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- Histological Evidence of Thyroid Disruption in Wild Mice from Conventional and Organic Farming EnvironmentsPublication . Coelho, Nádia; Carminho, Ricardo; Garcia, Patrícia; Bernardo, Filipe; dos Santos Rodrigues, Armindo; Fortin, ClaudeABSTRACT: The main objective of this work is to assess the potential negative impact of organic farming on the thyroid gland and compare it with the negative impact of conventional farming on this organ. Previous studies have linked exposure to conventional farming with thyroid disruption; relatively less is known about effects of exposure to organic farming on the thyroid. Mus musculus were the bioindicators in this work, captured in a conventional farm (CF), an organic farm (OF), and two reference areas (RF’) without agriculture. Histomorphometric and histomorphological measurements of the thyroid were performed. Hypothyroidism signs were observed in mice exposed to either farming system, being less pronounced in organic farming-exposed mice: epithelium thickness and the epithelial cells’ area and volume were lower than in non-exposed mice [epithelium thickness (µm): 4.16 ± 0.51 (CF); 6.28 ± 0.19 (OF); 7.46 ± 0.25 (RF’)]. Histomorphologic alterations included decreased follicular sphericity, increased epithelium irregularity, increased exfoliation into the colloid, and increased inflammation of thyroid tissue. Results suggest that, while organic farming might be a better alternative to conventional farming, it is not completely free of health hazards. Exposure to an organic farming environment can cause thyroid disruption, although with less pronounced effects than conventional farming. Despite there being risks to be considered, results support the benefit of transitioning from conventional farming systems towards organic farming systems.
- Global insular leaf size shifts follow the island rule, independently of insect herbivory and macroclimatePublication . Moreira, Xoaquín; Abdala-Roberts, Luis; Amorim do Rosário, Isabel; Baider, Claúdia; Burns, Kevin; Caujapé-Castells, Juli; Cubas, Jonay; Dean, Lydia; Domínguez-Lapido, Paula; Endara, María-José; Florens, F. B. Vincent; Galmán, Andrea; Guevara-Andino, Juan Ernesto; Hutton, Ian; Lago-Núñez, Beatriz; Mooney, Kailen; Larrinaga, Asier; Pereira, Fernando; Randimbiarison, Finaritra; Razafindratsima, Onja; Rivas-Torres, Gonzalo; Vázquez-González, Carla; de Lafontaine, GuillaumeABSTRACT: The island rule, originally formulated for animals, predicts that small-bodied mainland species evolve larger body sizes on islands (gigantism), but that this effect weakens with increasing mainland body size, ultimately reversing and leading to dwarfism for the largest species. This dynamic is expected to produce a positive, saturating relationship between island and mainland body size, with insular size increases at small sizes and reductions at large sizes. Despite extensive support in animals, this prediction has rarely been tested in plants. Consequently, it remains unclear whether the island rule applies to plants, whether it operates consistently across evolutionary scales, and how biotic and abiotic drivers jointly shape insular size shifts. We tested the island rule in plants by examining leaf size variation—an organ-level analogue of body size—across 48 island species from six oceanic systems and their mainland counterparts. We conducted both conspecific comparisons (same species on islands and the mainland; n = 19 pairs) and congeneric comparisons (island endemics paired with closely related mainland species; n = 29 pairs) to assess patterns across evolutionary scales. We also measured insect herbivory and recorded climatic variables to explore ecological correlates of island–mainland variation in leaf size. Although mean leaf size did not differ significantly between island and mainland populations for either conspecific or congeneric comparisons, we detected a non-linear, positive saturating relationship between mainland and island leaf sizes, consistent with an island rule-like pattern. Small-leaved mainland species tended to evolve larger leaves on islands, whereas this effect diminished for larger leaved species, a pattern observed in both conspecific and congeneric comparisons. Insect herbivory and climate did not explain these relationships. Synthesis: These findings demonstrate that plants follow the island rule for leaf size and suggest that mainland-to-island shifts at opposite ends of the mainland leaf size spectrum offset one another, possibly explaining no overall difference in leaf size between island and mainland populations.