129 research outputs found

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    A Political Economy? Some Preliminary Thoughts on Economic Privileges in Early Modern Venice

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    The paper provides a general view of different typologies of privilege existing in the Republic of Venice from 1500 to 1800, connecting together the results of previous research on the subject to build a more complex view of the Venetian “political economy”. The focus on the Venetian case is justified by its alleged exceptionality, which challenges both the usual assumptions about the operation of economic and political privileges, and the general interpretations of their historical evolution. Yet Venice is here used as a laboratory in which historians could elaborate new questions and concepts useful in the investigation of privileges in pre-industrial economies. In this perspective, the authors deal with 1) fair and export privileges of subject cities, their origin and adaptation from the Renaissance up to the fall of the Republic; 2) the role of commercial privileges and how they were used by central authority in order to allow business cooperation, market integration and industrial development; 3) the functions that industrial privileges performed as tools of the Venetian mercantilist policy in order to foster import-substituting and export activities

    Long-term geochemical monitoring and extensive/compressive phenomena: case study of the Umbria Region (Central Apennines, Italy)

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    Long-term geochemical monitoring performed in the seismic area of the Umbria-Marche region of Italy (i.e. Central Apennines) has allowed us to create a model of the circulation of fluids and interpret the temporal chemical and isotopic variations of both the thermal springs as well as the gas vents. Coincident with the last seismic crisis, which struck the region in 1997-1998, an enhanced CO2 degassing on a regional scale caused a pH-drop in all the thermal waters as a consequence of CO2 dissolution. Furthermore, much higher 3He/4He isotope ratios pointed to a slight mantle-derived contribution. Radon activity increased to well above the ±2 sinterval of the earlier seismic period, after which it abruptly decreased to very low levels a few days before the occurrence of the single deep-located shock (March 26, 1998, 51 km deep). The anomalous CO2 discharge was closely related to the extensional movement of the normal faults responsible for the Mw 5.7, 6.0 and 5.6 main shocks that characterized the earlier seismic phase. In contrast, a clear compressive sign is recognizable in the transient disappearance of the deep-originating components related to the Mw 5.3, 51 km-deep event that occurred on March 26, 1998. Anomalies were detected concomitantly with the seismicity, although they also occurred after the seismic crisis had terminated. We argue that the observed geochemical anomalies were driven by rock permeability changes induced by crustal deformations, and we describe how, in the absence of any release of elastic energy, the detection of anomalies reveals that a seismogenic process is developing. Indeed, comprehensive, long-term geochemical monitoring can provide new tools allowing us to better understand the development of seismogenesis

    New observations in Central Italy of groundwater responses to the worldwide seismicity

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    Chemical and physical responses of groundwater to seismicity have been documented for thousands of years. Among the waves produced by earthquakes, Rayleigh waves can spread to great distances and produce hydrogeological perturbations in response to their passage. In this work, the groundwater level, which was continuously recorded in a monitoring well in Central Italy between July 2014 and December 2019, exhibited evident responses to dynamic crustal stress. In detail, 18 sharp variations of the groundwater level due to worldwide Mw ≥ 6.5 earthquakes were observed. Apart from earthquakes that occurred in Papua New Guinea and those with a hypocentral depth > 150 km, all far away Mw ≥ 7.6 earthquakes produced impulsive oscillations of groundwater. As the earthquake magnitude decreased, only some earthquakes with 6.5 ≤ Mw < 7.6 caused groundwater level perturbations, depending on the data acquisition frequency and epicentral distance from the monitoring well. A clear correlation between earthquake distance and magnitude in hydrogeological responses was found. Our results shed light on the hydrosensitivity of the study site and on the characteristics of fractured aquifer systems. Detecting the water table variations induced by distant earthquakes is another step towards a correct identification of (preseismic) hydrogeological changes due to near-field seismicity

    Geochemistry of fluid inclusions in travertines from Western and Northern Turkey: inferences on the role of active faults in fluids circulation

