Controlled Deformation of Light Activated Polymers

The motivation for this research was to demonstrate the ability to program the deformation of light activated polymers (LAPs) by controlling the chemical makeup, the mechanical parameters of the test, and the optical stimulus. The deformation of LAPs is a product of the network reformation that occurs due to the initiation of the Radical-Mediated Additional Fragmentation Chain Transfer (RAFT) mechanism. The RAFT mechanism minimizes the free energy present in the system, which can result in a localized plastic deformation under certain experimental parameters. Tests were done to demonstrate the ability of controlled surface patterning and out of plane bending by manipulating this RAFT mechanism. Surface patterning was exhibited by initiating the RAFT mechanism in localized regions of an optically thin sample under some strain. To demonstrate bending, “optically thick” samples were used to create a gradient of network reformation, and thereby curvature. In addition to creating deformation, the objective of this work included predicting and prescribing surface features through control and modification of the testing parameters. To assist in this work, an FEA model was constructed in ABAQUS that effectively predicted the deformation caused by imposed values of applied strain, region of irradiation and maximum stress relaxation potential. This study showed that by sufficiently characterizing the network rearrangement of optically thin and optically thin photoactive polymers, the deformation behavior could be predicted and controlled. In the optically thin case, this translates into precise control of surface patterning through the use of physical masks to define irradiation zones. In the optically thick case, tests illustrated that by using multiple prescribed irradiation steps based on the characterization studies, appropriate testing procedures could be defined to create bending out of plane. This work ultimately demonstrated the versatility of the deformation possible in LAPs

Role of perfectionism, self-compassion, and cultural values on help-seeking attitudes of Asian American college students

Perfectionism, cultural values, and self-compassion can all impact the ways in which a person may present themselves. The desire to appear perfect has been found to mask psychological distress. Our study examines how perfectionism, as well as other variables that influence self-presentation, can impact help-seeking attitudes. We focus on the influence of perfectionistic self-presentation on mental health outcomes in Asian American college students. We predicted that self-compassion will be correlated with positive help-seeking attitudes, while perfectionistic self-presentation will be related to more unfavorable help-seeking attitudes. We also examine how culture, specifically emotional self-control and family recognition through achievement, can alter these relationships. Data collection is still ongoing, but preliminary correlations based on 101 Asian American college students indicated that help-seeking attitudes was correlated with cultural value of emotional restraint, and the perfectionistic self-presentation subscale of non-disclosure of imperfection

NASA ExoPAG Study Analysis Group 11: Preparing for the WFIRST Microlensing Survey

NASA's proposed WFIRST-AFTA mission will discover thousands of exoplanets with separations from the habitable zone out to unbound planets, using the technique of gravitational microlensing. The Study Analysis Group 11 of the NASA Exoplanet Program Analysis Group was convened to explore scientific programs that can be undertaken now, and in the years leading up to WFIRST's launch, in order to maximize the mission's scientific return and to reduce technical and scientific risk. This report presents those findings, which include suggested precursor Hubble Space Telescope observations, a ground-based, NIR microlensing survey, and other programs to develop and deepen community scientific expertise prior to the mission.Comment: 35 pages, 5 Figures. A brief overview of the findings is presented in the Executive Summary (2 pages

A polymorphism in the interleukin-4 receptor affects the ability of interleukin-4 to regulate Th17 cells: a possible immunoregulatory mechanism for genetic control of the severity of rheumatoid arthritis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94408/1/Wallis_2011_Polymorphism_interleukin-4_receptor.pdf165

KMT-2016-BLG-1107: A New Hollywood-Planet Close/Wide Degeneracy

We show that microlensing event KMT-2016-BLG-1107 displays a new type of degeneracy between wide-binary and close-binary Hollywood events in which a giant-star source envelops the planetary caustic. The planetary anomaly takes the form of a smooth, two-day "bump" far out on the falling wing of the light curve, which can be interpreted either as the source completely enveloping a minor-image caustic due to a close companion with mass ratio $q=0.036$, or partially enveloping a major-image caustic due to a wide companion with $q=0.004$. The best estimates of the companion masses are both in the planetary regime ($3.3^{+3.5}_{-1.8}\,M_{\rm jup}$ and $0.090^{+0.096}_{-0.037}\,M_{\rm jup}$) but differ by an even larger factor than the mass ratios due to different inferred host masses. We show that the two solutions can be distinguished by high-resolution imaging at first light on next-generation ("30m") telescopes. We provide analytic guidance to understand the conditions under which this new type of degeneracy can appear.Comment: 23 pages, 7 figures, accepted for publication in A

Cyclic DI-GMP Phosphodiesterases RmdA and RmdB are involved in regulating colony morphology and development in Streptomyces coelicolor. Journal of Bacteriology

