Explaining External Support for Insurgent Groups

AbstractMany rebel organizations receive significant assistance from external governments, yet the reasons why some rebels attract foreign support while others do not is poorly understood. We analyze factors determining external support for insurgent groups from a principal-agent perspective. We focus on both the supply side, that is, when states are willing to support insurgent groups in other states, and the demand side, that is, when groups are willing to accept such support, with the conditions that this may entail. We test our hypotheses using new disaggregated data on insurgent groups and foreign support. Our results indicate that external rebel support is influenced by characteristics of the rebel group as well as linkages between rebel groups and actors in other countries. More specifically, we find that external support is more likely for moderately strong groups where support is more likely to be offered and accepted, in the presence of transnational constituencies, international rivalries, and when the government receives foreign support.</jats:p

Who Should Be at the Table?: Veto Players and Peace Processes in Civil War

Civil wars contain a set of actors that have the ability to block settlement and continue the war on their own. When they contain more “veto players,” conflicts are much longer and negotiations are more likely to break down. The rate of success of international efforts to resolve multi-party civil wars is much lower than when there is only one rebel group fighting the government. This article discusses implications for peacemakers designing responses to conflicts with multiple veto players. Negotiations in these conflicts are most likely to lead to a peace agreement that successfully ends the war if they include all veto players and exclude non-veto players

Forces and Moments on Pointed Blunt-nosed Bodies of Revolution at Mach Numbers from 2.75 to 5.00

Results of tests to determine the aerodynamic forces and moments on bodies of revolution at angles of attack from 0 degrees to 25 degrees are presented and compared with theory. Cones and ogives of fineness ratios 3 to 7 and two blunt-nosed body shapes with fineness ratios 3 and 5 were tested at Mach numbers from 2.75 to 5.00. Reynolds numbers were from 0.5 million to 6.4 million, depending on Mach number and body fineness ratio

Subscale Flight Testing for Aircraft Loss of Control: Accomplishments and Future Directions

Subscale flight-testing provides a means to validate both dynamic models and mitigation technologies in the high-risk flight conditions associated with aircraft loss of control. The Airborne Subscale Transport Aircraft Research (AirSTAR) facility was designed to be a flexible and efficient research facility to address this type of flight-testing. Over the last several years (2009-2011) it has been used to perform 58 research flights with an unmanned, remotely-piloted, dynamically-scaled airplane. This paper will present an overview of the facility and its architecture and summarize the experimental data collected. All flights to date have been conducted within visual range of a safety observer. Current plans for the facility include expanding the test volume to altitudes and distances well beyond visual range. The architecture and instrumentation changes associated with this upgrade will also be presented

Performance Degradation Due To Specular Multipath Intersymbol Interference

Plots of performance degradation are used to compare the effects of fading and intersymbol interference in a two-component specular multipath digital communications channel. Similar plots are then used to compare two practical receivers designed to combat the interference. Degradation plots are shown to allow easy identification of each receiver\u27s range of usefulness, as well as identification of variance bounds demanded of channel parameter estimates which the receivers require. Copyright © 1973 by The Institute of Electrical and Electronics Engineers, Inc

The Role of GLUK5-Containing Kainate Receptors in Entorhinal Cortex Gamma Frequency Oscillations

Using in vitro brain slices of hippocampus and cortex, neuronal oscillations in the frequency range of 30–80 Hz (gamma frequency oscillations) can be induced by a number of pharmacological manipulations. The most routinely used is the bath application of the broad-spectrum glutamate receptor agonist, kainic acid. In the hippocampus, work using transgenic kainate receptor knockout mice have revealed information about the specific subunit composition of the kainate receptor implicated in the generation and maintenance of the gamma frequency oscillation. However, there is a paucity of such detail regarding gamma frequency oscillation in the cortex. Using specific pharmacological agonists and antagonists for the kainate receptor, we have set out to examine the contribution of kainate receptor subtypes to gamma frequency oscillation in the entorhinal cortex. The findings presented demonstrate that in contrast to the hippocampus, kainate receptors containing the GLUK5 subunit are critically important for the generation and maintenance of gamma frequency oscillation in the entorhinal cortex. Future work will concentrate on determining the exact nature of the cellular expression of kainate receptors in the entorhinal cortex

The Role of GLUK5-Containing Kainate Receptors in Entorhinal Cortex Gamma Frequency Oscillations

Using in vitro brain slices of hippocampus and cortex, neuronal oscillations in the frequency range of 30–80 Hz (gamma frequency oscillations) can be induced by a number of pharmacological manipulations. The most routinely used is the bath application of the broad-spectrum glutamate receptor agonist, kainic acid. In the hippocampus, work using transgenic kainate receptor knockout mice have revealed information about the specific subunit composition of the kainate receptor implicated in the generation and maintenance of the gamma frequency oscillation. However, there is a paucity of such detail regarding gamma frequency oscillation in the cortex. Using specific pharmacological agonists and antagonists for the kainate receptor, we have set out to examine the contribution of kainate receptor subtypes to gamma frequency oscillation in the entorhinal cortex. The findings presented demonstrate that in contrast to the hippocampus, kainate receptors containing the GLUK5 subunit are critically important for the generation and maintenance of gamma frequency oscillation in the entorhinal cortex. Future work will concentrate on determining the exact nature of the cellular expression of kainate receptors in the entorhinal cortex

Software Considerations for Subscale Flight Testing of Experimental Control Laws

The NASA AirSTAR system has been designed to address the challenges associated with safe and efficient subscale flight testing of research control laws in adverse flight conditions. In this paper, software elements of this system are described, with an emphasis on components which allow for rapid prototyping and deployment of aircraft control laws. Through model-based design and automatic coding a common code-base is used for desktop analysis, piloted simulation and real-time flight control. The flight control system provides the ability to rapidly integrate and test multiple research control laws and to emulate component or sensor failures. Integrated integrity monitoring systems provide aircraft structural load protection, isolate the system from control algorithm failures, and monitor the health of telemetry streams. Finally, issues associated with software configuration management and code modularity are briefly discussed