L'epistola del Ventoso e le misure della rappresentazione petrarchesca della realtà

Nell'epistola del Ventoso Petrarca esprime non solo la prospettiva «agostiniana» di una nuova concezione, antinaturalistica etica introspettiva, del sapere ma mette in scena il superamento della rappresentazione teologico-medievale del mondo (il simbolismo dell'alto viene sottratto al suo significato di purificazione e di innalzamento al divino, in un primo momento esplicitamente richiamato, per essere collegato alla negatività della curiositas scientifica) e introduce potentemente nella visione delle cose la dimensione della temporalità.The epistle of Ventoso Petrarca expresses the «Augustinian» prospective of a new conception of understanding, introspective ethical anti-naturalism. However, it also creates the overpowering of the theological-medieval representation of the world (subtracting high symbolism from its meaning of purification and ascension to the divine, in an initial, clearly- defined moment, through its relation to the negativity of scientific curiositas) and strongly introduces the dimension of time into the grand scheme of things

Exoskeletons at work: opportunities, suggestions for implementation and future research needs

Exoskeletons are wearable devices that use mechanical interaction with the body to augment, assist, and enhance physical activity, motion, and body posture. In the last decades, these devices have been extensively studied and applied in motor rehabili- tation. More recently, both industrial and academic researchers have been working to explore the effectiveness of exoskeletons in supporting human upper and lower extre- mities during manual material handling to eliminate or reduce the risk of Work-related Musculoskeletal Disorders (WMSDs). If on the one hand, the effects for the prevention of WMSDs seem evident, on the other hand, some studies are carefully evaluating the overall impact of exoskeletons on the health and safety of workers. Still, there is limited evidence on the long-term effects of these devices. Hence, more research is necessary to understand the benefits and the potential opportunities arising from the introduction of exoskeletons in the workplace, as well as the potential limitations and risks that may arise for workers. This paper aims to address these challenges, pro- viding the results of a structured analysis of the scientific literature on occupational exoskeletons. A conceptual framework describes the benefits and the potential limi- tations of occupational exoskeletons, supporting the safe and effective selection and adoption of these devices in workplaces. The findings in this paper support academic, industrial practitioners, and researchers to understand the opportunities behind the use of exoskeletons, the future research needs, and to predict the benefits and the potential limitations of their implementation in workplaces

Trasporto di metalli verso i laghi del sistema Flumendosa Campidano in conseguenza dell'erosione dei suoli

Weathering of mine tailings represents an important metal source in Sardinia. The accumulation of mobilized metals onto soil in the mineralized areas and the subsequent erosional transport of soil towards the freshwater reservoirs endangers the quality of drinking water. The here described study on the Flumendosa-Campidano system shows the prescence and spatial distribution of metals in the system and underlines the necessity to control the more mobile and dangerous metals, as for exampIe cadmium

Combining hydrogeochemistry, statistics and explorative mapping to estimate regional threshold values of trace elements in groundwater (Sardinia, Italy)

Assessing geochemical baseline and threshold values of potentially toxic elements at adequate scales is fundamental for distinguishing geogenic contamination from anthropogenic pollution in groundwater. This study was aimed to estimate the regional threshold values of Li, Be, B, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Te, Ba, Hg, Tl, Pb, Bi, and U (elements listed according to atomic numbers) in groundwater, compare results to guidelines established for drinking water and the protection of groundwater from contamination, investigate the geographical distribution of trace elements, and assess the potential influence of water-rock interaction. A pre-selection aimed at excluding groundwater samples affected by known anthropogenic activities was carefully carried out based on hydrogeochemical characteristics of waters and considering the potential sources of contamination. The resulting dataset was comprised of 1227 groundwater sampling sites located in Sardinia (Italy). Undetected values were treated using the Regression on Order Statistics method. For elements containing >75 % of undetected values and/or a limited number of samples in the dataset (Li, Rb, Sr, Mo, Ag, Te, Tl, Sb, Hg and Bi), the threshold values were estimated using either the 95th or 97.7th percentiles. For the other elements the mean + 2SD (Standard Deviation), the median + 2MAD (Median Absolute Deviation), and the TIF (Tukey Inner Fence) estimators were also calculated. Geochemical maps allowed to recognize the threshold value of each element at different scales. Regional threshold values of the regulated elements B, Al, V, Cr, Cu and Cd in groundwater were below the Italian and World Health Organization drinking water guidelines, whereas Mn and As were above them. Regional threshold values estimated with TIF exceeded the drinking water guidelines for Ni, Se, Pb and U. Results of this study showed that high concentrations of trace elements in groundwater were primarily dependent on the corresponding amount in parent materials with which the groundwater came into contact. Physical-chemical parameters and geochemical characteristics may contribute to enhancing concentrations of some trace elements in groundwater, e.g. As via reductive dissolution of Fe(III)-Mn(IV) hydroxides/oxides, Pb via formation of stable aqueous complexes, and other elements via adsorption onto fine particles with size below 0.4 μm (i.e. the pore size of filters used). Maps drawn on the centered log-ratio (clr) transformation of hydrogeochemical data, following the CoDA (Compositional Data Analysis) approach, allowed to pinpoint critical areas to be investigated in more detail. For each geological complex, groundwater samples likely representing nearly pristine conditions were identified. The monitoring of these representative groundwater samples may help to pinpoint eventual changes in environmental conditions

