| 1. |
- Álvarez-Buylla, Elena R., et al.
(författare)
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B-Function Expression in the Flower Center Underlies the Homeotic Phenotype of Lacandonia schismatica (Triuridaceae)
- 2010
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 22:11, s. 3543-3559
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Tidskriftsartikel (refereegranskat)abstract
- Spontaneous homeotic transformations have been described in natural populations of both plants and animals, but little is known about the molecular-genetic mechanisms underlying these processes in plants. In the ABC model of floral organ identity in Arabidopsis thaliana, the B- and C-functions are necessary for stamen morphogenesis, and C alone is required for carpel identity. We provide ABC model-based molecular-genetic evidence that explains the unique inside-out homeotic floral organ arrangement of the monocotyledonous mycoheterotroph species Lacandonia schismatica (Triuridaceae) from Mexico. Whereas a quarter million flowering plant species bear central carpels surrounded by stamens, L. schismatica stamens occur in the center of the flower and are surrounded by carpels. The simplest explanation for this is that the B-function is displaced toward the flower center. Our analyses of the spatio-temporal pattern of B- and C-function gene expression are consistent with this hypothesis. The hypothesis is further supported by conservation between the B-function genes of L. schismatica and Arabidopsis, as the former are able to rescue stamens in Arabidopsis transgenic complementation lines, and Ls-AP3 and Ls-PI are able to interact with each other and with the corresponding Arabidopsis B-function proteins in yeast. Thus, relatively simple molecular modifications may underlie important morphological shifts in natural populations of extant plant taxa.
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| 2. |
- Ramírez-Torres, Carlos Eduardo, et al.
(författare)
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Influence of tannic acid concentration on the physicochemical characteristics of saliva of spider monkeys (Ateles geoffroyi)
- 2022
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Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Tannins are a chemical defense mechanism of plants consumed by herbivores. Variations in salivary physicochemical characteristics such as pH, total protein concentration (TP), and presence of proline-rich proteins (PRPs) in animals have been reported as a mechanism to protect the oral cavity when consuming food with variations in pH and tannins. Variations in salivary physiochemistry as adaptations for consuming tannin-rich foods have been found in omnivorous and folivorous primates, but have not yet been reported in frugivorous species such as spider monkeys. We therefore assessed changes in pH using test strips, TP concentration by measuring absorbance at 595 nm in a spectrophotometer and salivary PRPs using the SDS-PAGE electrophoresis technique in the saliva of nine captive spider monkeys in response to the consumption of solutions with different concentrations of tannic acid. The results showed variations in pH, TP concentration and the presence and variation of possible salivary PRPs associated with tannic acid concentration. These findings suggest that spider monkeys may tailor their salivary physicochemical characteristics in response to the ingestion of potentially toxic compounds.
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| 3. |
- Bernal, Ximena E., et al.
(författare)
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Empowering Latina scientists
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 363:6429, s. 825-826
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Budtova, Tatiana, et al.
(författare)
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Biorefinery Approach for Aerogels
- 2020
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Ingår i: Polymers. - : MDPI. - 2073-4360. ; 12:12
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Forskningsöversikt (refereegranskat)abstract
- According to the International Energy Agency, biorefinery is “the sustainable processing of biomass into a spectrum of marketable bio-based products (chemicals, materials) and bioenergy (fuels, power, heat)”. In this review, we survey how the biorefinery approach can be applied to highly porous and nanostructured materials, namely aerogels. Historically, aerogels were first developed using inorganic matter. Subsequently, synthetic polymers were also employed. At the beginning of the 21st century, new aerogels were created based on biomass. Which sources of biomass can be used to make aerogels and how? This review answers these questions, paying special attention to bio-aerogels’ environmental and biomedical applications. The article is a result of fruitful exchanges in the frame of the European project COST Action “CA 18125 AERoGELS: Advanced Engineering and Research of aeroGels for Environment and Life Sciences”.
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| 5. |
- Espinosa, Eduardo, et al.
(författare)
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Nanocellulose-Based Inks-Effect of Alginate Content on the Water Absorption of 3D Printed Constructs.
- 2019
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Ingår i: Bioengineering (Basel, Switzerland). - : MDPI AG. - 2306-5354. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- 2,2,6,6-tetramethylpyperidine-1-oxyl (TEMPO) oxidized cellulose nanofibrils (CNF) were used as ink for three-dimensional (3D) printing of porous structures with potential as wound dressings. Alginate (10, 20, 30 and 40 wt%) was incorporated into the formulation to facilitate the ionic cross-linking with calcium chloride (CaCl2). The effect of two different concentrations of CaCl2 (50 and 100 mM) was studied. The 3D printed hydrogels were freeze-dried to produce aerogels which were tested for water absorption. Scanning Electronic Microscopy (SEM) pictures demonstrated that the higher the concentration of the cross-linker the higher the definition of the printed tracks. CNF-based aerogels showed a remarkable water absorption capability. Although the incorporation of alginate and the cross-linking with CaCl2 led to shrinkage of the 3D printed constructs, the approach yielded suitable porous structures for water and moisture absorption. It is concluded that the 3D printed biocomposite structures developed in this study have characteristics that are promising for wound dressings devices.
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| 6. |
- Espinosa, Eduardo, et al.
