Articles publicats (Química, Física i Ciències Ambientals i del Sòl)
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- ItemOpen AccessBiofortification for space farming: Maximising nutrients using lettuce as a model plant(Elsevier, 2024) Burgess, Alexandra J.; Pranggono, Raihannah; Escribà i Gelonch, Marc; Hessel, VolkerSpace exploration requires consideration of the dietary requirements of astronauts. Not only do nutritional requirements differ in space versus Earth, but limitations to payload combined with the length of space missions means that astronauts will need to produce as much food as possible in situ. Lettuce (Lactuca sativa) possesses many traits that make it suitable for space farming. Its small size, quick life cycle, large harvestable fraction and previous successful cultivation aboard the International Space Station (ISS) means that it represents a model plant for space cultivation. Here we discuss the suitability and requirements of lettuce as a dietary source on space missions. Using simplex linear programming, we identify the ration sizes of existing lettuce varieties to optimise nutrient delivery to both men and women on Earth and in Space. Whilst, unsurprisingly, a diet consisting only of lettuce cannot provide full nutrient requirements, there are differences in ration size and composition depending upon gender and location, indicating the importance of group composition when designing farming systems. We then review different routes to the biofortification of lettuce based on current literature and perform the modelling approach to determine portion sizes of theoretical ‘maximally fortified lettuce’, whose nutritional content was predicted based on the combined biofortification strategies. Finally, we conclude with the application of these approaches towards future space farming of a variety of crop species.
- ItemOpen AccessConstant-pH simulations of a coarse-grained model of polyfunctional weak charged biopolymers(MDPI, 2024) Naranjo, David; Blanco, Pablo M.; Garcés, Josep Lluís; Madurga, Sergio; Mas, FrancescA coarse-grained model of linear polyfunctional weak charged biopolymers was implemented, formed of different proportions of acid-base groups resembling the composition of humic substances. These substances are mainly present in dissolved organic matter in natural water. The influence of electrostatic interactions computing methods, factors concerning the structure of the chain, different functional groups, and the ionic strength on polyelectrolytes were studied. Langevin dynamics with constant pH simulations were performed using the ESPResSO package and the Python-based Molecule Builder for ESPResSo (pyMBE) library. The coverage was fitted to a polyfunctional Frumkin isotherm, with a mean-field interaction between charged beads. The composition of the chain affects the charge while ionic strength affects both the charge and the radius of gyration. Additionally, the parameters intrinsic to the polyelectrolyte model were well reproduced by fitting the polyfunctional Frumkin isotherm. In contrast, the non-intrinsic parameters depended on the ionic strength. The method developed and applied to a polyfunctional polypeptide model, that resembles a humic acid, will be very useful for characterizing biopolymers with several acid-base functional groups, where their structure, the composition of the different functional groups, and the determination of the main intrinsic proton binding constants and their proportion are not exactly known.
- ItemOpen AccessBiogenic carbonates (queras) in loess-palaeosol sequences of the Ebro Basin and their potential use as a palaeoenvironmental proxy(Elsevier, 2024) Álvarez, Daniela; Torres-Guerrero, Carlos Alberto; Travé, Anna; Preusser, Frank; Plata Moreno, José Manuel; Poch, Rosa M.Secondary carbonate accumulations are very common in arid and semi-arid soils but are often poorly described and classified. This is the case for queras that are observed in several loess-palaeosol sequences of the Ebro Basin. Micromorphologically, queras are complex pedogenic features basically consisting of infillings of calcified root cells in channels, surrounded by decarbonated hypocoatings. They apparently result from biologically mediated calcification/decalcification processes at a microscale. The aim of this study is to systematically characterize biocalcifications found in dated loess-palaeosol sequences, to determine the main factors of formation, and to discuss their possible use as a palaeoenvironmental proxy. Different queras show a similar number of biosparite layers (four to five) around a central channel, and a decarbonated hypocoating around the queras. This supports the hypothesis that queras originate from the calcification of root tips and are related to the acidification of surrounding soil for nutrient absorption. Under cathodoluminescence microscopy, biosparite has a different behaviour than non-biological calcite crystals: the latter appears reddish while biosparite remains black. The queras, with ages corresponding to Marine Isotope Stages 1–3, are younger than that of the loess where they are found in. The stable isotope values likely correspond to C3 plants, and the estimated temperatures of formation reflect a Mediterranean temperate climate. This suggests that the biocalcifications developed during short moist seasons amidst arid periods of the Quaternary.
- ItemOpen AccessPhase structure of charged AdS black holes surrounded by exotic fluid with modified Chaplygin equation of state(Springer, 2024) Sekhmani, Y.; Rayimbaev, J.; Luciano, Giuseppe Gaetano; Myrzakulov, R.; Gogoi, D. J.By considering the concept of the modified Chaplygin gas (MCG) as a single fluid model unifying dark energy and dark matter, we construct a static, spherically charged black hole (BH) solution in the framework of General Relativity. The P–V criticality of the charged anti-de Sitter (AdS) BH with a surrounding MCG is explored in the context of the extended phase space, where the negative cosmological constant operates as a thermodynamical pressure. This critical behavior shows that the small/large BH phase transition is analogous to the van der Waals liquid/gas phase transition. Accordingly, along the P–V phase spaces, we derive the BH equations of state and then numerically evaluate the corresponding critical quantities. Similarly, critical exponents are identified, along with outcomes demonstrating the scaling behavior of thermodynamic quantities near criticality to a universal class. The use of geometrothermodynamic (GT) tools finally offers a new perspective on the discovery of the critical phase transition point. At this stage, we apply a class of GT tools, such as Weinhold, Ruppeiner, HPEM, and Quevedo classes I and II. The findings are therefore non-trivial, as each GT class metric captures at least either the physical limitation point or the phase transition critical point. Overall, this paper provides a detailed study of the critical behavior of the charged AdS BH with surrounding MCG.
- ItemOpen AccessNIR-HSI as a tool to predict deoxynivalenoland fumonisins in maize kernels: a stepforward in preventing mycotoxincontamination(John Wiley & Sons Ltd, 2024) Borràs-Vallverdú, Bernat; Marín Sillué, Sònia; Sanchís Almenar, Vicente; Gatius Cortiella, Ferran; Ramos Girona, Antonio J.Maize is frequently contaminated with deoxynivalenol (DON) and fumonisins B1 (FB1) and B2 (FB2). In the European Union, these mycotoxins are regulated in maize and maize-derived products. To comply with these regulations, industries require a fast, economic, safe, non-destructive and environmentally friendly analysis method. RESULTS: In the present study, near-infrared hyperspectral imaging (NIR-HSI) was used to develop regression and classification models for DON, FB1 and FB2 in maize kernels. The best regression models presented the following root mean square error of cross validation and ratio of performance to deviation values: 0.848 mg kg−1 and 2.344 (DON), 3.714 mg kg−1 and 2.018 (FB1) and 2.104 mg kg−1 and 2.301 (FB2). Regarding classification, European Union legal limits for DON and FB1 + FB2 were selected as thresholds to classify maize kernels as acceptable or not. The sensitivity and specificity were 0.778 and 1 for the best DON classification model and 0.607 and 0.938 for the best FB1 + FB2 classification model. CONCLUSION: NIR-HSI can help reduce DON and fumonisins contamination in the maize food and feed chain. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.