Chicana Photography: The Power of Place

Abstract: The concern with space, location, place, and geographic site has received heightened attention from artists and theorists from the 1960s onward. For critics and creators engaged with these concepts, the analysis of the interaction between of the processes of spatialization, identity formation, and memory has emerged as an important aspect of critical discourse. Lucy Lippard defines space as a physical site, understood as landscape or nature, while place implies intimacy, a familiarity with a certain geographic location. For Lippard, human interaction and, most importantly, the infusion of memory into space or a geographic site produces place. Michel de Certeau proposes that everyday practices create a text or unseen pathway in the physical nvironment. People transform space into place through interaction in their daily lived locale. Contemporary Chicana photographers Laura Aguilar, Kathy Vargas, and Delilah Montoya have produced extensive bodies of work during the past four decades that investigate the body, land, memory, and the issues of identity formation in relationship to location. The essay considers each artist in turn and first provides a general overview of each photographer’s art production. The essay then uses Lippard and Certeau’s concepts of space and place to analyze selected images from Aguilar’s Stillness (1999), Motion (1999), and Center (2001), Vargas’ My Alamo (1995), and Delilah Montoya’s Sed: The Trail of Thirst (2004). The work excavates the multiple meanings of the locations and bodies portrayed in these works, and demonstrates how the depiction of geographic space in these artists’ work becomes an intimate, personal site where the construction of places and identities occur

The effect of salts on the derivatization and chromatography of amino acids

Effect of salts on derivatization and chromatography of amino acid

Cardiac safety of tiotropium in patients with cardiac events: a retrospective analysis of the UPLIFT® trial.

BackgroundTiotropium is an anticholinergic bronchodilator for symptom relief and reducing exacerbations with an established safety profile in patients with chronic obstructive pulmonary disease (COPD). Using data from the 4-year Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFT®) study, we re-evaluated the safety of tiotropium HandiHaler® in patients who experienced recent myocardial infarction (MI), heart failure or unstable rhythm disorder during the study.MethodsA post-hoc analysis of all-cause mortality and serious cardiac adverse events (cardiac SAEs), including cardiac deaths and death unknown, was conducted in patients who had experienced cardiac arrhythmia, MI or cardiac failure during UPLIFT® and who completed the study. Descriptive analyses were performed.ResultsMost patients experiencing cardiac events, for which they would have been excluded at baseline, remained in the trial. Kaplan-Meier analyses revealed a trend to later occurrence of cardiac SAEs with tiotropium HandiHaler® versus placebo. Patients who experienced a cardiac event and continued in UPLIFT® were not found to be at subsequently increased risk of all-cause mortality or cardiac SAEs with tiotropium treatment. Evaluation of deaths by major adverse cardiac events composite endpoints also showed that patients treated with tiotropium were not at increased risk of mortality or cardiac SAEs compared with placebo.ConclusionsRisk of cardiac events, mortality or SAEs was not increased by tiotropium in patients experiencing cardiac events for which they would have been excluded at study baseline. The findings support the cardiac safety of tiotropium HandiHaler® in patients with COPD

Analysis of a Reduced-Order Model for the Simulation of Elastic Geometric Zigzag-Spring Meta-Materials

We analyze the performance of a reduced-order simulation of geometric meta-materials based on zigzag patterns using a simplified representation. As geometric meta-materials we denote planar cellular structures which can be fabricated in 2d and bent elastically such that they approximate doubly-curved 2-manifold surfaces in 3d space. They obtain their elasticity attributes mainly from the geometry of their cellular elements and their connections. In this paper we focus on cells build from so-called zigzag springs. The physical properties of the base material (i.e., the physical substance) influence the behavior as well, but we essentially factor them out by keeping them constant. The simulation of such complex geometric structures comes with a high computational cost, thus we propose an approach to reduce it by abstracting the zigzag cells by a simpler model and by learning the properties of their elastic deformation behavior. In particular, we analyze the influence of the sampling of the full parameter space and the expressiveness of the reduced model compared to the full model. Based on these observations, we draw conclusions on how to simulate such complex meso-structures with simpler models.Comment: 14 pages, 12 figures, published in Computers & Graphics, extended version of arXiv:2010.0807

Measuring a Cognitive Apprenticeship Model of Instruction in Statistics Education

