Influence of poverty concerns on demand for healthier processed foods: A field experiment in Mexico City

Marrit Van den Berg Jason Donovan (2023, [Artículo])

Living in poverty can present cognitive biases that exacerbate constraints to achieving healthier diets. Better diets could imply food choice upgrades within certain food categories, such as electing processed foods with an improved nutritional profile. This study evaluated the influence of monetary and health concerns on the willingness to pay (WTP) for healthier processed foods in a low-income section of Mexico City. We employed priming techniques from the scarcity literature, which are applied for the first time to healthier food purchasing behaviours in low-income settings. Our predictions are based on a dual system framework, with choices resulting from the interaction of deliberative and affective aspects. The WTP was elicited through a BDM mechanism with 423 participants. Results showed that induced poverty concerns reduced the valuations of one of the study's healthier food varieties by 0.17 standard deviations. The latter effect did not differ by income level. The WTP for a healthier bread product but one with relatively high sugar and fat content was reduced by induced poverty concerns only among certain consumers without bread purchasing restrictions (78% of the sample). Potential mechanisms were assessed through regression analysis and structural equation modelling. The relationship between poverty concerns and WTP was mediated by increased levels of stress. While we could not rule out impact on cognitive load, it was not deemed a mediator in this study. Our findings signal that improvements in economic and psychological well-being among low-income consumers may aid to increase their demand for healthier processed foods.

Healthier Diets Poverty Psychology Dual System Model CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA DIET POVERTY PSYCHOLOGY STRESS WILLINGNESS TO PAY

OPTICAL PROPERTIES OF BLUE PHOSPHORENE CONSIDERING MANY-BODY EFFECTS

Juan Jose Nava (2023, [Tesis de maestría])

"The electronic band structure of blue phosphorene was obtained by using Density Functional Theory within the Generalized Gradient Approximation. It is observed, based on its band structure, that blue phosphorene shows a semiconducting nature, with an indirect band gap. The energy corrections to the bands were calculated in a specific set of k points within the irreducible Brillouin zone by employing the GW approximation and the complete quasiparticle band structure was determined by using maximally-localized Wannier functions. The excitonic spectrum is obtained and compared with both the independent-particle and GW optical response."

DFT Primeros principios BSE GW Función dieléctrica CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA ÓPTICA

Diseño y desarrollo de dispositivo de sujeción hidráulica para el proceso de brochado

Design and development of hydraulic clamping device for broaching process

Jorge Morales Carlos Álvarez Raúl Pérez Bustamante (2023, [Artículo])

Se desarrollo un dispositivo de sujeción hidráulica para el proceso de brochado de Brackets usados en los sistemas de frenado de automóviles, que permite reducir la variación del proceso de corte al mejorar el sistema de sujeción y con ello limitar la deformación de la pieza luego de haber sido procesada. Con este concepto de dispositivo es posible mejorar las condiciones del proceso de producción, como lo son: velocidad de corte, reducción de tiempo ciclo, rendimiento de la operación, reducción de costo de scrap, y reducción de tiempo muerto por sobre ajuste de proceso y cambio de modelo. Adicional, se hizo el desarrollo de un sistema de detección de pieza presente que permite captar cuando una pieza no es colocada correctamente en el dispositivo antes de iniciar el ciclo de corte, con esto es posible detectar fallas en el proceso que representen un riesgo para la operación. Durante la etapa de diseño se realizó una simulación del proceso de maquinado en condiciones extremas y condiciones ideales para medir la deformación de la pieza y con esto obtener los parámetros adecuados de corte para la puesta en marcha del dispositivo de sujeción. Para la validación del modelo, se realizó un estudio de habilidad de proceso Cpk y Ppk (acorde a los requerimientos de cliente) para evaluar que el nuevo proceso es eficiente y se encuentra bajo control.

A hydraulic clamping device was developed for the broaching process of Brackets used in automotivebraking systems, which allows reducing the variation of the cutting process by improving the clamping system andthereby limiting the deformation of the piece after having been processed. With this concept of device, it is possibleto improve the conditions of the production process such as: cutting speed, cycle time reduction, operationperformance, scrap cost reduction, and downtime reduction due to process over-adjustment and change over.Additionally, the development of a part detection system was made that allows capturing when a part is not correctlyplaced in the device before starting the cutting cycle, with this it is possible to detect failures in the process thatrepresent a risk to the operation. During the design stage, a simulation of the machining process was carried outin extreme conditions and ideal conditions to measure the deformation of the part and with this obtain theappropriate cutting parameters for the implementation of the clamping device. For the validation of the model, aCpk and Ppk process ability study was carried out (according to customer requirements) to assess that the newprocess is efficient and is under control.

