285 research outputs found

    Stand and coarse woody debris dynamics in subalpine Norway spruce forests withdrawn from regular management

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    We studied structural characteristics, amount and quality of coarse woody debris (CWD), intensity of competition and mortality in two subalpine Norway spruce stands withdrawn from regular management. The stands, that we measured twice (in 1993 and 2005), have similar age and structure, but a different time has elapsed since the last silvicultural treatments (respectively 22 and about 55 y). The main purposes were to analyze the current stage of development as compared to the old-growth one and to highlight the legacies of past management. Although relatively old, the first plot (Valbona 1) was at the end of the pole stage. CWD was low in volume and was mainly of man-made origin (stumps). A recent thinning from below has reduced density-dependent competition and delayed the development of old-growth characteristics. The second plot (Valbona 2a) was at the beginning of the transition stage, with density-dependent and allogenic mortality both active at the same time. CWD volume was higher in plot Valbona 2a than in Valbona 1, but neither was comparable yet to the reference old-growth sites from Central Europe, both in quantity and in quality (e.g., decay rate continuity). The effects of the past management were: (1) reducing the quality and quantity of the CWD, (2) alleviating competition, (3) increasing resistance to minor disturbances and, as a consequence, (4) delaying the development processes. In mature or overmature subalpine Norway spruce stands withdrawn from regular management many decades are necessary to develop old-growth characteristics and a longer period of time is necessary to reach a true old-growth stage

    Tumor suppressors in chronic lymphocytic leukemia: From lost partners to active targets

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    Tumor suppressors play an important role in cancer pathogenesis and in the modulation of resistance to treatments. Loss of function of the proteins encoded by tumor suppressors, through genomic inactivation of the gene, disable all the controls that balance growth, survival, and apoptosis, promoting cancer transformation. Parallel to genetic impairments, tumor suppressor products may also be functionally inactivated in the absence of mutations/deletions upon post-transcriptional and post-translational modifications. Because restoring tumor suppressor functions remains the most effective and selective approach to induce apoptosis in cancer, the dissection of mechanisms of tumor suppressor inactivation is advisable in order to further augment targeted strategies. This review will summarize the role of tumor suppressors in chronic lymphocytic leukemia and attempt to describe how tumor suppressors can represent new hopes in our arsenal against chronic lymphocytic leukemia (CLL)

    ADVANTEX: Research of innovative tools to support the logistics of the use of excavation materials produced by the Lyon-Turin railway line for the best sustainability and circular economy of the process

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    The Mont-Cenis Base Tunnel is the key work of the new Lyon-Turin railway line. The project envisages a total volume of 37.2 million tons of excavated material over a period of 10 years: a considerable part of the excavated material will be used for the tunnel lining (con-crete or railway embankments) and for the embankments of the open-air sectors, while the remaining part will be transported by rail, conveyor belts, and heavy vehicles to the temporary and permanent storage sites. To maximize the circular economy and the efficiency of the materials logistic, TELT is working with the Politecnico di Torino (Department of Environment, Land, and Infrastructure Engineering, Department of Structural, Geotechnical and Building Engineering, and Department of Applied Science and Technology) and the Interdepartmental Laboratory SISCON - Safety of Infrastructures and Constructions, to study innovative solutions for the char-acterization and reuse of the excavated materials. Given that the materials are substantially undif-ferentiated during the excavation and that the geological classification requires long and complex additional verification activities, which can negatively affect the process, a significant sample of materials excavated at the survey tunnel of La Maddalena (place where the base tunnel will be excavated) were analyzed. The objective of this first phase is the search for new technologies and new processes for the early characterization of the excavated material in order to determine its intended use, designing green concretes (defining its sustainability and mechanical characteristics for structural use, through synthetic parameters, including durability analysis) and backfilling, seeking innovative tools for optimal logistics, in order to “industrialize” the identification process and optimal technologies for automatic process control and traceability, in order to give strength and speed to all activities. The subject of this work is the results of the early characterization experimentation process with the application of artificial intelligence and possible innovative circu-lar solutions

    A bilayer polymer electrolyte encompassing pyrrolidinium-based RTIL for binder-free silicon few-layer graphene nanocomposite anodes for Li-ion battery

