Universidad Nacional Experimental del Táchira

Outdoor mobile robots must navigate uneven terrains with obstacles that sometimes cannot be avoided; therefore, strategies have been developed for robots to overcome them. In most cases, these strategies have been modeled considering movement over horizontal surfaces and with the robot positioned directly in front of the obstacle, but this idealization does not occur in most real cases. Therefore, this article describes a strategy for obstacle overcoming, useful when the robot faces obstacles on inclined terrains and at an oblique angle relative to the robot’s trajectory, considering rollover stability during the process, based on the reaction force criterion. This strategy can be used by mobile robots with wheels and an articulated arm whose end effector can contact the ground, and it consists of a sequence of standard movements that include the use of the arm, whose variable location was defined through a system developed using fuzzy logic. The designed strategy was validated through simulations and then implemented on the Lázaro robot, verifying its effectiveness through experimental tests. With it, the robot can overcome obstacles such as steps, ramps, and ditches from any position; additionally, it increased the ability to overcome obstacles with a height close to twice the radius of the robot’s wheels.

Resumen Investigación de aplicación didáctica, interpretativa y descriptiva con el propósito de obtener una aproximación a los conocimientos previos de estudiantes de Ingeniería Agronómica, acerca de las principales técnicas de la Biología Molecular, con la finalidad de recabar información relevante para construcción de Unidades Educacionales Potencialmente Significativas con auxilio en laboratorios virtuales y remotos. En la evaluación de los mapas conceptuales se siguió la propuesta del Método de Puntuación Unitaria y el Índice General de Construcción Integrativa de Significados. El análisis de las informaciones generó contribuciones en dos direcciones: la primera en el acercamiento a los conceptos inclusores, su organización y posibles niveles de complejidad, así como el nivel de construcción integrativa de significados de partida de cada uno de los estudiantes; la segunda, en la utilización de dichas concepciones en el proceso de construcción de futuras estrategias de facilitación de Aprendizaje Significativo.

Background Dysfunctional allostatic-interoception, altered processing of bodily signals in response to environmental demands, occurs in behavioural-variant frontotemporal dementia (bvFTD) patients. Previous research has not investigated the dynamic nature of interoception using methods like intrinsic neural timescales. We hypothesised that longer intrinsic neural timescales of interoception would occur in bvFTD patients, evidencing dysfunctional allostatic-interoception. Methods One-hundred and twelve participants (31 bvFTD patients, 35 Alzheimer's disease patients, AD and 46 healthy controls) completed a well-validated task measuring cardiac-interoception and exteroception. Simultaneous EEG and ECG were recorded. Intrinsic neural timescales were measured via the autocorrelation window (ACW) of broadband EEG signals from each heartbeat and a time-lagged version of itself. Spatiotemporal clustering analyses identified clusters with significant between-group differences in each condition. Voxel-based morphometry was used to target the allostatic-interoceptive network. Neuropsychological tests of cognition and social cognition were assessed. Findings In bvFTD patients, longer interoceptive-ACWs than controls were observed in the bilateral fronto-temporal and parietal regions. In AD patients, longer interoceptive-ACWs than controls were observed in central and occipitoparietal brain regions. No differences were observed during exteroception. In bvFTD patients only, longer interoceptive-ACW was linked to worse sociocognitive performance. Structural neural correlates of interoceptive-ACW in bvFTD involved the anterior cingulate, insula, orbitofrontal cortex, hippocampus, and angular gyrus. Interpretation Our findings suggest a core allostatic-interoceptive deficit occurs in people with bvFTD. Further, altered interoceptive intrinsic neural timescales may provide a neurobiological mechanism underpinning the complex behaviours observed in bvFTD patients. Our findings support synergistic models of brain disease and can inform clinical practice. Funding All funding sources are reported in the Acknowledgements.

The agricultural sector faces significant pressure to meet the growing global demand for food while managing the planet’s limited natural resources. Addressing this challenge requires the strategic use of abundant materials and accessible biotechnologies that farmers can effectively implement. This study evaluated the effects of various substrate mixtures, including combinations of coconut fiber with compost or vermicompost (50:50 v/v). It also assessed the impact of heat treatment and inoculation with the antagonist Trichoderma asperellum on the production of basic potato seeds grown in 70 L plastic baskets. Statistical analysis revealed that the vermicompost-based mixture outperformed others, demonstrating superior biometric variables for potato plants. The treatment with sterilized vermicompost led to a 41% increase in seed weight, underscoring the beneficial effects of vermicompost. Correlation analysis indicated a positive relationship between the phosphorus content of the mixture and a negative relationship with the E4/E6 ratio—a parameter recognized as a reliable and easily measurable indicator of substrate quality, along with pH and electrical conductivity.

