VALUTAZIONE DELLE POTENZIALITÀ DEL BIOCHAR COME COMPONENTE DEI SUBSTRATI DI COLTIVAZIONE

The possibility of using biochar as a soil amendment for agricultural land has been intensively investigated, but it is only recently that biochar is proposed for greenhouse applications. Biochar can be used as a partial substitute of commercial peat for the cultivation of potting plants, so reducing the use of a non-renewable material like peat. In fact peat has a slow regrowth rate of 0.5-2 mm per year, and costs of extraction and transportation of peat are increasing. In this dissertation, the effects of four biochars added to a peat-based growing media are explored. Biochars are produced via pyro-gasification of plant derived feedstocks, (chipped and pelletized poplar and spruce wood), and analized for their properties useful to predict their behaviour in a potting mix. All the studied biochars are alkaline, show good physical stability (lack of shrinking), are richness in basic cations, particularly potassium, and show different particle size distributions. The first experiments carried on on mixtures of biochar and peat focuse on: 1) the liming power of biochars; 2) the influence of biochars on the pore water composition; 3) the effects of biochar application on the plant growth and nutrient uptake. When added to an acidic peat in a dose of 30% v/v , biochars neutralize both peat acidity and the acidification induced by root activity, that is inversely related to the size of particles and not influenced by biochars pH. Incubations of mixtures with and without plants highlight a dramatic influence of biochars on pore water composition.The poplar wood biochar induces an almost complete depletion of the fertilizer-derived NH4 +-N and high levels of NO3 --N in pore water, even though a decline over time is detected. On the contrary, in the sprucewood biochar added mixture NH4 +-N is immobilized in a lesser extent and only trace amounts of NO3 --N are detected. Further, the abilities of biochars to adsorb ammonia and nitrate are explored and a greater capacity for ammonia adsorption is detected. Then biochars are loaded with ammonium and an incubation test and a plant growth trial are performed on the ammonium-enriched materials added to a peat based growing media, compared with (NH4)2SO4 and with a loaded zeolite. Ammonia from the loaded biochars are more bioavailable than that carried by zeolite and both the studied biochars promote plant nitrogen uptake. Lastly, a trial is conducted in a commercial greenhouse using two biochars for total replacements of lime and partial substitution of the inorganic component (perlite). The growth of Ciclamen persicum plants results only slightly influenced by the biochars while pore water solution composition is deeply modified by the biochars. It can be concluded that biochar efficiently substitutes lime in buffering peat acidity and may be used as a partial replacement for peat and a source of potassium. Its highly reactive surfaces account its potential to significantly alter soil solution chemistry

Four cases of audio-vestibular disorders related to immunisation with SARS-CoV-2 mRNA vaccines.

To gain medical insight into the clinical course and safety of otolaryngologic disorders following immunisation with severe acute respiratory coronavirus (SARS-CoV-2) mRNA-based vaccines. Case description. We report four cases of transient audio-vestibular symptoms, which occurred shortly after inoculation of two BNT162b2 (Pfizer-BioNTech <sup>®</sup> ) and mRNA-1273 (Moderna®) vaccines. Hearing loss was unilateral in all cases and recovered at least partially: it was associated with persistent gait instability in two cases, after 1 and 7 months. Trigger mechanisms underpinning audio-vestibular impairment remain uncertain. Immune tolerance mechanisms with off-target innate activation of T-lymphocytes may be involved in vestibulocochlear nerve disorders, as for other cranial nerves involvement. The occurrence of audio-vestibular manifestations following mRNA-based vaccines needs ENT monitoring to support their causality in such rare vaccine-related adverse events. Audio-vestibular disorders appeared of transitory nature, including hearing loss, and should not deter further efforts in large-scale vaccination campaigns against SARS-CoV-2

Biochar versus hydrochar as growth media constituents for ornamental plant cultivation

