41 results on '"Cabrera, Miguel"'
Search Results
2. Methanol production from residual streams of natural gas sweetening for achieving the sustainable development goals
- Author
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Solis-Jacome, Alejandro, Ramírez-Márquez, César, Morales-Cabrera, Miguel A., and Ponce-Ortega, José M.
- Published
- 2024
- Full Text
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3. How water table level influences C balance under different fertilization regimes
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Longo, Matteo, Delle Vedove, Gemini, Grignani, Carlo, Peressotti, Alessandro, Lazzaro, Barbara, Cabrera, Miguel, and Morari, Francesco
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- 2023
- Full Text
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4. A global and comparative assessment of the level of economic circularity in the EU
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Martínez Moreno, María Magdalena, Buitrago Esquinas, Eva M, Yñiguez, Rocío, and Puig-Cabrera, Miguel
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- 2023
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5. Assessment of flumioxazin soil behavior and thermal stability in aqueous solutions
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Eason, Kayla, Grey, Timothy, Cabrera, Miguel, Basinger, Nicholas, and Hurdle, Nicholas
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- 2022
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6. Primer registro de Myocastor coypus (Molina 1782) (Mammalia, Rodentia) para el estado de Mato Grosso do Sul, Brasil y su distribución en el sur de Sudamérica
- Author
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Rodney Murillo Peixoto-Couto, Anderson Correa-Branco, and Maiara Cabrera-Miguel
- Subjects
expansión de la distribución ,exótico ,nutria ,coipo ,sudamérica ,Biology (General) ,QH301-705.5 - Abstract
Este estudio presenta el primer registro de Myocastor coypus en el estado de Mato Grosso do Sul, además de señalar su distribución al sur de América del Sur, destacando dónde se considera nativo y exótico en Brasil. El 23 de abril de 2018, aproximadamente a las 6:00 pm, se registró, con un LC (longitud corporal) de 40 cm, un espécimen adulto atropellado en un camino lateral cerca de humedales y una represa, en un área rural en el municipio de Bataguassu, al este del estado de Mato Grosso do Sul. No es posible determinar el origen de M. coypus reportado en el presente estudio; tampoco es posible establecer si fue introducido o dispersado de forma natural por las zonas pantanosas del río Paraná, ya que la especie tiene registros en la frontera de los estados de Mato Grosso do Sul y Paraná.
- Published
- 2021
- Full Text
- View/download PDF
7. Deciphering Tourism's Role in Antarctica's Geosocial Concerns through Data Mining Techniques.
- Author
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Calderón-Fajardo, Víctor, Puig-Cabrera, Miguel, and Rodríguez-Rodríguez, Ignacio
- Abstract
This study explores the changing dynamics of tourism in Antarctica, focusing on the impact of digitalisation and User-Generated Content on platforms like Tripadvisor. It aims to understand how online reviews influence perceptions and decisions to visit Antarctica, a region known for its pristine environment and status as 'the last frontier'. Utilising Environmental Perception and Behaviour Geography (EPBG) principles, this research conducts a quantitative analysis of reviews from potential and current travellers. Through text mining, topic modelling, sentiment analysis, and Natural Language Processing (NLP), it investigates the emotional and perceptual discourse surrounding Antarctic tourism and its alignment with Agenda 2030 and Sustainable Development Goals. The findings reveal a detailed narrative of sustainability challenges and the emotional geography related to tourism in Antarctica, highlighting emotions such as happiness, anger, surprise, fear, disgust, and sadness among visitors. This study uncovers differences in perception based on visitors' backgrounds, noting that individuals from nature-focused cities display strong environmental concerns, whereas those from advanced urban centres show a more positive attitude. This research contributes to the understanding of EPBG, text mining, and NLP, offering insights into sustainable tourism practices in Antarctica. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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8. Keynote lecture. The planar setup: A window through the complex interactions in granular flows
- Author
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Cabrera Miguel, Cote Laura, and Caro Santiago
- Subjects
Environmental sciences ,GE1-350 - Abstract
Granular flows are a complex process, involving a wide range of grain sizes, materials, varied viscous fluids, among others. For this reason, the simulation of granular flows requires a certain level of simplification, allowing the isolated study of its governing variables and extending the global observations to field events. Here, we present the planar setup as an alternative for studying simplified processes associated to granular flows. The planar setup consists of two windows separated by a thin gap and enclosing a granular assembly. We present two examples where the planar setup is adapted for the study of the competing action of segregation and disaggregation in a fractured grain under shear flow, and for the study of the stability scenarios of a flow impacting a permeable obstacle. The close visualization of the kinematics at the particle scale provides an ideal opportunity for describing the mechanisms behind the grain disaggregation or controlling the obstacle stability. Both examples highlight the advantages of the planar setup for the study of granular flows.
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- 2023
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9. Granular column collapse: The role of particle size polydispersity on the velocity and runout
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Polanía Oscar, Estrada Nicolás, Renouf Mathieu, Azéma Emilien, and Cabrera Miguel
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Environmental sciences ,GE1-350 - Abstract
Geophysical mass flows involve particles of different sizes, a property termed polydispersity. The granular column collapse is a simplified experiment for studying transitional granular flows. Our research focuses on the role that polydispersity has on the velocity and runout distance of dry and immersed granular columns, undergoing a numerical and experimental study. Our results highlight that polydispersity does not have a strong effect on the collapse of dry columns. On the contrary, the collapse sequence of immerse granular columns strongly depend on the polydispersity level.
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- 2023
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10. Assessing corn recovery from early season nutrient stress under different soil moisture regimes.
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Amissah, Solomon, Ankomah, Godfred, Lee, Robert D., Perry, Calvin D., Washington, Bobby J., Porter, Wesley M., Virk, Simerjeet, Bryant, Corey J., Vellidis, George, Harris, Glendon H., Cabrera, Miguel, Franklin, Dorcas H., Diaz-Perez, Juan C., and Sintim, Henry Y.
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SOIL moisture ,MICROIRRIGATION ,CORN ,SPRINKLER irrigation ,RYE - Abstract
Corn (Zea mays) biomass accumulation and nutrient uptake by the six-leaf collar (V6) growth stage are low, and therefore, synchronizing nutrient supply with crop demand could potentially minimize nutrient loss and improve nutrient use efficiency. Knowledge of corn's response to nutrient stress in the early growth stages could inform such nutrient management. Field studies were conducted to assess corn recovery from when no fertilizer application is made until the V6 growth stage, and thereafter, applying fertilizer rates as those in non-stressed conditions. The early season nutrient stress and nonstress conditions received the same amount of nutrients. As the availability of nutrients for plant uptake is largely dependent on soil moisture, corn recovery from the early season nutrient stress was assessed under different soil moisture regimes induced via irrigation scheduling at 50% and 80% field capacity under overhead and subsurface drip irrigation (SSDI) systems. Peanut (Arachis hypogaea) was the previous crop under all conditions, and the fields were under cereal rye (Secale cereale) cover crop prior to planting corn. At the V6 growth stage, the nutrient concentrations of the early season-stressed crops, except for copper, were above the minimum threshold of sufficiency ranges reported for corn. However, the crops showed poor growth, with biomass accumulation being reduced by over 50% compared to non-stressed crops. Also, the uptake of all nutrients was significantly lower under the early season nutrient stress conditions. The recovery of corn from the early season nutrient stress was low. Compared to non-stress conditions, the early season nutrient stress caused 1.58 Mg ha
-1 to 3.4 Mg ha-1 yield reduction. The percent yield reduction under the SSDI system was 37.6-38.2% and that under the overhead irrigation system was 11.7-13%. The high yield reduction from the early season nutrient stress under the SSDI system was because of water stress conditions in the topsoil soil layer. The findings of the study suggest ample nutrient supply in the early season growth stage is critical for corn production, and thus, further studies are recommended to determine the optimum nutrient supply for corn at the initial growth stages. [ABSTRACT FROM AUTHOR]- Published
- 2024
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11. Psychometrics of Emotional Intelligence in Hospitality: A Cross-Sectional Study on Human Capital and Quality of Service.