Background Forage production in tropical soils is primarily limited by nutrient deficiencies, especially nitrogen (N) and phosphorus (P). The use of phosphate rock by plants is limited by its low and slow P availability and microbial phosphate solubilization is the main mechanism for P bioavailability in the soil-root system. The objectives of this study were (i) select a nitrogen-fixing bacteria which could be used as a co-inoculant with the Penicillium rugulosum IR94MF1 phosphate-solubilizing fungus and (ii) evaluate under field conditions the effect of inoculation combined with phosphate rock (PR) application on yield and nutrient absorption of a Urochloa decumbens pasture which was previously established in a low-fertility, acidic soil. Methods Various laboratory and greenhouse tests allowed for the selection of Enterobacter cloacae C17 as the co-inoculant bacteria with the IR94MF1 fungus. Later, under field conditions, a factorial, completely randomized block design was used to evaluate the inoculation with the IR94MF1 fungus, the IR94MF1+C17 co-inoculation, and a non-inoculated control. Two levels of fertilization with PR treatment (0 kg/ha and 200 kg/ha P 2 O 5 ) were applied to each. Results During five consecutive harvests it was observed that the addition of biofertilizers significantly increased ( p < 0.05) the herbage mass and N and P assimilation compared to the non-inoculated control. However, no statistically significant differences were observed for the PR application as P source. Conclusion P. rugulosum IR94MF1 is capable of solubilizing and accumulating P from the phosphate rock, making it available for plants growing in acid soils with low N content. These inoculants represent a good option as biofertilizers for tropical grasses already established in acidic soils with low N content.

Background Structural income inequality – the uneven income distribution across regions or countries – could affect brain structure and function, beyond individual differences. However, the impact of structural income inequality on the brain dynamics and the roles of demographics and cognition in these associations remains unexplored. Methods Here, we assessed the impact of structural income inequality, as measured by the Gini coefficient on multiple EEG metrics, while considering the subject‐level effects of demographic (age, sex, education) and cognitive factors. Resting‐state EEG signals were collected from a diverse sample (countries = 10; healthy individuals = 1394 from Argentina, Brazil, Colombia, Chile, Cuba, Greece, Ireland, Italy, Turkey and United Kingdom). Complexity (fractal dimension, permutation entropy, Wiener entropy, spectral structure variability), power spectral and aperiodic components (1/f slope, knee, offset), as well as graph‐theoretic measures were analysed. Findings Despite variability in samples, data collection methods, and EEG acquisition parameters, structural inequality systematically predicted electrophysiological brain dynamics, proving to be a more crucial determinant of brain dynamics than individual‐level factors. Complexity and aperiodic activity metrics captured better the effects of structural inequality on brain function. Following inequality, age and cognition emerged as the most influential predictors. The overall results provided convergent multimodal metrics of biologic embedding of structural income inequality characterised by less complex signals, increased random asynchronous neural activity, and reduced alpha and beta power, particularly over temporoposterior regions. Conclusion These findings might challenge conventional neuroscience approaches that tend to overemphasise the influence of individual‐level factors, while neglecting structural factors. Results pave the way for neuroscience‐informed public policies aimed at tackling structural inequalities in diverse populations.

