193 research outputs found
Rapid Prototype Development of a Remotely-Piloted Aircraft Powered by a Hybrid-Electric Propulsion System
Remotely-Piloted Aircraft (RPA) provide users with unique mission capabilities, particularly on-demand overhead surveillance. However, a capability gap has been identified between the range and endurance of RPAs powered by internal combustion engines (ICE) and the reduced acoustic signature and smaller logistical footprint associated with electric-powered RPAs. This research, sponsored by the Office of the Secretary of Defense, aims at advancing systems engineering education by evaluating the utility of a tailored systems engineering approach. The tailored systems engineering approach used herein focuses on conducting a concept evaluation study on the rapid prototype development of a parallel hybrid-electric RPA (HE-RPA) and its ability to fill an identified mission capability gap. The concept evaluation utilizes a tailored systems engineering process to conduct a rapid prototype development and system evaluation. Two prototype RPAs and a support system are designed, integrated, and tested within a 13 month time window, in accordance with an established architectural framework. The integration of a parallel hybrid-electric system into an RPA demonstrated a potential reduction in acoustic signature and improves endurance over electric powered RPAs; however, immature technology and added system complexity result in overall performance that is currently on par with ICE-powered RPAs and only partially satisfies the capability gap
Re-visualising international relations:Audio-visual projects and direct encounters with the political in security studies tla
In this paper we discuss how an innovative audio-visual project was adopted to foster active, rather than declarative learning, in critical International Relations (IR). First, we explore the aesthetic turn in IR, to contrast this with forms of representation that have dominated IR scholarship. Second, we describe how students were asked to record short audio or video projects to explore their own insights through aesthetic and non-written formats. Third, we explain how these projects are understood to be deeply embedded in social science methodologies. We cite our inspiration from applying a personal sociological imagination, as a way to counterbalance a ‘marketised’ slant in higher education, in a global economy where students are often encouraged to consume, rather than produce knowledge. Finally, we draw conclusions in terms of deeper forms of student engagement leading to new ways of thinking and presenting new skills and new connections between theory and practice
Inhibition of HSV-1 by chemoattracted neutrophils: supernatants of corneal epithelial cells (HCE) and macrophages (THP-1) treated with virus components chemoattract neutrophils (PMN), and supernatants of PMN treated with these conditioned media inhibit viral growth
The role of PMNs (neutrophils) in corneal herpes was studied using an in vitro system. Human corneal cells (HCE) and macrophages (THP-1) infected with HSV-1 or treated with virus components (DNA or virus immune complexes) released chemokines, which attracted PMNs. Highly reactive oxygen species were detected in PMNs. PMNs inhibited HSV when overlaid onto infected HCE cells (50:1). PMNs incubated with the supernatants of HCE cells treated with virus components released H2O2 and myeloperoxidase. These inhibited virus growth. PMNs released NO and MIG, which may differentiate CD4 T cells to Th1. PMNs participate in innate immune responses, limit virus growth, and initiate immunopathology
Uptake of home-based voluntary HIV testing in sub-Saharan Africa: a systematic review and meta-analysis
Improving access to HIV testing is a key priority in scaling up HIV treatment and prevention services. Home-based voluntary counselling and testing (HBT) as an approach to delivering wide-scale HIV testing is explored here
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'I once wore an angry bird t-shirt and went to read Qur’an': asymmetrical institutional complexity and emerging consumption practices in Pakistan
This article brings together theories of institutional logics and the exploration of the lives of tweens in Pakistan to understand how emerging consumption practices fit within Pakistani children’s daily lives, and how institutional complexity that includes the dominance of religion under Pakistani Islamization is negotiated to separate and maintain the differences between them. We identify resolutions to asymmetrical institutional complexity in the consumption of character T-shirts: spatial–temporal practices, visual practices, symbolic substitution practices and single logic practices. We contribute to an understanding of how consumption happens in an Eastern Muslim culture, and how multiple institutional logics shape the consumption practices of children, by articulating how halal consumption practices, far from being essentialist, or presented as market segmentation, form from negotiations and reflections at the boundaries where Islam and Market logics meet
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Drama and discounting in the relational dynamics of corporate social responsibility
Employing theoretical resources from Transactional Analysis (TA) and drawing from interviews with managers dealing with social or environmental issues in their role, we explain how CSR activity provides a context for dramas in which actors may ignore, or discount aspects of self, others, and the contexts of their work as they maintain and reproduce the roles of Rescuers, Persecutors and Victims. In doing so, we add to knowledge about CSR by providing an explanation for how the contradictions of CSR are avoided in practice even when actors may be aware of them. Specifically, we theorise how CSR work can produce dramatic stories where adversity is apparently overcome, whilst little is actually achieved at the social level. We also add to the range of psychoanalytic tools used to account for organisational behaviours, emphasising how TA can explain the relational dynamics of CSR
Spectroscopic Evidence for an Oxazolone Structure in Anionic b-Type Peptide Fragments
Infrared spectra of anionic b-type fragments generated by collision induced dissociation (CID) from deprotonated peptides are reported. Spectra of the b2 fragments of deprotonated AlaAlaAla and AlaTyrAla have been recorded over the 800–1800 cm–1 spectral range by multiple-photon dissociation (MPD) spectroscopy using an FTICR mass spectrometer in combination with the free electron laser FELIX. Structural characterization of the b-type fragments is accomplished by comparison with density functional theory calculated spectra at the B3LYP/6-31++G(d,p) level for different isomeric structures. Although diketopiperazine structures represent the energetically lowest isomers, the IR spectra suggest an oxazolone structure for the b2 fragments of both peptides. Deprotonation is shown to occur on the oxazolone α-carbon, which leads to a conjugated structure in which the negative charge is practically delocalized over the entire oxazolone ring, providing enhanced gas-phase stability
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When prototypes are not best: Judgments made by children with autism
The current study used a factorial comparison experimental design to investigate conflicting findings on prototype effects shown by children with autism (Klinger & Dawson, 2001; Molesworth, Bowler, & Hampton, 2005). The aim was to see whether children with high –functioning autism could demonstrate prototype effects via categorization responses and whether failure to do so was related to difficulty understanding ambiguous task demands. Two thirds of the autism group did show an effect. The remainder, a sub-group defined by performance on a control task, did not. The discussion focuses on the influence of heterogeneity within the autism group and the ability to resolve ambiguity on task performance. Finally, an alternative experimental design is recommended for further research into these issues
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