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- Evaluation of a Tomato Waste Biofilter for the Retention of Gaseous Losses from Pig Slurry Hygienization by pH ModificationPublication . Pereira, José L.S.; Perdigão, Adelaide; Fangueiro, DavidThe use of pig slurry as organic fertilizer in intensive horticulture could be possible after hygienization to avoid contamination of products. This research aimed to evaluate a mixture of a tomato waste and rice husk as biofilter media to reduce NH3, N2O, CO2, and CH4 losses from a simple and low-cost solution for slurry hygienization by pH modification. The experiment was made in a system of laboratory scale biofilters connected to jars filled with raw slurry as control and three treatment methods: acidified slurry, alkalinized slurry, and neutralized slurry. The gas concentrations were measured for 35 days, and the composition of slurries and biofilters were determined. The results of this study showed that the mixture of biofiltering media, composed of tomato waste and rice husk, has the potential to retain NH3 and greenhouse gases (GHG) from a simple and low-cost solution for slurry hygienization by pH modification. Compared to the treatment raw slurry biofilter, the treatment neutralized slurry biofilter, subjected to a combined treatment by alkalinization/neutralization, retained 19% NH3, 4% CO2, and 83% CH4 losses and had no impact on N2O and global warming potential. Thus, the use of tomato waste biofilter during alkalinization did not increase the loss of NH3 and reduced GHG compared to raw slurry, avoiding the subsequent neutralization of slurry for environmental reasons, and could be used as an organic fertilizer in horticulture. However, using the combined alkalinization/neutralization treatment will improve the fertilizer value of the slurry by adjusting the pH from 9.5 to 7.5.
- Definition of Low Disease Activity State based on the SLE-DAS: Derivation and validation in a multicentre real-life cohortPublication . Assunção, Helena; Jesus, Diogo; Larosa, Maddalena; Henriques, Carla; Matos, Ana; Le Guern, Véronique; Rubiño, Francisco; Silva, José A P da; Rua-Figueroa, Iñigo; Costedoat-Chalumeau, Nathalie; Doria, Andrea; Inês, Luís SObjectives To derive and validate a definition of low disease activity (LDA) for SLE based on the SLE Disease Activity Score (SLE-DAS), in a real-life multicentre cohort of SLE patients. Methods Derivation was conducted using data from a monocentric cohort of SLE (Portugal), and validation was performed in a multicentre cohort (Italy, France and Spain). The Lupus Low Disease Activity State (LLDAS) was used as comparator. We applied receiver operating characteristics curve analysis against the LLDAS to determine the cut-off of SLE-DAS for LDA using bootstrap methodology. In a second step, we tested a definition of SLE-DAS LDA that included: (i) the statistically derived SLE-DAS upper threshold for LDA and (ii) prednisone dose ≤7.5 mg/day. In the multicentre validation cohort, we assessed the classification performance of this SLE-DAS LDA definition. Results We included 774 patients, 300 in the derivation and 474 in the validation cohort. In the derivation cohort, the optimal cut-off to identify patients in LLDAS was SLE-DAS ≤2.48, presenting an area under the curve of 0.965 (95% CI 0.935, 0.994). When applied to the multicentre validation cohort, the SLE-DAS LDA definition showed a sensitivity of 97.1% and a specificity of 97.7% for LLDAS and an almost perfect agreement (Cohen’s Kappa = 0.933; P < 0.001). McNemar’s test found no significant differences between the two definitions (P = 0.092). Conclusion The SLE-DAS LDA is a validated, accurate and easy-to-use definition for classifying SLE patients in LDA state.