The sustainability of the primary sector is closely linked to meeting the demand for seeds using agro-industrial waste and bioresidues. Sustainability is a multidimensional concept focused on achieving environmental health, social justice, and economic viability. To this end, an experiment was designed based on a combination of biotechnological strategies accessible to many individuals. The first strategy involves the use of compost and vermicompost as cultivation substrates; the second is the in vitro acclimatization of potato plants to these substrates; and the third is the incorporation of Trichoderma asperellum into these substrates to determine the synergistic effect of both. The compost used in this work came from sewage sludge from an agri-food company (Cp); a dining room and pruning waste from a university campus (Cu); and vermicomposted coffee pulp waste (Cv). Each sample was mixed with coconut fiber (Fc) in proportions of 100, 75, 50, and 25%. In the resulting mixtures, María Bonita variety vitroplants were planted and placed in a greenhouse. The biometric response in the three cases indicated a dependence on the type of compost and the proportion of the coconut fiber mixture. The inoculation of Trichoderma asperellum with sewage sludge compost increased stem thickness (42.58%) and mini-tuber weight (6.74%). In contrast, uninoculated treatments showed the best performance in terms of the number of mini-tubers. A 50:50 mixture of sewage sludge compost with coconut fiber and without inoculation of Trichoderma asperellum was the best treatment for the production of pre-basic seeds of the María Bonita potato variety. The use of composted agricultural waste and bioresidues is shown as a valid and low-cost alternative for the sector, even independently of the incorporation of additional inoculants.

Brain clocks, which quantify discrepancies between brain age and chronological age, hold promise for understanding brain health and disease. However, the impact of diversity (including geographical, socioeconomic, sociodemographic, sex and neurodegeneration) on the brain-age gap is unknown. We analyzed datasets from 5,306 participants across 15 countries (7 Latin American and Caribbean countries (LAC) and 8 non-LAC countries). Based on higher-order interactions, we developed a brain-age gap deep learning architecture for functional magnetic resonance imaging (2,953) and electroencephalography (2,353). The datasets comprised healthy controls and individuals with mild cognitive impairment, Alzheimer disease and behavioral variant frontotemporal dementia. LAC models evidenced older brain ages (functional magnetic resonance imaging: mean directional error = 5.60, root mean square error (r.m.s.e.) = 11.91; electroencephalography: mean directional error = 5.34, r.m.s.e. = 9.82) associated with frontoposterior networks compared with non-LAC models. Structural socioeconomic inequality, pollution and health disparities were influential predictors of increased brain-age gaps, especially in LAC (R² = 0.37, F² = 0.59, r.m.s.e. = 6.9). An ascending brain-age gap from healthy controls to mild cognitive impairment to Alzheimer disease was found. In LAC, we observed larger brain-age gaps in females in control and Alzheimer disease groups compared with the respective males. The results were not explained by variations in signal quality, demographics or acquisition methods. These findings provide a quantitative framework capturing the diversity of accelerated brain aging.

Pharmaceuticals in aquatic environments pose threats to aquatic organisms because of their continuous release and potential accumulation. Monitoring methods for these contaminants are inadequate, with targeted analyses falling short in assessing water quality's impact on biota. The present study advocates for integrated strategies combining suspect and targeted chemical analyses with molecular biomarker approaches to better understand the risks posed by complex chemical mixtures to nontarget organisms. The research aimed to integrate chemical analysis and transcriptome changes in fathead minnows to prioritize contaminants, assess their effects, and apply this strategy in Wascana Creek, Canada. Analysis revealed higher pharmaceutical concentrations downstream of a wastewater‐treatment plant, with clozapine being the most abundant in fathead minnows, showing notable bioavailability from water and sediment sources. Considering the importance of bioaccumulation factor and biota–sediment accumulation factor in risk assessment, these coefficients were calculated based on field data collected during spring, summer, and fall seasons in 2021. Bioaccumulation was classified as very bioaccumulative with values >5000 L kg –1 , suggesting the ability of pharmaceuticals to accumulate in aquatic organisms. The study highlighted the intricate relationship between nutrient availability, water quality, and key pathways affected by pharmaceuticals, personal care products, and rubber components. Prioritization of these chemicals was done through suspect analysis, supported by identifying perturbed pathways (specifically signaling and cellular processes) using transcriptomic analysis in exposed fish. This strategy not only aids in environmental risk assessment but also serves as a practical model for other watersheds, streamlining risk‐assessment processes to identify environmental hazards and work toward reducing risks from contaminants of emerging concern. Environ Toxicol Chem 2024;00:1–22. © 2024 SETAC

