Estudio de las emociones y su persistencia en la clase de matemáticas usando un enfoque cognitivo

En esta ponencia se analizan las emociones que experimentan los alumnos en la clase de matemáticas así como su persistencia referidas por ellos mismos. Se utiliza una teoría cognitiva de las emociones para clasificar y analizar el entorno emocional ante acontecimientos, agentes y objetos, en un CECyT del IPN

Mapping Informal Settlements in Developing Countries using Machine Learning and Low Resolution Multi-spectral Data

Informal settlements are home to the most socially and economically vulnerable people on the planet. In order to deliver effective economic and social aid, non-government organizations (NGOs), such as the United Nations Children's Fund (UNICEF), require detailed maps of the locations of informal settlements. However, data regarding informal and formal settlements is primarily unavailable and if available is often incomplete. This is due, in part, to the cost and complexity of gathering data on a large scale. To address these challenges, we, in this work, provide three contributions. 1) A brand new machine learning data-set, purposely developed for informal settlement detection. 2) We show that it is possible to detect informal settlements using freely available low-resolution (LR) data, in contrast to previous studies that use very-high resolution (VHR) satellite and aerial imagery, something that is cost-prohibitive for NGOs. 3) We demonstrate two effective classification schemes on our curated data set, one that is cost-efficient for NGOs and another that is cost-prohibitive for NGOs, but has additional utility. We integrate these schemes into a semi-automated pipeline that converts either a LR or VHR satellite image into a binary map that encodes the locations of informal settlements.Comment: Published at the AAAI/ACM Conference on AI, ethics and society. Extended results from our previous workshop: arXiv:1812.0081

Land-use effects on soil quality of agricultural systems in the Central Andes of Bolivia

Increasing demands for food of the growing world population has led to agricultural intensification and rapid changes in land use worldwide. Resulting modifications of soil characteristics could have cascading effects on soil functioning and the delivery of ecosystem services (e.g. food production). Maintenance of soil quality, the capacity of a soil to function to sustain biological productivity while maintaining environmental quality, is thus of central importance in order to ensure long-term provision of food, and its evaluation allows to understand the soil responses and to predict potential consequences of land-use changes. Over the last decades, agricultural systems of the Central Andean region of Bolivia have experienced rapid changes of land use and management practices such as shortening of fallow periods, use of chicken manure fertilization to improve soil fertility, and the plantation of Eucalyptus globulus L. on arable soils. So far, the effects of these changes on soil quality have not been assessed. Improving agricultural production while contributing to sustainability of these ecosystems requires soil quality evaluations under the current land uses. This thesis evaluated the effect of fields cultivated with potato, fallow fields (2-6 years old), eucalyptus plantations, and the use of chicken manure for fertilization on soil quality in agricultural ecosystems of the Central Andes. The combined responses of soil physico-chemical properties, soil aggregates, microbial processes, and their interactions were evaluated as indicators of soil quality. Short-term fallowing did not contribute to soil fertility restoration or soil structure improvement, indicating a neutral effect on soil quality compared to fields cultivated with potato. However, fallowing soils lead to reduced net nitrogen transformation rates and lower abundance and activity of ammonia oxidizing bacteria, suggesting sensitivity of these processes to land-use change. Fertilization with chicken manure improved soil quality by increasing labile carbon and nitrogen fractions and microbial activity. Manure also promoted seed germination and plant growth, however, immature manure caused root damage on Avena sativa L. seedlings. Turning manure piles accelerated the composting process and reduced root damage. It is recommended to compost manure for 100 days and to conduct turning events to reduce the risk of manure phytotoxicity. The plantation of eucalyptus promoted organic matter accumulation, and increased the total amount of carbon in different fractions. Soil structure was also improved and contributed to carbon stabilization. These changes are commonly associated with an improvement of soil quality for cultivation, but increased exchangeable Al and potential allelopathic interactions reduced biological soil quality compared to cultivated fields (reduced metabolic potential of soil bacteria, N transformation rates, and increased microbial energy maintenance demands) The plantation of eucalyptus should be avoided in agricultural areas, and careful land-use planning should guide its plantation to avoid negative effects on crops. Under the three land uses, ammonia-oxidizing archaea were dominant nitrifying organisms in terms of abundance and activity, but the contribution of ammonia-oxidizing bacteria to nitrification significantly increased with pH. We have also demonstrated that the activity of ammonia oxidizers should not be inferred from amoA gene abundances alone, but that their nitrification rates should be measured separately to determine their role in the environment. Labile carbon fractions (hot water extractable carbon and microbial biomass carbon) were strongly associated to microbial processes and were sensitive to land-use changes. Moreover, increases in microbial activity (respiration potential and net nitrogen mineralization) were associated to aggregate formation and stability. Labile carbon fractions and microbial processes should be considered for monitoring soil quality in response to land-use change and agricultural practices. This study demonstrated that the short fallow periods did not contribute to soil quality improvement for cultivation compared to fields cultivated with potato. The use of composted chicken manure for fertilizing soils improved to soil quality for agricultural production but the use of immature manure should be avoided to reduce the risk of phytotoxic effects. The introduction of eucalyptus to the Andean agricultural systems reduced soil quality for cultivation compared to fields cultivated with potato. Labile carbon fractions and microbial processes stand out as sensitive and informative soil quality indicators of the early changes occurring in these agricultural systems following land-use change.Land use effects on soil quality of agricultural systems in the Central Andes of Bolivi

