Bacterial diversity in vadose cave pools: evidence for isolated ecosystems

Microbial diversity of cave pools, especially vadose pools, has received relatively little attention. To help fill this gap, this study reports on the bacterial diversity of 17 pools in three New Mexican arid land caves: Carlsbad Cavern, Lechuguilla Cave, and Hell Below Cave. These pools are spread throughout the caves and, with two exceptions, are not connected. The pools share a basic water chemistry, with fresh water of the calcium-magnesium-bicarbonate type. These 17 pools have Chao1 values between 40 and 1738; the Shannon diversity averages 4.6 ± 1.1, ranging from 2.6 to 6.4; and the Simpson averages 0.881 ± 0.099, ranging from 0.622 to 0.981. No two pools had the same communities, even at the phylum level. Nitrospirae, Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria were found >5% abundance in nine or more cave pools. Actinobacteria, Chloroflexi, Fibrobacteres, Firmicutes and Plantomycetes were at >5 % in four to six pools. Of the top ten widespread bacterial genera, Nitrospira was found in all pools, with >5 % in eleven pools. Other common genera include Polyclorovans, Propionibacterium, Polaromonas, Haliangium, Bacillus, Subgroup 6 uncultured Acidobacteria, Candidatus Omnitrophica, and uncultured Nitrosomonadaceae. Presence of several potential nitrogen cycling bacteria (e.g., Nitrospira) in the study pools suggests that nitrogen cycling may be an important bacterial role. There is some evidence of human contamination, particularly in the heavily visited Big Room, Carlsbad Cavern, but it is not the dominant control. Rather than a single stable cave pool community, adapted to the cave pool ecosystem, the data show 17 different communities, despite relatively similar conditions. The data support the hypothesis that each pool is a unique, isolated ecosystem, with differences likely caused more by the isolation of each pool than by variable chemistry. Thus, the common habit of grouping samples, while useful for some questions, may not capture the diversity present in cave ecosystems.

A new locality for the rare Guerreran Centipede Snake, Tantilla coronadoi Hartweg, 1944 (Squamata, Colubridae), with comments on morphological variation

We record the third known specimen of Tantilla coronadoi Hartweg, 1944 from Guerrero, Mexico. Our new record extends this species’ distribution by 90 km and to a new Mexican biogeographic province (Balsas Basin). The morphological similarity between this and the two previously known specimens supports the validity of the taxon, and otherwise points to the possible presence of an undescribed taxon on the coast of Guerrero. Additional fieldwork yielding a larger series of this and other infrequently encountered species may enable a better understanding of their distribution, natural history, ecology, and conservation.

Description of four new species of Anelaphus Linsley (Coleoptera, Cerambycidae, Cerambycinae, Elaphidiini), correction of the spelling of species-group names, and description of the female of Anelaphus pilosus Chemsak and Noguera

Eight species-group names of longhorned woodboring beetles in the genus Anelaphus are corrected. Four new species of Anelaphus Linsley, 1936 are described: A. steveni Santos-Silva, sp. nov., from Mexico (Chiapas); A. erici Santos-Silva, sp. nov., from Nicaragua (Granada); A. izabalensis Santos-Silva, sp. nov., from Guatemala (Izabal); and A. zacapensis Santos-Silva, sp. nov., from Guatemala (Zacapa). New Mexican state records for Anelaphus undulatus (Bates, 1880) are provided. The female of Anelaphus pilosus Chemsak and Noguera, 2003 is described for the first time, and the species is newly recorded from Guatemala. The inclusion of Anelaphus nitidipennis Chemsak and Linsley, 1968 in this genus is questioned.

A new species of Ambrysus Stål from the Central Mexican Plateau and new state records for species of the genus in the country (Heteroptera: Nepomorpha: Naucoridae)

The genus Ambrysus Stål is a species-rich genus in which multiple species groups have been proposed, including the North American Ambrysus signoreti Stål complex. The new Mexican species Ambrysus altiplanus Reynoso n. sp., which belongs to the A. signoreti complex, is described and illustrated, bringing the total number of described species of Ambrysus to 67. Also, new state records are reported for three species of the same complex, two of which are endemic to Mexico.

Aprendizajes Clave en el marco del Nuevo Modelo Educativo mexicano / Key Learning in the framework of the New Mexican Educational Model

Este artículo pone al centro del debate el concepto de aprendizajes clave para la educación integral y hace una descripción somera sobre su conceptualización, su planteamiento curricular y su relación con la sociedad del conocimiento con el propósito de brindar un acercamiento a los docentes sobre este enfoque educativo. Para su abordaje, se empleó la investigación documental que permitió caracterizar los aprendizajes clave, el planteamiento pedagógico, metodológico y didáctico que se deriva de sus alcances epistemológicos. Aborda también, el enfoque socioformativo como un nuevo paradigma pedagógico que pone al servicio de los docentes, herramientas y estrategias didácticas para conducir el proceso de enseñanza bajo ambientes interactivos, reflexivos, críticos e inclusivos que pueden favorecer el desarrollo integral de los estudiantes. Los resultados aluden que los aprendizajes clave, expresan los saberes fundamentales o esenciales que los estudiantes deben aprehender en término de aprendizajes esperados para lograr el desarrollo de competencias integrales.

Estimated effects of the implementation of the Mexican warning labels regulation on the use of health and nutrition claims on packaged foods

Background The use of health and nutrition claims on front-of-pack labels may impact consumers’ food choices; therefore, many countries have established regulations to avoid misinformation. This study describes the prevalence of health and nutrition claims on the front-of-pack of food products in retail stores in Mexico and estimate the potential effects of the Official Mexican Standards 051 (new regulation that includes specifications for implementing warning labels and other packaging elements such as health and nutrition claims on less healthy foods) on the prevalence of these claims. Methods This is a cross-sectional study in which health and nutrition claims, nutrition information panels, and the list of ingredients of all foods and beverages available in the main retail stores in Mexico City were collected. The products were grouped by level of processing according to the NOVA food system classification. Claims were classified using the internationally harmonized INFORMAS taxonomy. According to the criteria of the new Mexican front-of-pack labelling regulation, the effect on the reduction on the prevalence of health and nutrition claims was estimated by type of food and by energy and nutrients of concern thresholds. Results Of 17,264 products, 33.8% displayed nutrition claims and 3.4% health claims. In total, 80.8% of all products in the Mexican market were classified as “less healthy”; 48.2% of products had excess calories, 44.6% had excess sodium, and 40.7% excess free sugars. The new regulation would prevent 39.4% of products with claims from displaying health and nutrition claims (P < 0.001); the largest reduction is observed for ultra-processed foods (51.1%, P < 0.001). The regulation thresholds that resulted in the largest reduction of claims were calories (OR 0.62, P < 0.001) and non-sugar sweeteners (OR 0.54, P < 0.001). Conclusions The new Mexican front-of-pack labelling regulation will prevent most processed and ultra-processed foods from displaying health and nutrition claims and will potentially improve information on packaging for consumers.