The objective of this work is to evaluate the potential use of gold and silver tailings (GST) as Supplementary Cementitious Material (SCM). Physical, chemical, and mineralogical characteristics of GST were evaluated. Based on the initial characterization of GST, mechanical and thermal activation were proposed to improve GST reactivity. The effect of both activation processes in crystallite size and Full Width at Half Maximum (FWHM) were determined by X-Ray Diffraction (XRD). Mechanical activation at 140 min of milling and thermal activation at 1000 °C allowed the most significant reduction of crystallite size and particle size. The unconfined compressive strength (UCS) and the Strength Activity Index (SAI) were tested in mortar cubes partially substituted with activated tailings. Results showed that 10, 15, and 20 wt% substitution with activated tailings exceed the 75% SAI according to ASTM standards. Micrographs showed the presence of a calcium silicate hydrate (C-S-H) gel rich matrix in experimental mortars.

The genus Hamadryas has a neotropical distribution. In 1983, the subspecies H. glauconome grisea from Mexico was recognized with subtle and subjective differences in color, size and distribution and limited to the northwest. Since then, there has been a debate about whether it is a different lineage from H. glauconome because adult-stage morphology studies have not found significant differences. This study aims to delimitate H. g. glauconome and H. g. grisea lineages with two sources of evidence: ecological and molecular—the former through ecological niche modeling using the accessible area for the species and estimating the minimum volume ellipsoid overlapping as a fundamental niche using occurrences databases. The molecular evidence is found through the methods of phylogenetic inference and the generalized mixed yule coalescent approach, using sequences of cytochrome oxidase I. Ecological and molecular evidence suggest that H. g. grisea is a different lineage from H. glauconome. Also, molecular evidence of a third lineage from the south of Texas needs further study. This study suggests that different evidence should be provided when morphology is not enough for delimiting species, especially in recently diverged species. Furthermore, the H. g. grisea cytochrome oxidase I sequence (658 bp) is published for the first time.

Computational Fluid Dynamics (CFD) software is well known for its application feasibility as well as reliable results in modeling electrochemical, thermal, and fluid transport processes. CFD has been used to investigate the phenomena involved in the operation of fuel cells, providing a large amount of data that must be analyzed to improve cell efficiency. This paper aims to demonstrate that programming can be used in the post-processing phase, using scripts in Python language to automate data analysis, based on the results of the simulation of oxygen transport in Polymer Electrolyte Membrane Fuel Cell (PEMFC). The OpenFOAM open-source CFD tool solved the fluid governing equations through the SIMPLE algorithm of three proposed Gas Diffusion Layer (GDL) case studies. In this work, an algorithm is presented to extract, compute and visualize the post-process results, supporting the GDL selection.

This article provides an overview of the work reported in the past decade in the field of microfluidic fuel cells. To develop appropriate research, the most commonly used electrocatalytic materials were considered and a new classification was proposed based on their nature: abiotic, hybrid, or biological. This classification allowed the authors to discern the information collected. In this sense, the types of electrocatalysts used for the oxidation of the most common fuels in different environments, such as glucose, ethanol, methanol, glycerol, and lactate, were presented. There are several phenomena presented in this article. This information gives an overview of where research is heading in the field of materials for electrocatalysis, regardless of the fuel used in the microfluidic fuel cell: the synthesis of abiotic and biological materials to obtain hybrid materials that allow the use of the best properties of each material.

