All-Digital Simulation of Simple Automobile Maneuvers

A new, all-digital simulation describes straight- line acceleration and braking of an automobile. The model has five degrees of freedom: longitudinal velocity, vertical velocity, pitch angular velocity, and the angular velocities of the front and rear wheels. The model is capable of handling severe maneuvers. Special provisions allow the user to in clude antilock systems, average suspension forces, perform braking studies, and assess the importance of nonlinear terms. A validation study shows a close comparison with results from earlier models. The model is modular, well-documented, and readily available to researchers in a convenient form.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68927/2/10.1177_003754978103700603.pd

Graph-to-Graph Meaning Representation Transformations for Human-Robot Dialogue

In support of two-way human-robot communication, we leverage Abstract Meaning Representation (AMR) to capture the core semantic content of natural language search and navigation instructions. In order to effectively map AMR to a constrained robot action specification, we develop a set of in-domain, task-specific AMR graphs augmented with speech act and tense and aspect information not found in the original AMR. This paper presents our efforts and results in transforming AMR graphs into our in-domain graphs by employing both rule-based and classifier-based methods, thereby bridging the gap from entirely unconstrained natural language input to a fixed set of robot actions

Drinking in social groups. Does 'groupdrink' provide safety in numbers when deciding about risk?

AimsTo investigate the impact of alcohol consumption on risk decisions taken both individually and while part of a four- to six-person ad-hoc group.DesignA 2 (alcohol: consuming versus not consuming alcohol) x 2 (decision: individual, group) mixed-model design; decision was a repeated measure. The dependent variable was risk preference, measured using choice dilemmas.SettingOpportunity sampling in campus bars and a music event at a campus-based university in the United Kingdom.ParticipantsA total of 101 individuals were recruited from groups of four to six people who either were or were not consuming alcohol.MeasurementsParticipants privately opted for a level of risk in response to a choice dilemma and then, as a group, responded to a second choice dilemma. The choice dilemmas asked participants the level of accident risk at which they would recommend someone could drive while intoxicated.FindingsFive three-level multi-level models were specified in the software program HLM 7. Decisions made in groups were less risky than those made individually (B = -0.73, P < 0.001). Individual alcohol consumers opted for higher risk than non-consumers (B = 1.27, P = 0.025). A significant alcohol?×?decision interaction (B = -2.79, P = 0.001) showed that individual consumers privately opted for higher risk than non-consumers, whereas risk judgements made in groups of either consumers or non-consumers were lower. Decisions made by groups of consumers were less risky than those made by groups of non-consumers (B = 1.23, P < 0.001).ConclusionsModerate alcohol consumption appears to produce a propensity among individuals towards increased risk-taking in deciding to drive while intoxicated, which can be mitigated by group monitoring processes within small (four- to six-person) groups

Topological Graph Inverse Semigroups

To every directed graph $E$ one can associate a \emph{graph inverse semigroup} $G(E)$, where elements roughly correspond to possible paths in $E$. These semigroups generalize polycylic monoids, and they arise in the study of Leavitt path algebras, Cohn path algebras, Cuntz-Krieger $C^*$-algebras, and Toeplitz $C^*$-algebras. We investigate topologies that turn $G(E)$ into a topological semigroup. For instance, we show that in any such topology that is Hausdorff, $G(E)\setminus \{0\}$ must be discrete for any directed graph $E$. On the other hand, $G(E)$ need not be discrete in a Hausdorff semigroup topology, and for certain graphs $E$, $G(E)$ admits a $T_1$ semigroup topology in which $G(E)\setminus \{0\}$ is not discrete. We also describe, in various situations, the algebraic structure and possible cardinality of the closure of $G(E)$ in larger topological semigroups.Peer reviewe

Phenotypic Plasticity Opposes Species Invasions by Altering Fitness Surface

Understanding species invasion is a central problem in ecology because invasions of exotic species severely impact ecosystems, and because invasions underlie fundamental ecological processes. However, the influence on invasions of phenotypic plasticity, a key component of many species interactions, is unknown. We present a model in which phenotypic plasticity of a resident species increases its ability to oppose invaders, and plasticity of an invader increases its ability to displace residents. Whereas these effects are expected due to increased fitness associated with phenotypic plasticity, the model additionally reveals a new and unforeseen mechanism by which plasticity affects invasions: phenotypic plasticity increases the steepness of the fitness surface, thereby making invasion more difficult, even by phenotypically plastic invaders. Our results should apply to phenotypically plastic responses to any fluctuating environmental factors including predation risk, and to other factors that affect the fitness surface such as the generalism of predators. We extend the results to competition, and argue that phenotypic plasticity's effect on the fitness surface will destabilize coexistence at local scales, but stabilize coexistence at regional scales. Our study emphasizes the need to incorporate variable interaction strengths due to phenotypic plasticity into invasion biology and ecological theory on competition and coexistence in fragmented landscapes

Research findings from the Memories of Nursing oral history project.

Capturing the stories of nurses who practised in the past offers the opportunity to reflect on the changes in practice over time to determine lessons for the future. This article shares some of the memories of a group of 16 nurses who were interviewed in Bournemouth, UK, between 2009 and 2016. Thematic analysis of the interview transcripts identified a number of themes, three of which are presented: defining moments, hygiene and hierarchy. The similarities and differences between their experiences and contemporary nursing practice are discussed to highlight how it may be timely to think back in order to take practice forward positively in the future

Surfactant protein D modulates HIV infection of both T-cells and dendritic cells

Surfactant Protein D (SP-D) is an oligomerized C-type lectin molecule with immunomodulatory properties and involvement in lung surfactant homeostasis in the respiratory tract. SP-D binds to the enveloped viruses, influenza A virus and respiratory syncytial virus and inhibits their replication in vitro and in vivo. SP-D has been shown to bind to HIV via the HIV envelope protein gp120 and inhibit infectivity in vitro. Here we show that SP-D binds to different strains of HIV (BaL and IIIB) and the binding occurs at both pH 7.4 and 5.0 resembling physiological relevant pH values found in the body and the female urogenital tract, respectively. The binding of SP-D to HIV particles and gp120 was inhibited by the presence of several hexoses with mannose found to be the strongest inhibitor. Competition studies showed that soluble CD4 and CVN did not interfere with the interaction between SP-D and gp120. However, soluble recombinant DC-SIGN was shown to inhibit the binding between SP-D and gp120. SP-D agglutinated HIV and gp120 in a calcium dependent manner. SP-D inhibited the infectivity of HIV strains at both pH values of 7.4 and 5.0 in a concentration dependent manner. The inhibition of the infectivity was abolished by the presence of mannose. SP-D enhanced the binding of HIV to immature monocyte derived dendritic cells (iMDDCs) and was also found to enhance HIV capture and transfer to the T-cell like line PM1. These results suggest that SP-D can bind to and inhibit direct infection of T-cells by HIV but also enhance the transfer of infectious HIV particles from DCs to T-cells in vivo