Active Printed Materials for Complex Self-Evolving Deformations

We propose a new design of complex self-evolving structures that vary over time due to environmental interaction. In conventional 3D printing systems, materials are meant to be stable rather than active and fabricated models are designed and printed as static objects. Here, we introduce a novel approach for simulating and fabricating self-evolving structures that transform into a predetermined shape, changing property and function after fabrication. The new locally coordinated bending primitives combine into a single system, allowing for a global deformation which can stretch, fold and bend given environmental stimulus

High contrast dual-mode optical and 13C magnetic resonance imaging in diamond particles

Multichannel imaging -- the ability to acquire images of an object through more than one imaging mode simultaneously -- has opened interesting new perspectives in areas ranging from astronomy to medicine. Visible optics and magnetic resonance imaging (MRI) offer complementary advantages of resolution, speed and depth of penetration, and as such would be attractive in combination. In this paper, we take first steps towards marrying together optical and MR imaging in a class of biocompatible particulate materials constructed out of diamond. The particles are endowed with a high density of quantum defects (Nitrogen Vacancy centers) that under optical excitation fluoresce brightly in the visible, but also concurrently electron spin polarize. This allows the hyperpolarization of lattice 13C nuclei to make the particles over three-orders of magnitude brighter than in conventional MRI. Dual-mode optical and MR imaging permits immediate access to improvements in resolution and signal-to-noise especially in scattering environments. We highlight additional benefits in background-free imaging, demonstrating lock-in suppression by factors of 2 and 5 in optical and MR domains respectively. Ultimate limits could approach as much as two orders of magnitude in each domain. Finally, leveraging the ability of optical and MR imaging to simultaneously probe Fourier-reciprocal domains (real and k-space), we elucidate the ability to employ hybrid sub-sampling in both conjugate spaces to vastly accelerate dual-image acquisition, by as much as two orders of magnitude in practically relevant sparse-imaging scenarios. This is accompanied by a reduction in optical power by the same factor. Our work suggests interesting possibilities for the simultaneous optical and low-field MR imaging of targeted diamond nanoparticles

Finding the most variable stars in the Orion Belt with the All Sky Automated Survey

We look for high-amplitude variable young stars in the open clusters and associations of the Orion Belt. We use public data from the ASAS-3 Photometric V-band Catalogue of the All Sky Automated Survey, infrared photometry from the 2MASS and IRAS catalogues, proper motions, and the Aladin sky atlas to obtain a list of the most variable stars in a survey area of side 5 deg centred on the bright star Alnilam (eps Ori) in the centre of the Orion Belt. We identify 32 highly-variable stars, of which 16 had not been reported to vary before. They are mostly variable young stars and candidates (16) and background giants (8), but there are also field cataclysmic variables, contact binaries, and eclipsing binary candidates. Of the young stars, which typically are active Herbig Ae/Be and T Tauri stars with Halpha emission and infrared flux excess, we discover four new variables and confirm the variability status of another two. Some of them belong to the well known sigma Orionis cluster. Besides, six of the eight giants are new variables, and three are new periodic variables.Comment: Astronomische Nachrichten, in pres

A critical role for dendritic cells in the evolution of IL-1beta-mediated murine airway disease.

peer reviewedChronic airway inflammation and fibrosis, known as airway remodeling, are defining features of chronic obstructive pulmonary disease and are refractory to current treatments. How and whether chronic inflammation contributes to airway fibrosis remain controversial. In this study, we use a model of chronic obstructive pulmonary disease airway disease utilizing adenoviral delivery of IL-1beta to determine that adaptive T cell immunity is required for airway remodeling because mice deficient in alpha/beta T cells (tcra(-/-)) are protected. Dendritic cells (DCs) accumulate around chronic obstructive pulmonary disease airways and are critical to prime adaptive immunity, but they have not been shown to directly influence airway remodeling. We show that DC depletion or deficiency in the crucial DC chemokine receptor ccr6 both protect from adenoviral IL-1beta-induced airway adaptive T cell immune responses and fibrosis in mice. These results provide evidence that chronic airway inflammation, mediated by accumulation of alpha/beta T cells and driven by DCs, is critical to airway fibrosis

The supervisor helps vicar in preaching [sound recording].

Address to Vicar Supervisor\u27s Conference, Concordia Seminary, St. Louis, June 6-10, 1966

Address to Faculty

Goals of Psychotherap

Studying the Effects of Familial Alzheimer’s Disease Mutations on the Assembly of a Constrained β-Hairpin Peptide Derived from Aβ And Developing and Implementing Specifications Grading Systems in an Organic Chemistry Laboratory Course and a Chemistry Writing Course

