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Poster presented at the Annual Conference of the Marie Curie Alumni Association (MCAA Annual Conference), Online event, 5-7 March 2021 (Session Poster Session).

Self-organized functional soft materials, enabled by specific chemical architectures, are currently attracting tremendous attention because of their stimuli-responsive attributes and applications in advanced technological devices. A novel axially chiral molecular switch containing two azo linkages and six terminal allcyl chains on two elongated rod-shaped wings, that exhibits superior solubility, high helical twisting power, and reversible photoisomerization in an achiral liquid crystal host, is synthesized and utilized in the development of a photoresponsive, self-organized helical superstructure, that is, cholesteric liquid crystal (CLC). The planar CLC adopts a standing helix (SH) configuration because of surface alignment layers on the substrates. This SH can be transitioned to a lying helix configuration, enabling tunable diffraction gratings under the application of electric field. Adjustment of the initial pitch of the planar CLC by photoirradiation yields the diffraction gratings with stripes either parallel or perpendicular to the rubbing direction upon the application of an appropriate electric field. Tunable beam steering along orthogonal directions has been demonstrated. Such tunable stimuli-responsive soft materials fabricated with artificial chiral switches show great potential in optics, photonics, and beyond.

Stochastic approximation (SA) is a powerful class of iterative algorithms for nonlinear root-finding that can be used for minimizing a loss function, $L(\boldsymbol{\theta})$, with respect to a parameter vector $\boldsymbol{\theta}$, when only noisy observations of $L(\boldsymbol{\theta})$ or its gradient are available (through the natural connection between root-finding and minimization); SA algorithms can be thought of as stochastic line search methods where the entire parameter vector is updated at each iteration. The cyclic approach to SA is a variant of SA procedures where $\boldsymbol{\theta}$ is divided into multiple subvectors that are updated one at a time in a cyclic manner. This dissertation focuses on studying the asymptotic properties of cyclic SA and of the generalized cyclic SA (GCSA) algorithm, a variant of cyclic SA where the subvector to update may be selected according to a random variable or according to a predetermined pattern, and where the noisy update direction can be based on the updates of any SA algorithm (e.g., stochastic gradient, Kiefer--Wolfowitz, or simultaneous perturbation SA). The convergence of GCSA, asymptotic normality of GCSA (related to rate of convergence), and efficiency of GCSA relative to its non-cyclic counterpart are investigated both analytically and numerically. Specifically, conditions are obtained for the convergence with probability one of the GCSA iterates and for the asymptotic normality of the normalized iterates of a special case of GCSA. Further, an analytic expression is given for the asymptotic relative efficiency (when efficiency is defined in terms of mean squared error) between a special case of GCSA and its non-cyclic counterpart. Finally, an application of the cyclic SA scheme to a multi-agent stochastic optimization problem is investigated. This dissertation also contains two appendices., Comment: Johns Hopkins University Dissertation

Maestría en Educación Familiar - Tesis presentada en UP Aguascalientes

Introducción: el consumo de stevia a nivel mundial se ha incrementado en los diferentes grupos etarios; sin embargo, existen pocos estudios que muestren la ingesta y asociación con el peso corporal en adultos. Objetivo: evaluar el consumo de stevia en jóvenes universitarios de primer año de cinco ciudades de Chile (Santiago, Temuco, Viña del Mar, Concepción y Antofagasta) de acuerdo al estado nutricional, nivel socioeconómico, sexo y pertenencia al área de la salud. Materiales y métodos: se evaluaron 486 estudiantes universitarios (EU) de primer año, pertenecientes a cuatro universidades chilenas. A cada participante se le aplicó una encuesta de frecuencia de consumo semanal con alimentos y bebidas que contienen stevia. Se solicitó el autoinforme de peso y talla. Resultados: el 69,8% de los estudiantes consumen stevia durante la semana. La stevia en gotas constituye el mayor aporte de stevia en la dieta de los estudiantes, con un 63%. Solo el 1,4% de los estudiantes sobrepasaban el IDA para stevia. Las mujeres normopeso presentan una ingesta mayor de stevia que las que tienen sobrepeso u obesidad (p

Introducción: el consumo de stevia a nivel mundial se ha incrementado en los diferentes grupos etarios; sin embargo, existen pocos estudios que muestren la ingesta y asociación con el peso corporal en adultos. Objetivo: evaluar el consumo de stevia en jóvenes universitarios de primer año de cinco ciudades de Chile (Santiago, Temuco, Viña del Mar, Concepción y Antofagasta) de acuerdo al estado nutricional, nivel socioeconómico, sexo y pertenencia al área de la salud. Materiales y métodos: se evaluaron 486 estudiantes universitarios (EU) de primer año, pertenecientes a cuatro universidades chilenas. A cada participante se le aplicó una encuesta de frecuencia de consumo semanal con alimentos y bebidas que contienen stevia. Se solicitó el autoinforme de peso y talla. Resultados: el 69,8% de los estudiantes consumen stevia durante la semana. La stevia en gotas constituye el mayor aporte de stevia en la dieta de los estudiantes, con un 63%. Solo el 1,4% de los estudiantes sobrepasaban el IDA para stevia. Las mujeres normopeso presentan una ingesta mayor de stevia que las que tienen sobrepeso u obesidad (p