Universidad Autónoma de Tlaxcala
Recent publications
Two new species of Onthophagus Latreille, 1802 from the Pacific Slope of Mexico are described and illustrated: Onthophagus gonzaloi Moctezuma, Hernández & Sánchez-Huerta, sp. nov., and Onthophagus yescaensis Moctezuma, Hernández & Sánchez-Huerta, sp. nov. New records for Onthophagus browni Howden & Cartwright, 1963 from the Mexican states of Jalisco (the southernmost locality known to date) and Zacatecas are provided. urn:lsid:zoobank.org:pub:51AA52C6-41BF-4A8B-9BC9-D78600EDB32E
Intracerebroventricular (ICV) administration of estradiol benzoate (E2B) and progesterone (P) induces intense lordosis behavior in ovariectomized rats primed peripherally with E2B. The present study tested the hypothesis that the Kisspeptin (Kiss) and melanin-concentrating hormone (MCH) pathways regulate female sexual behavior induced by these steroid hormones. In Experiment 1, we tested the relevance of the Kiss pathway by ICV infusion of its inhibitor, kiss-234, before administration of E2B or P in estrogen-primed rats. Lordosis induced by E2B alone or with the addition of P was reduced significantly at 30, 120, and 240 min. In Experiment 2, ICV infusion of MCH 30 min before E2B or P significantly reduced lordosis in rats primed with E2B alone. These data support the hypothesis that the Kiss and MCH pathways, which can release or modulate gonadotropin-releasing hormone (GnRH), are involved in E2B- and P-induced lordosis.
Ecogeographical patterns describe predictable variation in phenotypic traits between ecological communities. For example, high-altitude animals are expected to show elevated hematological values as an adaptation to the lower oxygen pressure. Mountains act like ecological islands and therefore are considered natural laboratories. However, the majority of ecophysiological studies on blood traits lack replication that would allow us to infer if the pattern reported is a local event or whether it is a widespread pattern resulting from larger-scale ecological processes. In lizards, in fact, the increase of hematological values at high altitudes has received mixed support. Here, for the first time, we compare blood traits in lizards along elevational gradients with replication. We tested the repeatability of blood traits in mesquite lizards between different elevations in three different mountains from the Trans-Mexican Volcanic Belt. We measured hematocrit, hemoglobin concentration, mean corpuscular hemoglobin concentration, and erythrocyte size in blood samples of low, medium, and high-elevation lizards. We obtained similar elevational patterns between mountains, but the blood traits differed among mountains. Middle-altitude populations had greater oxygen-carrying capacity than lizards from low and high altitudes. The differences found between mountain systems could be the result of phenotypic plasticity or genetic differentiation as a consequence of abiotic factors not considered.
Deforestation has a large impact on soil fertility, especially on steep slopes, but by applying sustainable management practices, local communities in Oaxaca (Mexico) have tried to avoid the most negative effects on the forest ecosystems they manage. In this study, the characteristics and bacterial community structure were investigated from soil sampled in triplicate (n = 3) with different land use, i.e., arable, natural forest, sustainable managed, and reforested soil. The pH was significantly higher in the arable (6.2) than in the forest soils (≤ 5.3), while the organic matter was > 2 times higher in the natural forest (80.4 g/kg) and sustainable managed soil (86.3 g/kg) than in the arable (36.8 g/kg) and cleared and reforested soil (39.3 g/kg). The higher organic matter content in the first two soils was due to leaf litter, absent in the other soils. The species richness (q = 0), the typical (q = 1) and dominant bacteria (q = 2) were not affected significantly by land use. The beta diversity, however, showed a significant effect of land use on species richness (p = 0.0029). Proteobacteria (40.135%) and Actinobacteria (20.15%) were the dominant bacterial phyla, and Halomonas (14.50%) and the Verrucomicrobia DA101 (3.39%) were the dominant genera. The bacterial communities were highly significantly different in soil with different land use considering the taxonomic level of genus and OTUs (p ≤ 0.003). It was found that the sustainable managed forest provided the local community with sellable wood while maintaining the soil organic matter content, i.e., sequestered C and without altering the bacterial community structure.
