumbel method to the Return Time of the Annual Maximum (AM) series, owing to the recent anomalous variations of Annual Maximum daily precipitation (mmO24 h), has revealed an increase of heavy rainfall in the last thirty years. Moreover, the return times of these events are remarkably shortened

    Geo-hydrological hazard underlined by toponymy of Italian Military Geographycal Institute maps at 1:25,000 scale. Contributions to the knowledge of floodplain and hillslope dinamycs

    Get PDF
    Toponymy is a linguistic discipline, which has already been used as a tool for geographical studies in Italy and particularly in Liguria. Geographical studies have already classified the toponyms in several categories: physical geography, human geography and socio-economic geography. By selecting the place names connected to physical geography, we study those suggesting the presence of landslides or floods. We focussed on the Italian Military Geographic Institute maps at 1: 25.000 scale, edited between 1936-1939 and related to a territory approximately located between Genoa and Chiavari, in Ligurian coastal area, and Tortona and Piacenza in Po valley. On the Ligurian slopes we have examined the maps relating to the Polcevera, Bisagno and Entella streams catchments. For the Po side we dealt with maps of the Scrivia and Trebbia rivers catchments: From the Ligurian-Po watershed, these rivers flow into the Adriatic Sea. The place names have been compared with landslide and flood hazard maps of Basin Master Plans for geo-hydrological risk reduction. The toponyms feature a linguistic layer linked to different historical periods. In particular in the study area several layers have been recognized: the ancient Ligurian pre-Roman, Latin, ancient Lombard, vulgar Gaulish-Italic of local languages and Italian terms related to the twentieth century. The first three layers and the last one match in the entire area of study. The vulgar Gaulish-Italic is structured into two Ligurian and Emilian groups: the latter is further splitted into the Oltrepo variants of Tortona and Piacenza. The identified names were distinguished in related-landslides or floods. In addition, the toponyms have been further divided into three linguistic influence areas: Ligurian, from Ligurian Sea up to Novi Ligure and Bobbio, the language of Tortona, downstream of Novi Ligure and Piacenza from Bobbio to Po river. Overall, place names linked to physical geography features represent nearly 25% of toponyms with a density of about 0.5 per km2. Almost half of these are toponyms related to landslides, floods or predisposing factors such as erosion, steepness or water. The names of places linked to landsliding prevail in Liguria, while those related to the waters or floods in the Po areas are located in plain areas or in very gentle slopes. The most common names related to landslides or erosion are \u201cmoggia\u201d, \u201cliggia\u201d or \u201ccrosi\u201d and similar, which respectively mean swampy deposits, landslides or gullies. Names related to floods are \u201criva\u201d, \u201cpiana\u201d \u201cponte\u201d or \u201cisola\u201d which mean respectively edge of fluvial scarp, floodplain, bridge or isle. The comparison with the Basin Master Plan gave satisfying results: we found a good correspondence between names and geo-hydrological hazard. The use of toponyms allowed a geographycal interpretation of the slope and floodplain dynamics. It suggests a possible use of toponymys in land planning activities

    Geomorphic hazards and intense rainfall: the case study of the Recco Stream catchment (Eastern Liguria, Italy)

    Get PDF
    A critical pluviometric event occurred in the central-eastern Ligurian Riviera, 15 km from Genoa, on 1 June 2007. This event caused landslides and hydraulic problems between Sori and Camogli and in the inland area of the Recco Valley. <br><br> An analysis of the heavy rainfall was conducted. Hourly precipitation data revealed a critical event between 04:00 a.m. and 07:00 a.m. local time, with more than 220 mm of precipitation over three hours. <br><br> Slope movements were mainly debris flows that detached from the lateral valleys of the Recco Stream catchment and from well-maintained, wooded slopes that were also characterised by cultivated terraces. <br><br> Numerous slide planes corresponded to the interface between the surface cover and the underlying bedrock, which presents an unfavourable geologic structure in terms of stability assessment. <br><br> In most cases, the displaced material had a limited thickness. Debris cover was rapidly channelled along small valleys, which controlled the critical hydraulic conditions in the secondary drainage network. <br><br> Man-made drainage systems were partially or totally blocked in a very short time and, like the natural watercourses, accumulated thick and extensive alluvial fans. <br><br> Most of the instability phenomena occurred in areas that had been designated medium or low-risk areas during land planning, and in sectors that were defined as stable, because they lacked geomorphic indicators connected to landslide risks. <br><br> The above considerations highlight some gaps of the Recco Stream Master Plan. Therefore, to update this land planning tool, it is necessary to extensively investigate local geomorphological characteristics and to adopt a different method for assigning weights to the geohazard maps

    Effect of tamoxifen and transdermal hormone replacement therapy on cardiovascular risk factors in a prevention trial. Italian Chemoprevention Group.