Geochemistry, stable isotopes and statistic tools to estimate threshold and source of nitrate in groundwater (Sardinia, Italy)

In the European Union, nitrate vulnerable zone (NVZ) should be designed for the mitigation of nitrate (NO3−) contamination caused by agricultural practices. Before establishing new NVZ, the sources of NO3− must be recognized. A geochemical and multiple stable isotopes approach (hydrogen, oxygen, nitrogen, sulfur and boron) and statistical tools were applied to define the geochemical characteristics of groundwater (60 samples), calculate the local NO3− threshold and assess potential sources of NO3− contamination in two study areas (hereafter Northern and Southern), located in a Mediterranean environment (Sardinia, Italy). Results of the integrated approach applied to two case study, permits to highlight the strengths of integrating geochemical and statistical methods to provide nitrate source identification as a reference by decision makers to remediate and mitigate nitrate contamination in groundwater. Hydrogeochemical features in the two study areas were similar: near neutral to slightly alkaline pH, electrical conductivity in the range of 0.3 to 3.9 mS/cm, and chemical composition ranging from Ca-HCO3− at low salinity to Na-Cl− at high salinity. Concentrations of NO3− in groundwater were in the range of 1 to 165 mg/L, whereas the nitrogen reduced species were negligible, except few samples having NH4+ up to 2 mg/L. Threshold values in the studied groundwater samples were between 4.3 and 6.6 mg/L NO3−, which was in agreement with previous estimates in Sardinian groundwater. Values of δ34S and δ18OSO4 of SO42− in groundwater samples indicated different sources of SO42−. Sulfur isotopic features attributed to marine SO42− were consistent with groundwater circulation in marine-derived sediments. Other source of SO42− were recognize due to the oxidation of sulfide minerals, to fertilizers, manure, sewage fields, and SO42− derived from a mix of different sources. Values of δ15N and δ18ONO3 of NO3− in groundwater samples indicated different biogeochemical processes and NO3− sources. Nitrification and volatilization processes might have occurred at very few sites, and denitrification was likely to occur at specific sites. Mixing among various NO3− sources in different proportions might account for the observed NO3− concentrations and the nitrogen isotopic compositions. The SIAR modeling results showed a prevalent NO3− source from sewage/manure. The δ11B signatures in groundwater indicated the manure to be the predominant NO3− source, whereas NO3− from sewage was recognized at few sites. Geographic areas showing either a predominant process or a defined NO3− source where not recognize in the studied groundwater. Results indicate widespread contamination of NO3− in the cultivated plain of both areas. Point sources of contamination, due to agricultural practices and/or inadequate management of livestock and urban wastes, were likely to occur at specific sites

Efficient Saturation Control for Fully Differential Integrator in Continuous-Time Sigma-Delta Modulators

This paper presents an alternative approach to saturation control in an integrator, that occurs in Sigma-Delta modulators (SDMs). This solution simplifies the design process with a 1.2- V power supply and consumes significantly less power than conventional saturation control methods. Additionally, this solution provides a good phase margin, that guarantees the stability, without requiring additional compensation techniques, and it has the added benefit of reducing the gain of the integrator as the system enters saturation, while also maintaining integrator inputs fixed at the proper common-mode voltage. This innovative approach offers a promising solution for efficient and stable saturation control in SDM integrators, preventing distortion in the output signal, with potential applications in a wide range of electronic systems, such as audio systems. The circuit has been designed in a 90-nm CMOS technology

Triple positive breast cancer. A distinct subtype?

Breast cancer is a heterogeneous disease, and within the HER-2 positive subtype this is highly exemplified by the presence of substantial phenotypical and clinical heterogeneity, mostly related to hormonal receptor (HR) expression. It is well known how HER-2 positivity is commonly associated with a more aggressive tumor phenotype and decreased overall survival and, moreover, with a reduced benefit from endocrine treatment. Preclinical studies corroborate the role played by functional crosstalks between HER-2 and estrogen receptor (ER) signaling in endocrine resistance and, more recently, the activation of ER signaling is emerging as a possible mechanism of resistance to HER-2 blocking agents. Indeed, HER-2 positive breast cancer heterogeneity has been suggested to underlie the variability of response not only to endocrine treatments, but also to HER-2 blocking agents. Among HER-2 positive tumors, HR status probably defines two distinct subtypes, with dissimilar clinical behavior and different sensitivity to anticancer agents. The triple positive subtype, namely, ER/PgR/Her-2 positive tumors, could be considered the subset which most closely resembles the HER-2 negative/HR positive tumors, with substantial differences in biology and clinical outcome. We argue on whether in this subgroup the "standard" treatment may be considered, in selected cases, i.e., small tumors, low tumor burden, high expression of both hormonal receptors, an overtreatment. This article review the existing literature on biologic and clinical data concerning the HER-2/ER/PgR positive tumors, in an attempt to better define the HER-2 subtypes and to optimize the use of HER-2 targeted agents, chemotherapy and endocrine treatments in the various subsets