The dissertation is composed of two main parts. The first half describes efforts to study amyloid peptides using macrocyclic peptide model systems, and the potential deleterious effects of uronium peptide coupling agents on human health. The second half focuses on my experience in chemistry teaching and the chemical education research I conducted.Chapter 1 describes the design and synthesis of seven peptides and acetylated variants containing familial Alzheimer’s disease mutations (FADs). All peptides are based on a macrocyclic β-hairpin peptide derived from amyloid beta (Aβ), residues 16-36. The supramolecular structure of Aβ aggregates remains unknown due to the heterogeneous and unstable nature of Aβ oligomer formation. Elucidating the structure of Aβ aggregates will lead to insights into the function of Aβ in the progression of AD and FAD. Peptides derived from Aβ assemble in a crystalline state as dimers, trimers, hexamers, and even dodecamers, which recapitulates oligomeric species observed of full-length Aβ. In particular, the Aβ16-36 region is important for Aβ oligomer formation. Lactate dehydrogenase release assays and dye-release assays with lipid-bilayers indicate that the mutant peptides exhibit more toxicity towards neuronally derived SH-SY5Y cells and cause more membrane destabilization than the parent peptide. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis reveals that mutant peptides assemble as higher-order oligomers, and the E22 mutant peptides all assemble to form hexamers, similar to the parent peptide. Size exclusion chromatography and circular dichroism indicate that similarly charged mutant peptides exhibit similar solution-phase behavior. X-ray crystallography reveals that the E22 mutant peptides assemble to form hexamers in the crystal state. These studies will aid in our understanding of how mutations of full-length Aβ perturb the biophysical characteristics and assembly of Aβ oligomers, which may give insight into Aβ’s mode of causing toxicity in AD and FAD.Chapter 2 presents a case study of chemical sensitization. Anaphylactic reactions can occur from repeated exposure to peptide coupling agents. Many researchers in the peptide and protein chemistry fields recognize the peptide coupling agent DCC as an infamous immune sensitizer. Fewer researchers know that the uronium coupling agents HATU and HBTU are also sensitizers. Reports of sensitization caused by these peptide coupling agents have been published in allergy and immunology journals, but these sources are not generally read by researchers who use uronium coupling agents. In this chapter, I present my case study of anaphylaxis induced by three uronium agents: HATU, HBTU, and HCTU, as a cautionary note for researchers who handle peptide coupling agents frequently. I also include recommendations for handling coupling agents more safely in the research laboratory.Chapter 3 overviews my journey towards becoming an effective instructor. I chronicle my experience as a TA, Head TA, and Instructor of Record. I also discuss my time as a Pedagogical Fellow, TAP-STEM trainee, TA Mentor, and the Safety Fellow for the Department of Chemistry. Each experience taught me something different that helped prepare me to pursue and obtain a teaching focused faculty position at Emory University starting in summer 2020.Chapter 4 describes the design and implementation of specifications grading systems in organic chemistry laboratory courses and a “Writing for Chemists” course. I worked with Dr. Renée Link to convert her entire three-course organic chemistry laboratory series from a traditional, points-based grading system to a specifications grading system, first as a pilot study during a summer term course and then scaled up for the large (1,000+ students) course in winter 2020. I worked with Dr. Stephen Mang concurrently to redesign the “Writing for Chemists” course he started in 2017 using a specifications grading system and adapting assignments from a textbook on the practice of nonfiction writing. I taught the course in fall 2019 and used the redesigned course materials. In both courses, we collected surveys of students perceptions of the grading system, and in the organic chemistry laboratory courses we also collected feedback from the course TAs. Responses from students about the nature of the grading system in the laboratory course were mixed. Their perceptions indicate that initial buy-in and multiple reminders about the bigger picture of the grading system will be essential to the success of this grading system on a larger scale. After the writing course, students self-reported increased propensities to pre-write and edit, and several mentioned that they appreciated the transparency of rubrics and the control the specifications system gave them over their grades.Chapter 5 describes the development of an educational activity I designed and implemented with Dr. Renée Link — the Extraction on Paper Activity. Undergraduate students often find it difficult to understand the chemical principles underlying liquid-liquid extractions. Explanationson how extractions work at the molecular level in textbook and internet resources are plentiful, but students still do not seem able to grasp how extractions work before having to perform the technique in a laboratory course. To address student discomfort with conducting extractions, I developed an Extraction on Paper Activity. I envision this activity as a tool to help students understand and apply the chemical principles underlying liquid-liquid extractions outside of and before entering into a laboratory setting

Leisure behavior patterns: a study of residents in the lower Brazos Valley of Texas

The primary objective of this research was to determine if a relationship existed between selected socioeconomic characteristics and free time and its use. Hypotheses were developed and tested to investigate the effect of occupation, family income, education, place of residence, and sex on the availability and use of leisure time. Data concerning the quantity of free time available to the individual were collected through the use of time budget diaries and personal interviews were designed to gather information for the activity analysis. The secondary objective was, in fact, a requirement of the first. In the course of investigating the relationships described above, it was necessary to combine existing research techniques into a methodology broad enough to evaluate the effects of the socio-economic variables on leisure time and its use. The study area for the research included the following southeastern Texas counties: Brazos, Burleson, Grimes, Leon, Madison, Robertson, and Washington. A random block technique was used to select the sample. The population surveyed included only those residents of the seven county area that were eighteen years of age or older. Data for the study were collected between February 1, 1973 and March 1, 1973 by members of Squadron One, Texas A&M University Corps of Cadets. Seventy-two percent of the dwelling units contacted during the course of the project returned usable interview schedules. ..

Knitting behavior : a material-centric design process

Thesis: S.M., Massachusetts Institute of Technology, Department of Architecture, 2015.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis. Pages 54 to 57 blank.Includes bibliographical references (pages 51-53).This thesis explores computation as a communicative device between the physical and the digital, establishing a conversation between a material assembly and a digital model as a tool to inform the logic of the assembly's internal organization. In this research, the material assembly, which is defined as a material whose properties derive from the programming of raw matter to form unique internal structures, manifests through the technique of knitting, a material practice defined by pattern as rule-based code. A key contribution of this research is the development of a framework to help designers better understand how the topology of a knit structure can align with formal and structural motivations of tension activated architectural forms. This was accomplished through the identification of the knit pattern as code. Whereas traditionally the pattern is a static visual representation, in this research it is both the physical sequence of stitches and the dynamic properties of each stitch within a digital model. The dynamic properties of the physical material communicate through the knit pattern to the digital model, which explores the possibilities of form within the constraints of the material to remap the pattern's code and thereby re-informing the physical. This new framework may help designers create and evaluate material assemblies to better satisfy the local and global needs of form, structure, and aesthetics. The play between the physical and the digital is recursive, experimental, and interpretative - each informs the other while never truly resulting in the same output.by Carrie Lee McKnelly.S.M