The input reduction principle of agroecology is wrong when it comes to mineral fertilizer use in sub-Saharan Africa

Gatien Falconnier Marc Corbeels Frédéric Baudron Antoine Couëdel leonard rusinamhodzi bernard vanlauwe Ken Giller (2023, [Artículo])

Can farmers in sub-Saharan Africa (SSA) boost crop yields and improve food availability without using more mineral fertilizer? This question has been at the center of lively debates among the civil society, policy-makers, and in academic editorials. Proponents of the “yes” answer have put forward the “input reduction” principle of agroecology, i.e. by relying on agrobiodiversity, recycling and better efficiency, agroecological practices such as the use of legumes and manure can increase crop productivity without the need for more mineral fertilizer. We reviewed decades of scientific literature on nutrient balances in SSA, biological nitrogen fixation of tropical legumes, manure production and use in smallholder farming systems, and the environmental impact of mineral fertilizer. Our analyses show that more mineral fertilizer is needed in SSA for five reasons: (i) the starting point in SSA is that agricultural production is “agroecological” by default, that is, very low mineral fertilizer use, widespread mixed crop-livestock systems and large crop diversity including legumes, but leading to poor soil fertility as a result of widespread soil nutrient mining, (ii) the nitrogen needs of crops cannot be adequately met solely through biological nitrogen fixation by legumes and recycling of animal manure, (iii) other nutrients like phosphorus and potassium need to be replaced continuously, (iv) mineral fertilizers, if used appropriately, cause little harm to the environment, and (v) reducing the use of mineral fertilizers would hamper productivity gains and contribute indirectly to agricultural expansion and to deforestation. Yet, the agroecological principles directly related to soil fertility—recycling, efficiency, diversity—remain key in improving soil health and nutrient-use efficiency, and are critical to sustaining crop productivity in the long run. We argue for a nuanced position that acknowledges the critical need for more mineral fertilizers in SSA, in combination with the use of agroecological practices and adequate policy support.

Manure Crop Yields Smallholder Farming Systems Environmental Hazards CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA BIOLOGICAL NITROGEN FIXATION LEGUMES NUTRIENT BALANCE SOIL FERTILITY AGROECOLOGY YIELD INCREASES LITERATURE REVIEWS

Closing the yield gap of soybean (Glycine max (L.) Merril) in Southern Africa: a case of Malawi, Zambia, and Mozambique

Siyabusa Mkuhlani Isaiah Nyagumbo (2023, [Artículo])

Introduction: Smallholder farmers in Sub-Saharan Africa (SSA) are increasingly producing soybean for food, feed, cash, and soil fertility improvement. Yet, the difference between the smallholder farmers’ yield and either the attainable in research fields or the potential from crop models is wide. Reasons for the yield gap include low to nonapplication of appropriate fertilizers and inoculants, late planting, low plant populations, recycling seeds, etc. Methods: Here, we reviewed the literature on the yield gap and the technologies for narrowing it and modelled yields through the right sowing dates and suitable high-yielding varieties in APSIM. Results and Discussion: Results highlighted that between 2010 and 2020 in SSA, soybean production increased; however, it was through an expansion in the cropped area rather than a yield increase per hectare. Also, the actual smallholder farmers’ yield was 3.8, 2.2, and 2.3 times lower than the attainable yield in Malawi, Zambia, and Mozambique, respectively. Through inoculants, soybean yield increased by 23.8%. Coupling this with either 40 kg ha−1 of P or 60 kg ha−1 of K boosted the yields by 89.1% and 26.0%, respectively. Overall, application of 21–30 kg ha-1 of P to soybean in SSA could increase yields by about 48.2%. Furthermore, sowing at the right time increased soybean yield by 300%. Although these technologies enhance soybean yields, they are not fully embraced by smallholder farmers. Hence, refining and bundling them in a digital advisory tool will enhance the availability of the correct information to smallholder farmers at the right time and improve soybean yields per unit area.

