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Enfocaments teòrics sobre la disciplina escolar

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Role of Poly(ADP-Ribose) Polymerase (PARP) Enzyme in the Systemic Acquired Acclimation Induced by Light Stress in Phaseolus vulgaris L. Plants

Plants are able to acclimate to environmental constraints through functional modifications that may also occur in tissues that are not directly exposed to stress. This process is termed “systemic acquired acclimation.” The present study aims to evaluate the involvement of PolyADP-ribose) polymerase (PARP) protein in the acclimation process to high light (HL) stress in Phaseolus vulgaris plants. For this purpose, some leaves located at the top of the plant, in the apical position, were directly exposed to HL (“inducing” leaves), while others on the same plant, distal from the top, continued to be exposed to growth light (“receiving” leaves) to verify the hypothesis that an “alert” message may be transferred from injured tissues to distal ones. Biochemical and eco-physiological analyses, namely PARP activity, H2O2 and water- and fat-soluble antioxidants (i.e., ascorbic acid, tocopherol, glutathione (GSH), phenols, carotenoids, etc.) content, and chlorophyll fluorescence measurements were performed on both “inducing” and “receiving” leaves. Even if no change in PARP expression was found, its activity increased in “receiving” unstressed leaves in response to the light stress duration experimented by “inducing” leaves, while antioxidant capacity declined. When the “receiving” leaves were exposed to HL, the PARP activity returned to the control value, while antioxidant capacity photosynthetic electron transport rate (Jf) decreased and increased, respectively, compared to Control. Our results seem to show an acclimation pathway triggered in remote tissues not yet subjected to stress, likely involving a reactive oxygen species wave activating the PARP enzyme in a mechanism still to be clarified. In addition, the increased tolerance of plants directly exposed to HL could implicate a boosted synthesis of soluble antioxidants accompanied by a reduction of PARP activity to reduce excessive consumption of NAD(P)

Microplastics in commercial bivalves harvested from intertidal seagrasses and sandbanks in the Ria Formosa lagoon, Portugal

Through seafood consumption, microplastic (MP) pollution is potentially threatening human health. Commercial bivalves in particular are a cause of major concern because their filter-feeding activity directly exposes them to MP in the water column and they are then ingested by humans. Here, we provide a quantitative and qualitative baseline data on MP content in the soft tissues of three commercially important bivalves (Ruditapes decussatus, Cerastoderma spp. and Polititapes spp.) collected in Ria Formosa lagoon, southern Portugal. The abundance of MPs (items per soft tissue weight) did not significantly differ among species. On average, R. decussatus exhibited the highest MP abundance (on average, 18.4 +/- 21.9 MP items g(-1) WW), followed by Cerastoderma spp. (11.9 +/- 5.5 MP items g(-1) WW) and Polititapes spp. (10.4 +/- 10.4 MP items g(-1) WW). Overall, 88% of the MPs found were synthetic fibres, the majority of which were blue (52%). Size categories >0.1-1 mm and >1-5 mm were the most common (60% and 34% respectively). The most represented polymers were polyethylene (PE) and polystyrene (PS). The unexpectedly high number of MPs recorded in the three commercially exploited species suggests that this semi-closed lagoon system is experiencing a higher anthropogenic pressure than are open coastal systems.Portuguese Foundation for Science and Technology: PTDC/MAR-EST/3223/2014 IF/01413/2014/CP1217/CT0004 UIDB/04326/2020 SFRH/BPD/119344/2016info:eu-repo/semantics/publishedVersio

Aerated Buffalo Slurry Improves Spinach Plant Growth and Mitigates CO2 and N2O Emissions from Soil

Manure management is the main strategy for mitigating gas emissions from livestock farming. In this study, a laboratory-scale experiment was set up to identify suitable conditions to be applied in a farm-scale experiment. The liquid fraction (LF) of slurry was aerobically treated and greenhouse gas emissions from soil were evaluated. Furthermore, the value of treated LF as a fertilizer on spinach plants was also tested. The aeration of LF determined an increase in mean alkalinity due to ammonia loss. The mass fraction of heavy metals also decreased, likely due to the reduction in solubility. After being applied on soil, aerated LF determined lower CO2 and N2O emissions compared to untreated LF due to a reduced nitrogen load. Spinach plants fertilized with treated LF showed a lush growth and exhibited a lower heavy metal mass fraction as well as a higher content of antioxidants compared to plants fertilized with untreated slurry. Our results show that aeration might be an effective alternative for slurry management as it is able to produce an eco-friendly final product with a high fertilizing value