(författare)
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PVA/(ligno)nanocellulose biocomposite films. Effect of residual lignin content on structural, mechanical, barrier and antioxidant properties
- 2019
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier B.V.. - 0141-8130 .- 1879-0003. ; 141, s. 197-206
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Tidskriftsartikel (refereegranskat)abstract
- Nanocelluloses with and without residual lignin were isolated from wheat straw. In addition, the effect of TEMPO-mediated oxidation on the production of lignin-containing nanocellulose was studied. The different nanocelluloses were used as reinforcing agent in Poly(vinyl alcohol) films. The morphology, crystallinity, surface microstructure, barrier properties, light transmittance, mechanical and antioxidant properties were evaluated. The translucency of films was reduced by the addition of nanocellulose, however, the ability to block UV-light increased from 10% for PVA to >50% using lignin-containing nanocellulose, and 30% for lignin-free samples. The mechanical properties increased considerably, however, for loads higher than 5% a negative trend was observed presumptively due to a clustering of nanocellulose components in PVA matrix. The barrier properties of the films were improved with the use of nanocellulose, especially at small amounts (1–3%). The antioxidant capacity of films was increased up to 10% using lignin-containing nanocellulose compared to 4.7% using PVA. © 2019 Elsevier B.V.
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| 7. |
- Pick, Cari M., et al.
(författare)
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Fundamental social motives measured across forty-two cultures in two waves
- 2022
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Ingår i: Scientific Data. - : Springer Nature. - 2052-4463. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- How does psychology vary across human societies? The fundamental social motives framework adopts an evolutionary approach to capture the broad range of human social goals within a taxonomy of ancestrally recurring threats and opportunities. These motives-self-protection, disease avoidance, affiliation, status, mate acquisition, mate retention, and kin care-are high in fitness relevance and everyday salience, yet understudied cross-culturally. Here, we gathered data on these motives in 42 countries (N = 15,915) in two cross-sectional waves, including 19 countries (N = 10,907) for which data were gathered in both waves. Wave 1 was collected from mid-2016 through late 2019 (32 countries, N = 8,998; 3,302 male, 5,585 female; M-age = 24.43, SD = 7.91). Wave 2 was collected from April through November 2020, during the COVID-19 pandemic (29 countries, N = 6,917; 2,249 male, 4,218 female; M-age = 28.59, SD = 11.31). These data can be used to assess differences and similarities in people's fundamental social motives both across and within cultures, at different time points, and in relation to other commonly studied cultural indicators and outcomes.
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| 8. |
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| 9. |
- Serra-Parareda, Ferran, et al.
(författare)
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Feasibility of Barley Straw Fibers as Reinforcement in Fully Biobased Polyethylene Composites: Macro and Micro Mechanics of the Flexural Strength
- 2020
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Ingår i: Molecules. - : MDPI AG. - 1420-3049 .- 1420-3049. ; 25:9
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Tidskriftsartikel (refereegranskat)abstract
- Awareness on deforestation, forest degradation, and its impact on biodiversity and global warming, is giving rise to the use of alternative fiber sources in replacement of wood feedstock for some applications such as composite materials and energy production. In this category, barley straw is an important agricultural crop, due to its abundance and availability. In the current investigation, the residue was submitted to thermomechanical process for fiber extraction and individualization. The high content of holocellulose combined with their relatively high aspect ratio inspires the potential use of these fibers as reinforcement in plastic composites. Therefore, fully biobased composites were fabricated using barley fibers and a biobased polyethylene (BioPE) as polymer matrix. BioPE is completely biobased and 100% recyclable. As for material performance, the flexural properties of the materials were studied. A good dispersion of the reinforcement inside the plastic was achieved contributing to the elevate increments in the flexural strength. At a 45 wt.% of reinforcement, an increment in the flexural strength of about 147% was attained. The mean contribution of the fibers to the flexural strength was assessed by means of a fiber flexural strength factor, reaching a value of 91.4. The micromechanical analysis allowed the prediction of the intrinsic flexural strength of the fibers, arriving up to around 700 MPa, and coupling factors between 0.18 and 0.19, which are in line with other natural fiber composites. Overall, the investigation brightness on the potential use of barley straw residues as reinforcement in fully biobased polymer composites.
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| 10. |
- Vilaseca, Fabiola, et al.
(författare)
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Valorization of hemp core residues: Impact of NaOH treatment on the flexural strength of PP composites and intrinsic flexural strength of hemp core fibers
- 2020
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Ingår i: Biomolecules. - : MDPI AG. - 2218-273X. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Hemp core is a lignocellulosic residue in the production chain of hemp strands. Huge amounts of hemp core are gathered annually in Europe (43,000 tons) with no major application end. Such lignocellulosic wastes have potential as filling or reinforcing material to replace synthetic fibers and wood fibers in polymer composites. In this study, hemp core biomass was treated under different NaOH concentrations and then defibrated by means of Sprout Waldron equipment to obtain single fibers. Polypropylene matrix was reinforced up to 50 wt.% and the resulting hemp core fibers and the flexural properties were investigated. The results show that the flexural strength of composites increased with the intensity of NaOH treatment. The effect of NaOH was attributed to the removal of extractives and lignin in the fiber cell wall leading to improved interfacial adhesion characteristics. Besides, a methodology was established for the estimation of the intrinsic flexural strength of hemp core fibers. The intrinsic flexural strength of hemp core fibers was calculated to be 940 MPa for fibers treated at 10 wt.% of NaOH. In addition, a relationship between the lignin content and the intrinsic strength of the fibers was established.
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