[EN] Biochar and hydrochar have been proposed as novel materials for providing soilless growth media. However, much more knowledge is required before reliable advice can be given on the use of these materials for this purpose. Depending on the material and the technology applied (pyrolysis or hydrothermal carbonization), phytotoxicity and greenhouse gas emissions have been found for certain chars. In this study, our aim was to assess the feasibility of three chars as substrate constituents. We compared two biochars, one from forest waste and the other from olive mill waste, and a hydrochar from forest waste. We studied how chars affected substrate characteristics, plant performance, water economy and respiratory CO2 emission. Substrates containing biochar from forest waste showed the best characteristics, with good air/water relationships and adequate electrical conductivity. Those with biochar from olive mill waste were highly saline and, consequently, low quality. The substrates with hydrochar retained too much water and were poorly aerated, presenting high CO2 concentrations due to high respiratory activity. Plants performed well only when grown in substrates containing a maximum of 25 % biochar from forest waste or hydrochar. After analyzing the char characteristics, we concluded that biochar from forest waste could be safely used as a substrate constituent and is environmentally friendly when applied due to its low salinity and low CO2 emission. However, biochar from olive mill waste and hydrochar need to be improved before they can be used as substrate constituents.This study was funded by the Polytechnic University of Valencia (Projects on New Multidisciplinary Research; PAID-05-12). We thank Molly Marcus-McBride for supervising the English.Fornes Sebastiá, F.; Belda Navarro, RM. (2018). Biochar versus hydrochar as growth media constituents for ornamental plant cultivation. Scientia Agricola (Online). 75(4):304-312. https://doi.org/10.1590/1678-992X-2017-0062S304312754Abad, M., Noguera, P., & Burés, S. (2001). National inventory of organic wastes for use as growing media for ornamental potted plant production: case study in Spain. Bioresource Technology, 77(2), 197-200. doi:10.1016/s0960-8524(00)00152-8Bargmann, I., Martens, R., Rillig, M. C., Kruse, A., & Kücke, M. (2013). Hydrochar amendment promotes microbial immobilization of mineral nitrogen. Journal of Plant Nutrition and Soil Science, 177(1), 59-67. doi:10.1002/jpln.201300154Bargmann, I., Rillig, M. C., Buss, W., Kruse, A., & Kuecke, M. (2013). Hydrochar and Biochar Effects on Germination of Spring Barley. Journal of Agronomy and Crop Science, 199(5), 360-373. doi:10.1111/jac.12024Bedussi, F., Zaccheo, P., & Crippa, L. (2015). Pattern of pore water nutrients in planted and non-planted soilless substrates as affected by the addition of biochars from wood gasification. Biology and Fertility of Soils, 51(5), 625-635. doi:10.1007/s00374-015-1011-6Belda, R. M., Lidón, A., & Fornes, F. (2016). Biochars and hydrochars as substrate constituents for soilless growth of myrtle and mastic. Industrial Crops and Products, 94, 132-142. doi:10.1016/j.indcrop.2016.08.024Costello, R. C., & Sullivan, D. M. (2013). Determining the pH Buffering Capacity of Compost Via Titration with Dilute Sulfuric Acid. Waste and Biomass Valorization, 5(3), 505-513. doi:10.1007/s12649-013-9279-yFernandes, C., & Corá, J. E. (2004). Bulk density and relationship air/water of horticultural substrate. Scientia Agricola, 61(4), 446-450. doi:10.1590/s0103-90162004000400015Fornes, F., Belda, R. M., Carrión, C., Noguera, V., García-Agustín, P., & Abad, M. (2007). Pre-conditioning ornamental plants to drought by means of saline water irrigation as related to salinity tolerance. Scientia Horticulturae, 113(1), 52-59. doi:10.1016/j.scienta.2007.01.008Fornes, F., Belda, R. M., & Lidón, A. (2015). Analysis of two biochars and one hydrochar from different feedstock: focus set on environmental, nutritional and horticultural considerations. Journal of Cleaner Production, 86, 40-48. doi:10.1016/j.jclepro.2014.08.057Fornes, F., & Belda, R. M. (2017). Acidification with nitric acid improves chemical characteristics and reduces phytotoxicity of alkaline chars. Journal of Environmental Management, 191, 237-243. doi:10.1016/j.jenvman.2017.01.026Fornes, F., Belda, R. M., Fernández de Córdova, P., & Cebolla-Cornejo, J. (2017). Assessment of biochar and hydrochar as minor to major constituents of growing media for containerized tomato production. Journal of the Science of Food and Agriculture, 97(11), 3675-3684. doi:10.1002/jsfa.8227Fornes, F., Carrión, C., García-de-la-Fuente, R., Puchades, R., & Abad, M. (2010). Leaching composted lignocellulosic wastes to prepare container media: Feasibility and environmental concerns. Journal of Environmental Management, 91(8), 1747-1755. doi:10.1016/j.jenvman.2010.03.017GARCIADELAFUENTE, R., CARRION, C., BOTELLA, S., FORNES, F., NOGUERA, V., & ABAD, M. (2007). Biological oxidation of elemental sulphur added to three composts from different feedstocks to reduce their pH for horticultural purposes. Bioresource Technology, 98(18), 3561-3569. doi:10.1016/j.biortech.2006.11.008Genty, B., Briantais, J.-M., & Baker, N. R. (1989). The relationship between the quantum yield of photosynthetic electron transport and quenching of chlorophyll fluorescence. Biochimica et Biophysica Acta (BBA) - General Subjects, 990(1), 87-92. doi:10.1016/s0304-4165(89)80016-9Hoitink, H. A. J., Stone, A. G., & Han, D. Y. (1997). Suppression of Plant Diseases by Composts. HortScience, 32(2), 184-187. doi:10.21273/hortsci.32.2.184Libra, J. A., Ro, K. S., Kammann, C., Funke, A., Berge, N. D., Neubauer, Y., … Emmerich, K.-H. (2011). Hydrothermal carbonization of biomass residuals: a comparative review of the chemistry, processes and applications of wet and dry pyrolysis. Biofuels, 2(1), 71-106. doi:10.4155/bfs.10.81Mazuela, P., Salas, M. del C., & Urrestarazu, M. (2005). Vegetable Waste Compost as Substrate for Melon. Communications in Soil Science and Plant Analysis, 36(11-12), 1557-1572. doi:10.1081/css-200059054Méndez, A., Paz-Ferreiro, J., Gil, E., & Gascó, G. (2015). The effect of paper sludge and biochar addition on brown peat and coir based growing media properties. Scientia Horticulturae, 193, 225-230. doi:10.1016/j.scienta.2015.07.032Nieto, A., Gascó, G., Paz-Ferreiro, J., Fernández, J. M., Plaza, C., & Méndez, A. (2016). The effect of pruning waste and biochar addition on brown peat based growing media properties. Scientia Horticulturae, 199, 142-148. doi:10.1016/j.scienta.2015.12.012Sáez, J. A., Belda, R. M., Bernal, M. P., & Fornes, F. (2016). Biochar improves agro-environmental aspects of pig slurry compost as a substrate for crops with energy and remediation uses. Industrial Crops and Products, 94, 97-106. doi:10.1016/j.indcrop.2016.08.035Smith, B. R., Fisher, P. R., & Argo, W. R. (2004). Growth and Pigment Content of Container-grown Impatiens and Petunia in Relation to Root Substrate pH and Applied Micronutrient Concentration. HortScience, 39(6), 1421-1425. doi:10.21273/hortsci.39.6.1421Solaiman, Z. M., Murphy, D. V., & Abbott, L. K. (2011). Biochars influence seed germination and early growth of seedlings. Plant and Soil, 353(1-2), 273-287. doi:10.1007/s11104-011-1031-4Steiner, C., & Harttung, T. (2014). Biochar as a growing media additive and peat substitute. Solid Earth, 5(2), 995-999. doi:10.5194/se-5-995-2014Tian, Y., Sun, X., Li, S., Wang, H., Wang, L., Cao, J., & Zhang, L. (2012). Biochar made from green waste as peat substitute in growth media for Calathea rotundifola cv. Fasciata. 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Loss of cholinergic innervation differentially affects eNOS-mediated blood flow, drainage of Aβ and cerebral amyloid angiopathy in the cortex and hippocampus of adult mice