Decision Support Tools Digital Tools Site-Specific Recommendations CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA DECISION SUPPORT SYSTEMS LEGUMES YIELDS SOYBEANS

Audiometría automatizada mediante visión computacional

Automated audiometry througt computer vision

Fernando Serrano Monroy (2023, [Tesis de maestría])

La pérdida de audición se refiere a la disminución de la capacidad auditiva, éste es un proceso progresivo e irreversible, en el que la mayoría de las ocasiones el individuo que presenta pérdida no se da cuenta de su evolución hasta que el proceso se encuentra avanzado. Dado que la audición es la vía principal a través de la cual se desarrolla el lenguaje y el habla, se debe tener presente que cualquier trastorno en la percepción auditiva de un individuo en edades tempranas, afectará su desarrollo lingüístico y comunicativo, sus procesos cognitivos y consecuentemente su posterior integración escolar, social y laboral. Todas estas consideraciones explican la necesidad de detectar este problema en sus comienzos, incluso antes de que el individuo se percate de que existe. La audiometría es una exploración del sistema auditivo, en la cual se mide la capacidad del oído humano de percibir sonidos. El objetivo principal de esta tesis es el diseño y desarrollo de un audiómetro automatizado, que con el reconocimiento de imágenes pueda interpretar la respuesta de la persona al realizar evaluación audiometría, Para ello, se desarrolló un sistema de visión computacional. Se presentan algunos beneficios del audiómetro digital, tales como la realización de pruebas de manera estandarizada para cada persona, la facilidad de almacenamiento de los resultados en formato digital, y la ampliación del acceso a las pruebas auditivas en lugares remotas.

Hearing loss refers to the decrease in auditory capacity, which is a progressive and irreversible process. In most cases, individuals with hearing loss are unaware of its progression until it has advanced. Since hearing is the main pathway through which language and speech development, it is essential to consider that any impairment in auditory perception during the early stages of life will affect linguistic and communicative development, cognitive processes, and subsequently, their educational, social, and occupational integration. All these considerations highlight the need to detect this problem early on, even before the individual becomes aware of its existence. Audiometry examines the auditory system that measures the human ear’s ability to perceive sounds. The main objective of this thesis is the design and development of an automated audiometer that, through image recognition, can interpret a person’s response during audiological evaluations. To achieve this, a computer vision system was developed. Some benefits of the digital audiometer are highlighted, such as conducting standardized tests for each individual, ease of storing results in digital format, and expanding access to auditory tests in remote locations.

audición, audiometría tonal, visión computacional, reconocimiento de patrones, salud auditiva hearing, tonal audiometry, computer vision, pattern recognition, hearing health INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA MÉDICA OTRAS OTRAS

Seasonal climate forecasts (SCFs) based risk management strategies: A case study of rainfed rice cultivation in India

Nand Lal Kushwaha Paresh Shirsath Dipaka Ranjan Sena (2022, [Artículo])

FResampler1 Seasonal Climate Forecasts Decision Support System for Agrotechnology Transfer CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CLIMATE CHANGE DECISION SUPPORT SYSTEMS YIELDS RICE RISK MANAGEMENT

How a holobiome perspective could promote intensification, biosecurity and eco-efficiency in the shrimp aquaculture industry

Eric Daniel Gutiérrez Pérez RICARDO VAZQUEZ JUAREZ FRANCISCO JAVIER MAGALLON BARAJAS MIGUEL ANGEL MARTINEZ MERCADO GRISEL ALEJANDRA ESCOBAR ZEPEDA Paola Magallón Servín (2022, [Artículo])