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    The understanding of the relationship between the geochemistry of fluids circulating during travertine deposition and the presence of active faults is crucial for evaluating the seismogenetic potential of an area. Here we investigate travertines from Pamukkale and Reşadiye (Turkey), sited in seismic regions and next to thermal springs. These travertines formed ~24,500–50,000 (Pamukkale) and ~240–14,600 years (Reşadiye) BP. We characterize fluid inclusions (FIs) and studied concentration of H2O, CO2, O2 + N2, and 3He, 4He, 20Ne, and 40Ar, and bulk composition (trace elements and δ13C‐δ18O). FIs from both localities are mainly primary with low salinity and homogenization temperature around 136–140 °C. H2O is the major component followed by CO2, with the highest gas content measured in Pamukkale travertines. Concentrations of Ne‐Ar together with O2 + N2 indicate that travertines from both areas precipitated from atmosphere‐derived fluids. The 3He/4He is 0.5–1.3 Ra in Pamukkale and 0.9–4.4 Ra in Reşadiye. Samples with R/Ra > 1 are modified by cosmogenic 3He addition during exposure to cosmic rays. Excluding these data, FIs of Reşadiye are mostly atmosphere‐derived. This implies a shallow formation where the circulation was dominated by meteoric waters, which is consistent with their young age. Instead, FIs of Pamukkale show mixing of mantle‐, crustal‐, and atmosphere‐derived He, indicating that these travertines formed in lithospheric fractures. Based on the δ13CCO2 and δ18O of bulk rocks, we infer that travertines formed involving crustal‐ (mechanochemical rather than organic) and mantle‐derived CO2. Trace elements of Pamukkale and Reşadiye show comparable rare earth element patterns. We conclude that travertines formed in response of seismogenetic activity.Published5473-54982T. Deformazione crostale attiva7T. Variazioni delle caratteristiche crostali e precursori sismici6A. Geochimica per l'ambiente e geologia medicaJCR Journa

    Geochemistry of CO2-Rich Gases Venting From Submarine Volcanism: The Case of Kolumbo (Hellenic Volcanic Arc, Greece)

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    Studies of submarine hydrothermal systems in Mediterranean Sea are limited to the southern Italian volcanism, while are totally missing in the Aegean. Here, we report on the geochemistry of high-temperature fluids (up to 220°C) venting at 500 m b.s.l. from the floor of Kolumbo submarine volcano (Hellenic Volcanic Arc, Greece), which is located 7 km northeast of Santorini Island. Despite the recent unrest at Santorini, Kolumbo submarine volcano is considered more active due to a higher seismicity. Rizzo et al. (2016) investigated the He-isotope composition of gases collected from seven chimneys and showed that are dominated by CO2 (>97%), with only a small air contamination. Here we provide more-complete chemical data and isotopic compositions of CO2 and CH4, and Hg(0) concentration. We show that the gases emitted from different vents are fractionated by the partial dissolution of CO2 in water. Fractionation is also evident in the C-isotope composition (δ13CCO2), which varies between -0.04 and 1.15‰. We modeled this process to reconstruct the chemistry and δ13CCO2 of intact magmatic gases before fractionation. We argue that the CO2 prior to CO2 dissolution in water had δ13C ∼-0.4‰ and CO2/3He ∼1 × 1010. This model reveals that the gases emitted from Kolumbo originate from a homogeneous mantle contaminated with CO2, probably due to decarbonation of subducting limestone, which is similar to other Mediterranean arc volcanoes (e.g., Stromboli, Italy). The isotopic signature of CH4 (δ13C ∼-18‰ and δD ∼-117‰) is within a range of values typically observed for hydrothermal gases (e.g., Panarea and Campi Flegrei, Italy), which is suggestive of mixing between thermogenic and abiotic CH4. We report that the concentrations of Hg(0) in Kolumbo fluids are particularly high (∼61 to 1300 ng m-3) when compared to land-based fumaroles located on Santorini and worldwide aerial volcanic emissions. This finding may represent further evidence for the high level of magmatic activity at Kolumbo. Based on the geo-indicators of temperature and pressure, we calculate that the magmatic gases equilibrate within the Kolumbo hydrothermal system at about 270°C and at a depth of ∼1 km b.s.l

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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