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102 resultados, página 6 de 10

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

La cartografía como producto cultural: interpretación del Plano General de indicación de la Ciudad de México de 1886

María Esther Sánchez Martínez Maria del Carmen Bernardez de la Granja (2023, [Capítulo de libro])

Universidad Autónoma Metropolitana (México). Unidad Azcapotzalco. División de Ciencias y Artes para el Diseño. Departamento de Evaluación del Diseño en el Tiempo. Área de Estudios Urbanos.

Este trabajo reconstruye la historia del Plano General de indicación de la Ciudad de México. Con la nueva división de los cuarteles y nomenclatura de las calles de 1886. Examina la imagen que estampa de la capital y cuestiona el aura de objetividad cartográfica. Los estudios sobre mapas abundan cada vez más, pese a eso aún es frecuente que ocupen un lugar secundario. Con base en el método de análisis de la cartografía crítica, propuesta por J. B. Harley (2005), ofrecemos una interpretación del plano de 1886 para referir la autoría, los propósitos, la imagen que proyecta de la Ciudad de México y la relación entre dichos aspectos. Los planos son fuentes documentales de carácter visual que arrojan luz sobre la época para la cual sirvieron. Un acercamiento cuidadoso nos lleva a comprender los ideales de los que participaba.

Cartography--Mexico--Mexico City--History. Mexico City (Mexico)--Maps. Mexico City (Mexico)--Historical geography--Maps. City planning--Mexico--Mexico City--History--19th century. Cartografía -- Historia. Ciudad de México -- Historia. Urbanismo -- Ciudad de México. G1549.M6 HUMANIDADES Y CIENCIAS DE LA CONDUCTA CIENCIAS DE LAS ARTES Y LAS LETRAS ARQUITECTURA URBANISMO

Elevación del piso del seno maxilar con técnica transcrestal.

SALVADOR REYES FERNANDEZ NORMA SAMANTA ROMERO CASTRO NATALIA HERNANDEZ TREVIÑO DANIEL SANDOVAL GUEVARA XENIA TERESA COBOS CRUZ (2023, [Artículo])

Introduction: the elevation of the transcrestal floor of the maxillary sinus consists of the vertical reconstruction of the atrophic alveolar ridge in an apical direction, with which it is possible to place the correct number and length of oral implants. Objective: to describe the procedure of a case of transcrestal maxillary sinus floor elevation with the placement of three dental implants. Clinical case: 62 year old female patient with missing teeth 16, 25 and 26. Treatment: three implants were placed to replace the missing teeth. Due to the decrease in height of the remaining alveolar ridge due to pneumatization of the maxillary sinuses, elevation of the sinus floor was planned with the transcrestal Summers¿s technique and placement of graft material. Results: by means of the grafts, sufficient height was achieved for the correct stability of the implants, each área had an average gain of 3 mm in bone height, with which length was obtained to give the implants adequate primary stability. Conclusion: sinus floor elevation with a transcrestal approach is a good alternative for rehabilitation with implants in the posterior edentulous sector, associated with pneumatization of the maxillary sinuses.

Elevation of the floor of the maxillary sinus Transcrestal technique Implants Graft Bone height MEDICINA Y CIENCIAS DE LA SALUD CIENCIAS MÉDICAS CIRUGÍA ORTODONCIA-ESTOMATOLOGÍA

The new proletariat of the north at Ciudad Juarez: Current trends.

Nolberto Tlacaelel Acosta Pérez (2022, [Artículo, Artículo])

The arrival of the nowadays renamed Manufacturing, Maquiladora and Export Service Industry brought within the formation of a new labor subject in the region: the new proletariat of the north. The proposal of the present article is to identify and describe the specific traits of this working class sub-fraction, by a reevaluation of its meaning, the most relevant socioeconomic indicators which serve to understand it, the political organization chapters that it has undertaken in the past years, and its most characteristic cultural attributes.

new proletariat of the north maquiladora U.S.-Mexico border social classes Ciudad Juarez nuevo proletariado del norte frontera norte clases sociales Ciudad Juárez CIENCIAS SOCIALES CIENCIAS SOCIALES

