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The objective of this study is to investigate the drying kinetics of fruit and vegetable peel biowaste using a sustainable technique as a key-pretreatment for its conversion into useful feedstock. Biowaste represents a missed potential source of bioenergy and bioproducts, but moisture removal is required, and conventional drying methods are expensive since they require great quantity of energy supplied, almost always, by a non-renewable energy. In this study six batches with the same quantity of biowaste, and heterogeneous physical composition were dried under open-sun conditions. We evaluated the influence of the interaction between drying area and the initial moisture content on drying rate. Eight semi-theoretical models were fitted using Levenberg-Marquardt algorithm to predict drying rate, and their accuracy was assessed through goodness-of-fit tests. Maximum moisture content to preserve biomass (10%) was reached on 5 th day and the equilibrium on 16 th day of drying. According to goodness-of-fit test ( R 2  = 0.999, χ 2  = 4.666 × 10 -5 , RMSE = 0.00683) the best model to predict drying rate was Two-term model. The mathematical model obtained from Fick's second law is reliable to predict drying kinetics, R 2 (0.9648 ± 0.0106); despite the variation between drying area and initial moisture content. Kruskal-Wallis test showed that drying rates between batches are not significantly different ( p  = 0.639; 0.05); nor effective diffusion coefficient ( D eff  = 4.97 × 10 -11   ±  0.3491 × 10 -11 ), ( p  = 0.723; 0.05). The study of drying kinetics is crucial for selecting the optimal biowaste treatment based on its generation context. This could enable its use as feedstock for bioproduct or bioenergy production, thereby reducing waste accumulation in landfills and environmental impact., Competing Interests: The authors declare there are no competing interests., (©2024 Barajas Godoy et al.)

Fireflies are charismatic and conspicuous animals that often evoke childhood memories, which make firefly watching an emotional and even transformative experience. Citizen science projects have the potential to enhance transformative interactions with nature. Like many insects, firefly populations are declining due to land-use change, urbanization and watershed pollution, but ecological data for this group is scarce, particularly in Mexico. Virtual Citizen Science (VCS) initiatives can serve as a scientific instrument, yield reliable and relevant scientific data, and may also offer a platform to promote broader educational outcomes. We established a VCS project to document fireflies through a Facebook page named Buscando Luciernagas with the following hashtag in every post #veobrillar in 2015. After seven years we complied the gathered data and analyzed the results. We had 647 reports in total, with strong fluctuations from year to year that were correlated with the number of posts and publicity we made each year. The largest number of sightings (319) occurred in 2021, coinciding with a change in our reporting format. Most of the reports came from central Mexico (91.5%), but we had reports from eight states and also received some international reports from nine different countries. Fireflies were most frequently seen in habitats characterized as grasslands (35%) or forests (27%), followed by gardens (17%), vacant lots (9%) and parks (5%) but also paved areas and agricultural lands were reported (3% each). Most citizen scientists reported few fireflies, 1-5 individuals (31%) while only 11% reported more than 50 fireflies per sighting. Our study can serve as a preliminary approach to explore more focused research areas in the future. For example, in areas with no sightings, we could reach out to specific local people to corroborate that there are no fireflies in the region, or in areas with high sightings we could promote conservation measures. Notably, we found it intriguing to discover numerous sightings of fireflies in urban areas, which could offer a potential avenue for further research in urban ecology., Competing Interests: The authors declare that they have no competing interests., (© 2024 del-Val et al.)