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Sanz-García, Alberto, Ros-Martínez, Almudena, López-Navas, Ana, and Puig-Cabrera, Miguel
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QUALITY of service ,EMOTIONAL intelligence ,PSYCHOMETRICS ,HOSPITALITY studies ,PERSONNEL management - Abstract
Little research has been conducted specifically on emotional intelligence (EI) and perceived quality of service in the hospitality industry. The main goal of this research consists of providing empirical evidence related to EI regarding its importance in quality of hospitality service (QHS). To do so, a hypothetical and conceptual model was tested by Partial Least Square-Structural Equation Modeling (PLS-SEM) techniques based on a sample of 408 employees in the hospitality sector in the region of Murcia (Spain). The findings of this work reveal the incidence that EI has on the QHS of human capital, despite a scenario that is characterized by a high rate of talent shortage worldwide and an increasing digitalization that could reduce human interaction. Also, implications are given so that EI could be more deeply analyzed for EI strategy-building within organizational behavior and human resource management areas from a practical approach, increasing engagement and preventing the so-called quality service sabotage. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Digital Twins in Software Engineering—A Systematic Literature Review and Vision.
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Guinea-Cabrera, Miguel A. and Holgado-Terriza, Juan A.
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DIGITAL twins ,LITERATURE reviews ,COMPUTER software industry ,DIGITAL transformation ,SOFTWARE engineering ,DATA scrubbing - Abstract
Featured Application: Secure Integration of the IoT and Digital Twins. Digital twins are a powerful consequence of digital transformation. In fact, they have been applied to many industries to enhance operations, predict needs, improve decision making, or optimize performance, even though the definition of digital twins is still evolving. However, their impact on the software industry is still limited. Thus, this work aims to analyze the current adoption of digital twins in the software industry as a potential path to integrate them into application lifecycle management. To achieve this objective, first, the significant characteristics of current digital twins are analyzed in their application to manufacturing to understand how the knowledge and the lessons learned can be transferred to the software industry. Second, a systematic literature review was conducted on Scopus, the Web of Science, and the ScienceDirect database. The literature review revealed 93 documents after data screening and cleaning 251 initial documents. Our main findings are that digital twins are already influencing and will significantly affect the software industry, revolutionizing various aspects of the software development lifecycle. This study tackles what identifies a digital twin in the software industry, the specific domains and areas where they can be applied in the software lifecycle, and the proposed approaches explored to build digital twins for developing, deploying, and maintaining software systems. Finally, this study proposes some guidelines for building digital twins in the context of application lifecycle management. Determining an appropriate roadmap shortly is essential to achieve a widespread applicability to building suitable digital twins and preparing organizations for the software industry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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13. The optics of the human eye at 8.6 µm resolution
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Bonaque-González, Sergio, Trujillo-Sevilla, Juan M., Velasco-Ocaña, Miriam, Casanova-González, Óscar, Sicilia-Cabrera, Miguel, Roqué-Velasco, Alex, Ceruso, Sabato, Oliva-García, Ricardo, Martín-Hernández, Javier, Gomez-Cardenes, Oscar, Marichal-Hernández, José G., Gatinel, Damien, Holladay, Jack T., and Rodríguez-Ramos, José M.
- Published
- 2021
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14. The Use of Two Locally Sourced Bio-Inocula to Improve Nitrogen and Phosphorus Cycling in Soils and Increase Macro and Micronutrient Nutrient Concentration in Edamame (Glycine max. L.) and Pumpkin (Cucurbita maxima).
- Author
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Mahmud, Kishan, Franklin, Dorcas, Cabrera, Miguel, Ney, Laura, Dahal, Subash, and Subedi, Anish
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SOYBEAN ,PHOSPHORUS in soils ,NITROGEN cycle ,PUMPKIN seeds ,CUCURBITA ,PUMPKINS ,PLANT nutrients ,MICROBIAL inoculants ,COVER crops - Abstract
Soil macro- and micronutrient nutrient availability and their uptake by plants are critically reliant upon an active presence of the soil microbiome. This study investigated the effect of two locally sourced bio-inocula, local effective microorganisms (LEMs) and false-local effective microorganisms (F-LEMs), on plant available nitrogen (N) and phosphorus (P), and the uptake of calcium (Ca), magnesium (Mg), potassium (K), and zinc (Zn) content in edamame (Glycine max. L.) and pumpkin (Cucurbita maxima) grown in a randomized complete block design with four reps, summer 2017 and 2018, respectively. LEM plots showed greater plant-available N during the first week (edamame season) and fourth week (pumpkin season) after treatment applications. During the pumpkin season, post-treatment plant-available P was greater in both summers in LEM plots. Edamame bean had 19%, 3%, 5%, and 16% greater Ca, Mg, K, and Zn content in LEM plots compared to the Control, respectively. The concentration of K in pumpkin pulp at harvest was 31% higher in LEMs than in F-LEMs, while Mg concentration was 42% higher. Pumpkin pulp and seeds also had 27% and 34% greater Ca and Zn concentrations compared to the Control. Our study suggests that LEMs were effective in solubilizing macro- and micronutrients, which led to increased plant uptake. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. The planar setup: A window through the complex interactions in granular flows.
- Author
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Cabrera, Miguel, Cote, Laura, and Caro, Santiago
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- 2023
- Full Text
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16. MorphoArms: Morphogenetic Teleoperation of Multimanual Robot
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Martynov, Mikhail, Darush, Zhanibek, Cabrera, Miguel Altamirano, Karaf, Sausar, and Tsetserukou, Dzmitry
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FOS: Computer and information sciences ,Computer Science - Robotics ,Robotics (cs.RO) - Abstract
Nowadays, there are few unmanned aerial vehicles (UAVs) capable of flying, walking and grasping. A drone with all these functionalities can significantly improve its performance in complex tasks such as monitoring and exploring different types of terrain, and rescue operations. This paper presents MorphoArms, a novel system that consists of a morphogenetic chassis and a hand gesture recognition teleoperation system. The mechanics, electronics, control architecture, and walking behavior of the morphogenetic chassis are described. This robot is capable of walking and grasping objects using four robotic limbs. Robotic limbs with four degrees-of-freedom are used as pedipulators when walking and as manipulators when performing actions in the environment. The robot control system is implemented using teleoperation, where commands are given by hand gestures. A motion capture system is used to track the user's hands and to recognize their gestures. The method of controlling the robot was experimentally tested in a study involving 10 users. The evaluation included three questionnaires (NASA TLX, SUS, and UEQ). The results showed that the proposed system was more user-friendly than 56% of the systems, and it was rated above average in terms of attractiveness, stimulation, and novelty., IEEE International Conference on Automation Science and Engineering (CASE 2023), Cordis, New Zeland, 26-30 August, 2023, in print
- Published
- 2023
17. Interaction of Filth Flies and Epigeal Arthropods with Soil Nitrogen and Gas Emissions in Grazing Systems under a Legacy of Low Fertilization.
