Towards Establishing a Process for Preserving Historic Landscapes in Mexico: The Casa Cristo Gardens in Guadalajara, Jalisco, Mexico

Landscape Architecture is a field that is in process of development in Mexico. However, although empirically, the landscape was considered in the past as part of the human\u27s environment, and this is the Mexican heritage. Thus, this heritage is important to considered because is part of the people\u27s identity, and therefore, vital to protect. However, Mexico focuses its attention to the preservation of its\u27 national heritage in the fields of architecture and fine arts, leaving without protective regulations and guidelines the field of landscape architecture. The following thesis intends to create awareness in people of the importance of the landscape and of the importance of the history of landscape architecture that has been happening in Mexico. To accomplish this task, the Casa Cristo, designed by Luis Barragán was chosen as a case study. This case study involved the development of the first part of a Cultural Landscape Report (CLR). Since Mexico does not have any protective laws for its\u27 landscapes, to develop the CLR it was use guidelines and processes proposed by National Park Service in the United States of America. The study contributes to the field of preservation in Mexico, and to encourage the protection of Luis Barragán\u27s work, specially the Casa Cristo

Unveiling the mechanical behavior of the rod-like microstructure in the radular teeth of cryptochiton stelleri

Natural ceramics provided with high volume fractions of mineralized materials that are surrounded by a weak organic interface combine the stiff mechanical behavior of building blocks, like hydroxyapatite or aragonite, and the compliance of the organic surroundings. Unique mechanical properties (e.g. light density and toughness) distinguish bio-composites from common engineering materials. A key example is the highly mineralized shell of the radular teeth of the Crypochiton stelleri. Nature has provided the radular teeth with a highly oriented rod-like microstructure of nano-scale dimensions embedded in a matrix of chitin sheaths. Compared to other biological materials, the external iron oxide layer of the mature teeth is characterized with an outstanding abrasion resistance. Studies of the functionality of the tooth have been performed so far with site-specific estimations made by nanoindentation tests and advanced microscopic imaging techniques. ^ The aim of this work is to analyze the mechanical behavior of the rod-like microstructure of the teeth with biomimetic composites and computational models. A three-dimensional computational model is implemented to unveil the role of the nanoscale features in the response of the microstructure to the penetration of a cube corner indenter. The computational model considers isotropic rods surrounded by cohesive interfaces. The analysis of the damage model indicates competing mechanisms between energy dissipation at the interfaces and rod material. While the localization of damage leads to a higher resistance to penetration, it enhances the probability of failure in the rods.^ An experimental approach was developed with additive manufacturing, mimicking the mineral/organic composites with strong materials surrounded by weak interfaces. To assess the role of the geometrical features, a detailed set of experiments was used to quantify the effect of rod orientation and aspect ratio in the site-specific properties measured. Both the experimental and computational frameworks indicate that during indentation the aspect ratio of the rods influences the abrasion resistance and toughness, where the rod deformation plays a critical role in the dynamic response of the microstructure. Finally, to demonstrate the possible applications of the computational and biomimetic approaches presented in this work, the abrasion resistance of another gastropod has been studied. The findings of this research are applicable to other biomineralized materials, and to gain insights into the development of wear resistant composites

T-Lineage Specification and Commitment Requires Constraint of Myeloid Gene Expression Programs by Hes1

Early thymic progenitors (ETPs) are not committed to the T cell lineage; however, whether ETPs realize alternative (non T cell) lineage potentials in vivo is not well understood and indeed controversial. Notch signaling induces T cell lineage gene expression and discourages alternative fate outcomes; however, the mechanisms by which this occurs remain unclear. The work described here provides insight into two related questions in the field of early T cell development: first, we address whether ETPs adopt alternative fates in the thymus (Chapter 2) and second, we investigate the mechanisms used to constrain alternative gene expression programs as progenitors commit to the T cell lineage (Chapter 3 and 4). We found that ETPs do in fact access myeloid developmental fates in vivo, since the majority of thymic granulocytes appear to derive from ETPs. Next, we identified the Notch target and transcriptional repressor Hes1 as an important mechanism that constrains myeloid gene expression programs in T cell progenitors. Hes1 deficiency in hematopoietic progenitors severely compromises T cell development; however, this defect can be completely rescued by deletion of the myeloid regulator C/EBPα. Thus, our findings indicate that ETPs are bona fide myelo-lymphoid progenitors and establishes the critical importance of constraining myeloid developmental programs early in T cell development

Photoluminescence in Raman Scattering: Effects of HfO2 Template Layer on Ultrananocrystalline Diamond (UNCD) Films Grown on Stainless Steel Substrates