Background: Obesity leads to an elevated risk of developing gastrointestinal disease such as gastric ulcers. Callistemon citrinus leaf extract has shown antioxidant, antimicrobial, hepatoprotective, and chemoprotective effects against colon cancer. The aim of this study is to evaluate the gastroprotective effect of C. citrinus leaf extract on indomethacin-induced gastric ulcers in obese rats., Methods: Gastric ulcers were induced in female obese Wistar rats using a single oral dose of indomethacin (IND). In the first stage, the rats were fed with a high fat sugar diet (HFSD) for 15 weeks to induce obesity and, at the same time, the diet of the other group of animals included daily administration of ethanolic C. citrinus leaf extract (250 mg/kg) in addition to HFSD. In the second stage, gastric ulcers were induced with IND (30 mg/kg). The gastroprotective activity of C. citrinus , the inflammatory enzyme activities, and cytokines in the stomach were determined., Results: C. citrinus produced a reduction of gastric lesions caused by IND. Myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) activities also decreased. Although inflammatory biomarkers such as TNFα, IL-6, AOPP, and leptin were significantly decreased by C. citrinus , adiponectin levels increased. Moreover, C. citrinus decreased weight gain and morphological and biochemical parameters., Conclusion: The use of indomethacin in rats fed with a high fat-sugar diet increased gastric ulcers. Gastroprotective effect of C. citrinus in obese rats is attributed to the reduction of pro-inflammatory cytokines and the inflammatory enzymes., Competing Interests: The authors declare that they have no competing interests., (© 2024 Piñón-Simental et al.)

Coleopterans are the most diverse animal group on Earth and constitute good indicators of environmental change. However, little information is available about Coleopteran communities' responses to disturbance and land-use change. Tropical dry forests have undergone especially extensive anthropogenic impacts in the past decades. This has led to mosaic landscapes consisting of areas of primary forest surrounded by pastures, agricultural fields and secondary forests, which negatively impacts many taxonomic groups. However, such impacts have not been assessed for most arthropod groups. In this work, we compared the abundance, richness and diversity of Coleopteran morphospecies in four different successional stages in a tropical dry forest in western Mexico, to answer the question: How do Coleopteran assemblages associate with vegetation change over the course of forest succession? In addition, we assessed the family composition and trophic guilds for the four successional stages. We found 971 Coleopterans belonging to 107 morphospecies distributed in 28 families. Coleopteran abundance and richness were greatest for pastures than for latter successional stages, and the most abundant family was Chrysomelidae, with 29% of the individuals. Herbivores were the most abundant guild, accounting for 57% of the individuals, followed by predators (22%) and saprophages (21%) beetles. Given the high diversity and richness found throughout the successional chronosequence of the studied tropical dry forest, in order to have the maximum number of species associated with tropical dry forests, large tracts of forest should be preserved so that successional dynamics are able to occur naturally., Competing Interests: The authors declare that they have no competing interests., (© 2023 Díaz-Álvarez et al.)

Background: Mining deposits often contain high levels of toxic elements such as mercury (Hg) and arsenic (As) representing strong environmental hazards. The purpose of this study was the isolation for plant growth promoting bacteria (PGPBs) that can improve phytoremediation of such mine waste deposits., Methods: We isolated native soil bacteria from the rhizosphere of plants of mine waste deposits and agricultural land that was previously mine tailings from Tlalpujahua Michoacán, Mexico, and were identified by their fatty acid profile according to the MIDI Sherlock system. Plant growth promoting traits of all bacterial isolates were examined including production of 3-indoleacetic acid (IAA), siderophores, biofilm formation, and phosphate solubilization. Finally, the response of selected bacteria to mercury and arsenic was examined an in-vitro assay., Results: A total 99 bacterial strains were isolated and 48 identified, representing 34 species belonging to 23 genera. Sixty six percent of the isolates produced IAA of which Pseudomonas fluorescens TL97 produced the most. Herbaspirillum huttiense TL36 performed best in terms of phosphate solubilization and production of siderophores. In terms of biofilm formation, Bacillus atrophaeus TL76 was the best., Discussion: Most of the bacteria isolates showed high level of tolerance to the arsenic (as HAsNa 2 O 4 and AsNaO 2 ), whereas most isolates were susceptible to HgCl 2 . Three of the selected bacteria with PGP traits Herbispirillum huttiense TL36, Klebsiella oxytoca TL49 and Rhizobium radiobacter TL52 were also tolerant to high concentrations of mercury chloride, this might could be used for restoring or phytoremediating the adverse environmental conditions present in mine waste deposits., Competing Interests: The authors declare that they have no competing interests., (© 2023 Rojas-Solis et al.)