- Author
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Espinoza, Natalia, Franklin, Dorcas H., Cabrera, Miguel, Hinkle, Nancy C., Stewart, Lawton, and Subedi, Anish
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During the summers of 2021 and 2022, we conducted a study in four Georgia Piedmont pastures to assess the effect of the presence of filth flies and epigeal arthropods on carbon and nitrogen emissions and soil nitrogen retention from lax rotational grazing systems under a legacy of low fertilization. Carbon dioxide (CO
2 ), nitrous oxide (N2 O), and ammonia (NH3 ) emissions were measured from dung on days 0, 4, 8, and 15 following depositions. Soil and manure samples were collected on days 0 and 16 and analyzed for ammonium (NH4 + ), nitrate (NO3 − ), plant-available nitrogen (PAN), and potentially mineralizable nitrogen (PMN). Manure samples were analyzed for total Kjeldahl nitrogen (TKN). The numbers of filth flies ovipositing and emerging from manure, fire ants, and epigeal arthropods around the manure were determined. Our results indicated that more than 12 ovipositing filth flies per manure pat can reduce PMN by up to 14.7 kg of nitrogen per hectare, while an increase in the biodiversity and abundance of predators may help to increase PAN and PMN in grazing systems, as well as decrease the number of emerging filth flies. [ABSTRACT FROM AUTHOR]- Published
- 2023
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18. Chemical differences in cover crop residue quality are maintained through litter decay.
- Author
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Thapa, Resham, Cabrera, Miguel, Schomberg, Harry H., Reberg-Horton, Chris, Poffenbarger, Hanna, and Mirsky, Steven B.
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CROP residues , *POULTRY manure , *CROP quality , *RYE , *PLANT litter - Abstract
As plant litter decomposes, its mass exponentially decreases until it reaches a non-zero asymptote. However, decomposition rates vary considerably among litter types as a function of their overall quality (i.e., carbon:nitrogen (C:N) ratio and litter chemistry). We investigated the effects of hairy vetch (HV: Vicia villosa Roth):cereal rye (RYE: Secale cereale L.) biomass proportions with or without broadcasted poultry manure on overall litter quality before and during decomposition. As HV biomass proportions increased from 0 to 100%, the relative susceptibility of HV:RYE mixtures to microbial decomposition increased due to: (i) decrease in the initial C:N ratio (87:1 to 10:1 in 2012 and 67:1 to 9:1 in 2013), (ii) increase in the non-structural labile carbohydrates (33 to 61% across years), and (iii) decrease in the structural holo-cellulose (59 to 33% across years) and lignin (8 to 6% across years) fractions. Broadcasted poultry manure decreased the overall initial quality of HV-dominated litters and increased the overall initial quality of RYE-dominated litters. Across all HV:RYE biomass proportions with or without poultry manure, chemical changes during litter decay were related to proportional mass loss. Therefore, the relative decrease in carbohydrates and the concomitant increase in holo-cellulose and lignin fractions were more pronounced for fast decomposing litter types, i.e., litters dominated by HV rather than RYE. While our results suggest possible convergence of litter C:N ratios, initial differences in litter chemistry neither converged nor diverged. Therefore, we conclude that the initial chemistry of litter before decomposition exerts a strong control on its chemical composition throughout the decay continuum. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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19. Predicting partner fitness based on spatial structuring in a light-driven microbial community.
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Sakkos, Jonathan K., Santos-Merino, María, Kokarakis, Emmanuel J., Li, Bowen, Fuentes-Cabrera, Miguel, Zuliani, Paolo, and Ducat, Daniel C.
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MICROBIAL communities ,SYNECHOCOCCUS elongatus ,COMMUNITIES ,NUTRIENT uptake ,PLANT nutrients - Abstract
Microbial communities have vital roles in systems essential to human health and agriculture, such as gut and soil microbiomes, and there is growing interest in engineering designer consortia for applications in biotechnology (e.g., personalized probiotics, bioproduction of high-value products, biosensing). The capacity to monitor and model metabolite exchange in dynamic microbial consortia can provide foundational information important to understand the community level behaviors that emerge, a requirement for building novel consortia. Where experimental approaches for monitoring metabolic exchange are technologically challenging, computational tools can enable greater access to the fate of both chemicals and microbes within a consortium. In this study, we developed an in-silico model of a synthetic microbial consortia of sucrose-secreting Synechococcus elongatus PCC 7942 and Escherichia coli W. Our model was built on the NUFEB framework for Individual-based Modeling (IbM) and optimized for biological accuracy using experimental data. We showed that the relative level of sucrose secretion regulates not only the steady-state support for heterotrophic biomass, but also the temporal dynamics of consortia growth. In order to determine the importance of spatial organization within the consortium, we fit a regression model to spatial data and used it to accurately predict colony fitness. We found that some of the critical parameters for fitness prediction were inter-colony distance, initial biomass, induction level, and distance from the center of the simulation volume. We anticipate that the synergy between experimental and computational approaches will improve our ability to design consortia with novel function. Author summary: Microbial communities, play important, yet poorly understood roles in health and agriculture. As we develop a better understanding of how these communities interact together, as well as with their host organisms, there is growing interest in engineering communities with specific functions, such as for treating disease, personalized probiotics, or aiding plants with nutrient uptake. To better understand how these microbes interact with each other, we want to monitor the exchange of metabolites and the locations of the microbes, tasks which at present are technically challenging, if not impossible. Where experimental approaches for monitoring metabolites are limited, computational tools can enable greater access to the fate of both chemicals and microbes within a community. In this study, we developed a computerized model of a synthetic microbial community of two bacteria, one which performs photosynthesis and supplies sugar and another which consumes the sugar for growth. We showed that the relative level of sugar secretion regulates not only the steady-state support for the consumer partner's growth, but also how the community changes with time. To determine the importance of spatial organization within the community, we fit a model and used it to predict colony growth. We anticipate that the synergy between experimental and computational approaches will improve our ability to design microbial communities with new functions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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20. Exploring the Role of Electro-Tactile and Kinesthetic Feedback in Telemanipulation Task
- Author
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Trinitatova, Daria, Cabrera, Miguel Altamirano, Ponomareva, Polina, Fedoseev, Aleksey, and Tsetserukou, Dzmitry
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FOS: Computer and information sciences ,Computer Science - Robotics ,Robotics (cs.RO) - Abstract
Teleoperation of robotic systems for precise and delicate object grasping requires high-fidelity haptic feedback to obtain comprehensive real-time information about the grasp. In such cases, the most common approach is to use kinesthetic feedback. However, a single contact point information is insufficient to detect the dynamically changing shape of soft objects. This paper proposes a novel telemanipulation system that provides kinesthetic and cutaneous stimuli to the user's hand to achieve accurate liquid dispensing by dexterously manipulating the deformable object (i.e., pipette). The experimental results revealed that the proposed approach to provide the user with multimodal haptic feedback considerably improves the quality of dosing with a remote pipette. Compared with pure visual feedback, the relative dosing error decreased by 66\% and task execution time decreased by 18\% when users manipulated the deformable pipette with a multimodal haptic interface in combination with visual feedback. The proposed technology can be potentially implemented in delicate dosing procedures during the antibody tests for COVID-19, chemical experiments, operation with organic materials, and telesurgery., Accepted paper in IEEE CASE (International Conference on Automation Science and Engineering) 2022, IEEE copyrigh
- Published
- 2022
21. Primer registro de Myocastor coypus (Molina 1782) (Mammalia, Rodentia) para el estado de Mato Grosso do Sul, Brasil y su distribución en el sur de Sudamérica
- Author
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Murillo Peixoto-Couto, Rodney, Correa-Branco, Anderson, and Cabrera-Miguel, Maiara
- Subjects
exotic ,nutria ,Sudamérica ,coipo ,Expansion of distribution ,South America ,exótico ,coypu ,expansión de la distribución - Abstract
This study presents the first record of Myocastor coypus in the state of Mato Grosso do Sul, in addition to detailing its distribution within southern South America, highlighting where it is considered native or exotic in Brazil. On April 23, 2018, at approximately 18:00, an adult specimen with a 40 cm BL (body length) was registered after being run over on a side road near wetlands and a dam in a rural area in the municipality of Bataguassu, eastern state of Mato Grosso do Sul. It is not possible to state the origin of the M. coypus reported in the present study; whether it was introduced or dispersed naturally through the flooded areas of the Paraná River, since the species has records on the border of the states of Mato Grosso do Sul and Paraná. Resumen Este estudio presenta el primer registro de Myocastor coypus en el estado de Mato Grosso do Sul, además de señalar su distribución al sur de América del Sur, destacando dónde se considera nativo y exótico en Brasil. El 23 de abril de 2018, aproximadamente a las 6:00 pm, se registró, con un LC (longitud corporal) de 40 cm, un espécimen adulto atropellado en un camino lateral cerca de humedales y una represa, en un área rural en el municipio de Bataguassu, al este del estado de Mato Grosso do Sul. No es posible determinar el origen de M. coypus reportado en el presente estudio; tampoco es posible establecer si fue introducido o dispersado de forma natural por las zonas pantanosas del río Paraná, ya que la especie tiene registros en la frontera de los estados de Mato Grosso do Sul y Paraná.