Cambio de actitud hacia el aprendizaje de las matemáticas: el caso de Frida

El objetivo de esta investigación es analizar el cambio de actitud (de negativa a positiva) hacia el aprendizaje de las matemáticas experimentado por Frida, una estudiante de bachillerato. El análisis se hizo con el marco teórico de la estructura cognitiva de las emociones. Éste establece que las emociones son causadas por la interpretación que la persona realiza sobre las consecuencias que, para sus metas, normas y actitudes, representan los acontecimientos, la actuación de otras personas y su relación con las cosas, respectivamente. El cambio de actitud se analizó por medio del reporte de las experiencias emocionales que Frida experimentó a través de un año escolar, en el que ella asistió a dos cursos de matemáticas y a clases de asesorías personalizadas. Los resultados indican que el cambio de actitud se inició cuando sus reacciones no fueron en el sentido sugerido por la teoría para emociones de la misma valencia (con base en metas, en normas y en actitudes), sino en sentido opuesto; es decir, Frida, durante los cursos de asesoría, comenzó a desestructurar una actitud negativa hacia las matemáticas, debido a nuevas evaluaciones sobre agentes y eventos basadas en sus normas y metas personales. Al final del artículo, se hacen algunas recomendaciones para la enseñanza

Influencia de Calidad del Concreto, Acero y Compactación en Construcción de Cimientos en Torres de Alta Tensión

Esta investigación formuló como problema general: ¿Cómo es la calidad de la cimentación en la construcción de torres de alta tensión de la línea de transmisión 138 kV?? así también planteó como objetivo General: Establecer cómo es la calidad de la cimentación en la construcción de torres de alta tensión de la línea de transmisión 138 kV. y como hipótesis general, La calidad de la cimentación es adecuada en la construcción de torres de alta tensión de la línea de transmisión 138 kV. El método de la investigación fue el método Científico, el tipo de investigación fue Aplicada, así mismo el nivel de investigación fue el descriptivo-explicativo y el diseño no experimental. Para la población se utilizó el proyecto de transmisión eléctrica La Virgen-Caripa, y la muestra una torre el cual se conocía las anomalías presentadas. Se llegó a la conclusión de que Cuando la calidad del concreto disminuye, el esfuerzo resistente disminuye pero no determina la estabilidad del mismo, luego cuando la calidad del acero disminuye a uno de menor cuantía, este valor se reduce y comparado con el diseño, la resistencia a momentos flexionantes es menor, esto induce a transmitir los esfuerzos al concreto, así mismo, Cuando la calidad de la compactación disminuye, el peso estabilizante se reduce y verificándolo por el principio de arrancamiento incrementa el riesgo de volteo considerablemente.Tesi

Large magnetic anisotropy in mononuclear metal complexes

This review examines mononuclear metal complexes with high magnetic anisotropy and the theoretical approaches used to rationalize their magnetic properties. Electronic structure calculations based on CASSCF (or CASPT2/NEVPT2) methods provide a quantitative agreement of the zero- field splitting parameters either for mononuclear transition metal complexes or for equivalent lanthanide systems. To produce a more qualitative tool for predicting the magnetic anisotropy of metal complexes, we have developed a set of simple models. For transition metal systems, a simple model based on the splitting of the d orbitals, considering the coordination mode of the metal and its electronic configuration, is enough to qualitatively predict the system's magnetic anisotropy. A similar approach does not work with the f orbitals of the lanthanide complexes. As an alternative, we studied the electrostatic field generated by the ligands and found that this magnitude controls the shape and the orientation of the anisotropic electron density. This procedure allows us to rationalize and to predict whether the system will have a strong axial character, and also to determine the direction of the magnetic moment