Vascular dysregulation and cholinergic basal forebrain degeneration are both early pathological events in the development of Alzheimer’s disease (AD). Acetylcholine contributes to localised arterial dilatation and increased cerebral blood flow (CBF) during neurovascular coupling via activation of endothelial nitric oxide synthase (eNOS). Decreased vascular reactivity is suggested to contribute to impaired clearance of β-amyloid (Aβ) along intramural periarterial drainage (IPAD) pathways of the brain, leading to the development of cerebral amyloid angiopathy (CAA). However, the possible relationship between loss of cholinergic innervation, impaired vasoreactivity and reduced clearance of Aβ from the brain has not been previously investigated. In the present study, intracerebroventricular administration of mu-saporin resulted in significant death of cholinergic neurons and fibres in the medial septum, cortex and hippocampus of C57BL/6 mice. Arterial spin labelling MRI revealed a loss of CBF response to stimulation of eNOS by the Rho-kinase inhibitor fasudil hydrochloride in the cortex of denervated mice. By contrast, the hippocampus remained responsive to drug treatment, in association with altered eNOS expression. Fasudil hydrochloride significantly increased IPAD in the hippocampus of both control and saporin-treated mice, while increased clearance from the cortex was only observed in control animals. Administration of mu-saporin in the TetOAPPSweInd mouse model of AD was associated with a significant and selective increase in Aβ40-positive CAA. These findings support the importance of the interrelationship between cholinergic innervation and vascular function in the aetiology and/or progression of CAA and suggest that combined eNOS/cholinergic therapies may improve the efficiency of Aβ removal from the brain and reduce its deposition as CAA