Research has continued to support the need for investigating the role of pedagogical models in relation to students’ statistical anxiety, statistical self-efficacy, and academic performance within statistics education. Although models in the literature such as the Cognitive Apprenticeships Model of Instruction (CA-MOI) have emerged and have shown positive educational outcomes for teaching disciplines that involve the use of complex tasks (Kuo, Hwang, Chen, & Chen, 2012; Poitras & Poitras, 2011; Wegner, 2011), only one study has actually measured the degree to which this model was implemented, using the Maastrict Clinical Teaching Questionnaire (MCTQ) (Stalmeijer et al., 2008). Consequently the problem lies in the notion that researchers are claiming to use this model of instruction and are making generalizations about the effectiveness of the model, yet are failing to measure if and to what degree this method of instruction is actually being implemented within their classroom(s) and/or fields. Although the scores on the MCTQ have been validated in the literature as an evaluation instrument based on the CA-MOI, the MCTQ is specifically geared toward measuring supervisory skills in clinical education and consequently may not be an appropriate instrument for determining the degree to which a CA-MOI is being implemented within statistics education. In aiming to resolve the current measurement issue, the purpose of this study was to first develop an instrument that reflects the instructional methods of the CA-MOI in statistics education called the MCASE (Measuring Cognitive Apprenticeship in Statistics Education), secondly to receive expert review on the items, third to test and validate the instrument on a select group of college students, and lastly to determine what relationships, if any are found among students who report being taught using a CA-MOI, and their self-reported statistical anxiety, statistical self-efficacy, and academic performance. A total of 628 college students from across the nation participated in the current study. When collectively comparing scores on the SAM, the CSSE, and student’s self-reported academic performance with scores on the MCASE, results illustrated that utilizing a CA-MOI helped a student’s statistical anxiety, statistical self-efficacy, and his or her academic performance. Furthermore, results of this dissertation suggest that a cognitive apprenticeship model of instruction can be measured in statistics education and be represented by a seven-dimension solution: modeling, coaching, articulation, comparative reflection, true reflection, instructor-guided exploration, and true exploration. Moreover, the MCASE provides to date the most useful and theoretical measure of a cognitive apprenticeship model of instruction within statistics education, which can be rephrased to fit other fields of study that claim to use a CA-MOI. Additional findings and implications from this study for educational settings in which a CA-MOI may be utilized are provided, as well as limitations and recommendations for future research

A computational model for continual learning and synaptic consolidation

How humans are able to learn and memorize is a long-standing question in science. Much progress has been achieved in recent decades to answer this question but the are still many open problems. One of these problems refers to the human ability to learn several tasks in sequence without forgetting. In neuronal networks learning can interfere with pre-existing memories when the network is engaged in continual learning. The interference is particularly pronounced if, for instance, similar sensory stimuli require different responses depending on the context. Unlike in humans, this can lead to a memory loss termed catastrophic forgetting. To avoid interference and its fatal consequences, only a subset of synaptic weights should be consolidated. In this work we propose as computational model which performs selective consolidation by incorporating the synaptic tagging and capture hypothesis. This hypothesis, well grounded by experimental evidences, claims that synaptic consolidation requires both a synaptic-specific tag and diffusible plasticity-related proteins. We show that synaptic tagging and capture can be modeled by two classes of synaptic processes acting on different time scales. The two classes, characterized whether protein synthesis is required, are represented in our model by two synaptic components interacting with each other. With our approach we demonstrate that synaptic consolidation can not only diminishes the problem of catastrophic forgetting during continual learning but also enables fast learning through strongly changing synaptic strengths during the early phase of long-term potentiation. The model reproduces various experimental observations on synaptic tagging and cross-tagging. It also explains why learning in psychophysical experiments is hampered when different types of stimuli are randomly intermixed

Investigations on the system boron-carbon silicon

The above elements form with each other binary compounds which are very interesting from the point of view of their structure and their chemistry and which are important for technology. The present investigation is concerned with the three-component system and the behavior of the binary compounds occurring in it. Investigations employing various techniques, such as X-ray, chemical analysis, microscopy and fusion experiments showed that no ternary phase exists within the boundary of the ternary system. There is no compound with a higher abrasion capacity than boron carbide. The probable phase field divisions at two isothermic intersections and the fusion isotherms are indicated