Soil properties and microbial processes in response to land-use change in agricultural highlands of the Central Andes

peer reviewedAbstract Understanding changes in soil functions in response to land-use change is important for guiding agricultural practices towards sustainable soil management. We evaluated the differences in soil properties (soil organic matter, water extractable carbon (C) and nitrogen (N), microbial biomass, pHKCL and exchangeable cations) and microbial processes (respiration potential, net N mineralization, net nitrification and metabolic potential of soil bacteria), as well as the relative importance of soil properties in explaining changes in processes under three land uses (potato crops, fallow fields and eucalyptus plantations) in the agricultural highlands of the Central Andes. Soils under potato crops were characterized by the highest net N mineralization and net nitrification rates, and extractable phophorus (P), and the lowest microbial biomass P. Conversion to eucalyptus plantations led to an increase in soil organic matter, water extractable C and microbial biomass, and a decrease in extractable P and metabolic diversity of soil bacteria. Higher exchangeable aluminium (Al) indicated soil acidification under eucalyptus. Fallow practices did not lead to major changes in soil properties and microbial processes, indicating that fallow practices for up to 6 years were too short to substantially contribute to soil fertility restoration. Hot water extractable carbon (HWC) showed the best relationship with soil processes (respiration potential, net N mineralization and net nitrification). Our results highlight the necessity of alternative management practices for maintaining soil fertility under potato crops, the drastic modification of soil properties and processes under eucalyptus plantations, and the potential of HWC as a proxy for monitoring land-use-induced changes in soil functions related to C and N cycling. Highlights Effects of conversion from potato crops to eucalyptus and fallow on soil properties and processes were assessed. Under eucalyptus, soil respiration increased; metabolic diversity and N transformations decreased. Short fallow periods did not result in soil fertility restoration. Hot water extractable C was the best indicator of changes in soil processes

Metal-Organic Nanocapsules with Functionalized s-Heptazine Ligands

A metalloorganic capsule was synthesized where the ligand is a derivative of heptazine with three carboxylic groups that are coordinated to CuII cations, forming paddle-wheel motifs. Each nanocapsule is neutral, with 12 CuII centers and 8 ligands adopting a rhombicuboctahedron shape. It has almost 3 nm diameter, and the main intermolecular interactions in the solid are π··· π stacking between the C6N7 heptazine moieties. The nanocapsules can form monolayers deposited on graphite as observed by atomic force microscopy, which confirms their stability in solution

Soil microbial biomass and oxy-hydroxides contribute to aggregate stability and size distribution under different land uses in the Central Andes

peer reviewedContext: Agricultural intensification leads to land use changes with potential consequences for soil aggregate stability and size distribution, affecting nutrient and water retention capacity, aeration, sequestration of soil organic carbon, and biogeochemical cycling. Aims: This study evaluated soil aggregate stability and size distribution under potato, fallow and Eucalyptus globulus L. land uses in Cambisols of the eastern branch of the Central Andes, Bolivia. We also investigated the relation between aggregates and total C, extractable C, oxy-hydroxides, microbial biomass and activity. Methods: Aggregate stability, size distribution and oxy-hydroxides were measured in soil samples from eight plots of each land use. Key results: Compared to fields cultivated with potato (Solanum tuberosum L.), Eucalyptus increased aggregate stability, megaaggregate content, and C and N in the free silt + clay fraction. Fallow did not lead to significant changes in soil structure. Soil aggregate stability was related to both microbial biomass and oxy-hydroxides. Microbial biomass C, microbial activity and dithionite extractable Fe were positively related to megaaggregates and aggregate stability. Oxalate extractable Fe and Mn were related to microaggregates. Conclusions: The plantation of Eucalyptus is suitable for soil structural amelioration and C sequestration, but its introduction to cultivated areas should be carefully evaluated due to its effects on soil chemistry and microbiology. Short-term fallowing did not contribute to the maintenance of soil structure. Implications: In a context of land uses change, modifications of microbial biomass and activity would affect megaaggregate formation and stability. Alternative management practices are required to maintain soil structure and optimize sustainable land use of cultivated and fallow fields.2. Zero hunger15. Life on lan