Agradecemos al Centro de Investigación y Asistencia Técnica del Estado de Querétaro, A.C. (CIATEQ) y a la empresa donde fue desarrollado el proyecto por todas las facilidades otorgadas para la realización de dicho proyecto, de igual manera, agradecer por el apoyo brindado a todas las personas involucradas directa o indirectamente en el desarrollo de este trabajo.

Agradecimientos de autoría: Jorge Alberto Morales Martínez: Conceptualización; Metodología; Software; Análisis formal; Investigación; Adquisición de fondos; Recursos; Análisis de datos; Borrador original; Administración de proyecto, Revisión y edición. Carlos Marín: Conceptualización; Ideas; Análisis de datos; Software; Análisis formal y Supervisión. Raúl Pérez Bustamante: Revisión y edición.

Dispositivo de sujeción Proceso de brochado Bracket Sistema de frenado Parámetros de corte Cpk Ppk Clamping device Broaching process Brake system Cutting parameters INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

Cálculo del tensor dieléctrico efectivo de medios anisotrópicos granulados

Calculation of the effective dielectric tensor of granular anisotropic media

Carlos Enrique Román Velázquez (1999, [Tesis de doctorado])

En este trabajo nos hemos dedicado al problema del cálculo de la respuesta dieléctrica de sistemas formados por partículas anisotrópicas. Desarrollamos dos enfoques que aplicamos a dos distintos tipos de sistemas. En el primero, dentro de la aproximación dipolar, desarrollamos un formalismo para el cálculo del tensor dieléctrico efectivo de un medio compuesto granular con partículas anisotrópicas. Esto se hace dentro de la Aproximación de Campo Medio (ACM) basados en un modelo estadístico microscópico del material. Siguiendo un desarrollo riguroso, justificado en todo momento, desarrollamos una extensión de la ACM para este tipo de materiales. Esto nos ha permitido obtener correcciones al tensor dieléctrico efectivo al considerar correlaciones orientación-posición de las partículas, que son despreciadas usualmente en el método de cálculo de la ACM. Uno de los objetivos en esta parte es presentar una alternativa a los modelos fenomenológicos basados en la extensión de la ecuación de Maxwell Garnett o del método de Lorentz tomados de la teoría de la respuesta dieléctrica de medios con inclusiones isotrópicas. Por otra parte, lo riguroso de nuestro formalismo nos permite resolver controversias existentes entre los resultados de otros modelos no suficientemente justificados. En un segundo enfoque desarrollamos una representación espectral multipolar de la respuesta dieléctrica efectiva de un medio constituido por partículas esferoidales con tamaños, posiciones y orientaciones arbitrarias. Esta representación permite determinar la respuesta del sistema directamente de sus propiedades geométricas. Este método lo hemos aplicado a dos importantes sistemas de partículas anisotrópicas de geometría restringida. En el primero de ellos calculamos la polarizabilidad efectiva de una partícula esferoidal situada sobre un sustrato. En este caso la representación espectral de la respuesta dieléctrica nos ha permitido desarrollar un estudio sistemático de las propiedades ópticas de este sistema y determinar la importancia de las contribuciones multipolares en la respuesta del sistema como función de la forma de la partícula, su distancia al sustrato, y las propiedades dieléctricas del sustrato y el medio en que está inmersa. Aplicamos este...

esferoides, dieléctrico, multipolo CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA OTRAS ESPECIALIDADES FÍSICAS OTRAS ESPECIALIDADES FÍSICAS

Effect of Pectimorf on the rooting ability, and morpho-physiological physiological trials of national cocoa (Theobroma cacaoL.) under different substrates

JUAN JOSE REYES PEREZ Luis Tarquino Llerena Ramos Víctor Hugo Reynel Chila Juan Antonio Torres Rodríguez FAROUK SAAD Luis Guillermo Hernández Montiel Wilmer Tezara (2022, [Artículo])

"Cocoa is an economical cash crop that is formerly planted worldwide. Cuttings are a method of vegetative propagation suitable for maintaining desirable characteristics in cocoa trees. A greenhouse experiment was performed to evaluate the optimal concentrations of Pectimorf® (0, 10, 50, and 100 mg L-1) for rooting ability and seedling establishment as well as some physiological trials of 4 months EETP-800 national cocoa cuttings grown under two different substrates (S1: 80% soil + 20% sand and S2: 70% soil + 20% sand + 10% rice husk). The data showed that in most cases there are no significant differences in vegetative growth and root characteristics as well as gas exchange parameters between the two substrates. On the other hand, the application of Pectimorf® concentration enhanced all tested traits compared to untreated plants. The most effective in this regard was 100 mg L-1, that giving the highest value of all trials. As for the interaction effect, the result also shows that the application of Pectimorf® concentration in special at 100 mg L-1 among two substrates had an additive effect on plant growth, gas exchange, and survival percentage compared to non-treated cuttings. The application of 100 mg L-1 Pectimorf® with S2 substrate produced stronger seedlings with a higher survival percentage. This protocol can be used commercially for cocoa propagation commercially."