The niche comprises the set of abiotic and biotic environmental conditions in which a species can live. Consequently, those species that present broader niches are expected to be more tolerant to changes in climatic variations than those species that present reduced niches. In this study, we estimate the amplitude of the climatic niche of fourteen species of rattlesnakes of the genus Crotalus to evaluate whether those species that present broader niches are less susceptible to the loss of climatically suitable zones due to the projected climate change for the time period 2021-2040. Our results suggest that for the species under study, the breadth of the niche is not a factor that determines their vulnerability to climatic variations. However, 71.4% of the species will experience increasingly inadequate habitat conditions, mainly due to the increase in temperature and the contribution that this variable has in the creation of climatically suitable zones for most of these species., Competing Interests: The authors declare there are no competing interests., (©2022 Becerra-López et al.)

Teleost fish are the most diverse group of extant vertebrates and have varied digestive anatomical structures and strategies, suggesting they also possess an array of different host-microbiota interactions. Differences in fish gut microbiota have been shown to affect host development, the process of gut colonization, and the outcomes of gene-environment or immune system-microbiota interactions. There is generally a lack of studies on the digestive mechanisms and microbiota of agastric short-intestine fish however, meaning that we do not understand how changes in gut microbial diversity might influence the health of these types of fish. To help fill these gaps in knowledge, we decided to study the Mexican pike silverside ( Chirostoma estor ) which has a simplified alimentary canal (agastric, short-intestine, 0.7 gut relative length) to observe the diversity and metabolic potential of its intestinal microbiota. We characterized gut microbial populations using high-throughput sequencing of the V3 region in bacterial 16S rRNA genes while searching for population shifts resulting associated with fish development in different environments and cultivation methods. Microbiota samples were taken from the digesta, anterior and posterior intestine (the three different intestinal components) of fish that grew wild in a lake, that were cultivated in indoor tanks, or that were raised in outdoor ponds. Gut microbial diversity was significantly higher in wild fish than in cultivated fish, suggesting a loss of diversity when fish are raised in controlled environments. The most abundant phyla observed in these experiments were Firmicutes and Proteobacteria, particularly of the genera Mycoplasma , Staphylococcus , Spiroplasma , and Aeromonas . Of the 14,161 OTUs observed in this experiment, 133 were found in all groups, and 17 of these, belonging to Acinetobacter , Aeromonas , Pseudomonas , and Spiroplasma genera, were found in all samples suggesting the existence of a core C. estor microbiome. Functional metagenomic prediction of bacterial ecological functions using PICRUSt2 suggested that different intestinal components select for functionally distinct microbial populations with variation in pathways related to the metabolism of amino acids, vitamins, cofactors, and energy. Our results provide, for the first time, information on the bacterial populations present in an agastric, short-gut teleost with commercial potential and show that controlled cultivation of this fish reduces the diversity of its intestinal microbiota., Competing Interests: The authors declare there are no competing interests., (©2022 Amillano-Cisneros et al.)

Background: Alkamides are plant-specific bioactive molecules. They are low molecular weight N-substituted α-unsaturated acyl amides that display biological explicit activities in different organisms from bacteria, fungi, insects to mammals and plants. The acyl chain has been proposed to be biosynthesized from a fatty acid; however, this has not been demonstrated yet. Heliopsis longipes (Asteraceae) accumulates in root a C10 alkamide called affinin in its roots, but not in leaves. The closely related species Heliopsis annua does not produce alkamides. To elucidate the biosynthetic pathway of the alkamides acyl chain, a comparative global gene expression analysis contrasting roots and leaves of both species was performed., Methods: Transcriptomics analysis allowed to identify genes highly expressed in H. longipes roots, but not in tissues and species that do not accumulate alkamides. The first domain searched was the Ketosynthase (KS) domain. The phylogenetic analysis using sequences of the KS domain of FAS and PKS from different organisms, revealed that KS domains of the differentially expressed transcripts in H. longipes roots and the KS domain found in transcripts of Echinacea purpurea , another alkamides producer species, were grouped together with a high bootstrap value of 100%, sharing great similarity. Among the annotated transcripts, we found some coding for the enzymatic domains KS, AT, ACP, DH, OR and TE, which presented higher expression in H. longipes roots than in leaves. The expression level of these genes was further evaluated by qRT-PCR. All unigenes tested showed higher expression in H. longipes roots than in any the other samples. Based on this and considering that the acyl chain of affinin presents unsaturated bonds at even C numbers, we propose a new putative biosynthesis pathway mediated by a four modules polyketide synthase (PKS)., Results: The global gene expression analysis led to the selection of a set of candidate genes involved in the biosynthesis of the acyl chain of affinin, suggesting that it may be performed by a non-iterative, partially reductive, four module type I PKS complex (PKS alk ) previously thought to be absent from the plant kingdom., Competing Interests: The authors declare that they have no competing interests., (© 2020 Buitimea-Cantúa et al.)