Acoustic signals play a crucial role in communication among animals, particularly in dolphins. Signature whistles, one of their most extensively studied vocalizations, enable dolphins to convey their identity to conspecifics through individually distinct whistle contours. However, it remains unclear whether rough-toothed dolphins (Steno bredanensis) also produce signature whistles with individually identifying contours and, if so, whether they are associated with stress and poor health, such as in bottlenose dolphins. To bridge this knowledge gap, we recorded sounds emitted by a live-stranded rough-toothed dolphin during its rehabilitation in May 2017 at Isla Mujeres, Quintana Roo, Mexico. We assessed if the dolphin produced a signature whistle and whether whistle rate, inter-whistle interval, mean low and high frequencies, and blood chemistry measures, changed significantly over time. While isolated from conspecifics during rehabilitation, the dolphin generated a single, repeated, and stereotyped whistle contour that met the previously established SIGnature IDentification criteria for signature whistle emissions for bottlenose dolphins. Whistle characteristics varied over the 11 recording days: whistle rate and inter-whistle interval significantly decreased over time; the number of whistles with preceding echolocation click trains decreased over time; and mean low and high frequencies changed over recording days. We conclude that this rough-toothed dolphin possessed what resembles a signature whistle contour, and the emission of this contour underwent significant changes throughout the rehabilitation process. While our study presents evidence of a single rough-toothed dolphin producing a signature whistle, further research is necessary to determine whether this vocal behavior is prevalent across the species.

Most paleoecological investigations use different biotic or abiotic proxies for climate and environmental reconstructions. Although fossil pollen is one of the most used biological proxies, Non-Pollen Palynomorphs (NPPs), especially fungal spores and tissues, have an underestimated potential to infer local and regional climate dynamics. This dataset describes the most common Non-pollen palynomorphs of fungal origin from mangrove sediments in the Caribbean Sea, southeastern Mexico. A detailed descriptive Atlas is presented, with light micrographs taken from routine pollen slides in paleoecological reconstructions. Microphotographs were included to facilitate their identification. A total of 59 spores, 4 tissues, 2 hyphae, and 11 unidentified fungal palynomorphs are described.

Two new species of Travisiidae, Travisia satunensis sp. nov. and T. thailandensis sp. nov., were collected from different locations in Thailand waters. Travisia satunensis sp. nov. was collected in the Andaman Sea, at 214 m water depths. Travisia thailandensis sp. nov. was collected from offshore petroleum concession areas in the Gulf of Thailand, at 5080 m water depths. Travisia satunensis sp. nov. differs from all other species by having branched annulated branchiae on chaetigers 235, each annulated with a single filament, chaetae throughout the body and pygidium with 10 anal cirri, six digitiform and four short cirri, alternately arranged. Travisia thailandensis sp. nov. differs from all other species by having 21 pairs of cirriform, annulated branchiae from chaetiger 2, a mid-ventral groove along body, two last segments achaetous, and nephridiopores on chaetigers 714. A key for Travisia species from the Indo-Pacific region is also provided.

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) have shown great promise in lacustrine temperature reconstructions across different continents. While brGDGTs have been reported from many different regions and global brGDGT-temperature calibrations have been developed with various methods, southern North America remains an understudied area with little available data. In this study, we analyzed 101 lake surface sediment samples across Mexico and Central America and compared their distributions with those in other lacustrine systems. Nine major brGDGTs were found in all samples. We investigated the relationships between the distribution of the fractional abundances of the nine major brGDGTs and temperature and developed regional calibrations for Mean Annual Temperature using three different approaches, including a novel machine learning method – Ridge Regression. All the regional calibrations provide similar results with very close error ranges (RMSE = 3.1 °C). The majority of global brGDGT-temperature calibrations tend to reconstruct lower temperatures when it is below 15 °C. Interestingly, regional brGDGT calibrations appear to reduce the “cold bias”, but the various global and regional calibrations tested here are not significantly different in their predictive capability.

This paper presents the structural, magnetic properties, and spin moment cancelation phenomenon of the zirconium oxide with a gradual change of zirconium for Iridium. The density functional theory (DFT) is shown to be a key feature of magnetic properties of solid materials treatment. It is shown that a small adjustment of the spin moment (less than 6%) is allowed. The Zr1-xIrxO2 crystal structure deformation leads to a magnetic compensation that occurs at x=0.06. Spin and orbital moments behaviors are discussed. The stability of the alloy compounds is confirmed by energy calculations. The material presents ferromagnetic stability and an indirect exchange coupling with a hybridization effect that permitted the evolution from a non-magnetic to a host material with magnetic properties. The Ir orbitals are set at the Fermi level and are spin polarized which indicates a half metallic behavior then makes the material a good candidate for spintronics’ applications.