Despite recent improvements in computer vision, artificial visual systems’ design is still daunting since an explanation of visual computing algorithms remains elusive. Salient object detection is one problem that is still open due to the difficulty of understanding the brain’s inner workings. Progress in this research area follows the traditional path of hand-made designs using neuroscience knowledge or, more recently, deep learning, a particular branch of machine learning. Recently, a different approach based on genetic programming appeared to enhance handcrafted techniques following two different strategies. The first method follows the idea of combining previous hand-made methods through genetic programming and fuzzy logic. The second approach improves the inner computational structures of basic hand-made models through artificial evolution. This research proposes expanding the artificial dorsal stream using a recent proposal based on symbolic learning to solve salient object detection problems following the second technique. This approach applies the fusion of visual saliency and image segmentation algorithms as a template. The proposed methodology discovers several critical structures in the template through artificial evolution. We present results on a benchmark designed by experts with outstanding results in an extensive comparison with the state of the art, including classical methods and deep learning approaches to highlight the importance of symbolic learning in visual saliency.
Plant-associated microorganisms that affect plant development, their composition, and their functionality are determined by the host, soil conditions, and agricultural practices. How agricultural practices affect the rhizosphere microbiome has been well studied, but less is known about how they might affect plant endophytes. In this study, the metagenomic DNA from the rhizosphere and endophyte communities of root and stem of maize plants was extracted and sequenced with the "diversity arrays technology sequencing," while the bacterial community and functionality (organized by subsystems from general to specific functions) were investigated in crops cultivated with or without tillage and with or without N fertilizer application. Tillage had a small significant effect on the bacterial community in the rhizosphere, but N fertilizer had a highly significant effect on the roots, but not on the rhizosphere or stem. The relative abundance of many bacterial species was significantly different in the roots and stem of fertilized maize plants, but not in the unfertilized ones. The abundance of N cycle genes was affected by N fertilization application, most accentuated in the roots. How these changes in bacterial composition and N genes composition might affect plant development or crop yields has still to be unraveled. IMPORTANCE We investigated the bacterial community structure in the rhizosphere, root, and stem of maize plants cultivated under different agricultural techniques, i.e., with or without N fertilization, and with or without tillage. We found that the bacterial community was defined mostly by the plant compartment and less by agricultural techniques. In the roots, N fertilizer application affected the bacterial community structure, the microbiome functionality, and the abundance of genes involved in the N cycle, but the effect in the rhizosphere and stem was much smaller. Contrary, tillage did not affect the maize microbiome. This study enriches our knowledge about the plant-microbiome system and how N fertilization application affected it.
17β-estradiol (E2) is the natural estrogen with the most significant potential for endocrine disruption in the biota of aquatic ecosystems at trace concentrations. It is, therefore, essential to study treatments for water polluted with E2 that would guarantee its complete elimination and mineralization. Denitrification is a biological process shown to have the capacity to completely bio-degrade drugs, such as ampicillin. This work is aimed to evaluate the biotransformation of 17β-estradiol by employing a denitrifying sludge. The assays performed were: (I) abiotic with 3.5 mg E2-C L −1 and (II) denitrifying with 10 mg CH3COO −-C L −1 as the reference, 10 mg E2-C L −1 as the sole electron donor, and a mixture of (mg L −1) 10 E2-C with 10 CH3COO −-C at C N −1 of 1.1. The E2-C and NO3 −-N consumption efficiencies were greater than 99%, and HCO3 −-C and N2 production yields were close to 1 in all assays. The denitrifying sludge could biodegrade up to 10 mg E2-C L −1 as the sole electron donor and when mixed with 10 mg CH3COO −-C L −1. No intermediate metabolites were generated from the process.