    Get PDF
    The combination of tamoxifen and transdermal hormone replacement therapy (HRT) may potentially reduce risks and side-effects of either agent, but an adverse interaction could attenuate their beneficial effects. We assessed the effects of their combination on cardiovascular risk factors within a prevention trial of tamoxifen. Baseline and 12-month measurements of total, low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol, platelets and white blood cells were obtained in the following four groups: tamoxifen (n = 1117), placebo (n = 1112), tamoxifen and HRT (n = 68), placebo and HRT (n = 87). The analysis was further extended to women who were on HRT at randomization but discontinued it during the 12-month intervention period (n = 33 on tamoxifen and n = 35 on placebo) and to women who were not on HRT but started it during intervention (n = 36 in both arms of the study). Compared with small changes in the placebo group, tamoxifen was associated with changes in total, LDL- and HDL-cholesterol of approximately -9%, -19% and +0.2% in continuous HRT users compared with -9%, -14% and -0.8% in never HRT users. Similarly, there was no interaction on platelet count. In contrast, the decrease in total and LDL-cholesterol levels induced by tamoxifen was blunted by two-thirds in women who started HRT while on tamoxifen (P = 0.051 for the interaction term). We conclude that the beneficial effects of tamoxifen on cardiovascular risk factors are unchanged in current HRT users, whereas they may be attenuated in women who start transdermal HRT while on tamoxifen. Whereas a trial of tamoxifen in women already on transdermal HRT is warranted, prescription of HRT during tamoxifen may attenuate its activity

    Methodology and Neuromarkers for Cetaceans’ Brains

    Get PDF
    Cetacean brain sampling may be an arduous task due to the difficulty of collecting and histologically preparing such rare and large specimens. Thus, one of the main challenges of working with cetaceans’ brains is to establish a valid methodology for an optimal manipulation and fixation of the brain tissue, which allows the samples to be viable for neuroanatomical and neuropathological studies. With this in view, we validated a methodology in order to preserve the quality of such large brains (neuroanatomy/neuropathology) and at the same time to obtain fresh brain samples for toxicological, virological, and microbiological analysis (neuropathology). A fixation protocol adapted to brains, of equal or even three times the size of human brains, was studied and tested. Finally, we investigated the usefulness of a panel of 20 antibodies (neuromarkers) associated with the normal structure and function of the brain, pathogens, age-related, and/or functional variations. The sampling protocol and some of the 20 neuromarkers have been thought to explore neurodegenerative diseases in these long-lived animals. To conclude, many of the typical measures used to evaluate neuropathological changes do not tell us if meaningful cellular changes have occurred. Having a wide panel of antibodies and histochemical techniques available allows for delving into the specific behavior of the neuronal population of the brain nuclei and to get a “fingerprint” of their real status

    Prioritization of high-cost new drugs for HCV: making sustainability ethical

    Get PDF
    Hepatitis C virus (HCV) infection is a major health problem worldwide. Chronic HCV infection may in the long run cause cirrhosis, hepatic decompensation and hepatocellular carcinoma, with an ultimate disease burden of at least 350,000 deaths per year worldwide. The new generation of highly effective direct acting antivirals (DAA) to treat HCV infection brings major promises to infected patients in terms of exceedingly high rates of sustained virological response (SVR) but also of tolerability, allowing even the sickest patients to be treated. Even in the face of the excellent safety and efficacy and wide theoretical applicability of these regimens, their introduction is currently facing cost and access issues denying their use to many patients in need. Health systems in all countries are facing a huge problem of distributive justice, since while they should guarantee individual rights, among which the right to health in its broader sense, therefore not limited to healing, but extended to quality of life, they must also grant equal access to the healthcare resources and keep the distribution system sustainable. In the face of a disease with a relatively unpredictable course, where many but not of all chronically infected will eventually die of liver disease, selective allocation of this costly resource is debatable. In most countries the favorite solution has been a stratification of patients for prioritization of treatment, which means allowing Interferon-free DAA treatment only in patients with advanced fibrosis or cirrhosis, while keeping on hold persons with lesser stages of liver disease. In this report, we will perform an ethical assessment addressing the issues linked to access to new therapies, prioritization and eligibility criteria, analyzing the meaning of the term “distributive justice” and the different approaches that can guide us (individualistic libertarianism, social utilitarianism and egalitarianism) on this specific matter. Even if over time the price of new DAA will be reduced through competition and eventual patent expiration, the phenomenon of high drug costs will go on in the next decades and we need adequate tools to face the problems of distributive justice that come with it
    • …
    corecore