Supersonic dynamic stability characteristics of a space shuttle orbiter

Supersonic forced-oscillation tests of a 0.0165-scale model of a modified 089B Rockwell International shuttle orbiter were conducted in a wind tunnel for several configurations over a Mach range from 1.6 to 4.63. The tests covered angles of attack up to 30 deg. The period and damping of the basic unaugmented vehicle were calculated along the entry trajectory using the measured damping results. Some parameter analysis was made with the measured dynamic derivatives. Photographs of the test configurations and test equipment are shown

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

Supersonic dynamic stability derivatives of a modified 089B shuttle orbiter

An experimental test program was conducted to measure the dynamic stability derivatives of a modified 089B shuttle orbiter. Supersonic forced oscillation tests were conducted in the Langley Unitary Plan Wind Tunnel over a range of Mach numbers from 1.6 to 4.63 for angles of attack up to 30 deg. The data were measured at the model resonant frequency with pitch and yaw amplitudes of 1 deg and a roll amplitude of 2.5 deg

The discursive construction of childhood and youth in AIDS interventions in Lesotho's education sector: Beyond global-local dichotomies

This is the post-print version of this article. The definitive, peer-reviewed and edited version of this article is published in Environment and Planning D,Society and Space 28(5) 791 – 810, 2010, available from the link below. Copyright @ 2010 Pion.In southern Africa interventions to halt the spread of AIDS and address its social impacts are commonly targeted at young people, in many cases through the education sector. In Lesotho, education-sector responses to AIDS are the product of negotiation between a range of ‘local’ and ‘global’ actors. Although many interventions are put forward as government policy and implemented by teachers in schools, funding is often provided by bilateral and multilateral donors, and the international ‘AIDS industry’—in the form of UN agencies and international NGOs—sets agendas and makes prescriptions. This paper analyses interviews conducted with policy makers and practitioners in Lesotho and a variety of documents, critically examining the discourses of childhood and youth that are mobilised in producing changes in education policy and practice to address AIDS. Focusing on bursary schemes, life-skills education, and rights-based approaches, the paper concludes that, although dominant ‘global’ discourses are readily identified, they are not simply imported wholesale from the West, but rather are transformed through the organisations and personnel involved in designing and implementing interventions. Nonetheless, the connections through which these discourses are made, and children are subjectified, are central to the power dynamics of neoliberal globalisation. Although the representations of childhood and youth produced through the interventions are hybrid products of local and global discourses, the power relations underlying them are such that they, often unintentionally, serve a neoliberal agenda by depicting young people as individuals in need of saving, of developing personal autonomy, or of exercising individual rights.RGS-IB

Synthetic Physiology

Optogenetic tools are DNA-encoded molecules that, when genetically targeted to cells, enable the control of specific physiological processes within those cells through exposure to light. These tools can pinpoint how these specific processes affect the emergent properties of a complex biological system, such as a mammalian organ or even an entire animal. They can also allow control of a biological system for therapeutic or bioengineering purposes. Many of the optical control tools explored to date are single-component reagents containing a photoactive signaling domain. An interesting question is raised by comparing optogenetics to synthetic biology. In the latter, interchangeable and modular DNA-encoded parts are assembled into complex biological circuits, thus enabling sophisticated logic and computation as well as the production of biologics and reagents (1, 2). Is it possible to devise strategies for the temporally precise cell-targeted optical control of complex engineered biological computational or chemical-synthetic pathways? Such a marriage of optogenetics and synthetic biology—which one might call synthetic physiology—would open up the ability to use optogenetics to trigger and regulate engineered synthetic biology systems, which in turn could execute computational and biological programs of great complexity (3). On page 1565 of this issue, Ye et al. (4) explore such a hybrid approach to controlling a biological system, as well as the bioengineering and preclinical capabilities opened up by such an approach

Hearing the light: neural and perceptual encoding of optogenetic stimulation in the central auditory pathway