- Published
- 2022
22. Developing a hetero-intelligence methodological framework for sustainable policy-making based on the assessment of large language models
- Author
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Buitrago-Esquinas, Eva M., Puig-Cabrera, Miguel, Santos, José António C., Custódio-Santos, Margarida, and Yñiguez-Ovando, Rocío
- Published
- 2024
- Full Text
- View/download PDF
23. Inferring assembly-curving trends of bacterial micro-compartment shell hexamers from crystal structure arrangements.
- Author
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Garcia-Alles, Luis F., Fuentes-Cabrera, Miguel, Truan, Gilles, and Reguera, David
- Subjects
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CRYSTAL structure , *CHEMICAL processes , *MOLECULAR dynamics , *MUTANT proteins , *BACTERIAL proteins - Abstract
Bacterial microcompartments (BMC) are complex macromolecular assemblies that participate in varied chemical processes in about one fourth of bacterial species. BMC-encapsulated enzymatic activities are segregated from other cell contents by means of semipermeable shells, justifying why BMC are viewed as prototype nano-reactors for biotechnological applications. Herein, we undertook a comparative study of bending propensities of BMC hexamers (BMC-H), the most abundant shell constituents. Published data show that some BMC-H, like β-carboxysomal CcmK, tend to assemble flat whereas other BMC-H often build curved objects. Inspection of available crystal structures presenting BMC-H in tiled arrangements permitted us to identify two major assembly modes with a striking connection with experimental trends. All-atom molecular dynamics (MD) supported that BMC-H bending is triggered robustly only from the arrangement adopted in crystals by BMC-H that experimentally form curved objects, leading to very similar arrangements to those found in structures of recomposed BMC shells. Simulations on triplets of planar-behaving hexamers, which were previously reconfigured to comply with such organization, confirmed that bending propensity is mostly defined by the precise lateral positioning of hexamers, rather than by BMC-H identity. Finally, an interfacial lysine was pinpointed as the most decisive residue in controlling PduA spontaneous curvature. Globally, results presented herein should contribute to improve our understanding of the variable mechanisms of biogenesis characterized for BMC, and of possible strategies to regulate BMC size and shape. Author summary: Bacterial microcompartments are complex macromolecular ensembles that participate in varied metabolic processes in many microorganisms. They consist of a proteinaceous shell that encapsulates enzymatic cargo that mediate connected chemical reactions. Being confined within shells, the overall efficiency of the process is thought to augment, and reactions that imply toxic intermediates, which are lethal to the host in free-diffusing context, become feasible. These natural nano-reactors are therefore appealing for biotechnology purposes. Understanding how such complex objects form is essential. Experimental studies demonstrated the existence of two possible pathways. Thus, shell components grew onto a preformed core of organized cargo in cyanobacterial carboxysomes, whereas in Pdu compartments, both cargo and shell formation seemed to occur randomly. With the aim to contribute to the understanding of the different biogenesis pathways, here we investigated the trend of the most abundant protein constituents of bacterial micro-compartment shells to form curved structures. We first discovered the occurrence of two major assembly modes in deposited BMC-H crystal structures that clustered proteins in two groups that correlate well to their experimental propensities to form bent or flat structures. Subsequently, molecular dynamic simulations supported that only one of the modes is ready to curve. Moreover, simulations on protein mutants pinpointed a residue that seems to be pivotal in triggering bending. Globally, our data permit to draw a scenario that explains BMC biogenesis differences as a result of the capture of some BMC-H, such as CcmK of carboxysomes, in local minima corresponding to flat states that would delay closure of BMC shells, something that might require the intervention of other molecular effectors. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Nutrient Sufficiency Ranges for Corn at the Early Growth Stage: Implications for Nutrient Management.
- Author
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Amissah, Solomon, Ankomah, Godfred, Agyei, Benjamin K., Lee, Robert D., Harris, Glendon H., Cabrera, Miguel, Franklin, Dorcas H., Diaz-Perez, Juan C., Habteselassie, Mussie Y., and Sintim, Henry Y.
- Subjects
CORN growth ,TISSUE analysis ,FIELD research ,PLANT cells & tissues ,COPPER ,CORN - Abstract
Growers rely on nutrient sufficiency ranges (NSRs) after plant tissue analysis to inform timely nutrient management decisions. The NSRs are typically established from survey studies across multiple locations, which could be confounded by several abiotic and biotic factors. We conducted field studies in 2020, 2021, and 2022 to validate the lower thresholds of the NSRs for corn (Zea mays) at the early growth stage as reported in the Southern Cooperative Series Bulletin #394. We induced various corn nutritional levels by making different nutrient application rates. If the NSRs are valid, samples within the same replication that satisfy the NSRs of all nutrients should have similar biomass accumulation. The results showed that the NSRs were not valid under the conditions tested. In total, 47.6% of the samples satisfied all the lower thresholds of the NSRs, and 25.4% of those samples had relative biomass <50%, with relative biomass even as low as 24.2% observed. Moreover, 9.6% of the total samples had P and Cu levels that failed to meet the lower threshold but still had relative biomass ≥75%. The findings highlight the sensitivity of corn to nutrient imbalance and the need to optimize nutrient diagnostic methods at the early growth stage. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. Video frame prediction of microbial growth with a recurrent neural network.
- Author
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Robertson, Connor, Wilmoth, Jared L., Retterer, Scott, and Fuentes-Cabrera, Miguel
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DEEP learning ,RECURRENT neural networks ,MICROBIAL growth ,MICROORGANISM populations ,MACHINE learning ,FLUORESCENCE microscopy - Abstract
The recent explosion of interest and advances in machine learning technologies has opened the door to new analytical capabilities in microbiology. Using experimental data such as images or videos, machine learning, in particular deep learning with neural networks, can be harnessed to provide insights and predictions for microbial populations. This paper presents such an application in which a Recurrent Neural Network (RNN) was used to perform prediction of microbial growth for a population of two Pseudomonas aeruginosa mutants. The RNN was trained on videos that were acquired previously using fluorescence microscopy and microfluidics. Of the 20 frames thatmake up each video, 10 were used as inputs to the network which outputs a prediction for the next 10 frames of the video. The accuracy of the network was evaluated by comparing the predicted frames to the original frames, as well as population curves and the number and size of individual colonies extracted from these frames. Overall, the growth predictions are found to be accurate in metrics such as image comparison, colony size, and total population. Yet, limitations exist due to the scarcity of available and comparable data in the literature, indicating a need for more studies. Both the successes and challenges of our approach are discussed. [ABSTRACT FROM AUTHOR]
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- 2023
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26. Fructan mixtures of Agave salmiana and chicory exhibit in vitro anticancer potential in human colon cells and prebiotic activity.