Current variability by wave propagation in Todos Santos Bay, Baja California

Variabilidad de corrientes por propagación de ondas en bahía Todos Santos, Baja California, México

EFRAIN MATEOS FARFAN SILVIO GUIDO LORENZO MARINONE MOSCHETTO (2017, [Artículo])

The temperature, velocity, and sea level fields for a summer climatological month (August) were analyzed using tridimensional and baroclinic model outputs in Todos Santos Bay (TSB), Baja California, Mexico. The numerical model was forced with wind (nonstationary), heat flux, and California Current System climatology on the open boundary. The 3- to 5-day current variability is related to a baroclinic wave traveling towards the northwest of the bay. Wave travel periodicity was due to the release of accumulated water from the Ensenada–Punta Banda Estuary (E–PBE) region. Local wind stress causes southeastward water flow and, given the TSB geometry, water accumulates in the E–PBE region. Weakening wind stress was the main cause of water release. In addition, complex empirical ortogonal function analysis found that outer TSB disturbances cause sea level variability.

Ondas subinerciales Modelos matemáticos Bahía Todos Santos CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Electrocoagulation to remove silica from cooling towers water

IVAN EMMANUEL VILLEGAS MENDOZA ALEJANDRA MARTIN DOMINGUEZ SARA PEREZ CASTREJON Silvia Gelover Santiago (2014, [Artículo])

El presente artículo muestra los resultados de un estudio que se llevó a cabo para evaluar el efecto de la calidad del agua en la remoción de sílice disuelto mediante un proceso de electrocoagulación utilizando electrodos de aluminio. La sílice se encuentra en el agua de repuesto (RW) y de purga de las torres de enfriamiento (CTBW). Las pruebas se hicieron a escala semipiloto a flujo continuo en un tren de tratamiento consistente de electrocoagulación (EC), floculación, sedimentación y filtración en arena. Se estudiaron dos RW y CTBW, con características fisicoquímicas diferentes. Las variables de respuesta analizadas fueron las siguientes: eficiencia del aluminio para remover sílice (relación mgl-1 de Al3+ dosificado/mgl-1 de sílice removido), eficiencia de remoción de Al3+ dosificado, pérdida de carga hidráulica a través del reactor electroquímico y el voltaje. Se calculó el costo del tratamiento de los cuatro tipos de agua. La relación mgl-1 de Al3+ dosificado/mgl-1 de sílice removido osciló de 1.09 ± 0.06 a 1.33 ± 0.05 al tratar RW, mientras que para CTBW fue de 0.85 ± 0.1. Los costos de energía, sustancias químicas y consumo de electrodos para el tratamiento de RW osciló de US$0.52 a US$ 0.74 m-3, y el costo del tratamiento de CTBW fue de aproximadamente US$0.53 m-3.

Aluminio Torre de enfriamiento Electrocoagulación Agua de repuesto Ciclos de concentración INGENIERÍA Y TECNOLOGÍA

Teacher training in the state of Chihuahua: Between the health challenge and teacher resilience

Evangelina Cervantes Holguín Pavel Roel Gutiérrez Sandoval Cely Celene Ronquillo Chávez (2023, [Artículo, Artículo])

 

The article proposes to recover the response of the Teacher Training and Updating Institutions in the state of Chihuahua regarding the various challenges imposed by the Coronavirus Disease (COVID-19). The qualitative exercise analyzes the experience of 10 institutions based on the voice of their students, teachers, and principals regarding changes in academic, administrative, and organizational processes. It is concluded that the pandemic has affected each institution in different ways and with diverse intensity. Despite the achievements, the experience analyzed reveals the relative success of the using virtual platforms in the face of three basic conditions: connectivity, technological competencies, and socio-emotional skills of the teaching staff. It highlights the importance of implementing tutoring, resilience, or awareness actions of teachers and students' needs, feelings, and sufferings. It is opportune to recover the experiences of other institutions and to question especially students, thesis students and graduates.

Acceso a la educación Aprendizaje en línea Educación a distancia Formación de docentes Tecnología educacional HUMANIDADES Y CIENCIAS DE LA CONDUCTA HUMANIDADES Y CIENCIAS DE LA CONDUCTA Access to education online learning distance education teacher education educational technology