The presence of insoluble aggregates of amyloid β (Aβ) in the form of neuritic plaques (NPs) is one of the main features that define Alzheimer’s disease. Studies have suggested that the accumulation of these peptides in the brain significantly contributes to extensive neuronal loss. Furthermore, the content and distribution of cholesterol in the membrane have been shown to have an important effect on the production and subsequent accumulation of Aβ peptides in the plasma membrane, contributing to dysfunction and neuronal death. The monomeric forms of these membrane-bound peptides undergo several conformational changes, ranging from oligomeric forms to beta-sheet structures, each presenting different levels of toxicity. Aβ peptides can be internalized by particular receptors and trigger changes from Tau phosphorylation to alterations in cognitive function, through dysfunction of the cholinergic system. The goal of this review is to summarize the current knowledge on the role of lipids in Alzheimer’s disease and their relationship with the basal cholinergic system, as well as potential disease-modifying therapies.
The evolutionary dynamics and phylogenetic utility of mitochondrial genomes (mitogenomes) have been of particular interest to systematists and evolutionary biologists. However, certain mitochondrial features, such as the molecular evolution of the control region in insects, remain poorly explored due to technological constraints. Using a combination of long- and short-read sequencing data, we assembled ten complete mitogenomes from ten Hercules beetles. We found large-sized mitogenomes (from 24 to 28 kb), which are among the largest in insects. The variation in genome size can be attributed to copy-number evolution of tandem repeats in the control region. Furthermore, one type of tandem repeat was found flanking the conserved sequence block in the control region. Importantly, such variation, which made up around 30% of the size of the mitogenome, may only become detectable should long-read sequencing technology be applied. We also found that, although different mitochondrial loci often inferred different phylogenetic histories, none of the mitochondrial loci statistically reject a concatenated mitochondrial phylogeny, supporting the hypothesis that all mitochondrial loci share a single genealogical history. We on the other hand reported statistical support for mito-nuclear phylogenetic discordance in 50% of mitochondrial loci. We argue that long-read DNA sequencing should become a standard application in the rapidly growing field of mitogenome sequencing. Furthermore, mitochondrial gene trees may differ even though they share a common genealogical history, and ND loci could be better candidates for phylogenetics than the commonly used COX1.
Oxidative stress plays an important role in vascular complications observed in patients with obesity and Type 2 Diabetes (T2D). Xanthine oxidase (XO) breaks down purine nucleotides into uric acid and contributes to the production of reactive oxygen species (ROS). However, the relationship between XO activity and glucose homeostasis in T2D subjects with obesity is unclear. We hypothesized that disordered glucose levels are associated with serum XO activity in overweight women and men with T2D and without hyperuricemia. We studied serum XO activity in women and men with and without T2D. Our results show that serum XO activity was greater in T2D patients with body mass index (BMI) ≥ 25 kg/m2 than in those with BMI < 25 kg/m2 (p < 0.0001). Sex-based comparative analyses of overweight T2D patients showed that serum XO activity correlated with homeostasis model assessment of β-cell function (HOMA-β), fasting plasma glucose (FPG), and hemoglobin A1C in overweight T2D women but not in overweight T2D men. In addition, as compared to overweight T2D men, women had higher high-sensitivity C-reactive protein (hs-CRP) levels. However, overweight T2D men had higher XO activity and uric acid levels than women. Our results suggest that XO activity is higher in overweight T2D patients, especially in men, but is more sensitive to disordered glucose levels in overweight women with T2D.
Robotics in logistics consists on a momentous incorporation of robotic systems in the physical processes of logistics. Nowadays, robotic systems have been introduced in the tasks of storage, loading, unloading, packaging and picking. In this paper, a robotical implementation for planning of collision-free logistical paths using the Resistive Grid Path Planning Methodology (RGPPM) algorithm is introduced herein. As an innovative and CPU-saving path planning technique based on resistive grids, the RGPPM algorithm has been evaluated to determine the feasibility and potential in planning collision-free logistical routes for robotic systems. Experimental results reveal that the robotical implementation of the RGPPM algorithm has been carried out with successful logistical paths for different kind of scenarios.
Phanaeus violae Halffter, Moctezuma, and Nogueira, new species is described, illustrated, and compared to the related species Phanaeus damocles Harold and Phanaeus palliatus Sturm. Locality data are provided for the three species. A modification to a previously published key to species of the Phanaeus quadridens species-group is given.