Litter decomposition and livestock excreta are two important sources for replenishing nutrients in the soil of the pastures, and their decomposition rates are affected by their quality, management practices, forage productivity, and biotic and abiotic factors. The objective of this research was to assess the effects of escalating levels of N fertilization (0, 100, 200, and 400 kg N ha−1 yr−1) on litter and fecal decomposition in an agroforestry system comprising palisadegrass [Urochloa brizantha (Hochst. Ex A. Rich.) Stapf. cv. Marandu] intercropped with hybrid eucalyptus trees [Eucalyptus urophylla × Eucalyptus tereticornis], in a two-year field trial. The experiment was set in a randomized complete block design with four treatments and three repetitions. Litter (0, 4, 8, 16, 32, 64, 128, and 256 days) and cattle excrement samples (0, 4, 8, 16, 32, 64, and 128 days) were incubated on the ground. For forage litter samples, the interaction between N fertilization × year was observed for the decomposition rate (k) of DM (P = 0.0014) and OM (P = 0.0094). The greatest litter OM disappearance was observed at 400 kg N fertilization ha−1 year−1 (651 g kg−1 DM at 256 days). The interaction between nitrogen fertilizer rate × incubation time, or the isolated effect of the treatment was not observed on fecal decomposition (P > 0.05). Higher levels of N fertilization associated with the rainy period resulted in faster decomposition of palisadegrass litter, however, it did not show to have a strong influence on the excreta decomposition in this agroforestry system.

Distributed energy resources have demonstrated their potential to mitigate the limitations of large, centralized generation systems. This is achieved through the geographical distribution of generation sources that capitalize on the potential of their respective environments to satisfy local demand. In a microgrid, the control problem is inherently distributed, rendering traditional control techniques inefficient due to the impracticality of central governance. Instead, coordination among its components is essential. The challenge involves enabling these components to operate under optimal conditions, such as charging batteries with surplus solar energy or deactivating controllable loads when market prices rise. Consequently, there is a pressing need for innovative distributed strategies like emergent control. Inspired by phenomena such as the environmentally responsive behavior of ants, emergent control involves decentralized coordination schemes. This paper introduces an emergent control strategy for microgrids, grounded in the response threshold model, to establish an autonomous distributed control approach. The results, utilizing our methodology, demonstrate seamless coordination among the diverse components of a microgrid. For instance, system resilience is evident in scenarios where, upon the failure of certain components, others commence operation. Moreover, in dynamic conditions, such as varying weather and economic factors, the microgrid adeptly adapts to meet demand fluctuations. Our emergent control scheme enhances response times, performance, and on/off delay times. In various test scenarios, Integrated Absolute Error (IAE) metrics of approximately 0.01% were achieved, indicating a negligible difference between supplied and demanded energy. Furthermore, our approach prioritizes the utilization of renewable sources, increasing their usage from 59.7% to 86.1%. This shift not only reduces reliance on the public grid but also leads to significant energy cost savings.

Forage cactus (FC) is a perennial crop primarily developed in semi-arid regions. In Brazil, it is one of the main feed sources for ruminants during the dry season. However, scientific research and publication on FC seem limited and recent. Bibliometric studies allow measuring publication patterns and understanding the evolution of scientific production. Thus, a bibliometric analysis was carried out to evaluate the scientific production on productive aspects, management, and use of FC in animal feed (1800-June 2022). The literature search was based on keywords, including “cactus, cacti, nopal, prickly pear, palma forrageira, cacto, Nopalea, Opuntia, forage, forragem, and forraje”. Data were analyzed using the Bibliometrix tool based on the R language through the Biblioshiny interface. A total of 514 publications were identified, with a predominance of research articles (92.6%). Scientific production includes authors from 40 countries, highlighting Brazil (1094 authors). The main sources were: Revista Brasileira de Zootecnia, Acta Horticulturae, Tropical Animal Health and Production, Revista Caatinga, Journal of the Professional Association for Cactus Development, and Revista Brasileira de Engenharia Agrícola e Ambiental. The 10 most frequent words were: Opuntia, Semiarid, Nopalea, Forage, Cactaceae, Opuntia fícus-indica, Cactus, Cactus pear, Intake, and Digestibility. Scientific production on FC is led by researchers from Brazil, notably from Northeastern Brazil. Publications on the economic evaluation, establishment and maintenance of promising species, soil conservation, micronutrient content and the use of FC as a supplementary source of water, are less frequent. These sub-areas suggest future lines of research that may be inter-institutional to increase collaboration networks between countries.