Effects of two nitrogen enriched biochars on barley grown on peat : preliminary observations

The ability of biochar to sorb ammonium is well known, with different mechanisms being postulated. In this study the possibility to use ammonium loaded biochars in growing media, in comparison to other sorbents like natural zeolites was exploited. A spruce biochar and a poplar biochar, obtained by high temperature pyro-gasification, and a natural zeolite (chabazite) were loaded with ammonium by soaking in 0.5M ammonium sulphate. An incubation test and a plant growth trial were performed on the ammonium-enriched materials added to a peat based growing media, compared with (NH4)2SO4. The peat was able to quickly retain the ammonium added with both mineral fertiliser and biochars. The loaded biochars do not act as slow release N carriers; nevertheless, they promote plant nitrogen uptake. The zeolite strongly retained ammonium throughout the experiment leaving an amount of soluble nitrogen lower than plant requirements

Pattern of pore water nutrients in planted and non-planted soilless substrates as affected by the addition of biochars from wood gasification

The primary objective of this study was to evaluate the effects of partial replacement of peat by hardwood (poplar) or softwood (spruce) gasification biochars on nutrient release and retention and the effectiveness of biochars to neutralize peat acidity in non-planted and planted (basil) substrates during 36 days of incubation. Pots (1L) filled with biochars+peat and with limed peat (control) were drenched with fertilizing solutions and watered at pF1. pH and nutrients content in substrate pore water were determined in Rhizon samples taken at 15, 22, 29, and 36 days of incubation. The hardwood biochar was more efficient than the softwood biochar in neutralizing both peat acidity and the acidification induced by root activity. Both biochars improved ammonia removal from pore water; this effect increased with time and was particularly noticeable for the hardwood biochar, which induced an almost complete depletion of the fertilizer-derived NH4 (+)-N. The hardwood biochar also account for high levels of NO3 (-)-N in pore water, even though a decline over time was detected. Both biochars increased pore water potassium with a higher buffering power of the softwood biochar in respect to the hardwood one. Fluctuation of calcium and magnesium concentrations was related with changes in pH due to abiotic and biotic processes. Pore water composition in planted substrates was affected by plant uptake and by root driven changes in substrates' pH

Biochar can enhance potassium availability during cyclamen cultivation

This study examined the feasibility of using biochar in soilless substrates as a substitute for mineral components and as an additive to buffer peat acidity and increase cation exchange capacity. Two different substrates were studied: a control mix composed of peat and perlite (80:20%, v/v) and a biochar mix, composed of peat and biochar (80:20%, v/v). To evaluate the role of biochar in the dynamic of plant available potassium, two levels of starter potassium fertilization were used (0 and 150 mg K L-1 substrate). A randomized trial was conducted in a commercial greenhouse, where 132 pots were filled with the control mix and with the biochar mix; then one young plant/pot of Cyclamen persicum Mill. \u2018Halios\u2019 was transplanted and cultivated for 150 days. Special attention was paid to the effect of biochar on potassium and other nutrients dynamic in pore water during the first phases of plant growth and in the substrate at the end of the cultivation. Cyclamen morphological properties (leaf number, plant height, flower number, fresh and dry biomass of aboveground) were surveyed at an early crop growth and at the end of the experiment. Biochar increased K, P and Mg concentrations in the pore water up to 16 days after transplanting. At 75 d, the growth of cyclamen was 30% enhanced by biochar, with statistically significant increases in fresh and dry weight. Leaf and flower numbers, and mineral content of leaves were not influenced by biochar and starter K addition. At the end of the cultivation, there was no more noticeable effect of biochar on cyclamen quality and leaf nutrient contents. Chemical analysis of the substrates showed that biochar was able to induce an increase in water extractable K (+23%) and in CAT (calcium chloride and DTPA) extractable K (+36%) in respect to control medium. Moreover, the significant interaction between biochar and starter potassium fertilization suggested that biochar can preserve potassium from leaching, being able to store potassium fertilizer in a plant available pool. These results demonstrated that biochar can be considered a good substitute for perlite in growing media, acting at the same time as a sink and a source of potassium available for plants