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Alvarez García, Paola, Alcántara Quintana, Luz Eugenia, Ruiz Cabrera, Miguel Ángel, Martínez Gutiérrez, Fidel, González García, Raúl, and Grajales Lagunes, Alicia
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- 2023
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27. Evaluation of Two Active System Encapsulant Matrices with Quercetin and Bacillus clausii for Functional Foods.
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Enciso-Huerta, Hector Alfonso, Ruiz-Cabrera, Miguel Angel, Lopez-Martinez, Laura Araceli, Gonzalez-Garcia, Raul, Martinez-Gutierrez, Fidel, and Saavedra-Leos, Maria Zenaida
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QUERCETIN , *INULIN , *BACILLUS (Bacteria) , *FUNCTIONAL foods , *OXIDANT status , *LIFE expectancy , *FOOD consumption - Abstract
Currently, demand for functional foods is increasing in the public interest in order to improve life expectations and general health. Food matrices containing probiotic microorganisms and active compounds encapsulated into carrier agents are essential in this context. Encapsulation via the lyophilisation method is widely used because oxidation reactions that affect physicochemical and nutritional food properties are usually avoided. Encapsulated functional ingredients, such as quercetin and Bacillus clausii, using two carrier agents' matrices—I [inulin (IN), lactose (L) and maltodextrin (MX)] and II [arabic (A), guar (G), and xanthan (X) gums)]—are presented in this work. A D-optimal procedure involving 59 experiments was designed to evaluate each matrix's yield, viability, and antioxidant activity (AA). Matrix I (33.3 IN:33.3 L:33.3 MX) and matrix II (33.3 A:33.3 G:33.3 X) exhibited the best yield; viability of 9.7 log10 CFU/g and 9.73 log10 CFU/g was found in matrix I (using a ratio of 33.3 IN:33.3 L:33.3 MX) and matrix II (50 G:50 X), respectively. Results for the antioxidant capacity of matrix I (100 IN:0 L:0M X) and matrix II (0 A:50 G:50 X) were 58.75 and 55.54 (DPPH* scavenging activity (10 µg/mL)), respectively. Synergy between matrices I and II with use of 100IN:0L:OMX and 0A:50G:50X resulted in 55.4 log10 CFU/g viability values; the antioxidant capacity was 9. 52 (DPPH* scavenging activity (10 µg/mL). The present work proposes use of a carrier agent mixture to produce a functional ingredient with antioxidant and probiotic properties that exceed the minimum viability, 6.0 log10 CFU/g, recommended by the FAO/WHO (2002) to be probiotic, and that contributes to the recommended daily quercetin intake of 10–16 mg/day or inulin intake of 10–20 g/day and dietary fibre intake of 25–38 g per day. [ABSTRACT FROM AUTHOR]
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- 2022
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28. Extreme Weather and Grazing Management Influence Soil Carbon and Compaction.
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Subedi, Anish, Franklin, Dorcas, Cabrera, Miguel, Dahal, Subash, Hancock, Dennis, McPherson, Amanda, and Stewart, Lawton
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RANGE management ,EXTREME weather ,SOIL compaction ,ROTATIONAL grazing ,CARBON in soils ,GRASSLAND soils ,EXTREME environments - Abstract
Understanding the influence of cattle grazing on soil carbon and bulk density during extreme dry to wet periods can help us design more resilient and sustainable grazing systems for low-input management scenarios. A study was conducted to evaluate changes in loss-on-ignition (LOI) carbon and bulk density (BD) in the top 20 cm soil layer when eight continuous grazing (CG) pastures were converted to either continuous grazing with hay distribution (CHD-4) or strategic grazing (STR-4). STR included lure management of cattle with movable-equipages, exclusion and over-seeding erosion-vulnerable areas, and a relaxed rotational grazing. Changes in relationships between cattle density (CD), LOI, and BD were evaluated for change in grazing management from 2015 to 2018. Reduction in LOI carbon (0–5, 5–10, 10–20 cm) and BD (5–10 cm) were observed in both CHD and STR pastures in 2018. CD in 2015 had either no relationship or a negative relationship on LOI while in 2018, CD positively influenced LOI in CHD (0–5 cm) and STR (0–5 and 5–10 cm) pastures. STR had lower BD with higher CD further away from concentrated flow paths mirroring cattle movement. Exclusions in the STR pastures had the greatest reduction in BD. Even with reduced carbon in the 0–5 cm soil layer the reduction in BD in the 5–10 cm soil layer helped build resilience in grazing systems that experience extreme weather events such as going from very dry to extensively wet. [ABSTRACT FROM AUTHOR]
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- 2022
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29. Investigating Carboxysome Morphology Dynamics with a Rotationally Invariant Variational Autoencoder.
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Fuentes-Cabrera, Miguel, Sakkos, Jonathan K., Ducat, Daniel C., and Ziatdinov, Maxim
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- 2022
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30. Bentonite Powder XRD Quantitative Analysis Using Rietveld Refinement: Revisiting and Updating Bulk Semiquantitative Mineralogical Compositions.
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Cuevas, Jaime, Cabrera, Miguel Ángel, Fernández, Carlos, Mota-Heredia, Carlos, Fernández, Raúl, Torres, Elena, Turrero, María Jesús, and Ruiz, Ana Isabel
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RIETVELD refinement , *BENTONITE , *CLAY minerals , *GOETHITE , *CRISTOBALITE , *METAL wastes , *POWDERS - Abstract
Bentonite is a claystone formed by a complex mineralogical mixture, composed of montmorillonite, illite, and accessory minerals like quartz, cristobalite, feldspars, carbonates, and minor amounts of iron oxy-hydroxides. Bentonite presents complexity at various scales: (1): a single mineral may present different chemical composition within the same quarry (e.g., feldspars solid solutions); (2): montmorillonite presents variability in the cation-exchange distribution while illite may be presented as mixed-layer with smectite sheets; and (3): hardness and crystal size are larger in accessory minerals than in clay minerals, preventing uniform grinding of bentonite. The FEBEX bentonite used is originally from Almería (Spain), and it is a predominantly calcium, magnesium, and sodium bentonite. This Spanish FEBEX bentonite has been hydrothermally altered at laboratory scale for 7–14 years. A thermal gradient was generated by heating a disk of pressed iron powder, simulating the metal waste canister, in contact with the compacted bentonite sample. Hydration was forced from the opposite direction. XRD recorded patterns were very similar. In order to minimize the bias of XRD semi-quantitative determination methods, Rietveld refinement was performed using BGMN software and different structural models. Confidence in the quantification of the main phases allows us to convincingly detect other subtle changes such as the presence of calcite in the hydration front, right at the interface between the saturated and unsaturated bentonite, or the presence of goethite, and not hematite, in the saturated bentonite, near the source of hydration. Smectite component was 72 ± 3% and the refinement was consistent with the presence of ~10% illite, comparable with previous characterizations. [ABSTRACT FROM AUTHOR]
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- 2022
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31. Geomorphology of the SW flank of the Doña Juana Volcanic Complex, Colombia: interplay of fluvial, denudational, structural, and volcanic processes.
