Of Tigers, Ghosts and Snakes: Children's Social Cognition in the Context of Conflict in Eastern Sri Lanka

This paper is based on field research with Tamil children and adolescents in the war-affected district of Batticaloa in eastern Sri Lanka. It examines young people's experiences of conflict in terms of their social worlds and their relations with the Liberation Tigers of Tamil Elam (LTTE), finding both to be permeated with ambiguity and dissonance. According to established understandings of social cognitive development this would suggest a significant threat to children's social perception, awareness and skills. Yet, it is found that these children and adolescents hold unexpectedly secure values of sociality. In light of this evidence, the paper raises various questions about the adequacy of current theoretical perspectives on social cognition from psychology and anthropology. In particular, it re-evaluates the common emphasis upon the critical importance of mutuality and durability in the socio-cultural dimension for effective cognitive development.

Children, War and World Disorder in the 21st Century: A Review of the Theories and the Literature on Children's Contributions to Armed Violence

Young populations, and particularly young males, have been attributed a proclivity to aggression and unrest that puts societies at risk. Theories about the dangers of a demographic 'youth bulge' inform public and policy debates about the predictors of violent conflict, as evidenced most recently in the World Bank's World Development Report for 2007. This paper evaluates the validity and utility of claims linking youth bulges to civil conflicts by reviewing different literatures concerning naturalist ideas of young humans' innate aggression and cognitive incompetence as well as environmentalist ideas of environmental stimuli, processes of socialisation, and the dialectical relationship of structural conditions and human agency. This review finds that the moral panic propagated by youth bulge theorists is too often based on only one form of influence on human development and action, whether an aspect of environment, personal experience, or individual traits. A more cogent analysis must integrate the highly complex and dynamic processes involved in cognition and behaviour and aim to develop theories that take account of the social power, ideational and structural forms, and emotional and cognitive processes that young people experience and draw on in times of war. Theories of causality that fail to account for this complexity obscure understanding of the many ways in which young people and conflict may be linked.

Protoplanetary Disks in the Orion Nebula Cluster: Gas Disk Morphologies and Kinematics as seen with ALMA

We present Atacama Large Millimeter Array CO(3$-$2) and HCO$^+$(4$-$3) observations covering the central $1\rlap{.}'5$$\times$$1\rlap{.}'5$ region of the Orion Nebula Cluster (ONC). The unprecedented level of sensitivity ($\sim$0.1 mJy beam$^{-1}$) and angular resolution ($\sim$$0\rlap{.}''09 \approx 35$ AU) of these line observations enable us to search for gas-disk detections towards the known positions of submillimeter-detected dust disks in this region. We detect 23 disks in gas: 17 in CO(3$-$2), 17 in HCO$^+$(4$-$3), and 11 in both lines. Depending on where the sources are located in the ONC, we see the line detections in emission, in absorption against the warm background, or in both emission and absorption. We spectrally resolve the gas with $0.5$ km s$^{-1}$ channels, and find that the kinematics of most sources are consistent with Keplerian rotation. We measure the distribution of gas-disk sizes and find typical radii of $\sim$50-200 AU. As such, gas disks in the ONC are compact in comparison with the gas disks seen in low-density star-forming regions. Gas sizes are universally larger than the dust sizes. However, the gas and dust sizes are not strongly correlated. We find a positive correlation between gas size and distance from the massive star $\theta^1$ Ori C, indicating that disks in the ONC are influenced by photoionization. Finally, we use the observed kinematics of the detected gas lines to model Keplerian rotation and infer the masses of the central pre-main-sequence stars. Our dynamically-derived stellar masses are not consistent with the spectroscopically-derived masses, and we discuss possible reasons for this discrepancy.Comment: 42 pages, 31 figure

Status of magnetic suspension technology

The reasons for the continuing interest in the Magnetic Suspension and Balance System (MSBS) are highlighted. Typical problems that can arise because of model-support interference in a transonic wind tunnel are shown to illustrate the need for MSBS. The two magnetic suspension systems in operation at Langley are the only ones active in the U.S. One of these systems is the 13 inch MSBS which was borrowed from the Air Force Arnold Engineering Development Center. The other system is the 6 inch MSBS which was developed by MIT Aerophysics Laboratory with NASA and DOD funding. Each of these systems is combined with a subsonic wind tunnel. Ongoing research in both of these systems is covered. Last year, Madison Magnetics, Inc., completed a contractual design and cost study utilizing some advance concepts for a large MSBS which would be compatible with an 8 foot transonic wind tunnel and the highlights of the study are presented. Sverdrup Technology, Inc., recently performed a study under contract for Langley on the potential usefulness to the aerospace industry of a proposed large MSBS combined with a suitable transonic wind tunnel. The results of that study are discussed. Langley has partially funded the MSBS work at the University of Southampton for about 6 years under a grant arrangement and the major results are summarized

Dynamic stability characteristics of the combination space shuttle orbiter and ferry vehicle

Subsonic forced-oscillation tests of a 0.015 scale model of the space shuttle orbiter/747 ferry vehicle were conducted in the Langley high speed 7- by 10-foot tunnel at Mach numbers of 0.2, 0.4, and 0.5 for angles of attack up to 12 deg. Tests were made of the basic 747 airplane, of the modified 747 (tip fins and struts added), of the ferry configuration, (747 plus orbiter at an incidence angle of 3 deg), and of the approach and landing test configuration (747 plus orbiter at an incidence angle of 6 deg)

Interpretation of Solar Magnetic Field Strength Observations

This study based on longitudinal Zeeman effect magnetograms and spectral line scans investigates the dependence of solar surface magnetic fields on the spectral line used and the way the line is sampled in order to estimate the magnetic flux emerging above the solar atmosphere and penetrating to the corona from magnetograms of the Mt. Wilson 150-foot tower synoptic program (MWO). We have compared the synoptic program \lambda5250\AA line of Fe I to the line of Fe I at \lambda5233\AA since this latter line has a broad shape with a profile that is nearly linear over a large portion of its wings. The present study uses five pairs of sampling points on the $\lambda5233$\AA line. We recommend adoption of the field determined with a line bisector method with a sampling point as close as possible to the line core as the best estimate of the emergent photospheric flux. The combination of the line profile measurements and the cross-correlation of fields measured simultaneously with \lambda5250\AA and \lambda5233\AA yields a formula for the scale factor 1/\delta that multiplies the MWO synoptic magnetic fields. The new calibration shows that magnetic fields measured by the MDI system on the SOHO spacecraft are equal to 0.619+/-0.018 times the true value at a center-to-limb position 30 deg. Berger and Lites (2003) found this factor to be 0.64+/-0.013 based on a comparison the the Advanced Stokes Polarimeter.Comment: Accepted by Solar Physic

Results of buffet tests in a cryogenic wind tunnel

Buffet tests on two semispan wing models with different leading edge sweep show that it is feasibile to use the standard dynamic wing root bending moment technique in a cryogenic wind tunnel. One model was a slender 65 deg swept delta wing with sharp leading edges. The other model was an unswept wing of aspect ratio 1.5 with a British NPL 9510 airfoil section. The results for the 65 deg swept delta wing indicate the importance of matching the reduced frequency parameter in model tests for planforms which are sensitive to reduced frequency parameter if quantitative buffet measurements are required. The unique ability of a pressurized cryogenic wind tunnel to separate the effects of Reynolds number and of static aeroelastic distortion by variations in the tunnel stagnation temperature and pressure were demonstrated