"The aquaculture industry faces many challenges regarding the intensification of shrimp rearing systems. One of these challenges is the release of excessive amounts of nitrogen and phosphorus into coastal areas, causing disruption in nutrient cycling and microbial equilibrium, which are important for coastal productivity. Biosecurity within the shrimp rearing systems can also be compromised by disruption to the nutrient fluxes, and as consequence the microbiome of the system. In certain conditions, these changes could lead to the blooming of potentially pathogenic bacteria. These changes in the external microbiome of the system and the constant fluctuations of nutrients can affect the intestinal microbiome of shrimp, which is involved in the growth and development of the host, affecting nutrient absorption, regulating metabolic processes, synthesising vitamins, modulating the immune response and preventing growth of pathogenic bacteria. It has been suggested that specific changes in the intestinal microbiome of Litopenaeus vannamei may be an avenue through which to overcome some of the problems that this industry faces, in terms of health, growth and waste. Recent research, however, has focussed mainly on changes in the intestinal microbiome. Researchers have overlooked the relevance of other aspects of the system, such as the microbiome from the benthic biofilms; zooplankton, plankton and bacterioplankton; and other sources of microorganisms that can directly affect the microbial status of the intestinal and epiphytic communities, especially in rearing systems that are based on intensification and microbial maturation processes, such as a biofloc system. It is therefore necessary to place holobiome studies into context, including the ‘holobiome of the aquaculture system’ (microbiomes that make up the culture system and their interactions) and not only the intestinal microbiome. Thus, we describe factors that affect the shrimp microbiome, the methodology of study, from sampling to bioinformatic workflows, and introduce the concept of the ‘holobiome of the aquaculture system’ and how this enables us to promote the intensification, biosafety and eco-efficiency of shrimp farming. The holobiome perspective implies a greater investment of resources and time for research, but it will accelerate the development of technology that will benefit the development and sustainability of the aquaculture industry."

litopenaeus vannamei, microbiome, intensification, biofloc, holobiome of aquaculture systems CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS PRODUCCIÓN ANIMAL NUTRICIÓN NUTRICIÓN

Evaluación de la cinética de liberación de compuestos hidrofílicos y lipofílicos a partir de nanopartículas híbridas polímero-lípido

Evaluation of the release kinetics of hydrophilic and lipophilic compounds from polymer-lipid hybrid nanoparticles

Juan Pablo Carmona Almazán (2023, [Tesis de maestría])

En el tratamiento de enfermedades, la administración de dosis múltiples es una estrategia común para mantener la concentración de los fármacos dentro de un margen terapéutico. Sin embargo, la adherencia de los pacientes a este tipo de tratamiento puede ser un desafío, llevando a una administración irregular de dosis. Una alternativa utilizada para abordar este reto son las nanopartículas híbridas polímero/lípido(NPPLs), las cuales, con menos administraciones, tienen el potencial de alcanzar la dosis necesaria en el tratamiento, posibilitando entonces el incremento del apego al tratamiento. En nuestro proyecto, se llevó a cabo la síntesis de nanopartículas de ácido poli láctico-co-glicólico (PLGA) recubiertas de lecitina de soya, por medio de técnicas de nanoprecipitación y autoensamblaje. Además, integramos estas nanopartículas en una matriz polimérica a base de aerogeles de gelatina de manera que estuvieran distribuidas de manera homogénea y concentrada. Nuestro enfoque central radica en entender la cinética de liberación de un compuesto hidrofílico (ácido gálico) y uno lipofílico (quercetina) a partir de este sistema. Logramos sintetizar nanopartículas con un diámetro hidrodinámico de 100 ± 15 nm, 153 ± 33 y149±21 nm, en el caso de las nanopartículas vacías y cargadas con ácido gálico y cargadas con quercetina, respectivamente. La eficiencia de encapsulación del ácido gálico fue del 90 ± 5 % y de la quercetina fue del 70 ± 10 %. Los resultados que obtuvimos muestran que el ácido gálico sigue una cinética del modelo de Korsmeyer-Peppas, con un valor de n = 1.01 y la quercetina una cinética de primer orden. Dado que los compuestos encapsulados tuvieron una liberación más lenta con respecto a los compuestos libres en los aerogeles de gelatina, nuestro trabajo indica que el encapsulamiento en NPPLs de un compuesto bioactivo, independientemente de su naturaleza química, puede ayudar a retrasar su liberación y reducir el número de dosis administradas, en consecuencia, esto pudiera contribuir a incrementar el apego de un paciente al tratamiento.

