584 research outputs found
Il viaggiatore perduto: Renzo Manzoni in Marocco e altrove
No full textBiografia dell'esploratore Renzo Manzoni, con analisi dei suoi rapporti con l'ambiente geografico italiano - e in particolare con la Società Geografica Italiana. Nuove informazioni sulla spedizione allo Scioa
In cerca dell'innocenza. Giovanni Chiarini e la spedizione allo Scioa
No full textRicostruzione della biografia di Giovanni Chiarini, con particolare riferimento alla sua partecipazione alla "spedizione allo Scioa" della Società Geografica Italiana (1876-1881). Analisi delle fonti disponibili sulla spedizione, rivalutazione storico-critica del ruolo della spedizione nella nascita del colonialismo italiano
People-centred policies for a just transition (digital, green and skills)
No full textThe paper contributes to the current debate on just transitions which is exploring what factors and conditions can lead to a twin transition that can also achieve an equitable redistribution of the outputs. The paper draws on the theories of justice, by bringing together three dimensions of justice: distributive, procedural and substantive justice. We apply this framework to explain the socio-economic impact of technology-pushed structural change on the future of work. We define just transition as a triple transition that requires digital and green shifts and crucially, a competence and skill transition that transversally cuts across industries, jobs and professions. The paper analyses the case of a specific region, Emilia Romagna in Italy, which has implemented, particularly since 2010, an original holistic approach to industrial development policy, comprising social and education policies. We conclude that within a national education framework tasked with pivoting the mix of necessary basic knowledge, regions have an important role to play by designing and implementing place-based education and training initiatives that are specific to the regional socio-economic characteristics
Sequential solidification/stabilization and thermal process under vacuum for the treatment of mercury in sediments
No full textPurpose Millions of cubic meters of sediments are dredged every year in the world. About 10–20%onweight basis of this material is contaminated by organic and/or inorganic pollutants. This work presents the laboratory tests performed to study a system for the remediation and reuse of mercurycontaminated sediments. The treatment is based on a cementbased granulation step (solidification/stabilization (S/S)), followed by a thermal process under vacuum during which volatile and semi-volatile compounds are removed. The experiments focused on: (1) cement hydration reactions; (2) pollutant removal efficiencies; and (3) leaching behavior, in relation to temperature and duration of the thermal process. Mercury speciation was also investigated.
Materials and methods Dredged at the marine harbor of Augusta (SR, Italy), the sediments used in the experiments were highly polluted by mercury (200 mgkg−1dry weight (d.w.)). The recipe applied in the S/S step was based on the particle size distribution of the resulting granulates. An indirectly–heated batch system operated under vacuum (2.6±1.3 103 Pa) at: (1) 150°C for 16 h; (2) 200°C for 6 h; (3) 250°C for 4 h; or (4) 280°C for 4 h. X-ray diffraction spectroscopy and scanning electron microscopy were used to study cement hydration reactions. Total mercury concentration and leaching tests were carried out to assess the effects of the different treatment conditions.
Results and discussion The best results were obtained by treating the granulate at 250°C for 4 h. Under these conditions, mercury final concentration was 49 mgkg−1 d.w., resulting in a removal efficiency of 63% referred to the granular material before thermal treatment, and 75% referred to the sediment. The concentrations measured in the leachate were compatible with the Italian requirements for reuse, with some exceptions (pH, chlorides, nickel, copper, and COD) ascribed to the specific nature of the sediment. Mercury speciation analyses pointed out changes after both the treatment steps.