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Salazar-Jaramillo, Susana, Camacho, Ricardo, Villota, Santiago, Pardo, Natalia, Velásquez, Andrés, Cabrera, Miguel A., and Pulgarín, Bernardo
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GEOMORPHOLOGY ,DRONE aircraft ,LANDFORMS ,COMMUNITIES ,RURAL geography ,DYNAMICAL systems - Abstract
In the SW flank of the Doña Juana Volcanic Complex, Colombia, the dynamic geomorphic system responds to the complex interaction between volcanic, climatic, and tectonic driving forces, where the recent landscape (last ~20 years) is being shaped as a function of denudational processes. Despite the rapid rates of landforms development, the geomorphology of this area is poorly documented. To overcome the lack of information we mapped the area using a GeoSAR DEM and an Unmanned Aerial Vehicle based DEM. This paper presents two maps, a 1:25,000 scale map and a 1:5,000 detailed map of landforms along the Humadal Creek. Detailed categorization of landforms (at 1:5,000) allowed us to identify geomorphic processes in the village of Las Mesas and rural areas that triggered hazards for the communities. The morphologic evolution interpretation of this volcanic tropical area serves as a tool for future geohazard assessment in inhabited areas with important information gaps. [ABSTRACT FROM AUTHOR]
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- 2022
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32. First record of Myocastor coypus (Molina 1782) (Mammalia, Rodentia) for the state of Mato Grosso do Sul, Brazil, and its distribution in southern South America.
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Murillo Peixoto-Couto, Rodney, Correa-Branco, Anderson, and Cabrera-Miguel, Maiara
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RODENTS ,MAMMALS ,RURAL geography ,PUBLIC records ,WETLANDS - Abstract
Copyright of Actualidades Biológicas is the property of Universidad de Antioquia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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33. Impact of Shared Control Modalities on Performance and Usability of Semi-autonomous Prostheses.
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Mouchoux, Jérémy, Bravo-Cabrera, Miguel A., Dosen, Strahinja, Schilling, Arndt F., and Markovic, Marko
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DUAL-task paradigm ,PROSTHETICS ,ARTIFICIAL arms ,COGNITIVE load ,PROSTHESIS design & construction ,COMPUTER vision ,DEGREES of freedom - Abstract
Semi-autonomous (SA) control of upper-limb prostheses can improve the performance and decrease the cognitive burden of a user. In this approach, a prosthesis is equipped with additional sensors (e.g., computer vision) that provide contextual information and enable the system to accomplish some tasks automatically. Autonomous control is fused with a volitional input of a user to compute the commands that are sent to the prosthesis. Although several promising prototypes demonstrating the potential of this approach have been presented, methods to integrate the two control streams (i.e., autonomous and volitional) have not been systematically investigated. In the present study, we implemented three shared control modalities (i.e., sequential, simultaneous , and continuous) and compared their performance, as well as the cognitive and physical burdens imposed on the user. In the sequential approach, the volitional input disabled the autonomous control. In the simultaneous approach, the volitional input to a specific degree of freedom (DoF) activated autonomous control of other DoFs, whereas in the continuous approach, autonomous control was always active except for the DoFs controlled by the user. The experiment was conducted in ten able-bodied subjects, and these subjects used an SA prosthesis to perform reach-and-grasp tasks while reacting to audio cues (dual tasking). The results demonstrated that, compared to the manual baseline (volitional control only), all three SA modalities accomplished the task in a shorter time and resulted in less volitional control input. The simultaneous SA modality performed worse than the sequential and continuous SA approaches. When systematic errors were introduced in the autonomous controller to generate a mismatch between the goals of the user and controller, the performance of SA modalities substantially decreased, even below the manual baseline. The sequential SA scheme was the least impacted one in terms of errors. The present study demonstrates that a specific approach for integrating volitional and autonomous control is indeed an important factor that significantly affects the performance and physical and cognitive load, and therefore these should be considered when designing SA prostheses. [ABSTRACT FROM AUTHOR]
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- 2021
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34. Influence of Prebiotic Activity of Agave salmiana Fructans on Mucus Production and Morphology Changes in Colonic Epithelium Cell of Healthy Wistar Rats.
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Castillo Andrade, Amneris Iraida, García Chávez, Erika, Rivera Bautista, Cecilia, Oros Ovalle, Cuauhtemoc, Ruiz Cabrera, Miguel Angel, and Grajales Lagunes, Alicia
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LABORATORY rats ,FRUCTANS ,AGAVES ,EPITHELIUM ,DIETARY supplements ,COLON (Anatomy) ,TUMOR necrosis factors - Abstract
The beneficial health of evaluating prebiotic effect by the consumption of Agave salmiana fructans (A. salmiana fructans) was assessed in the epithelium of the cecum and proximal colon of Wistar rats fed at different doses for 35 days with regards to mucus production, morphological cell changes, and the serum concentration of tumor necrosis factor-α (TNF-α). Results showed a significant increase in mucus-secreting cells (P < 0.05) and a normal structure with preserved crypts, without morphological damage to colonic cells for a dose of 12.5% (w/w) with respect to the control and the other doses evaluated. The concentration of pro-inflammatory cytokine TNF-α was decreased significantly (P < 0.05) in the groups with doses of 10 and 12.5% (w/w) at 7 and 35 days, respectively. This effect was positively correlated with the reduction of inflammation in epithelial cells. This study provides direct evidence of the effects of the A. salmiana fructans on the colonic epithelium, demonstrating that a diet supplemented with 12.5% of fructans for 35 days exerts health benefits through the strengthening of the mucosa layer, which favors the adherence of the bacterial population and suppresses inflammation. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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35. Simulations of Water and Thermal Dynamics for Soil Surfaces With Residue Mulch and Surface Runoff.
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Wang, Zhuangji, Thapa, Resham, Timlin, Dennis, Li, Sanai, Sun, Wenguang, Beegum, Sahila, Fleisher, David, Mirsky, Steven, Cabrera, Miguel, Sauer, Thomas, Reddy, Vangimalla R., Horton, Robert, and Tully, Katherine
- Subjects
WATER temperature ,GEOTHERMAL resources ,SURFACE dynamics ,RUNOFF ,SHALLOW-water equations ,SOIL dynamics - Abstract
Water and thermal dynamics at soil surfaces are influenced by multiple ambient factors, for example, weather, soil, residue mulch, and surface runoff. A surface water and temperature model should address those ambient factors, and their interactions and derivatives. In this study, we developed a process‐based simulation model for surface water and heat transfer with two main ambient factors, residue mulch and surface runoff. Surface water content and temperature are simulated with a modified Philip and de Vries (1957) model, including precipitation interception and radiation attenuation in residue mulch. Surface runoff is modeled with the Saint‐Venant equation. Residue decomposition, as a derivative, is computed via a modified CERES‐N model. Interactions between surface runoff and residue mulch, and dynamic decreases in residue mulch thickness due to decomposition are also included. The model was modularized and deployed with a "layered module architecture" in MAIZSIM, such that the main ambient factors, interactions, and derivatives can be activated or deactivated based on scenarios or user settings. Illustrative examples include non‐decomposable residue mulch, surface runoff and mulch decomposition scenarios. Results demonstrate that residue mulch can conserve soil water and reduce temporal variations of surface temperature. Surface runoff and its effects on water infiltration and surface temperature, and nitrogen mineralization during decomposition are also illustrated. The simulated surface temperature, water content, and mulch decomposition results are similar to literature results from field experiments. This study demonstrates the model workability in simulating surface water and temperature dynamics, and the feasibility of synthesizing multiple factors via a modularized model architecture. Plain Language Summary: Knowledge of the impacts on residue mulch and surface runoff on surface soil is important for agricultural field management. We developed a new method to simulate the moisture and thermal regimes on soil surface with residue mulch and/or surface runoff using a computer program. The computer program can also present the surface runoff and residue decomposition. The program can estimate the nitrogen and carbon (organic matter) exchanges between residue mulch and surface soil. This information will be useful to scientists, agricultural managers and consultants. Key Points: A numerical model is developed to simulate soil surface water and temperature with residue mulch and runoffWater and thermal simulations are adaptive to mulch decomposition and shrinkageMulch residue decomposition and N mineralization rate are estimated by the model [ABSTRACT FROM AUTHOR]
- Published
- 2021
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36. Application of Machine Learning Techniques to an Agent-Based Model of Pantoea.