Cyclic dimeric GMP (c-di-GMP) regulates numerous processes in Gram-negative bacteria, yet little is known about its role in Gram-positive bacteria. Here we characterize two c-di-GMP phosphodiesterases from the filamentous high-GC Gram-positive actinobacterium Streptomyces coelicolor, involved in controlling colony morphology and development. A transposon mutation in one of the two phosphodiesterase genes, SCO0928, hereby designated rmdA (regulator ofmorphology and development A), resulted in decreased levels of spore-specific gray pigment and a delay in spore formation. The RmdA protein contains GGDEF-EAL domains arranged in tandem and possesses c-di-GMP phosphodiesterase activity, as is evident from in vitro enzymatic assays using the purified protein. RmdA contains a PAS9 domain and is a hemoprotein. Inactivation of another GGDEF-EAL-encoding gene, SCO5495, designated rmdB, resulted in a phenotype identical to that of the rmdA mutant. Purified soluble fragment of RmdB devoid of transmembrane domains also possesses c-di-GMP phosphodiesterase activity. ThermdA rmdB double mutant has a bald phenotype and is impaired in aerial mycelium formation. This suggests that RmdA and RmdB functions are additive and at least partially overlapping. The rmdA and rmdB mutations likely result in increased local pools of intracellular c-di-GMP, because intracellular c-di-GMP levels in the single mutants did not differ significantly from those of the wild type, whereas in the double rmdA rmdB mutant, c-di-GMP levels were 3-fold higher than those in the wild type. This study highlights the importance of c-di-GMP-dependent signaling in actinomycete colony morphology and development and identifies two c-di-GMP phosphodiesterases controlling these processes

KMT-2018-BLG-1990Lb: A Nearby Jovian Planet From A Low-Cadence Microlensing Field

We report the discovery and characterization of KMT-2018-BLG-1990Lb, a Jovian planet $(m_p=0.57_{-0.25}^{+0.79}\,M_J)$ orbiting a late M dwarf $(M=0.14_{-0.06}^{+0.20}\,M_\odot)$, at a distance (D_L=1.23_{-0.43}^{+1.06}\,\kpc), and projected at $2.6\pm 0.6$ times the snow line distance, i.e., a_{\rm snow}\equiv 2.7\,\au (M/M_\odot), This is the second Jovian planet discovered by KMTNet in its low cadence ($0.4\,{\rm hr}^{-1}$) fields, demonstrating that this population will be well characterized based on survey-only microlensing data.Comment: 24 pages, 7 figures, 4 table

Molecular Response to Extreme Summer Temperatures Differs Between Two Genetically Differentiated Populations of a Coral Reef Fish

Extreme thermal events are increasing in frequency and duration as the climate continues to warm, with potential detrimental effects on marine organisms. However, the effects of heatwaves may differ among geographically separated populations depending on their capacity for thermal plasticity. Here, we compared the response to simulated summer heatwave temperatures (+1.5 and +3.0°C above average) in two populations of a coral reef damselfish with different capacities for thermal plasticity. We found that the more thermally tolerant population had greater plasticity of gene expression and had significantly more downregulated genes, which may provide more energy to repair damage associated with thermal stress and to maintain basic functions at these extreme temperatures. In contrast, the thermally sensitive population exhibited higher basal levels of heat shock proteins and had three times fewer changes in gene expression overall. The limited changes in gene regulation suggest that individuals have reduced genome plasticity to tolerate thermal fluctuations and consequently may not have enough energy to repair damage and resume cellular homeostasis at extreme temperatures. Thus, we have identified the molecular signatures of how two genetically distinct fish populations cope with an extreme thermal event, and why they differ in their capacity for thermal plasticity

Spatially localized cluster solutions in inhibitory neural networks

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.mbs.2021.108591. © 2021. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Neurons in the inhibitory network of the striatum display cell assembly firing patterns which recent results suggest may consist of spatially compact neural clusters. Previous computational modeling of striatal neural networks has indicated that non-monotonic, distance-dependent coupling may promote spatially localized cluster firing. Here, we identify conditions for the existence and stability of cluster firing solutions in which clusters consist of spatially adjacent neurons in inhibitory neural networks. We consider simple non-monotonic, distance-dependent connectivity schemes in weakly coupled 1-D networks where cells make stronger connections with their th nearest neighbors on each side and weaker connections with closer neighbors. Using the phase model reduction of the network system, we prove the existence of cluster solutions where neurons that are spatially close together are also synchronized in the same cluster, and find stability conditions for these solutions. Our analysis predicts the long-term behavior for networks of neurons, and we confirm our results by numerical simulations of biophysical neuron network models. Our results demonstrate that an inhibitory network with non-monotonic, distance-dependent connectivity can exhibit cluster solutions where adjacent cells fire together.American Institute of Mathematics, Structured Quartet Research Ensembles program || Natural Sciences and Engineering Research Council of Canada

KMT-2018-BLG-1292: A Super-Jovian Microlens Planet in the Galactic Plane

We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian $M_{\rm planet} = 4.5\pm 1.3\,M_J$ planet orbiting an F or G dwarf $M_{\rm host} = 1.5\pm 0.4\,M_\odot$, which lies physically within {\cal O}(10\,\pc) of the Galactic plane. The source star is a heavily extincted $A_I\sim 5.2$ luminous giant that has the lowest Galactic latitude, $b=-0.28^\circ$, of any planetary microlensing event. The relatively blue blended light is almost certainly either the host or its binary companion, with the first explanation being substantially more likely. This blend dominates the light at $I$ band and completely dominates at $R$ and $V$ bands. Hence, the lens system can be probed by follow-up observations immediately, i.e., long before the lens system and the source separate due to their relative proper motion. The system is well characterized despite the low cadence $\Gamma=0.15$--$0.20\,{\rm hr^{-1}}$ of observations and short viewing windows near the end of the bulge season. This suggests that optical microlensing planet searches can be extended to the Galactic plane at relatively modest cost.Comment: 35 pages, 3 Tables, 8 figure