El artículo tiene como objetivo conocer y analizar la gestión educativa de los Consejos Técnicos Escolares (CTE) en el estado de Tlaxcala, México, durante la pandemia de Covid-19. El estudio se sustenta en el diseño de la estrategia que la Dirección General de Gestión Escolar y Enfoque Territorial (DGGEyET) de la Secretaría de Educación Pública (SEP) federal realiza en el país. La metodología que se empleó fue cuantitativa descriptiva transversal con una muestra de 44 colectivos escolares de los diferentes niveles y modalidades educativas de aquellos cuyas sesiones se presenció durante el ciclo escolar 2020-2021. Los resultados se presentan mediante los promedios de las ponderaciones obtenidas de los CTE. Los hallazgos identificados reflejan la evolución y retos en los procesos de la gestión educativa a distancia y el alineamiento a las disposiciones de política educativa durante la crisis sanitaria.
The increasing influence of human activity and industrialization has adversely impacted the environment via pollution with organic contaminants, which are minimally soluble in water. These hydrophobic organopollutants may be present in sediment, water or biota and have created concern due to their toxic effects in mammals. The ability of microorganisms to degrade pollutants makes their use the most effective, inexpensive and ecofriendly method for environmental remediation. Microorganisms have the ability to produce natural surfactants (biosurfactants) that increase the bioavailability of hydrophobic organopollutants, which enables their use as carbon and energy sources. Due to microbial diversity in production, and the biodegradability, nontoxicity, stability and specific activity of the surfactants, the use of microbial surfactants has the potential to overcome problems associated with contamination by hydrophobic organopollutants. This review provides an overview of the current state of knowledge regarding microbial surfactant production, mode of action in the biodegradation of hydrophobic organopollutants and biosynthetic pathways as well as their applications using emergent strategy tools to remove organopollutants from the environment. It is also specified for the first time that biosurfactants are produced either as growth-associated products or secondary metabolites, and are produced in different amounts by a wide range of microorganisms.
Although individuals with schizophrenia typically present deficits in social interaction, little is known about the quality of their parent–infant interactions. In the present study, we assessed the behavioral effects of neonatal ventral hippocampus lesion (nVHL) in female rats (nVHL is known to induce schizophrenia‐like deficits in males). Sexually naïve adult nVHL or sham female rats received cognitive and social tests, and their maternal behavior was observed in independent groups of adult nVHL and sham rats on postpartum days 2, 6, and 12. Compared to Sham females, naïve nVHL rats displayed elevated locomotor activity, less social interaction, and disrupted habituation of the acoustic startle response (ASR), while dorsal immobility (a defensive behavioral response) and prepulse inhibition of ASR were not affected. Although all nVHL mothers retrieved their pups, adopted the crouching posture, and nursed them, they showed disturbances in the display of pup body licking and nest building. Furthermore, a high proportion of nVHL mothers displayed atypical retrieval of pups and re‐retrieving of pups, atypical nest‐building, excavation, and cannibalism, as well a high level of these behaviors. These data indicate that cognition, locomotor activity, and maternal care is disrupted in nVHL female, suggesting disturbances in mesocorticolimbic dopaminergic systems and/or in social cognition.
Body maintenance costs are often considered a proxy for performance in fitness traits. Maintenance energy requirements are measured as minimal metabolic rate of inactive, postabsorptive individuals in the laboratory. For mountain-dwelling species, translocation to the laboratory often means that they are also moved to another elevation. Due to physiological adaptations to local oxygen pressure, rapid elevational change can alter metabolic rate and translocation may result in erroneous estimates of body maintenance costs. In this study, we measured resting metabolic rate (RMR) of three populations of the Mesquite lizard (Sceloporus grammicus, Wiegmann 1828) at their native elevations (i.e., 2600, 3200 and 4100 m). Our results showed that at native elevations, mass specific RMR of lizards from the high elevation population (4100 m) did not differ from the RMR of the other populations (i.e., 2600 and 3200 m), whereas the lizards from the low elevation (2600 m) had lower RMR than those from the intermediate population. These results differ from a previous study in which the RMR of lizards from the same populations were reported to increase with native elevation when translocated and measured at an intermediate elevation. Hence, our results show that translocation in elevation can affect metabolic measures. We caution researchers that changes in elevation may preclude accurate measures of RMR in some animals and may therefore incorrectly predict performance of fitness-related traits.