The growth of polycrystalline diamond films can play an important role in industry if they can be grown on industrially used materials like aluminum (Al) or stainless steel (SS).   A critical issue related to the growth of ultrananocrystalline diamond (UNCD) thin films on metals like SS, in a Hydrogen rich environment like the one present during growth of UNCD films, is the diffusion of Hydrogen (H) into the SS substrate, as it has been observed in prior research, which results in hydride formation in the SS that induce brittleness in the SS substrate.  Several interface layers have been proposed described to avoid the H diffusion into the SS. However, HfO2 has not been explored.  The work reported here was focused on investigating the growth of UNCD films on commercially available SS substrates by using an interface layer of HfO2, which was found to be a good diffusion barrier for H to inhibit penetration into the SS substrate. The samples where characterized with SEM and Raman spectroscopy.  A photoluminescence (PL) effect, observed in the Raman scattering analysis, is present in all the samples.  The PL effect may be due to the interaction of the UNCD / HfO2 interface. and the SS substrate rather than UNCD film alone.  The novel result from the experiments described here, is the fact that it is possible to grow UNCD films on unseeded HfO2 layers on SS substrates.Keywords: Poly-crystalline diamond, photoluminescence, UNCD, Stainless Steel, Hafnium Dioxide

Síntesis y caracterización de membranas piezoeléctricas en base al polímero polifluoruro de vinilideno, utilizando la técnica de electrospinning

The present investigation is related to the synthesis of polymeric membranes with piezoelectric characteristics, using the vinylidene polyfluoride (PVDF) material, which is a thermoplastic semicrystalline polymer; the membranes will be made up of micro and nano piezoelectric fibers of this material, which were manufactured using the Electrospinning technique, the separation distance of 4.5 cm, 8.5 cm, 11.5 cm from the needle The hypodermic ones referring to the collecting cylinder were the one used to collect the samples. The hypothesis of manufacturing process parameters related to the diameter of the micro and nanofibers of the piezoelectric material PVDF with its rotational structure Beta (β) was tested. The following techniques were performed: XRD, where the dispersion of the samples were 18.3o, 19.9o, 20.6o, is related to the internal rotational structure α and β, for the SEM the approximate diameter of 100 to 250 nm was obtained of the micro and nano fibers of the PVDF, two protocols were applied to the FTIR for the analysis of the spectra, one of them with bibliographic reference and the other with the frequency changes shown with the baseline and modified the nano fibrous membranes of the PVDF , in Raman the spectrum from 800 to 840 cm-1 shows the changes in its internal rotational structure of the modified and unmodified PVDF by bibliographic reference is observed with a qualitative analysis.La presente investigación está relacionada con la síntesis de membranas poliméricas con características piezoeléctricas, utilizando el material polifloururo de vinilideno (PVDF), el cual es un polímero semicristalino termoplástico. Las membranas estarán conformadas por micro y nanofibras piezoeléctricas de este material, las cuales fueron fabricadas a través de la técnica de Electrospinning, en la misma se utilizaron distancias de separación de 4.5 cm, 8.5 cm, 11.5 cm entre la aguja hipodérmica y el cilindro electrizado colector de muestras.  Se sometió a prueba la hipótesis del efecto de los parámetros del proceso de fabricación de las membranas, sobre el diámetro de la micros y nanofibras del material piezoeléctrico (PVDF) y en la estructura rotacional de la fase piezoeléctrica Beta (β). Se realizaron las siguientes técnicas de caracterización. XRD, donde la  dispersión  de las muestras  eran 18.3o, 19.9o, 20.6o, lo cual tienen relación con la estructura interna rotacional α y β; SEM, en la que se obtuvo el diámetro aproximado 100 a 250 nm  de las micro y nano fibras del (PVDF); FTIR, en la cual se aplicaron dos protocolos para el análisis de los espectros: una de ella con referencia bibliográfica y otra con los cambios de frecuencia que se muestra con la línea de base y modificado de las membranas nano fibrosas del PVDF. Espectroscopía Raman, con la que se determinó un espectro de 800 a 840 cm-1, lo cual muestra los cambios de la estructura interna rotacional del PVDF modificado y no modificado, indicado en referencias bibliográficas con un análisis cualitativo

