29,719 research outputs found
Disentangling the Relationship Between Race and Attitudes Toward the Police: Police Contact, Perceptions of Safety, and Procedural Justice
Recent incidents involving police shootings of unarmed men of color have increased tensions between communities and police departments across the United States. In response, scholars have intensified efforts to understand the factors that shape attitudes toward the police. The current study examines individual and aggregate factors that influence satisfaction with the police. To this end, we address three research questions: (a) are there significant racial/ethnic differences in satisfaction with police; (b) do these differences persist after accounting for experiences with the police, perceptions of safety, and aggregate measures; and (c) can procedural justice help explain racial variation in attitudes toward the police? Study findings highlight the importance of perceptions of safety in explaining racial/ethnic variation in attitudes toward the police
Effects of pH on Growth of Salvinia molesta Mitchell
Growth of giant salvinia (
Salvinia molesta
Mitchell) under
different pH regimes was examined at the Lewisville Aquatic
Ecosystem Research Facility (LAERF) in Lewisville, Texas.(PDF has 5 pages.
Topological Aspects of Spin and Statistics in Nonlinear Sigma Models
We study the purely topological restrictions on allowed spin and statistics
of topological solitons in nonlinear sigma models. Taking as space the
connected -manifold , and considering nonlinear sigma models with the
connected manifold as target space, topological solitons are given by
elements of . Any topological soliton determines
a quotient \Stat_n(X,\alpha) of the group of framed braids on , such that
choices of allowed statistics for solitons of type are given by
unitary representations of \Stat_n(X,\alpha) when solitons are present.
In particular, when , as in the nonlinear sigma model with Hopf
term, and is a generator, we compute that
\Stat_n(\R^2,\alpha) = \Z, while \Stat_n(S^2,\alpha) = \Z_{2n}. It follows
that phase for interchanging two solitons of type on
must satisfy the constraint , , when such
solitons are present.Comment: 14 page
Best Practices for Evaluating Flight Deck Interfaces for Transport Category Aircraft with Particular Relevance to Issues of Attention, Awareness, and Understanding CAST SE-210 Output 2 Report 6 of 6
Attention, awareness, and understanding of the flight crew are a critical contributor to safety and the flight deck plays a critical role in supporting these cognitive functions. Changes to the flight deck need to be evaluated for whether the changed device provides adequate support for these functions. This report describes a set of diverse evaluation methods. The report recommends designing the interface-evaluation to span the phases of the device development, from early to late, and it provides methods appropriate at each phase. It describes the various ways in which an interface or interface component can fail to support awareness as potential issues to be assessed in evaluation. It summarizes appropriate methods to evaluate different issues concerning inadequate support for these functions, throughout the phases of development
The secondary structure of apolipoprotein A-I on 9.6-nm reconstituted high-density lipoprotein determined by EPR spectroscopy.
Apolipoprotein A-I (ApoA-I) is the major protein component of high-density lipoprotein (HDL), and is critical for maintenance of cholesterol homeostasis. During reverse cholesterol transport, HDL transitions between an array of subclasses, differing in size and composition. This process requires ApoA-I to adapt to changes in the shape of the HDL particle, transiting from an apolipoprotein to a myriad of HDL subclass-specific conformations. Changes in ApoA-I structure cause alterations in HDL-specific enzyme and receptor-binding properties, and thereby direct the HDL particle through the reverse cholesterol transport pathway. In this study, we used site-directed spin label spectroscopy to examine the conformational details of the ApoA-I central domain on HDL. The motional dynamics and accessibility to hydrophobic/hydrophilic relaxation agents of ApoA-I residues 99-163 on 9.6-nm reconstituted HDL was analyzed by EPR. In previous analyses, we examined residues 6-98 and 164-238 (of ApoA-I's 243 residues), and combining these findings with the current results, we have generated a full-length map of the backbone structure of reconstituted HDL-associated ApoA-I. Remarkably, given that the majority of ApoA-I's length is composed of amphipathic helices, we have identified nonhelical residues, specifically the presence of a β-strand (residues 149-157). The significance of these nonhelical residues is discussed, along with the other features, in the context of ApoA-I function in contrast to recent models derived by other methods
A middleware for a large array of cameras
Large arrays of cameras are increasingly being employed for producing high quality image sequences needed for motion analysis research. This leads to the logistical problem with coordination and control of a large number of cameras. In this paper, we used a lightweight multi-agent system for coordinating such camera arrays. The agent framework provides more than a remote sensor access API. It allows reconfigurable and transparent access to cameras, as well as software agents capable of intelligent processing. Furthermore, it eases maintenance by encouraging code reuse. Additionally, our agent system includes an automatic discovery mechanism at startup, and multiple language bindings. Performance tests showed the lightweight nature of the framework while validating its correctness and scalability. Two different camera agents were implemented to provide access to a large array of distributed cameras. Correct operation of these camera agents was confirmed via several image processing agents
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