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Chen, Serena H., Londoño-Larrea, Pablo, McGough, Andrew Stephen, Bible, Amber N., Gunaratne, Chathika, Araujo-Granda, Pablo A., Morrell-Falvey, Jennifer L., Bhowmik, Debsindhu, and Fuentes-Cabrera, Miguel
- Subjects
MACHINE learning ,RANDOM forest algorithms ,ON-demand computing ,MICROBIAL growth ,DYNAMICAL systems - Abstract
Agent-based modeling (ABM) is a powerful simulation technique which describes a complex dynamic system based on its interacting constituent entities. While the flexibility of ABM enables broad application, the complexity of real-world models demands intensive computing resources and computational time; however, a metamodel may be constructed to gain insight at less computational expense. Here, we developed a model in NetLogo to describe the growth of a microbial population consisting of Pantoea. We applied 13 parameters that defined the model and actively changed seven of the parameters to modulate the evolution of the population curve in response to these changes. We efficiently performed more than 3,000 simulations using a Python wrapper, NL4Py. Upon evaluation of the correlation between the active parameters and outputs by random forest regression, we found that the parameters which define the depth of medium and glucose concentration affect the population curves significantly. Subsequently, we constructed a metamodel, a dense neural network, to predict the simulation outputs from the active parameters and found that it achieves high prediction accuracy, reaching an R
2 coefficient of determination value up to 0.92. Our approach of using a combination of ABM with random forest regression and neural network reduces the number of required ABM simulations. The simplified and refined metamodels may provide insights into the complex dynamic system before their transition to more sophisticated models that run on high-performance computing systems. The ultimate goal is to build a bridge between simulation and experiment, allowing model validation by comparing the simulated data to experimental data in microbiology. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
37. Testing the EPIC Richards submodel for simulating soil water dynamics under different bottom boundary conditions.
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Longo, Matteo, Jones, Curtis Dinnen, Izaurralde, Roberto César, Cabrera, Miguel L., Dal Ferro, Nicola, and Morari, Francesco
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ZONE of aeration ,SOIL moisture ,GROUNDWATER ,BIOGEOCHEMICAL cycles ,SOIL quality - Abstract
Most biogeochemical models simulate water dynamics using the tipping bucket approach, which has been often found to be too simplistic to represent vadose zone dynamics adequately under shallow groundwater conditions. Recently, a solution to the Richards equation using the Mualem–van Genuchten model (Rich‐vGM) has been added into the EPIC (Environmental Policy Integrated Climate) model to address this shortfall. Its performance was tested using lysimeters operating under free drainage (FD) and at a shallow water table (60‐ [WT60] and 120‐cm depth [WT120]). Model accuracy was also compared with the upgraded tipping bucket‐based method implemented into EPIC (the variable saturation hydraulic conductivity method [VSHC]). Soil water content (SWC) data were split into calibration and validation subsets. Model evaluation also included annual evapotranspiration (ET), percolation (PRK), and upward water movements to assess underlying soil water balance factors. The submodels provided accurate and similar results upon comparison with SWC measures under FD (Nash–Sutcliffe coefficient [NSE] = 0.26 and 0.61 using VSHC and Rich‐vGM, respectively). The Rich‐vGM model accurately reproduced observed SWC and ET (e.g., NSE = 0.70 and percentage bias [PBIAS] = −3.7% for WT120, respectively) although it slightly overestimated PRK (PBIAS = 47.8%, on average). Instead, VSHC proved unable to correctly simulate shallow groundwater conditions (e.g., NSE = −1.85 for WT60 SWC). Under shallow groundwater conditions, the Rich‐vGM method is recommended, despite the additional data required and the need to define the bottom boundary conditions according to water table fluctuations. In conclusion, the Richards solver introduced and tested in EPIC improved the model's ability to represent complex biophysical and biogeochemical processes in terrestrial ecosystems associated with the hydrological balance. Core Ideas: EPIC Richards solver was tested in a 9‐yr experiment under different groundwater conditions.The new Richards algorithms were compared with the tipping‐bucket based method.Both methods predicted similar soil water content under free drainage.Water content and ET were better predicted by Richards under shallow water table.Under specific conditions, percolation was overestimated for both approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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38. PHILODRYAS MATTOGROSSENSIS.
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PEIXOTO COUTO, RODNEY MURILLO and CABRERA MIGUEL, MAIARA
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LIFE sciences , *BABY birds , *BIOTIC communities , *GREAT tit , *REPTILES , *PASSERIFORMES - Abstract
The article discusses the diet of Philodryas mattogrossensis, who prey upon Tropidurus torquatus, a medium-sized, terrestrial, saxicolous, or arboreal lizard.
- Published
- 2021
39. Physicochemical Properties, Antioxidant Capacity, Prebiotic Activity and Anticancer Potential in Human Cells of Jackfruit (Artocarpus heterophyllus) Seed Flour.
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Trejo Rodríguez, Ibna Suli, Alcántara Quintana, Luz Eugenia, Algara Suarez, Paola, Ruiz Cabrera, Miguel Angel, and Grajales Lagunes, Alicia
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JACKFRUIT ,FLOUR ,OXIDANT status ,SEEDS ,LACTOBACILLUS casei ,BIFIDOBACTERIUM longum ,PLANT polyphenols ,OLIGOSACCHARIDES - Abstract
The general aim of this study was to evaluate physicochemical properties, prebiotic activity and anticancer potential of jackfruit (Artocarpus heterophyllus) seed flour. The drying processes of jackfruit seeds were performed at 50, 60 and 70 °C in order to choose the optimal temperature for obtaining the flour based on drying time, polyphenol content and antioxidant capacity. The experimental values of the moisture ratio during jackfruit seed drying at different temperatures were obtained using Page's equation to establish the drying time for the required moisture between 5 and 7% in the flour. The temperature of 60 °C was considered adequate for obtaining good flour and for performing its characterization. The chemical composition, total dietary fiber, functional properties and antioxidant capacity were then examined in the flour. The seed flour contains carbohydrates (73.87 g/100 g), dietary fiber (31 g/100 g), protein (14 g/100 g) and lipids (1 g/100 g). The lipid profile showed that the flour contained monounsaturated (4 g/100 g) and polyunsaturated (46 g/100 g) fatty acids. Sucrose, glucose, and fructose were found to be the predominant soluble sugars, and non-digestible oligosaccharides like 1-kestose were also found. The total polyphenol content was 2.42 mg of gallic acid/g of the sample; furthermore, the antioxidant capacity obtained by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) was 901.45 µmol Trolox/100 g and 1607.87 µmol Trolox/100 g, respectively. The obtained flour exhibited good functional properties, such as water and oil absorption capacity, swelling power and emulsifier capacity. Additionally, this flour had a protective and preventive effect which is associated with the potential prebiotic activity in Lactobacillus casei and Bifidobacterium longum. These results demonstrate that jackfruit seed flour has good nutritional value and antioxidant and prebiotic activity, as well as potential protective effects and functional properties, making it an attractive food or ingredient in developing innovative functional products. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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40. An Integrated Approach for Nitrogen Management in Upland Cotton Production
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Ofori, Bright Kwabena, Crop and Soil Environmental Sciences, Frame, William Hunter, Cabrera, Miguel L., Stewart, Ryan Daniel, and Reiter, Mark S.
