193 research outputs found
Definition of ground test for verification of large space structure control
Control theory and design, dynamic system modelling, and simulation of test scenarios are the main ideas discussed. The overall effort is the achievement at Marshall Space Flight Center of a successful ground test experiment of a large space structure. A simplified planar model of ground test experiment of a large space structure. A simplified planar model of ground test verification was developed. The elimination from that model of the uncontrollable rigid body modes was also examined. Also studied was the hardware/software of computation speed
A Temporal Model of Negotiation Linkage Dynamics
This article exploresnegotiation linkagedynamics (howonenegotiation influences or determines the process or outcome of another) by exam-ining three bilateral trade treaty negotiations conducted by the govern
Crystal Structure of PrgI-SipD: Insight into a Secretion Competent State of the Type Three Secretion System Needle Tip and its Interaction with Host Ligands
Many infectious Gram-negative bacteria, including Salmonella typhimurium, require a Type Three Secretion System (T3SS) to translocate virulence factors into host cells. The T3SS consists of a membrane protein complex and an extracellular needle together that form a continuous channel. Regulated secretion of virulence factors requires the presence of SipD at the T3SS needle tip in S. typhimurium. Here we report three-dimensional structures of individual SipD, SipD in fusion with the needle subunit PrgI, and of SipD:PrgI in complex with the bile salt, deoxycholate. Assembly of the complex involves major conformational changes in both SipD and PrgI. This rearrangement is mediated via a π bulge in the central SipD helix and is stabilized by conserved amino acids that may allow for specificity in the assembly and composition of the tip proteins. Five copies each of the needle subunit PrgI and SipD form the T3SS needle tip complex. Using surface plasmon resonance spectroscopy and crystal structure analysis we found that the T3SS needle tip complex binds deoxycholate with micromolar affinity via a cleft formed at the SipD:PrgI interface. In the structure-based three-dimensional model of the T3SS needle tip, the bound deoxycholate faces the host membrane. Recently, binding of SipD with bile salts present in the gut was shown to impede bacterial infection. Binding of bile salts to the SipD:PrgI interface in this particular arrangement may thus inhibit the T3SS function. The structures presented in this study provide insight into the open state of the T3SS needle tip. Our findings present the atomic details of the T3SS arrangement occurring at the pathogen-host interface
Rent-Seekers’ Lost El Dorado: Vietnam's Financial Turmoil, 2007-2013
In this investigation, we examined 256 cases of financial failure and fraud in Vietnam’s chaotic years from 2007 to 2013. Categorical data analyses suggest that the rent-seeking approach, or resource-based orientation, alone does not help explain the outcome of a business intention while the association between Orientation and Approach is the best-fit predictor. Rampant financial collapse not only increases the cost of funds but also erodes trust in the economy. Entrepreneurship development and creativity capacity building, in light of this, are necessary to improve socio-economic conditions and the environment. In this manuscript, we also introduce intuitive and cognitive factors to predict ex-ante outcome of a financing scheme.info:eu-repo/semantics/publishe
New logics of Integration in European Security and Defence Policy: Change in Conflict-Resolution Mechanisms in the Intergovernmental Decision-Making Process.
The EU is undertaking important developments in the area of European security without asserting new fundamental goals. This paper proposes a conceptualisation of new logics of integration in the ESDP, by focusing on the transformation of conflict-resolution mechanisms in the adoption and implementation of policy provisions in the area. I argue that since 1998, pressing external events have led to an integrative policy change in the area of European security, manifest in an increasing use of expert incrementalist methods within the intergovernmental framework of the EU. The urgency of collective decisions adopted in substantive negotiations at a high political level combines with the incrementalist “filling-in” in the operational phase. While bargaining is highly determinant in the adoption of key compromises, the operational phase has become infused with administrative management and expert consultation, corresponding with the proliferation of newly created specialized agencies and think tanks, thus creating dynamics for the introduction of novel program specifications. Integrative outcomes are manifest in the progress in military operational capacity, the actual accomplishment of EU-based “Petersberg” operations, the focus on a more pragmatic understanding of the relationship with NATO and the proposals for coordination and flexibility envisaged in the draft of the Constitutional Treaty. The focus on conflict-resolution mechanisms provides theoretical determinants to explain integration logics in the ESDP, as a process of development of practical goals
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