Light-Scattering, Intrinsic Viscosity, and Gold Number Relationships for Some Dextran Fractions

Author Institution: Departments of Bacteriology and Chemistry, The Ohio State University, Columbus, Ohi

Robots Need the Ability to Navigate Abusive Interactions

Researchers are seeing more and more cases of abusive disinhibition towards robots in public realms. Because robots embody gendered identities, poor navigation of antisocial dynamics may reinforce or exacerbate gender-based violence. It is essential that robots deployed in social settings be able to recognize and respond to abuse in a way that minimises ethical risk. Enabling this capability requires designers to first understand the risk posed by abuse of robots, and hence how humans perceive robot-directed abuse. To that end, we experimentally investigated reactions to a physically abusive interaction between a human perpetrator and a victimized agent. Given extensions of gendered biases to robotic agents, as well as associations between an agent’s human likeness and the experiential capacity attributed to it, we quasi-manipulated the victim’s humanness (via use of a human actor vs. NAO robot) and gendering (via inclusion of stereotypically masculine vs. feminine cues in their presentation) across four video-recorded reproductions of the interaction. Analysis of data from 417 participants, each of whom watched one of the four videos, indicates that the intensity of emotional distress felt by an observer is associated with their gender identification, previous experience with victimization, hostile sexism, and support for social stratification, as well as the victim’s gendering

Effects of Partnerships between Adolescents with Developmental Disabilities and Service Dogs

Background: With increasing frequency, service dogs are being placed with children with developmental disabilities (DDs). Occupational therapists and other professionals have advocated for the therapeutic use of service dog partnerships to facilitate greater independence and quality of life. There are no studies that examine service dog intervention with adolescents. Method: This study focused on the effects of partnerships between service dogs and three participant dyads, each including an adolescent with DDs and a parent. A single-subject, alternating treatment design was used to compare the effects of two conditions (service dog present or not present). The effects were examined for adolescents’ anxiety behaviors during transitions and during grocery store shopping, for social interactions during grocery store shopping, and for parents’ reported levels of stress. Results: Findings were that service dog partnerships reduced the presence of anxiety behaviors during transitions for one of the three adolescents; reduced the presence of anxiety behaviors during grocery store visits for two of the three adolescents; increased social interactions for all three of the participant dyads; and had no meaningful impact on self-reported parental stress level. Conclusion: For adolescents with DDs, professionals may want to consider service dog partnerships to decrease anxiety behaviors and increase social interactions in the community

Factors Affecting the Degradation Processes for Dextran

Author Institution: Departments of Bacteriology and Chemistry, The Ohio State University, Columbus 1

Numerical Study of Structural Phase Transitions in a Vertically Confined Plasma Crystal

Dusty plasmas consists of an ionized gas containing small (usually negatively charged) particles. Dusty plasmas are of interest in both astrophysics and space physics as well as in research in plasma processing and nanofabrication. In this work, the formation of plasma crystals confined in an external one-dimensional parabolic potential well is simulated for a normal experimental environment employing a computer code called BOX_TREE. Such crystals are layered systems, with each layer a two dimensional lattice composed of grain particles. The number of layers is dependent upon the external potential parameter. For constant layer number, the intralayer structure transits from a square lattice to a hexagonal (triangular) lattice as the confining potential decreases. For hexagonal lattices, both hcp and fcc characteristics were found but hcp structures dominate. The relative thickness of the system was also examined. The results were compared with previous experimental and theoretical results and found to agree

ActS activates peptidoglycan amidases during outer membrane stress in <i>Escherichia coli</i>

The integrity of the cell envelope of E. coli relies on the concerted activity of multi-protein machineries that synthesize the peptidoglycan (PG) and the outer membrane (OM). Our previous work found that the depletion of lipopolysaccharide (LPS) export to the OM induces an essential PG remodeling process involving LD-transpeptidases (LDTs), the glycosyltransferase function of PBP1B and the carboxypeptidase PBP6a. Consequently, cells with defective OM biogenesis lyse if they lack any of these PG enzymes. Here we report that the morphological defects, and lysis associated with a ldtF mutant with impaired LPS transport, are alleviated by the loss of the predicted OM-anchored lipoprotein ActS (formerly YgeR). We show that ActS is an inactive member of LytM-type peptidoglycan endopeptidases due to a degenerated catalytic domain. ActS is capable of activating all three main periplasmic peptidoglycan amidases, AmiA, AmiB, and AmiC, which were previously reported to be activated only by EnvC and/or NlpD. Our data also suggest that in vivo ActS preferentially activates AmiC and that its function is linked to cell envelope stress

Buckling Instabilities of a Confined Colloid Crystal Layer

A model predicting the structure of repulsive, spherically symmetric, monodisperse particles confined between two walls is presented. We study the buckling transition of a single flat layer as the double layer state develops. Experimental realizations of this model are suspensions of stabilized colloidal particles squeezed between glass plates. By expanding the thermodynamic potential about a flat state of $N$ confined colloidal particles, we derive a free energy as a functional of in-plane and out-of-plane displacements. The wavevectors of these first buckling instabilities correspond to three different ordered structures. Landau theory predicts that the symmetry of these phases allows for second order phase transitions. This possibility exists even in the presence of gravity or plate asymmetry. These transitions lead to critical behavior and phases with the symmetry of the three-state and four-state Potts models, the X-Y model with 6-fold anisotropy, and the Heisenberg model with cubic interactions. Experimental detection of these structures is discussed.Comment: 24 pages, 8 figures on request. EF508