Background: The need for energy sources with low greenhouse gas emissions and sustainable production encourages the search for alternative biomass sources. However, the use of biomass fuels faces the problem of storage, transport and lower energy densities. Low-density values can negatively affect energy density, leading to an increase in transportation and storage costs. Use of pellets as alternative biomass source is a way to reduce the volume of biomass by densification, which improves their energy quality. They are produced by diverse biomass resources and mainly from wood materials. In all cases, it is important to evaluate the fuel characteristics, to determine their suitability on the heating system and handling properties., Methods: The present study determines and compares data from proximate analysis, calorific values, physical and mechanical properties of wood pellets produced from the common tropical species Acacia wrightii , Ebenopsis ebano and Havardia pallens . Data were obtained from pellets produced from each species chips collected from an experimental plantation and analyzed through ANOVA and Kruskal-Wallis test at 0.05 significance level., Results: The results of diameter, length and length/diameter ratio didn't show statistical differences ( p  > 0.05) among species. Acacia wrightii showed the highest density (1.2 g/cm 3 ). Values on weight retained and compression test showed statistical differences ( p  = 0.05) among species. Havardia pallens was more resistant to compression strength than A. wrightii and Ebenopsis ebano . Statistical differences ( p  < 0.01) were also observed for the volatile matter and calorific value. E. ebano has the lowest volatile matter (72%), highest calorific value (19.6 MJ/kg) as well as the fixed carbon (21%)., Discussion: The pellets of the species studied have a high energy density, which makes them suitable for both commercial and industrial heating applications.A pellet with low compression resistance tends to disintegrate easily, due to moisture adsorption. The percentages obtained for the resistance index were higher than 97.5%, showing that the pellets studied are high-quality biofuels. Proximate analysis values also indicate good combustion parameters. Pellets of Acacia wrightii and Ebenopsis ebano are the more favorable raw material sources for energy purposes because of their high density, calorific value, low ash content and they also met majority of the international quality parameters., Competing Interests: The authors declare there are no competing interests.

The Indo-West Pacific (IWP) coral-reef damselfish Neopomacentrus cyanomos is well established across the south-west Gulf of Mexico (SwGoMx). Comparisons of mtDNA sequences of the SwGoMx population with those from conspecifics from 16 sites scattered across its native geographic range show that the SwGoMx population is derived from two of four native lineages: one from the north-west Pacific Ocean, the other from the northern Indian Ocean. Three hypotheses address how this species was introduced to the SwGoMX: (1) aquarium release; (2) borne by cargo-ship; and (3) carried by offshore petroleum platform (petro-platform). The first is unlikely because this species rarely features in the aquarium trade, and " N. cyanomos " traded to the USA from the sole IWP source we are aware of are a misidentified congener, N. taeniurus . The second hypothesis is unlikely because shipping has not been associated with the introduction of alien damselfishes, there is little international shipping between the IWP and the SwGoMx, and voyages between those areas would be lengthy and along environmentally unfavorable routes. Various lines of evidence support the third hypothesis: (i) bio-fouled petro-platforms represent artificial reefs that can sustain large and diverse populations of tropical reef-fishes, including N. cyanomos in the SwGoMx; (ii) relocation of such platforms has been implicated in trans-oceanic introductions leading to establishment of non-native populations of such fishes; and (iii) genetic characteristics of the SwGoMx population indicate that it was established by a large and diverse group of founders drawn from the IWP regions where many petro-platforms currently in the SwGoMx and other Atlantic offshore oilfields originated., Competing Interests: D. Ross Robertson is an Academic Editor for PeerJ.