Guía para el seguimiento de becarios en la Universidad Tecnológica de Panamá

Con el fin de organizar y potenciar las oportunidades de avances en la conformación de redes de investigación y grupos de investigación en la UTP, se crea en el año 2016, en la Vicerrectoría de Investigación, Postgrado y Extensión, específicamente en la Dirección de Postgrado, la Unidad de Seguimiento de Becarios. Esta Unidad se encarga, no solamente de servir de enlace entre el becario y la UTP para guiarle en el proceso de licencias y sus extensiones, sino que también juega un papel importante en gestionar con las instancias pertinentes en la UTP una inserción eficiente y efectiva del becario a su retorno a la UTP. Es con mucha satisfacción que presentamos ante ustedes esta Guía de Seguimiento de Becarios, confiando en que servirá de orientación a todos los colaboradores de UTP que estén en el proceso de aplicar a becas para estudios de maestría, doctorado y postdoctorado.Con el fin de organizar y potenciar las oportunidades de avances en la conformación de redes de investigación y grupos de investigación en la UTP, se crea en el año 2016, en la Vicerrectoría de Investigación, Postgrado y Extensión, específicamente en la Dirección de Postgrado, la Unidad de Seguimiento de Becarios. Esta Unidad se encarga, no solamente de servir de enlace entre el becario y la UTP para guiarle en el proceso de licencias y sus extensiones, sino que también juega un papel importante en gestionar con las instancias pertinentes en la UTP una inserción eficiente y efectiva del becario a su retorno a la UTP. Es con mucha satisfacción que presentamos ante ustedes esta Guía de Seguimiento de Becarios, confiando en que servirá de orientación a todos los colaboradores de UTP que estén en el proceso de aplicar a becas para estudios de maestría, doctorado y postdoctorado

Conversão da energia das ondas eletromagnéticas artificiais dos meios urbanos em energia elétrica

Na atualidade, métodos de fontes alternativas de energias são alvos frequentes de estudos, com o intuito de mitigar as ações prejudiciais das mais diversas fontes de energias fósseis. Inúmeras tecnologias fazem usos de micro-ondas para estabelecer comunicação entre si, assim passa a existir diversas fontes de ondas eletromagnéticas sendo irradiada cotidianamente no espaço livre, sem utilização eficaz, abrindo espaço para o desenvolvimento de técnicas de colheitas de energia do meio ambiente do inglês energy harvesting. Na presente pesquisa foi realizado um projeto no qual consiste no reaproveitamento de energia eletromagnética dos meios urbanos denominada rectenna, sendo este formado basicamente por uma antena com um circuito retificador. A rectenna tem como objetivo interagir com fenômenos eletromagnéticos para converte-los em eletricidade. Por fim, foi simulado um sistema de arranjo de dezesseis elementos irradiantes de microfitas retangular com frequência de ressonância de 2,45 Ghz no software ADS® e verificado os seus parâmetros fundamentais, tais como: ganho, diretividade e eficiênci

Estudio de láminas delgadas de diamantes policristalinos: estructura cristalina, enalce químicos de átomos de carbono y efectos en la concentración de portadores de cargas eléctricas

Las películas delgadas de diamantes no sólo exhiben las propiedades del diamante cristalino, también se pueden utilizar para desarrollar dispositivos electrónicos. Este estudio hace una comparación de tres diferentes estructuras cristalinas de láminas delgadas de diamantes que fueron producidas utilizando métodos de deposición con vapor químico con plasma producido por microondas o con filamentos calientes y la concentración de cargadores eléctricos. La estructura de enlaces químicos de los átomos en las muestras se analizó utilizando espectroscopia de Raman y la concentración de los portadores de cargas eléctricas se midió utilizando un sistema del efecto de Hall. La data muestra que hay una relación entre la estructura cristalina y los enlaces químicos de los átomos de carbono en las láminas con la concentración de portadores de cargas eléctricas. Las láminas que exhiben una estructura de diamante nanocristalino muestran alta concentración de portadores de cargas eléctricas. En el otro extremo, la lámina que exhibe una estructura de diamante microcristalino tiene la menor concentración de portadores de carga eléctrica. Las láminas llamadas ultra-nano-cristalinas UNCD están compuestas de granos de diamantes cristalinos de 2 a 5 nm y contiene una amplia red de bordes de grano con átomos de carbono unidos en la configuración de sp2. Estas láminas de UNCD exhiben la mayor concentración de portadores eléctricos del orden de 1018. Estas películas de UNCD potencialmente pueden ser desarrolladas en dispositivos electrónicos alternos de alta potencia eléctrica y alta temperatura

Subset- and tissue-defined STAT5 thresholds control homeostasis and function of innate lymphoid cells

Innate lymphoid cells (ILCs) patrol environmental interfaces to defend against infection and protect barrier integrity. Using a genetic tuning model, we demonstrate that the signal-dependent transcription factor (TF) STAT5 is critical for accumulation of all known ILC subsets in mice and reveal a hierarchy of STAT5 dependency for populating lymphoid and nonlymphoid tissues. We apply transcriptome and genomic distribution analyses to define a STAT5 gene signature in natural killer (NK) cells, the prototypical ILC subset, and provide a systems-based molecular rationale for its key functions downstream of IL-15. We also uncover surprising features of STAT5 behavior, most notably the wholesale redistribution that occurs when NK cells shift from tonic signaling to acute cytokine-driven signaling, and genome-wide coordination with T-bet, another key TF in ILC biology. Collectively, our data position STAT5 as a central node in the TF network that instructs ILC development, homeostasis, and function and provide mechanistic insights on how it works at cellular and molecular levels