Introduction Dental caries and fluorosis are a public health problem; their relationship with the levels of fluoride consumed should be analyzed and reported. Aim. Analyze the levels of fluoride in the water consumed by school-aged children. Based on the results obtained, establish its relationship with the prevalence and severity of fluorosis and dental caries. Material and methods. In total, 52 tests were taken from four different community water sources. The prevalence and severity of fluorosis was determined using Dean's index and the caries were classified according to their depth in 64 children. Descriptive and multivariate statistics were carried out. Results. The highest fluoride values in water were those obtained in well water with 1.63 PPM, followed by spring water with 1.47 PPM. Fluoride levels in the purifiers were within the allowed range. The prevalence of fluorosis and caries in children turned out to be high. The following relationships were found: a) when a child reports not drinking water from a purifier, this is related to the presence of fluorosis and cavities, b) in children who do not drink water from the spring or the tap, but do drink water from purifying, fluorosis and caries are absent. Conclusions. The levels of fluoride in the spring water and the intake tap exceeded the permitted limits and its consumption is related to the presence of fluorosis and cavities.

Antecedentes: Allium glandulosum Link & Otto se distribuye ampliamente desde el sur de Estados Unidos, México y Centroamérica. En México se distribuye en 27 estados, en ambientes contrastantes. Sin embargo, no se ha estudiado si su patrón de distribución se refleja en una amplia variación morfológica. Pregunta y/o Hipótesis: ¿La variación morfológica vegetativa y floral en Allium glandulosum a lo largo de su distribución en México permite diferenciar entre poblaciones de esta especie? Especie de estudio: Allium glandulosum Link & Otto. Sitio y fechas de estudio: Poblaciones de Allium glandulosum con distribución en el Eje Volcánico Transmexicano y la Altiplanicie Mexicana, durante el 2020. Métodos: Se determinaron y midieron caracteres morfológicos cualitativos y cuantitativos de ejemplares herborizados y de especímenes recolectados en campo. Se emplearon métodos estadísticos univariados y multivariados para describir y sintetizar la variabilidad de las recolectas de campo y materiales herborizados. Resultados: El análisis de componentes principales mostró que 14 caracteres representan el 51.29 % de la variación total acumulada en los primeros tres componentes. El análisis discriminante lineal resulto en la formación de cuatro grupos y el porcentaje de clasificación de los individuos fue de 71.53 %. El análisis de conglomerados mostró cuatro agrupaciones, diferenciados por caracteres cuantitativos y cualitativos. Conclusiones: La variación morfológica vegetativa y floral de Allium glandulosum permite diferenciar entre las poblaciones de la especie a lo largo de su distribución en México.

Potential distribution models are used to predict the presence and geographic limits of a species as a function of bioclimatic variables. The lack of knowledge of the geographic distribution of species endemic to Mexico is a limiting factor in understanding their ecology, conservation, and potential applications. Distribution models were generated with occurrence data of 11 species of the genus Zephyranthes, 19 bioclimatic and three topographic variables with the Maximum Entropy (MaxEnt) method. The dimensionality reduction analysis (PCA) allowed determining that, of the 19 variables, four contributed the highest percentage to the classification of the models, explaining more than 80% of the accumulated variance. The resulting models were evaluated according to the value of the area under the curve (AUC) and potential distribution models with AUC values >0.89 were obtained. The results suggest that most species are distributed in the biogeographic province of the Transmexican Volcanic Belt. Zephyranthes concolor was the species with the largest potential distribution area. The species with the most restricted potential distribution was Zephyranthes sessilis.

Decadal changes in the community structure of coral reef-associated fishes reflect prevailing poor environmental conditions. This study analyzed temporal shifts in fish communities (e.g., diversity, density, and biomass) recorded via SCUBA belt transects across coral reefs on the center–southern coast of Quintana Roo (eastern Yucatan Peninsula) in the Mexican Caribbean. Sites were initially investigated in 1995 and revisited in 2024 after the construction of a cruise ship pier, and we compared sites under different protection categories. Mean density and biomass decreased significantly over time, particularly at reef sites outside of a protected area in 1995. While species richness and density of commercially important fishes were higher in protected sites in 1995, parrotfishes (Scarinae) maintained stable density and biomass across both years and protection status. No significant differences were found in the biomass of other fishes (e.g., Haemulidae, Lutjanidae). Changes recorded may reflect historical fishing pressure, including poaching, but probably also pollution from intense growth of coastal tourism infrastructure in 2024, as well as damage from the beached Sargassum influx. Ultimately, the positive effect offered by protected areas is not enough to mitigate the local and regional environmental impacts on coral reefs. Our findings serve as a reference point where coastal development and climate change interact and affect coral reefs.

The genus Zephyranthes is widely represented in Mexico, with 37 species of ornamental and medical importance. However, basic aspects of the genus, such as the environmental variables that determine its presence in certain sites, have not yet been addressed, which limits the knowledge of its ecology, potential applications and possible conservation strategies. Potential distribution models were generated with data on the presence of 13 species of the genus Zephyranthes, using 28 bioclimatic and edaphic variables with the maximum entropy method (Maxent). Of these variables, the most important and least correlated for each species were chosen by principal component analysis (PCA); the occurrence data were obtained from digital platforms and filtered to reduce spatial autocorrelation. The resulting models, had AUC values > 0.90 and Kappa index values > 0.6, in addition to being significant according to the results of the binomial test applied (p < 0.05). Maximum temperatures and humidity, as well as annual precipitation, are relevant environmental variables for the niche models. Most species are distributed in the biogeographic province of the Transmexican Volcanic Belt. Zephyranthes concolor and Zephyranthes lindleyana were the species with the largest potential range. The species with the most restricted potential distribution were Zephyranthes citrina and Zephyranthes sessilis. The most determinant variables for species with neotropical affinity are different from those identified for Nearctic species, reflecting niche differentiation, congruent with the evolutionary history of Zephyranthes.