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    A binder-free electrode made of polycrystalline carbon-coated silicon nanoparticles encapsulated in few-layer graphene flakes is coupled with a PEO-based crosslinked bilayer polymer electrolyte (BLPE). A soft polymer electrolyte layer enriched with a pyrrolidium-based ionic liquid (Pyr14TFSI) is deposited on top of the electrode and UV cured by an in situ process to achieve optimal interfacial contact. A hard layer consisting of a crosslinked PEO-based polymer electrolyte film with a lower amount of Pyr14TFSI is integrated with the electrode/electrolyte assembly to improve the self-standing and shape-retention abilities. Proof-of-concept lab-scale Si-C||Li-metal polymer cells demonstrate a reversible specific discharge capacity up to 1044 mAh gSi–1 at 80 °C, largely outperforming the one with Pyr14TFSI/LiTFSI liquid electrolyte under the same experimental condition. Our results highlight the beneficial effect of the crosslinked PEO-based polymer matrix on the cycling performance, despite the absence of any SEI-forming agent

    A BENCHMARK FOR LARGE-SCALE HERITAGE POINT CLOUD SEMANTIC SEGMENTATION

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    The lack of benchmarking data for the semantic segmentation of digital heritage scenarios is hampering the development of automatic classification solutions in this field. Heritage 3D data feature complex structures and uncommon classes that prevent the simple deployment of available methods developed in other fields and for other types of data. The semantic classification of heritage 3D data would support the community in better understanding and analysing digital twins, facilitate restoration and conservation work, etc. In this paper, we present the first benchmark with millions of manually labelled 3D points belonging to heritage scenarios, realised to facilitate the development, training, testing and evaluation of machine and deep learning methods and algorithms in the heritage field. The proposed benchmark, available at http://archdataset.polito.it/, comprises datasets and classification results for better comparisons and insights into the strengths and weaknesses of different machine and deep learning approaches for heritage point cloud semantic segmentation, in addition to promoting a form of crowdsourcing to enrich the already annotated databas

    Screening of bacterial endophytes able to promote plant growth and increase salinity tolerance

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    Bacterial endophytes can colonize plant tissues without harming the plant. Instead, they are often able to increase plant growth and tolerance to environmental stresses. In this work, new strains of bacterial endophytes were isolated from three economically important crop plants (sorghum, cucumber and tomato) grown in three different regions in soils with different management. All bacterial strains were identified by 16S rRNA sequencing and characterized for plant beneficial traits. Based on physiological activities, we selected eight strains that were further tested for their antibiotic resistance profile and for the ability to efficiently colonize the interior of sorghum plants. According to the results of the re-inoculation test, five strains were used to inoculate sorghum seeds. Then, plant growth promotion activity was assessed on sorghum plants exposed to salinity stress. Only two bacterial endophytes increased plant biomass, but three of them delayed or reduced plant salinity stress symptoms. These five strains were then characterized for the ability to produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which is involved in the increase of stress tolerance. Pseudomonas brassicacearum SVB6R1 was the only strain that was able to produce this enzyme, suggesting that ACC deaminase is not the only physiological trait involved in conferring plant tolerance to salt stress in these bacterial strains

    An electrochemical compatibility investigation of RTIL-based electrolytes with Si-based anodes for advanced Li-ion batteries

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    Silicon is amongst the most attractive anode materials for Li-ion batteries because of its high gravimetric and volumetric capacity; importantly, it is also abundant and cheap, thus sustainable. For a widespread practical deployment of Si-based electrodes, research efforts must focus on significant breakthroughs to addressing the major challenges related to their poor cycling stability. In this work, we focus on the electrolyte-electrode relationships to support the scientific community with a systematic overview of Si-based cell design strategies reporting a thorough electrochemical study of different room temperature ionic liquid (RTIL)-based electrolytes, which contain either lithium bis(fluorosulfonyl)imide (LiFSI) or lithium bis(trifluoromethylsulfonyl)imide (LiTFSI). Their galvanostatic cycling performance with mixed silicon/graphite/few-layer graphene electrodes are evaluated, with first cycle coulombic efficiency approaching 90% and areal capacity ≈2 mAh/cm2 in the limited cut-off range of 0.1–2 V vs. Li+/Li0. The investigation evidences the superior characteristics of the FSI-based RTILs with respect to the TFSI-based one, which is mostly associated with the superior SEI forming ability of FSI-based systems, even without the use of specific additives. In particular, the LiFSI-EMIFSI electrolyte composition shows the best performance in both Li-half cells and Li-ion cells in which the Si-based electrodes are coupled with 4V-class composite NMC-based cathodes
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