Pastures dedicated to cattle production in Venezuela have a low crude protein concentration. One of the nutritional strategies to correct the forage protein deficit is using non-protein nitrogen in the diet. To evaluate the effect of two non-protein nitrogen sources on the metabolic profile of lactating dairy cows, 31 F1 Holstein × Zebu multiparous cows averaging 419 ± 46 kg body weight and 17.1 ± 3.3 kg milk·animal·d-1 were randomly assigned to two treatments for 91 days: 1) 59 g·animal-1·d-1 of urea and 2) 64 g·animal-1·d-1 of Optigen II® as slow-release urea (SRU). The animals were grazing (2.12 AU·ha-1) on Urochloa decumbens, U. humidicola, and U. brizantha (7.98-9.61 % CP) and supplied with 4 kg·animal·d-1 of concentrate (15 % CP), and 108, 60, and 108 g·animal·d-1 of mineral, molasses, and bypass fat, respectively. Glucose, total protein, albumin, cholesterol, urea, and β-hydroxybutyrate concentrations, aspartate aminotransferase, and gamma-glutamyl transferase activities were determined in blood serum samples every 28 days. ANOVA analyzed data in a completely randomized design with repeated measures. There were no differences among treatments in the parameters investigated; however, collecting time influenced all of them. No treatment × time interactions were found except for albumin concentration, higher in urea at day 0. The results indicate that under the conditions assayed in the present work, Optigen II® offers no advantage over urea concerning blood indicators of energy and protein metabolism and hepatic functionality in dairy cows.

This study evaluated the effect of different fiber sources supplied with cactus cladodes in diets on the intake and digestibility of nutrients, ingestive behavior, milk yield, and composition of dairy goats. The fiber sources were corn silage, sorghum silage, Digitaria pentzii Stent. hay, and sugarcane bagasse. Twelve Saanen goats with an average weight of 48.9 ± 7.3 kg and average production of 2.8 ± 0.7 kg of milk/day were assigned in three simultaneous 4 × 4 Latin squares (four animals, four treatments, and four experimental periods). There was no difference between the fiber sources for intake (P > 0.05) of dry matter (2.58 kg/day), organic matter (2.30 kg/day), crude protein (0.385 kg/day), neutral detergent fiber (0.895 kg/day), non-fibrous carbohydrates (0.858 kg/day), and metabolizable energy (5.66 Mcal/day). Also, the fiber sources did not influence dry matter and nutrient digestibility (P > 0.05). The association of cactus cladodes with silages, hay, and sugarcane bagasse did not change milk production, milk production corrected for 3.5% of fat and corrected for energy (2.78; 2.53 and 2,55 kg/day, respectively), in addition to milk composition (P > 0.05). No differences were observed in ingestive behavior (P > 0.05). Any fiber sources evaluated are recommended.

Agricultural production activities generate a large amount of waste, most of which is of organic origin from plant remains. These residues could easily be transformed into a resource, specifically, into a substrate for use in soilless cultivation; however, in most cases, they are not used. Therefore, a characterization of local agricultural residues was carried out to determine their use as a substrate for crop cultivation without soil in a protected environment. The selected substrates were Sphagnum peat, coir fiber, and compost, which were managed alone or in mixtures of 50/50, 75/25, or 25/75% v/v ratios. We also included a mixture of virgin mountain soil and earthworm humus (known as INIA mixture) because it is used by local growers. The results showed that the substrates based on coir fiber, peat, and mixtures of both presented suitable characteristics for horticultural crops. On the contrary, compost-based substrates had high pH values and low organic matter contents that could be improved before use. The relationship found between the evaluated parameters of each substrate allowed us to establish that variables, such as the content of organic matter and water at different tensions and particle sizes, can be utilized to make a quick selection of the substrates produced locally, which would lead to the use of waste in a way that is more consistent with sustainable agricultural production and minimal environmental impact, by being used in the production of crops in containers without soil. In addition, these results can be used as an alternative reference in localities where these residues are easily available.