bioregulator, cuttings, root length, photosynthesis CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS AGROQUÍMICA REGULADORES DEL CRECIMIENTO DE LAS PLANTAS REGULADORES DEL CRECIMIENTO DE LAS PLANTAS

Ecología trófica del pez damisela Stegastes acapulcoensis (Pomacentridae) en un arrecife de Bahías de Huatulco, Oaxaca

Trophic ecology of the damselfish Stegastes acapulcoensis (Pomacentridae) in a reef of Bahías de Huatulco, Oaxaca

Diana Alejandra Vela Espinosa (2023, [Tesis de maestría])

Se caracterizó la alimentación y la morfología del sistema alimentario de la damisela Stegastes acapulcoensis en la bahía La Entrega, Oaxaca, con el objetivo de determinar su espectro trófico. En agosto de 2022, se recolectaron 30 ejemplares de S. acapulcoensis en el período de mayor actividad de alimentación, utilizando arpones caseros y equipo de buceo SCUBA. Las muestras se fijaron con formol al 5% para preservar sus tejidos y facilitar la identificación de presas. Cada ejemplar se sometió a un análisis biométrico detallado, incluyendo mediciones de peso total, longitud total y longitud estándar. Los componentes alimentarios se identificaron y clasificaron en nueve categorías, con las algas destacando como el componente más consumido, seguido del detritus y los invertebrados. El Índice de Importancia Relativa (%IIR) confirmó la importancia de estos componentes en la dieta de S. acapulcoensis. El análisis del espectro trófico reveló que esta especie es un depredador generalista, con una dieta que abarca una diversidad moderada de componentes alimentarios. Además, se encontró una correlación positiva significativa entre el peso de los individuos y su consumo de algas, lo que sugiere una relación entre el tamaño y los hábitos alimentarios. La morfología del sistema alimentario, incluyendo el aparato mandibular y las placas faríngeas, apoyó la adaptación de S. acapulcoensis a una dieta herbívora oportunista. Los dientes incisivos y las características de las placas faríngeas indicaron una especialización en la captura y procesamiento de alimentos vegetales. En conjunto, estos hallazgos proporcionaron una visión completa de la ecología alimentaria de S. acapulcoensis en La Entrega, resaltando la importancia de las algas en su dieta y su capacidad para ajustarse a diferentes fuentes de alimento. Además, se amplió nuestra comprensión de la relación entre la morfología y la ecología alimentaria en los peces damisela, lo que contribuye al conocimiento de estos ecosistemas marinos y su gestión.

The feeding and morphology of the food system of the damselfish Stegastes acapulcoensis in La Entrega Bay, Oaxaca, was characterized to determine its trophic spectrum. In August 2022, 30 specimens of S. acapulcoensis were collected during the period of peak feeding activity, using homemade harpoons and SCUBA diving equipment. Samples were fixed with 5% formalin to preserve their tissues and facilitate prey identification. Each specimen was subjected to detailed biometric analysis, including measurements of total weight, total length, and standard length. Food components were identified and classified into nine categories, with algae standing out as the most consumed component, followed by detritus and invertebrates. The Relative Importance Index (%IIR) confirmed the importance of these components in the diet of S. acapulcoensis. Trophic spectrum analysis revealed that this species is a generalist predator, with a diet encompassing a moderate diversity of food components. In addition, a significant positive correlation was found between the weight of individuals and their consumption of algae, suggesting a relationship between size and feeding habits. The morphology of the food system, including the mandibular apparatus and pharyngeal plates, supported the adaptation of S. acapulcoensis to an opportunistic herbivore. The incisor teeth and pharyngeal plate characteristics indicated a specialization in the capture and processing of plant foods. Taken together, these findings provided a comprehensive view of the feeding ecology of S. acapulcoensis in La Entrega, highlighting the importance of algae in its diet and its ability to adjust to different food sources. In addition, our understanding of the relationship between morphology and feeding ecology in damselfish was expanded, contributing to the knowledge of these marine ecosystems and their management.

Dieta, ecología, morfología mandibular Diet, ecology, jaw morphology BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA OTRAS ESPECIALIDADES DE LA BIOLOGÍA OTRAS OTRAS

Vibrissa growth rate in California sea lions based on environmental and isotopic oscillations

MARTHA PATRICIA ROSAS HERNANDEZ (2018, [Artículo])