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Nitrogen ,nitrate ,enhanced efficiency fertilizer ,cover crop ,legume ,volatilization ,placement ,nitrification - Abstract
Nitrogen (N) fertilizer application constitutes a major portion of farmers' cost of production since N is the most applied nutrient in U.S. cotton production. Despite this, N uptake and use efficiency (NUE) in cotton remains below 50%, which presents challenges of environmental quality. Studies were conducted across 4 states in the US Cotton Belt with the overall objective of evaluating strategies to reduce loss of N to the environment, increase N uptake and NUE. The first study had two objectives: 1) compare NH3 volatilization from surface versus subsurface application/placement of granular (urea) and fluid N source (urea ammonium nitrate; UAN32); and 2) compare NH3 volatilization from urea and UAN treated with enhanced-efficiency fertilizer products. For this study, four A horizon soils of different types were collected from four sites in Virginia (VA), Georgia (GA), Tennessee (TN), and Texas (TX). The EEF products were N-(n-butyl) thiophosphoric triamide (NBPT), nitrapyrin, and ESN. In the first set of experiments (N placement experiments), it was found that across soil types, subsurface placement of granular N source reduced NH3 volatilization by 58 – 81% and subsurface placement of UAN reduced NH3 volatilization by 56 – 98%. In the second set of experiments (EEF experiments), it was found that NBPT reduced NH3 volatilization by 5 – 77% across soil types, and the highest reduction in losses by NBPT was observed on sandier and low CEC soils. Treating urea with both nitrapyrin and NBPT was more effective at reducing NH3 volatilization compared to treating urea with nitrapyrin alone. Based on our findings, subsurface application of granular and fluid N sources is recommended as strategy to reduce NH3 volatilization. Where subsurface placement is not possible, EEF products should be considered. The objectives of the second study were: 1) determine the effects of small grain and legume cover crops on N cycling; 2) evaluate the effects of cover crops and N fertilization on N uptake; and 3) evaluate the effects of cover crops on lint yield. Cover crops were winter fallow (winter weeds), small grain [cereal rye (Secale cereale)], legume mix [(50% crimson clover (Trifolium incarnatum): 50% hairy vetch (Vicia villosa)], and legume mix + rye [(67% legume mix:33% hairy vetch)]. Fertilizer N application rates were 0, 45, 90, and 135 kg ha-1. Soil inorganic N in the top 30 cm depths of the legume mix and legume mix + rye plots was consistently higher than in the rye lone or fallow plots. Cotton lint yield following legume mix with 45 kg ha-1 fertilizer N application was comparable to following fallow plots with 135 kg N ha-1. Thus, fertilizer N rate could considerably be reduced when cotton follows legume cover crops. The objectives of the third study were: 1) evaluate urea and UAN placement (broadcast, dribbling, and injection) on lint yield and fiber quality of three cotton maturity groups (early-, mid-, and full-maturity); (2) assess N use and agronomic efficiencies as influenced by N source, rate, and placement; (3) evaluate the impact of N source and placement on fiber quality. A study including 9 site-years studies was conducted in VA, GA, and TX. It was found that placement had no effect on yield in VA, had effect in all 3 years in TX, and had effect in 1 year in GA. Yield responded to N application in 8 out of 9 site-years in this study. Nitrogen use efficiency was highest among the early- and mid-season varieties. Overall, N rate and variety, rather than application/placement strategy, had the most pronounced effects on lint yield. Doctor of Philosophy Nitrogen (N) is usually the major limiting nutrient in cotton production and represents a significant cost of production. On average, the current proportion of applied N recovered in the aboveground crop biomass, (i.e., nitrogen use efficiency, or NUE) ranges from 33 – 50%, meaning that up to two-thirds of applied N is not recovered by crops. This unrecovered N not only represents economic loss to growers, but acts as a potential pollutant in the environment. There is a need for practices which increase N uptake in cotton production, agronomic efficiency, and environmental sustainability. Previous studies conducted outside the U.S. Cotton Belt reported that NUE is influenced by N source and rate of application. Data on NUE of contemporary cotton varieties utilized in the humid and semi-arid regions of the U.S. Cotton Belt would prove useful in efficient N management in the region. First study evaluated gaseous N loss from fertilizer application. It was found that subsurface placement of granular urea reduced NH3 loss as much as 58 – 81% compared to surface broadcast granular urea and subsurface placement of fluid N source reduced NH3 loss by 56 – 98%. In a second study, N rate and method of application/placement were evaluated. Here, it was found that N rate and cotton variety, rather than application/placement strategy had a more pronounced effect on cotton yield. Lastly, the potential of cover crops as alternate N source in cotton production was investigated. It was found that cotton yield following legume mix and fertilized with 45 kg of N per hectare was comparable with cotton yield following no cover crop and fertilized with 135 kg of N per hectare. The results of these studies indicate that subsurface placement of granular and fluid N sources can reduce NH3 loss. In addition, all other things being equal, choosing the right cotton variety as well as applying the right N rate are critical for yield. Furthermore, by growing cotton after legume cover crops, N fertilizer application rates can be significantly reduced.
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- 2023
41. Microbial processes and community structure as influenced by cover crop residue type and placement during repeated dry-wet cycles.
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Thapa, Resham, Tully, Katherine L., Hamovit, Nora, Yarwood, Stephanie A., Schomberg, Harry H., Cabrera, Miguel L., Reberg-Horton, Chris, and Mirsky, Steven B.
- Subjects
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COVER crops , *CROP residues , *MICROBIAL communities , *RYE , *NUTRIENT cycles , *SOIL microbiology - Abstract
Soil microorganisms play a critical role in cover crop (CC) residue decomposition and nutrient cycling in agroecosystems. However, the impact of CC residue management and dry-wet cycles on soil and residue microbiota and their potential ecosystem functions is largely unknown. To fill these knowledge gaps, an incubation experiment was conducted with two CC residues, crimson clover (Trifolium incarnatum L.) and cereal rye (Secale cereale L.), and two residue placements (incorporated vs surface-applied). Each CCs by placement treatment was subjected to four dry-wet cycles (20-d each) for a total of 80-d. Crimson clover residues had higher water storage capacities than cereal rye, and the rate at which water was lost from surface-applied CC residues increased after each successive wetting event. Rapid drying of surface-applied CC residues quickly suppressed CO 2 fluxes, which increased immediately upon rewetting. Incorporated CC residues maintained water content for longer duration than surface-applied residues and showed greater colonization by soil prokaryotes and saprophytic fungi. Thus, significantly more C and N were mobilized from incorporated residues by 80-d than from surface-applied residues (p < 0.05). Due to differences in residue chemistry, CC residue types have a stronger impact on soil N levels than residue placement. Thus, residue chemistry strongly influenced soil prokaryotic and fungal diversity, community structure, and functionality. While crimson clover-amended soils (N-rich environments) were dominated by copiotrophs, oligotrophs dominated cereal rye-amended soils (N-poor soil environments). On the other hand, residue placement may have a greater effect than residue type in determining residue microbiota, particularly prokaryotes. Based on these findings, we can conclude that the effect of residue placement on C and N mineralization during repeated dry-wet cycles is primarily explained by differences in water dynamics between incorporated and surface-applied CC residues. • Cover crop residue type, residue placement, and dry-wet cycles strongly influenced microbial processes and functions. • Incorporated residues mineralized more C and N than surface-applied residues. • C mineralization from surface-applied residues quickly dropped following rewetting due to rapid loss of water. • Residue type influenced soil prokaryotic and fungal diversity, community structure, and functionality. • When incorporated, residues are more colonized by soil prokaryotes and saprophytic fungi. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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