Conclusions The final granulates accomplish most Italian requirements for reuse, even though an improvement in the S/S step or an additional washing step would help for the exceptions mentioned above. Different reuse options in civil engineering (e.g., filling material, road material, concrete aggregates, etc.) will be evaluated also taking into consideration the mechanical properties. Further studies will be carried out to assess the long-term leaching behavior and leaching under different pH conditions
Brightest cluster galaxies: The centre can(not?) hold
No full textWe explore the persistence of the alignment of brightest cluster galaxies (BCGs) with their local environment. We find that a significant fraction of BCGs do not coincide with the centroid of the X-ray gas distribution and/or show peculiar velocities (they are not at rest with respect to the cluster mean). Despite this, we find that BCGs are generally aligned with the cluster mass distribution even when they have significant offsets from the X-ray centre and significant peculiar velocities. The large offsets are not consistent with simple theoretical models. To account for these observations BCGs must undergo mergers preferentially along their major axis, the main infall direction. Such BCGs may be oscillating within the cluster potential after having been displaced by mergers or collisions, or the dark matter halo itself may not yet be relaxed.Fil: de Propris, Roberto. University of Turku; FinlandiaFil: West, Michael J.. Lowell Observatory; Estados UnidosFil: Andrade-Santos, Felipe. Harvard-Smithsonian Center For Astrophysics; Estados UnidosFil: Ragone Figueroa, Cinthia Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Rasia, Elena. Istituto Nazionale di Astrofisica; ItaliaFil: Forman, William. Harvard-Smithsonian Center For Astrophysics; Estados UnidosFil: Jones, Christine. Harvard-Smithsonian Center For Astrophysics; Estados UnidosFil: Kipper, Rain. University Of Tartu. Faculty Of Science And Technology. Tartu Observatory.; EstoniaFil: Borgani, Stefano. Istituto Nazionale di Astrofisica; ItaliaFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Romashkova, Elena A.. Massachusetts Institute Of Technology. Department Of Physics; Estados UnidosFil: Patra, Kishore C.. University of California; Estados Unido
Long-lasting response changes in deep cerebellar nuclei In vivo correlate with low-frequency oscillations
No full textThe deep cerebellar nuclei (DCN) have been suggested to play a critical role in sensorimotor learning and some forms of long-term synaptic plasticity observed in vitro have been proposed as a possible substrate. However, till now it was not clear whether and how DCN neuron responses manifest long-lasting changes in vivo. Here, we have characterized DCN unit responses to tactile stimulation of the facial area in anesthetized mice and evaluated the changes induced by theta-sensory stimulation (TSS), a 4 Hz stimulation pattern that is known to induce plasticity in the cerebellar cortex in vivo. DCN units responded to tactile stimulation generating bursts and pauses, which reflected combinations of excitatory inputs most likely relayed by mossy fiber collaterals, inhibitory inputs relayed by Purkinje cells, and intrinsic rebound firing. Interestingly, initial bursts and pauses were often followed by stimulus-induced oscillations in the peri-stimulus time histograms (PSTH). TSS induced long-lasting changes in DCN unit responses. Spike-related potentiation and suppression (SR-P and SR-S), either in units initiating the response with bursts or pauses, were correlated with stimulus-induced oscillations. Fitting with resonant functions suggested the existence of peaks in the theta-band (burst SR-P at 9 Hz, pause SR-S at 5 Hz). Optogenetic stimulation of the cerebellar cortex altered stimulus-induced oscillations suggesting that Purkinje cells play a critical role in the circuits controlling DCN oscillations and plasticity. This observation complements those reported before on the granular and molecular layers supporting the generation of multiple distributed plasticities in the cerebellum following naturally patterned sensory entrainment. The unique dependency of DCN plasticity on circuit oscillations discloses a potential relationship between cerebellar learning and activity patterns generated in the cerebellar network
Alternative surgical approach to treat aortic arch aneurysm after ascending aortic replacement with hybrid prosthesis.
No full textWe present a surgical technique to treat the distal aortic arch in patients who previously underwent ascending aortic replacement using the frozen elephant trunk. After debranching of the epiaortic vessels using a custom-made four-branch graft and systemic cooling, the extracorporeal circulation is interrupted, maintaining antegrade cerebral perfusion through the four-branch prosthesis. Then the "old" Dacron prosthesis, previously implanted for the ascending aortic replacement, is partially incised at its distal end, leaving a margin of prosthesis anastomosed to the native distal aorta, and the E-vita stent-graft is deployed under direct vision. Then the two margins of the "old" Dacron and the new Dacron E-vita prosthesis (Jotec Inc., Hechingen, Germany) are sutured together with one suture line to guarantee sealing and reconstruction of the aorta. This technique presents several advantages: the discrepancy between the graft size and the native aortic diameter is avoided, performing the anastomosis between two prosthetic materials with similar diameters is easier; there is no risk of tears in the diseased native aortic wall and related bleeding; and finally, it is easier to perform the anastomosis at the level of the ascending aorta rather than at the distal arch, especially when the disease of the aorta is extended to the descending segment
Possibility of progenitor cell mobilization during the hematological recovery following peripheral blood stem cell autograft.
No full textTwenty-four patients with hematological malignancies were studied during recovery following autografting in order to establish the proportion of patients that show CD34+ cell mobilization and the kinetics of mobilized CD34-positive cells. The patients showed a peak in peripheral blood (PB) CD34+ cells after a median of 14 days (range 12-20) following reinfusion. According to the number of circulating CD34+ cells, two groups could be clearly distinguished: 17 patients (group A) with 10 CD34+ cells/microl (median 51, range 13-123). Compared to group A, patients of group B showed a faster hematological reconstitution of both polymorphonuclear leukocytes >500/microl (12 vs. 15 days) and platelets >50,000/microl (12 vs. 17 days). The expression of the beta1 integrin CD49d was similar in the two groups of patients, while a lower expression of the beta2 integrin CD11a and a greater expression of the L-selectin CD62L were observed in the PB CD34+ cells of group B patients. Both in the PB and in the BM, the number of CFU-GEMM, CFU- GM, CFU-E and BFU-E of group B was significantly greater than that of group A. However, when the clonogenic potential of a single CD34+ cell was evaluated, no major differences in the number of colonies produced per CD34+ cell were found between the two groups
Auto- and heterotrophic acidophilic bacteria enhance the bioremediation efficiency of sediments contaminated by heavy metals
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