In the treatment of diseases, the administration of multiple doses is a common strategy to maintain drug concentrations within a therapeutic range. However, patient adherence to this type of treatment can be challenging, resulting in irregular dosing. An alternative approach used to address this challenge involves polymer/lipid hybrid nanoparticles (NPPLs), which have the potential to achieve the necessary drug dose with fewer administrations, thereby increasing treatment adherence. In our project, we synthesized poly(lactic-co-glycolic acid) (PLGA) nanoparticles coated with soy lecithin using nanoprecipitation and self-assembly techniques. These nanoparticles were then integrated into a polymer matrix based on gelatin aerogels to ensure homogeneous and concentrated distribution. Our main focus was to understand the release kinetics of a hydrophilic compound (gallic acid) and a lipophilic one (quercetin) from this system. We successfully synthesized nanoparticles with a hydrodynamic diameter of 100 ± 15 nm, 153 ± 33 nm, and 149 ± 21 nm for empty nanoparticles, gallic acid-loaded, and quercetin-loaded nanoparticles, respectively. The encapsulation efficiency was 90 ± 5 % for gallic acid and 70 ± 10 % for quercetin. The results we obtained indicate that gallic acid follows Korsmeyer-Peppas kinetics with a value of n = 1.01, while quercetin exhibits first-order kinetics. Since the encapsulated compounds showed slower release compared to free compounds in gelatin aerogels, our work suggests that encapsulation in NPPLs with a bioactive compound, regardless of its chemical nature, can help delay its release and reduce the number of doses administered. Consequently, this could contribute to improve patient treatment adherence.

nanopartículas híbridas, cinética de liberación, sistemas poliméricos, PLGA/lecitina, compuestos hidrofílicos y lipofílicos hybrid nanoparticles, release kinetics, polymeric systems, PLGA/lecithin, hydrophilic and lipophilic compounds INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS INGENIERÍA Y TECNOLOGÍA QUÍMICAS ANÁLISIS DE POLÍMEROS ANÁLISIS DE POLÍMEROS

Reconocimiento continuo de la Lengua de Señas Mexicana

Continuous recognition of Mexican Sign Language

Ricardo Fernando Morfín Chávez (2023, [Tesis de maestría])

La Lengua de Señas Mexicana (LSM) es la lengua utilizada por la comunidad Sorda en México, y, a menudo, subestimada y pasada por alto por la comunidad oyente, lo que resulta en la exclusión sistemática de las personas Sordas en diversos aspectos de la vida. Sin embargo, la tecnología puede desempeñar un papel fundamental en acercar a la comunidad Sorda con la comunidad oyente, promoviendo una mayor inclusión y comprensión entre ambas. El objetivo principal de este trabajo es diseñar, implementar y evaluar un sistema de reconocimiento continuo de señas estáticas en LSM mediante, visión por computadora y técnicas de aprendizaje máquina. Se establecieron objetivos específicos, que incluyen la generación de un conjunto de datos de señas estáticas, pertenecientes al alfabeto manual de la LSM, el diseño de un modelo de reconocimiento, y la evaluación del sistema, tanto en la modalidad aislada como en la continua. La metodología involucra dos evaluaciones distintas. La primera se enfoca en el reconocimiento de señas estáticas en el dominio aislado, para ello se capturaron datos de 20 participantes realizando movimientos de la mano en múltiples ángulos. Se evaluaron diversas técnicas de aprendizaje automático, destacando que el enfoque basado en Máquinas de Soporte Vectorial (SVM) obtuvo los mejores resultados (F1-Score promedio del 0.91). La segunda evaluación se concentra en el reconocimiento continuo de señas estáticas, con datos recopilados de seis participantes con diferentes niveles de competencia en LSM, logrando un rendimiento sólido con errores cercanos al 7 %. Además, se evaluó la viabilidad del sistema en aplicaciones de tiempo real, demostrando un excelente desempeño (velocidad promedio de procesamiento de 45 cuadros por segundo). A pesar de los logros alcanzados, es importante reconocer que este proyecto se centró en el reconocimiento continuo de señas estáticas en LSM. Queda pendiente, como un desafío interesante, la exploración del reconocimiento continuo de señas dinámicas en LSM para futuras investigaciones. Se considera esencial explorar enfoques orientados a la escalabilidad y aplicaciones en tiempo real en investigaciones posteriores.