Pinniped vibrissae provide information on changes in diet at seasonal and annual scales; however, species-specific growth patterns must first be determined in order to interpret these data. In this study, a simple linear model was used to estimate the growth rate of vibrissae from adult female California sea lions (Zalophus californianus) from San Esteban Island in the Gulf of California, Mexico. The δ15N and δ13C values do not display a marked oscillatory pattern that would permit direct determination of the time period contained in each vibrissa; thus, time (age) was calculated in two ways: 1) based on the correlation between the observed number of peaks (Fourier series) in the δ15N profile and the length of each vibrissa, and 2) through direct comparison with the observed number of peaks in the δ15N profile. Cross-correlation confirmed that the two peaks in the δ15N profile reflected the two peaks in the chlorophyll-a concentration recorded annually around the island. The mean growth rate obtained from the correlation was 0.08 ± 0.01 mm d-1, while that calculated based on the observed number of peaks was 0.10 ± 0.05 mm d-1. Both are consistent with the rates reported for adult females of other otariid species (0.07 to 0.11 mm d-1). Vibrissa growth rates vary by individual, age, sex, and species; moreover, small differences in the growth rate can result in significant differences over the time periods represented by the isotopic signal. Thus, it is important to assess this parameter on a species-by-species basis. © 2018 Rosas-Hernández et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

carbon, nitrogen, animal, California, chemistry, diet, female, island (geological), Mexico, Otariidae, physiology, Animals, California, Carbon Isotopes, Diet, Female, Islands, Mexico, Nitrogen Isotopes, Sea Lions BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA INMUNOLOGÍA INMUNOLOGÍA

Vibrissa growth rate in California sea lions based on environmental and isotopic oscillations

MARTHA PATRICIA ROSAS HERNANDEZ (2018, [Artículo])

Pinniped vibrissae provide information on changes in diet at seasonal and annual scales; however, species-specific growth patterns must first be determined in order to interpret these data. In this study, a simple linear model was used to estimate the growth rate of vibrissae from adult female California sea lions (Zalophus californianus) from San Esteban Island in the Gulf of California, Mexico. The δ15N and δ13C values do not display a marked oscillatory pattern that would permit direct determination of the time period contained in each vibrissa; thus, time (age) was calculated in two ways: 1) based on the correlation between the observed number of peaks (Fourier series) in the δ15N profile and the length of each vibrissa, and 2) through direct comparison with the observed number of peaks in the δ15N profile. Cross-correlation confirmed that the two peaks in the δ15N profile reflected the two peaks in the chlorophyll-a concentration recorded annually around the island. The mean growth rate obtained from the correlation was 0.08 ± 0.01 mm d-1, while that calculated based on the observed number of peaks was 0.10 ± 0.05 mm d-1. Both are consistent with the rates reported for adult females of other otariid species (0.07 to 0.11 mm d-1). Vibrissa growth rates vary by individual, age, sex, and species; moreover, small differences in the growth rate can result in significant differences over the time periods represented by the isotopic signal. Thus, it is important to assess this parameter on a species-by-species basis. © 2018 Rosas-Hernández et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

carbon, nitrogen, animal, California, chemistry, diet, female, island (geological), Mexico, Otariidae, physiology, Animals, California, Carbon Isotopes, Diet, Female, Islands, Mexico, Nitrogen Isotopes, Sea Lions CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

High quality diet improves lipid metabolic profile and breeding performance in the blue-footed booby, a long-lived seabird

ERICK GONZALEZ MEDINA (2018, [Artículo])

Understanding the role of diet in the physiological condition of adults during reproduction and hence its effect on reproductive performance is fundamental to understand reproductive strategies in long-lived animals. In birds, little is known about the influence of the quality of food consumed at the beginning of the reproductive period and its short-term effects on reproductive performance. To assess the role of diet in the physiological condition of female blue-footed booby, Sula nebouxii (BFBO), during reproduction we evaluated whether individual differences in diet (assessed by using δ13C and δ15N values of whole blood from female birds and muscle tissue of the principal prey species) prior to egg laying and during incubation influenced their lipid metabolic profile (measured as triglyceride levels and C:N ratio) and their reproductive performance (defined by laying date, clutch size and hatching success). Females with higher δ15N values in their blood during the courtship and incubation periods had a higher lipid metabolic profile, earlier laying date, greater clutch size (2–3 eggs) and higher hatching success. Females that laid earlier and more eggs (2–3 eggs) consumed more Pacific anchoveta (Cetengraulis mysticetus) and Pacific thread herring (Opisthonema libertate) than did other females. These two prey species also had high amounts of lipids (C:N ratio) and caloric content (Kcal/g fresh weight). The quality of food consumed by females at the beginning of reproduction affected their physiological condition, as well as their short-term reproductive performance. Our work emphasizes the importance of determining the influence of food quality during reproduction to understand the reproductive decisions and consequences in long-lived animals. © 2018 González-Medina et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

nitrogen 15, triacylglycerol, lipid, animal experiment, Article, breeding, carbon nitrogen ratio, clutch size, controlled study, courtship, diet, egg laying, female, food intake, hatching, lipid metabolism, muscle tissue, nonhuman, prey, reproduction CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA