1,266 research outputs found
Humanizing Scholarship: Going Public Via Multimodality
“Humanizing Scholarship” offers a look into the ways that multimodality can be used to make the scholarly conversations had within the academy more accessible to members of the public. This thesis acknowledges and echoes the responsibility academics have to bridging the gap between their research and the people who so often serve as the basis for the ethnographic work being done in academia. My project does two things: First, it brings together some of the conversations surrounding multimodality and public scholarship. Second, it offers some first-hand models of multimodal compositions—the short films Don Armando and The Adjunct, and the screenplay for Huevos Revueltos— which attempt to translate academic conversations through a narrative lens offered by the mediums of screenplays and short films. It is my hope that these models can help future scholars see the value in multimodality and the critical humanizing factor it can offer their research
Transmission electron microscopy characterization of microstructural features of Al-Li-Cu alloys
A transmission electron microscopy (TEM) examination of aluminum-lithium-copper alloys was conducted. The principal purpose is to characterize the nature, size, and distribution of stringer particles which result from the powder metallurgy (P/M) processing of these alloys. Microstructural features associated with the stringer particles are reported that help explain the stress corrosion susceptibility of the powder metallurgy-processed Al-Li-Cu alloys. In addition, matrix precipitation events are documented for a variety of heat treatments and process variations. Hot rolling is observed to significant alter the nature of matrix precipitation, and the observations are correlated with concomitant mechanical property variations
Genetically encoded biosensor for engineering branched-chain higher alcohol production pathway in saccharomyces cerevisiae
Branched-chain higher alcohols (BCHAs) including isobutanol, isopentanol, and 2-methyl-1-butanol, are promising alternatives to the first-generation biofuel ethanol. These alcohols have better fuel properties than ethanol, such as higher energy density, ease of refining, and better compatibility with existing gasoline engines and infrastructures 1. We have developed a genetically encoded biosensor to measure the metabolic activity of BCHA biosynthesis in Saccharomyces cerevisiae. This biosensor enables high-throughput screens to identify strains with higher metabolic flux to BCHA synthesis. The versatility of this tool has allowed us to use it in several applications, including in vivo BCHA metabolic pathway engineering/optimization and enzyme engineering. We have been able to screen for isobutanol hyper-producing stains with optimum combinations of genes from the mitochondrial isobutanol pathway (Mito-IbOH-pathway) 2. The ability of this biosensor to monitor the activity of both the mitochondrial 2 and cytosolic isobutanol pathways 3, has allowed us to engineer several enzymes and regulatory proteins involved in the isobutanol pathways in either compartment, boosting enzymatic activity by as much as 400%. Thus, we have demonstrated the use of this new technology to accelerate the development of strains and enzymes to boost BCHA production in mitochondria and the cytosol. Future applications include combining the biosensor with optogenetic regulation of BCHA biosynthesis for closed-loop dynamic control of this pathway, and using the biosensor to empower systems biology studies for gene discovery, enzyme evolving, and enzyme engineering to boost BCHA production.
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Hippocampal Memory Recovery After Acute Stress: A Behavioral, Morphological and Molecular Study
Indexación: Scopus.Laboratory of Neuroplasticity and Neurogenetics, Department of Biochemistry and Molecular Biology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile, 2Laboratorio Farmacología del Comportamiento, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile, 3Department of Kinesiology, Faculty of Health Sciences, Universidad Católica del Maule, Talca, Chile, 4Facultad de Psicología, Universidad de Talca, Talca, Chile, 5Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile, 6Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.This study was supported by the following grants: Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) 1120528 (JLF), Fondo Central de Investigación, Universidad de Chile ENL025/16 (JLF).Several studies have shown that a single exposure to stress may improve or impair learning and memory processes, depending on the timing in which the stress event occurs with relation to the acquisition phase. However, to date there is no information about the molecular changes that occur at the synapse during the stress-induced memory modification and after a recovery period. In particular, there are no studies that have evaluated—at the same time—the temporality of stress and stress recovery period in hippocampal short-term memory and the effects on dendritic spine morphology, along with variations in N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits. The aim of our study was to take a multidimensional approach to investigate concomitant behavioral, morphological and molecular changes induced by a single restraint stress exposure (2.5 h) and a recovery period of 6 and 24 h in rats. We found that acute stress elicited a reduced preference to explore an object placed in a novel position (a hippocampal-dependent task). These changes were accompanied by increased activity of LIM kinase I (LIMK; an actin-remodeling protein) and increased levels of NR2A subunits of NMDA receptors. After 6 h of recovery from stress, rats showed similar preference to explore an object placed in a novel or familiar position, but density of immature spines increased in secondary CA1 apical dendrites, along with a transient rise in GluA2 AMPA receptor subunits. After 24 h of recovery from stress, the animals showed a preference to explore an object placed in a novel position, which was accompanied by a normalization of NMDA and AMPA receptor subunits to control values. Our data suggest that acute stress produces reversible molecular and behavioral changes 24 h after stress, allowing a full reestablishment of hippocampal-related memory. Further studies need to be conducted to deepen our understanding of these changes and their reciprocal interactions.Adaptive stress responses are a promising avenue to develop interventions aiming at restoring hippocampal function impaired by repetitive stress exposure. © 2018 Aguayo, Tejos-Bravo, Díaz-Véliz, Pacheco, García-Rojo, Corrales, Olave, Aliaga, Ulloa, Avalos, Román-Albasini, Rojas and Fiedler.https://www.frontiersin.org/articles/10.3389/fnmol.2018.00283/ful
Phenomenological approach to non-linear Langevin equations
In this paper we address the problem of consistently construct Langevin
equations to describe fluctuations in non-linear systems. Detailed balance
severely restricts the choice of the random force, but we prove that this
property together with the macroscopic knowledge of the system is not enough to
determine all the properties of the random force. If the cause of the
fluctuations is weakly coupled to the fluctuating variable, then the
statistical properties of the random force can be completely specified. For
variables odd under time-reversal, microscopic reversibility and weak coupling
impose symmetry relations on the variable-dependent Onsager coefficients. We
then analyze the fluctuations in two cases: Brownian motion in position space
and an asymmetric diode, for which the analysis based in the master equation
approach is known. We find that, to the order of validity of the Langevin
equation proposed here, the phenomenological theory is in agreement with the
results predicted by more microscopic models.Comment: LaTex file, 2 figures available upon request, to appear in Phys.Rev.
Experimental evidence of solitary wave interaction in Hertzian chains
We study experimentally the interaction between two solitary waves that
approach one to another in a linear chain of spheres interacting via the Hertz
potential. When these counter propagating waves collide, they cross each other
and a phase shift respect to the noninteracting waves is introduced, as a
result of the nonlinear interaction potential. This observation is well
reproduced by our numerical simulations and it is shown to be independent of
viscoelastic dissipation at the beads contact. In addition, when the collision
of equal amplitude and synchronized counter propagating waves takes place, we
observe that two secondary solitary waves emerge from the interacting region.
The amplitude of secondary solitary waves is proportional to the amplitude of
incident waves. However, secondary solitary waves are stronger when the
collision occurs at the middle contact in chains with even number of beads.
Although numerical simulations correctly predict the existence of these waves,
experiments show that their respective amplitude are significantly larger than
predicted. We attribute this discrepancy to the rolling friction at the beads
contacts during solitary wave propagation
Public Perception of Desalinated Produced Water From Oil and Gas Field Operations: A Replication
This study is a replication of Theodori et al.’s (2009) research on public perception of desalinated produced water from oil and gas field operations. The data used in this paper were collected in twelve Texas counties. Overall, the findings of this investigation paralleled those uncovered in Theodori et al.’s original exploration. Our data reveal that small percentages of respondents are extremely familiar with the process of desalination and extremely confident that desalinated water could meet human drinking water quality and purity standards. Our data also indicate that respondents are more favorably disposed toward the use of desalinated water for purposes where the probability of human or animal ingestion is lessened. Lastly, our data show that individuals with higher levels of familiarity with the process of desalination were more likely than those with lower levels of familiarity to agree that desalinated water from oil and gas field operations could safely be used for each of nine proposed purposes. Possible implications of these findings are advanced
Aprendizaje basado en problemas en Biología Vegetal
El aprendizaje basado en problemas (ABP) es un método de enseñanzaaprendizaje
que usa el problema como punto de partida para la adquisición e
integración de nuevos conocimientos. En el desarrollo del ABP el problema es el
camino para que los estudiantes alcancen los objetivos de conocimientos,
destrezas y habilidades. El ABP y el estudio de casos se centran en el estudiante
lo cual implica necesariamente un cambio de función en el profesor que deja de
ser protagonista para convertirse en una guía o en tutor. El tutor plantea
problemas y cuestiones que contribuyen al entendimiento y a la resolución de
problemas promoviendo de esta forma un aprendizaje significativo. Por otra
parte, las nuevas tecnologías de la información y la comunicación introducen
cambios importantes en el proceso de enseñanza-aprendizaje en base a lo
siguiente: a) el acceso a la información y el modo de adquirir información, b) las
nuevas formas de relación profesor-alumno. Este trabajo muestra algunas
experiencias para el desarrollo de ABP, el estudio de casos y la elaboración de
mapas conceptuales e infografías, experiencias realizadas en el aula con
estudiantes de Biología de la Universidad Complutense de Madrid y en relación
con dos campos de la Biología: la Fisiología Vegetal y la Biología Evolutiva.The problem-based learning (PBL) is a teaching-learning method that uses
the problem as a starting point for the acquisition and integration of new
knowledge. In the development of PBL the problem is the way to achieve the
knowledge, skills and abilities. Problem-based learning and case study focuses
on the student and therefore imply a change in the teacher role: from protagonist
to tutor or guide. A tutor offers questions that contribute to understanding and
managing the problem promoting meaningful learning. On the other hand,
information and communication technologies introduces important changes in
teaching and learning on the basis of two issues: a) access and how to acquire
information, b) new forms of teacher-student relationship. This work shows
some experiences for the development of PBL, case studies and concept mapping
as classroom experiences for Biological Sciences students at the Complutense
University of Madrid. Two biological sciences fields were considered: plant
physiology and evolutionary plant biology
A reduced model for shock and detonation waves. II. The reactive case
We present a mesoscopic model for reactive shock waves, which extends a
previous model proposed in [G. Stoltz, Europhys. Lett. 76 (2006), 849]. A
complex molecule (or a group of molecules) is replaced by a single
mesoparticle, evolving according to some Dissipative Particle Dynamics.
Chemical reactions can be handled in a mean way by considering an additional
variable per particle describing a rate of reaction. The evolution of this rate
is governed by the kinetics of a reversible exothermic reaction. Numerical
results give profiles in qualitative agreement with all-atom studies
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