This study focuses on the continuous recognition of static signs in Mexican Sign Language (Lengua de Señas Mexicana (LSM)), the language used by the Deaf community in Mexico. Despite its significance, LSM is often underestimated and overlooked, leading to the systematic exclusion of Deaf individuals in various aspects of life. The primary objective of this work is to design, implement, and evaluate a continuous static sign recognition system in LSM using computer vision and machine learning techniques. Specific goals were established, including the creation of a dataset of static signs belonging to the manual alphabet of LSM, the design of a recognition model, and the evaluation of the system in both isolated and continuous modes. The methodology involves two distinct evaluations. The first one focuses on the recognition of static signs in the isolated domain, for which data from 20 participants performing hand movements at various angles were collected. Various machine learning techniques were evaluated, with the Máquinas de Soporte Vectorial (SVM)-based approach achieving the best results (average F1-Score of 0.91). The second evaluation centers on the continuous recognition of static signs, using data collected from six participants with varying levels of competence in LSM, achieving robust performance with errors close to 7 %. Furthermore, the feasibility of the system in real-time applications was assessed, demonstrating excellent performance (average processing speed of 45 frames per second). Despite the achievements, it is important to recognize that this project focused on continuous recognition of static signs in LSM. It remains an interesting challenge to explore the continuous recognition of dynamic signs in LSM for future research. It is considered essential to explore scalability-oriented approaches and real-time applications in subsequent investigations.

Lengua de Señas Mexicana (LSM), visión por computadora, aprendizaje automático, alfabeto manual de la LSM, reconocimiento automático de señas estáticas, reconocimiento aislado de señas, reconocimiento continuo de señas, aplicacion Mexican Sign Language (LSM), computer vision, machine learning, LSM manual alpahbet, automatic recognition of static signs, isolated sign recognition, continuous sign recognition, real-time aplications INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES ENSEÑANZA CON AYUDA DE ORDENADOR ENSEÑANZA CON AYUDA DE ORDENADOR

Usando la descomposición de un grafo Halin para el diseño de algoritmos autoestabilizantes

Using Halin graph decomposition for the design of self-stabilizing algorithm

Daniel Uriel Orozco Lomelí (2023, [Tesis de maestría])

Sea G = (V, E) un grafo no dirigido. El problema de encontrar un conjunto independiente fuerte en G, es identificar un conjunto S ⊆ V , tal que dados dos vértices arbitrarios de S, éstos estén separados entre sí por el menos tres aristas. Encontrar un conjunto S de tamaño máximo pertenece a la clase NP-Difícil. Por otro lado, el problema de encontrar un conjunto dominante total en G es identificar un conjunto D ⊆ V , tal que cualquier vértice en V tenga al menos un vecino que pertenezca a D. Encontrar un conjunto D de tamaño mínimo también pertenece a la clase NP-Difícil. En este trabajo de tesis se diseñaron dos algoritmos, uno que resuelve el problema de encontrar un conjunto independiente fuerte maximal y otro que resuelve el problema de encontrar un conjunto dominante total minimal. Estos dos problemas son menos restrictivos que las versiones de optimización descritas al principio de este texto y se sabe que pertenecen a la clase P. Los algoritmos diseñados corren en un sistema distribuido, son autoestabilizantes, son tolerantes a fallas transitorias y funcionan para grafos Halin. Los grafos Halin pertenecen a la clase de grafos 2-outerplanares y tienen la propiedad de que se pueden partir en dos subgrafos muy conocidos, un árbol y un ciclo. Los algoritmos propuestos aprovechan la propiedad anterior para disminuir la complejidad de los mismos. Hasta donde tenemos conocimiento, los algoritmos propuestos, que corren en tiempo lineal en el número de vértices, son los algoritmos más rápidos existentes para los problemas del conjunto independiente fuerte maximal y el conjunto dominante total minimal.