Rabbit maternal behavior (MB) impacts meat and fur production on the farm, survival of the species in the wild, and pet welfare. Specific characteristics of rabbit MB (i.e., three-step nest building process; single, brief, daily nursing bout) have been used as models for exploring particular themes in neuroscience, like obsessive-compulsive actions, circadian rhythms, and cognition. Particular hormonal combinations regulate nest building by acting on brain regions controlling MB in other mammals. Nonhormonal factors like type of lodging and the doe's social rank influence nursing and milk production. The concurrency of pregnancy and lactation, the display of nonselective nursing, and the rapid growth of altricial young - despite a minimal effort of maternal care - have prompted the study of mother-young affiliation, neurodevelopment, and weaning. Neurohormonal mechanisms, common to other mammals, plus additional strategies (perhaps unique to rabbits) allow the efficient, adaptive display of MB in multiple settings.
To investigate whether mother and sibling interactions during the preweaning period influence the histological and electrophysiological characteristics of the sensory sural nerve (SUn) in the adult rat, litters composed of 1, 3, 6, 9, and 12 male pups (P) were formed and the pups routinely weighed until postnatal day 60 (PND60). At PND9, 3P and 6P litters showed greater body weight than pups without siblings or from 9P or 12P litters, and such differences in weight were maintained until adulthood. Analysis of maternal licking at PND8 and 9 showed that pups from large litters received fewer licks than pups from small size litters. At PND60, SUn of rats from 6P and 9P litters had greater compound action potential (CAP) amplitude and a higher proportion of axons with large myelin thickness than nerves from rats of 1P, 3P, or 12P litters. SUn of heaviest rats from 9P and 12P litters had greater CAP area and myelination than the lightest rats from the same litters. We propose that a complex interplay of sensory, social, and nutritional factors arising from mother and littermate interactions during the preweaning period influence myelination and the propagation of action potentials in the SUn of adult rats.
Disorders of perineal musculature, as the bulbospongiosus muscle (Bsm), could cause male sexual dysfunctions, such as premature ejaculation. We determined the effect of sucrose water consumption during pregnancy-lactation and postweaning on the Bsm frequency during the urethrogenital reflex (UGR), which simulates erection and ejaculation, in adult male rat offspring. Twelve female rats were mated and grouped in control mothers consumed tap-water and sucrose mothers consumed sucrose-water during pregnancy-lactation. Male pups were weaned and assigned into four groups (n = 12 each): those from control mothers who continued drinking tap-water (CM–CO group) or sucrose-water (CM–SO group) until adult life, and those from sucrose mothers who drank tap-water (SM–CO group) or continued drinking sucrose-water (SM–SO group) until adult life. We analyzed Bsm electromyograms during penile stimulation and UGR in male rat offspring (n = 6; each group). We analyzed the frequency of the Bsm through Fourier Transform. Other males rat offspring (n = 6; each group) were killed and was collected the Bsm and processed into histological analysis. Two-way ANOVA followed by posthoc tests, considering P ≤ 0.05 significant difference. The results showed that the consumption of sucrose-water during critical stages increases significantly the frequency of Bsm during the UGR of the CM-SO, SM-CO and SM-SO. Also, the consumption of high-sugar diets changes the morphological arrangement of the Bsm. Our results suggest that a combination of a high-sugar diet during pregnancy, lactation, and post-weaning changes the Bsm morpho-physiology and could cause male sexual dysfunctions.
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534 members
Veronica Reyes-Meza
  • Centro Tlaxcala de Biología de la conducta
Amando Bautista
  • Centro Tlaxcala de Biología de la Conducta
Victor Moctezuma
  • Centro Tlaxcala de Biología de la Conducta
Carlos Lara
  • Centro de Investigación en Ciencias Biológicas
Yendi E Navarro-Noya
  • Centro de Investigación en Ciencias Biológicas