Optogenetics provides a means to dissect the organization and function of neural circuits. Optogenetics also offers the translational promise of restoring sensation, enabling movement or supplanting abnormal activity patterns in pathological brain circuits. However, the inherent sluggishness of evoked photocurrents in conventional channelrhodopsins has hampered the development of optoprostheses that adequately mimic the rate and timing of natural spike patterning. Here, we explore the feasibility and limitations of a central auditory optoprosthesis by photoactivating mouse auditory midbrain neurons that either express channelrhodopsin-2 (ChR2) or Chronos, a channelrhodopsin with ultra-fast channel kinetics. Chronos-mediated spike fidelity surpassed ChR2 and natural acoustic stimulation to support a superior code for the detection and discrimination of rapid pulse trains. Interestingly, this midbrain coding advantage did not translate to a perceptual advantage, as behavioral detection of midbrain activation was equivalent with both opsins. Auditory cortex recordings revealed that the precisely synchronized midbrain responses had been converted to a simplified rate code that was indistinguishable between opsins and less robust overall than acoustic stimulation. These findings demonstrate the temporal coding benefits that can be realized with next-generation channelrhodopsins, but also highlight the challenge of inducing variegated patterns of forebrain spiking activity that support adaptive perception and behavior

The Grapes of Roth

Shortly after Roth Greeting Cards was decided in 1970, its offhand reference to the “total concept and feel” of the cards at issue became the dominant standard in copyright law for determining whether two works were substantially similar. That is a remarkable achievement for a phrase that, in the words of the influential Nimmer treatise, “threatens to subvert the very essence of copyright.” It nevertheless had enormous appeal for federal judges, and the reason extends well beyond copyright law. “Total concept and feel” appeared at a critical juncture for the federal judiciary, as an older model of decision-making, based on discretion and reason, yielded to a more formalized process. For a time, the phrase allowed judges in copyright cases to continue using their discretion and aesthetic judgment in a legal world that had grown cold to both of those things. The history of “total concept and feel” in copyright law thus opens a window on an important but underappreciated transition point in the law, one that occurred in the 1960s with reverberations that continue to the present day. The history related here shows how judges first attempted to pay tribute to formalism with capacious doctrine, a maneuver that allowed them to retain decision-making power in infringement cases at a time when jury trials were rare and summary judgment standards only loosely observed. But “total concept and feel” provided only fleeting respite from the rise of formalism. The same forces that pushed judges to adopt a new definition of substantial similarity eventually took that decision away from them entirely, placing it instead with juries, with anarchic results. This history demonstrates two things. First, while copyright scholars tend to view the development of infringement doctrine as an unbroken chain of events, in fact copyright precedents come from three distinct eras, each with its own method of decision-making. The ready availability of judicial discretion in earlier eras can no longer be presumed. But second, the use of informed discretion in resolving copyright disputes is not so easily forgone. Even now, after discretion became anathema at trial and then at summary judgment, it is nevertheless reappearing at the pleadings stage as courts increasingly grant motions to dismiss. This development suggests that it would be better to end the “total concept and feel” maneuver and give judges and juries the information they need to make better decisions

Striosome–dendron bouquets highlight a unique striatonigral circuit targeting dopamine-containing neurons

The dopamine systems of the brain powerfully influence movement and motivation. We demonstrate that striatonigral fibers originating in striosomes form highly unusual bouquet-like arborizations that target bundles of ventrally extending dopamine-containing dendrites and clusters of their parent nigral cell bodies. Retrograde tracing showed that these clustered cell bodies in turn project to the striatum as part of the classic nigrostriatal pathway. Thus, these striosome-dendron formations, here termed "striosome-dendron bouquets," likely represent subsystems with the nigro-striato-nigral loop that are affected in human disorders including Parkinson's disease. Within the bouquets, expansion microscopy resolved many individual striosomal fibers tightly intertwined with the dopamine-containing dendrites and also with afferents labeled by glutamatergic, GABAergic, and cholinergic markers and markers for astrocytic cells and fibers and connexin 43 puncta. We suggest that the striosome-dendron bouquets form specialized integrative units within the dopamine-containing nigral system. Given evidence that striosomes receive input from cortical regions related to the control of mood and motivation and that they link functionally to reinforcement and decision-making, the striosome-dendron bouquets could be critical to dopamine-related function in health and disease

Aereo and the Problem of Machine Volition

Article published in the Michigan State Law Review

Music as a social force

Thesis (M.A.)--Boston Universit