Let G = (V, E) be an undirected graph. The problem of finding a strong stable set in G, is to identify a set S ⊆ V , such that given two arbitrary vertices of S, they are separated from each other by at least three edges. Finding a set S of maximum size belongs to the class NP-Hard. On the other hand, the problem of finding a total dominanting set in G is to identify a set D ⊆ V , such that any vertex in V has at least one neighbor belonging to D. Finding a set D of minimum size also belongs to the class NP-Hard. In this thesis work, two algorithms were designed, one that solves the problem of finding a maximal strong stable set and one that solves the problem of finding a minimal total dominanting set. These two problems are less restrictive than the optimization versions described at the beginning of this text and are known to belong to the P class. The designed algorithms run on a distributed system, are self-stabilizing, are transient fault tolerant, and work for Halin graphs. Halin graphs belong to the 2-outerplanar class of graphs and have the property that they can be split into two well-known subgraphs, a tree and a cycle. The proposed algorithms take advantage of the above property to decrease the complexity of the algorithms. To the best of our knowledge, the proposed algorithms, which run in linear time in the number of vertices, are the fastest existing algorithms for the maximal strong stable set and minimal total dominating set problems.

Grafo Halin, Sistemas Distribuidos, Autoestabilización, Conjunto Independiente Fuerte, Conjunto Dominante Total Halin Graph, Distributed Systems, Self-stabilizing, Strong Stable Set, Total Dominating Set INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES LENGUAJES ALGORÍTMICOS LENGUAJES ALGORÍTMICOS

Implementation of a Nickel-Electroless Coating in Heat Exchanger Pipes Considering the Problem of the Environmental Conditions ofthe Cooling Water Without Recirculation to Increase the Effectiveness Under Uncertainty

VICTOR MANUEL ZEZATTI FLORES GUSTAVO URQUIZA BELTRAN MIGUEL ANGEL BASURTO PENSADO LAURA LILIA CASTRO GOMEZ JUAN CARLOS GARCIA CASTREJON (2022, [Artículo])

This research is based on the operation tube heat exchangers, their use and problematic on hydroelectric power plants. It is based on the design heat exchanger tubes for industrial use, which took the parameters of operation, design, working fluids (air and water) and conditions to assemble a monitoring equipment at appropriate scale for the laboratory, with the necessary measurement instruments to analyze the behavior of heat energy transfer by means of thermocouples, the velocity of the air with a hot wire anemometer and the flow of water with a turbine flow meter, in pipes of different materials: copper, steel 1018 and stainless steel 316L, all in ideal conditions, and with this to found a comparative parameter with pipes of the same materials but under conditions of deterioration with the presence of forced oxidation and with the data mining and support vector machine can be minimized the corrosion problems in pipes.

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS Data mining, Support Vector Machine, Pattern Recognition and Decision Support System, Heat exchangers

OPTIMIZING THE TRANSFER OF ENERGY IN A HEAT EXCHANGER MINIMIZING THE CORROSION PROBLEMS IN PIPES IN A HYDROELECTRIC POWER STATION USING DATA MINING AND SUPPORT VECTOR MACHINE

VICTOR MANUEL ZEZATTI FLORES GUSTAVO URQUIZA BELTRAN MIGUEL ANGEL BASURTO PENSADO LAURA LILIA CASTRO GOMEZ (2019, [Artículo])

This research is based on the operation tube heat exchangers, their use and problematic on hydroelectric power plants. It is based on the design heat exchanger tubes for industrial use, which took the parameters of operation, design, working fluids (air and water) and conditions to assemble a monitoring equipment at appropriate scale for the laboratory, with the necessary measurement instruments to analyze the behavior of heat energy transfer by means of thermocouples, the velocity of the air with a hot wire anemometer and the flow of water with a turbine flow meter, in pipes of different materials: copper, steel 1018 and stainless steel 316L, all in ideal conditions, and with this to found a comparative parameter with pipes of the same materials but under conditions of deterioration with the presence of forced oxidation and with the data mining and support vector machine can be minimized the corrosion problems in pipes.

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS Data Mining, Support Vector Machine, Pattern Recognition and Decision Support System, heat exchangers.