Promoting environmental literacy from the educational space emerges as a way to provide students with theoretical and practical tools to establish harmonious and respectful links with the environment and its different resources, including the soil. The purpose of this study, developed from a quantitative approach, was to determine the guidelines for formulating soil conservation practices based on environmental literacy. To do this, a sample of 155 newly admitted students of Agronomic, Agroindustrial and Environmental Engineering was considered, selected from a census sample, to whom a Questionnaire with Likert-Type, Selection and Dichotomous items was applied. The results showed a high level of environmental sensitivity in the students; however, there was a lack of knowledge of basic concepts and the effect of factors linked to agricultural activities that took place in the geographical context, as well as specific soil conservation practices. It is concluded that the guidelines for formulating these practices must be based on the need to implement strategies to make relevant information available to students on the effects that the different anthropogenic factors generate on the soil, based on the knowledge of their contextual reality.

En la literatura existe poca información sobre datos físico-químicos de suelos de la región andina, aunque recientemente para el estado Táchira se mostraron las características físico-químicas de estos suelos en forma general, pero no detalladamente por cada municipio. En esta investigación se reportan las clases texturales, el contenido de materia orgánica del suelo, el pH y la conductividad eléctrica para cada uno de los veintinueve municipios del estado Táchira en Venezuela, con el fin de determinar su potencial agrícola y tener valores de referencia para los productores. Los datos se obtuvieron de 644 análisis físico-químicos realizados en el Laboratorio Bioambiental de la Universidad Nacional Experimental del Táchira para el período 2015-2019. Los resultados sugieren predominan en más del 70% de las muestras las texturas gruesas, en 55% los suelos con bajo contenido de materia orgánica, y los pH ácidos y los suelos desaturados en todos los municipios del estado. Las diferencias significativas mostraron que la textura del suelo influyó en el pH de este. Las condiciones de los suelos pueden ser mejoradas mediante enmiendas orgánicas y encalamiento para obtener condiciones óptimas para los cultivos.

Las investigaciones sobre escritura académica han aumentado en las últimas décadas, lo que ha dado paso a la fundación de un espacio disciplinar que ha contribuido a transformaciones en la enseñanza y estudios en el nivel universitario. El objetivo del presente artículo es describir cómo se ha trabajado la escritura académica en ingeniería para el contexto hispanoamericano. Se realizó una revisión exploratoria en revistas científicas de acceso abierto, a partir de lo cual se conformó y analizó un corpus de 36 publicaciones en el lapso 2011-2021. Según los hallazgos, los estudios sobre escritura académica en ingeniería se han incrementado en los últimos años; se encuentra una tendencia a estudiarla desde sus subdisciplinas y en el pregrado; se percibe un potencial desarrollo de trabajo interdisciplinario a partir de la incipiente colaboración entre docentes de lengua y docentes de ingeniería; metodológicamente, predominan las investigaciones empíricas; los estudios se caracterizan por una heterogeneidad teórica, y se advierte un enfoque de la escritura orientado hacia lo social, y se dejan de lado los estudios estrictamente cognitivos. En conclusión, hay un avance de la disciplina que aborda el estudio de la escritura en la universidad, ahora con marcos de referencia más delimitados, como es el caso del área de ingeniería.

Featured Application An extension of the DIVA model to include EEG is presented and initially validated using group-level statistics. The DIVA_EEG expands the number of scenarios in which vocal and speech behaviors can be assessed and has potential applications for personalized model-driven interventions. Abstract The neurocomputational model ‘Directions into Velocities of Articulators’ (DIVA) was developed to account for various aspects of normal and disordered speech production and acquisition. The neural substrates of DIVA were established through functional magnetic resonance imaging (fMRI), providing physiological validation of the model. This study introduces DIVA_EEG an extension of DIVA that utilizes electroencephalography (EEG) to leverage the high temporal resolution and broad availability of EEG over fMRI. For the development of DIVA_EEG, EEG-like signals were derived from original equations describing the activity of the different DIVA maps. Synthetic EEG associated with the utterance of syllables was generated when both unperturbed and perturbed auditory feedback (first formant perturbations) were simulated. The cortical activation maps derived from synthetic EEG closely resembled those of the original DIVA model. To validate DIVA_EEG, the EEG of individuals with typical voices (N = 30) was acquired during an altered auditory feedback paradigm. The resulting empirical brain activity maps significantly overlapped with those predicted by DIVA_EEG. In conjunction with other recent model extensions, DIVA_EEG lays the foundations for constructing a complete neurocomputational framework to tackle vocal and speech disorders, which can guide model-driven personalized interventions.