Light Spectral Composition Influences Structural and Eco-Physiological Traits of Solanum lycopersicum L. cv. ‘Microtom’ in Response to High-LET Ionizing Radiation

This study evaluated if specific light quality (LQ) regimes (white fluorescent, FL; full- spectrum, FS; red-blue, RB) during plant growth modified morphological and photosynthetic traits of Solanum lycopersicum L. ‘Microtom’ plants irradiated at the dry seed stage with 25 Gy 48Ca ions (IR). The irradiation reduced plant size while it increased leaf dry matter content (LDMC) and relative water content (RWC) compared to the control. FS and RB light regimes determined a decrease of plant height and a rise of RWC compared to FL plants. The irradiation under FS and RB regimes favoured the development of dwarf plants and improved the leaf water status. Under the FL regime, irradiated plants showed reduced photosynthesis and stomatal conductance. The opposite behavior was observed in RB irradiated plants in which gas exchanges were significantly stimulated. RB regime enhanced Rubisco expression in irradiated plants also inducing anatomical and functional adjustments (i.e., increase of leaf thickness and incidence of intercellular spaces). Finally, 48Ca ions did not prevent fruit ripening and the achievement of the ‘seed-to seed’ cycle, irrespective of the LQ regime. Overall, the present study evidenced that RB light regime was the most effective in optimising growth and photosynthetic efficiency of ‘Microtom’ irradiated plants. These outcomes may help to develop proper cultivation protocols for the growth of dwarf tomato in Controlled Ecological Life Support Systems (CELSS)

Radiation therapy during the coronavirus disease 2019 (covid-19) pandemic in Italy: a view of the nation's young oncologists

status: publishe

silicon based technology for ligand receptor molecular identification

One of the most important goals in the fields of biology and medicine is the possibility to dispose of efficient tools for the characterization of the extraordinary complexity of ligand-receptor interactions. To approach this theme, we explored the use of crystalline silicon (cSi) technology for the realization of a biotechnological device in which the ligand-receptor interactions are revealed by means of optical measurements. Here, we describe a chemical procedure for the functionalization of microwell etched on silicon wafers, and the subsequent anchoring of biological molecules like an antibody anti-A20 murine lymphoma cell line. The optical analysis of the interaction on the biochips between the bound biomolecule and their corresponding ligand indicated that the functionalized cSi is suitable for this application

Effects of the fertilizer added with dmpp on soil nitrous oxide emissions and microbial functional diversity

Agricultural sites contribute extensively to atmospheric emissions of climate-altering gases such as nitrous oxide. Several strategies have been considered to mitigate the impact of agriculture on climate, among these the utilization of fertilizers added with nitrification inhibitors such as DMPP (3,4-dimethylpyrazole phosphate) may represent a suitable solution. DMPP inhibits the growth and activity of ammonia-oxidizing microorganisms, particularly the ammonia-oxidizing bacteria, which are involved in N2O production. At present, little information is available on the effects of DMPP on the catabolic diversity of soil microbial community. In this study, the N2O emission by soil was performed by using the static chamber technique. The biological determinations of the microbial biomass carbon and the catabolic profile were assessed by measuring the substrate-induced respiration during the entire growing season of a potato crop under two nitrogen treatments: fertilization with and without DMPP. Our results did not show a clear mitigation of N2O emission by DMPP, even if a tendency to lower N2O fluxes in DMPP plots occurred when soil temperatures were lower than 20◦C. Conversely, DMPP deeply affected the microbial biomass and the catabolism of soil microorganisms, exerting a negative effect when it accumulated in excessive doses in the soil, limiting the growth and the capacity of soil microorganism communities to use different substrates