Artifacts in the Raymond Powell Collection from East Texas

In March 2010, Raymond Powell of Mansfield, Louisiana, allowed the examination and photographic documentation of several artifacts in his possession. The specimens were given to him approximately 60 years ago by a friend who reportedly excavated them from a burial located in either Cass County or Titus County in East Texas. The collection consists of six ceramic vessels and three stone artifacts. The vessels appear to relate to both the Late Caddo Titus phase (ca. A.D. 1430-1680) as well as to contemporaneous sites in Bowie and Cass counties on the Red River near the Great Bend area, and the lower Sulphur River, that have been associated with the Nasoni Caddo

Supernova Resonance-Scattering Profiles in the Presence of External Illumination

We discuss a simple model for the formation of a supernova spectral line by resonance scattering in the presence of external illumination of the line-forming region by light from circumstellar interaction (toplighting). The simple model provides a clear understanding of the most conspicuous toplighting effect: a rescaling or, as we prefer, a ``muting'' of the line profile relative to the continuum. This effect would be present in more realistic models, but would be harder to isolate. An analytic expression for a muting factor for a P-Cygni line is derived that depends on the ratio E of the toplighting specific intensity to the specific intensity from the supernova photosphere. If E<1, the line profile is reduced in scale or ``muted''. If E=1, the line profile vanishes altogether. If E>1, the line profile flips vertically: then having an absorption component near the observer-frame line center wavelength and a blueshifted emission component.Comment: accepted for publication in PAS

Contralateral inhibition of click- and chirp-evoked human compound action potentials

Cochlear outer hair cells (OHC) receive direct efferent feedback from the caudal auditory brainstem via the medial olivocochlear (MOC) bundle. This circuit provides the neural substrate for the MOC reflex, which inhibits cochlear amplifier gain and is believed to play a role in listening in noise and protection from acoustic overexposure. The human MOC reflex has been studied extensively using otoacoustic emissions (OAE) paradigms; however, these measurements are insensitive to subsequent “downstream” efferent effects on the neural ensembles that mediate hearing. In this experiment, click- and chirp-evoked auditory nerve compound action potential (CAP) amplitudes were measured electrocochleographically from the human eardrum without and with MOC reflex activation elicited by contralateral broadband noise. We hypothesized that the chirp would be a more optimal stimulus for measuring neural MOC effects because it synchronizes excitation along the entire length of the basilar membrane and thus evokes a more robust CAP than a click at low to moderate stimulus levels. Chirps produced larger CAPs than clicks at all stimulus intensities (50–80 dB ppeSPL). MOC reflex inhibition of CAPs was larger for chirps than clicks at low stimulus levels when quantified both in terms of amplitude reduction and effective attenuation. Effective attenuation was larger for chirp- and click-evoked CAPs than for click-evoked OAEs measured from the same subjects. Our results suggest that the chirp is an optimal stimulus for evoking CAPs at low stimulus intensities and for assessing MOC reflex effects on the auditory nerve. Further, our work supports previous findings that MOC reflex effects at the level of the auditory nerve are underestimated by measures of OAE inhibition

Urban Architecture: A Cognitive Neuroscience Perspective

The rapid urbanization of the past century has led to an accelerating demand for urban design that caters for city-dwellers in both physical and psychological domains. The field of architecture has begun to cultivate more analytic approaches to city design, in order to enable quantification and hypothesis-testing of design principles. In parallel, the cognitive science of human navigation has been developing rapidly, fuelled by neuroscientific findings from rodent research. The time seems ripe to bring these disciplines together. This paper reviews some of the most salient neuroscientific discoveries of recent decades and shows how these discoveries, and the design principles that emerge from them, can add important constraints on architectural design. By taking these cognitive constraints into account it is argued that urban spaces – particularly large, complex ones such as transport termini and convention centres – can be made more navigable and able to provide a better experience for users

Grid Cells Form a Global Representation of Connected Environments.

The firing patterns of grid cells in medial entorhinal cortex (mEC) and associated brain areas form triangular arrays that tessellate the environment [1, 2] and maintain constant spatial offsets to each other between environments [3, 4]. These cells are thought to provide an efficient metric for navigation in large-scale space [5-8]. However, an accurate and universal metric requires grid cell firing patterns to uniformly cover the space to be navigated, in contrast to recent demonstrations that environmental features such as boundaries can distort [9-11] and fragment [12] grid patterns. To establish whether grid firing is determined by local environmental cues, or provides a coherent global representation, we recorded mEC grid cells in rats foraging in an environment containing two perceptually identical compartments connected via a corridor. During initial exposures to the multicompartment environment, grid firing patterns were dominated by local environmental cues, replicating between the two compartments. However, with prolonged experience, grid cell firing patterns formed a single, continuous representation that spanned both compartments. Thus, we provide the first evidence that in a complex environment, grid cell firing can form the coherent global pattern necessary for them to act as a metric capable of supporting large-scale spatial navigation

Fire and Gold Build Seattle

The final decade of the 19th century established Seattle as the preeminent city in the Pacific Northwest. Prodigious changes resulting from the Fire of 1889 paved the way for Seattle to take full advantage of the Klondike Gold Rush eight years later. This work details the impact that each of these events had on Seattle and concludes that the compound effects of two events of happenstance created the foundation for the Seattle we know today

The Threat of a Second Constitutional Convention: Patrick Henry\u27s Lasting Legacy

The Bill of Rights secured the individual freedoms that constitute the mainstay of American liberty. The Framers of the Constitution did not include these vital rights in the original version of the document. In fact, the first ten amendments were proposed by Congress to secure ratification of the Constitution and, more importantly, to prevent a second constitutional convention