Traces of Transcendence: C. S. Lewis and the Ciphers of Being

C. S. Lewis experienced several moments of Sehnsucht in his life. In one incident, he reported “such a sudden intense feeling of delight that it sort of stopped me in my walk and spun me round. Indeed the sweetness was so great, & seemed so to affect the whole body as well as the mind.” This essay contends that new and significant light can be thrown on these fascinating episodes in Lewis’ life. In fact, the general philosophical features of the phenomenon causing Sehnsucht can be discerned, and described within the framework established by German existentialist Karl Jaspers (1883-1969). Like all such reflection, Sehnsucht reminds us that the world is “beyond our full comprehension.” We have to try and bring our initial perplexity about this “unnameable something” into reflective and explicit cognition in order to clarify what it means

Using Simple Neural Networks to Correct Errors in Optical Data Transmission.

We have demonstrated the applicability of neural-network-based systems to the problem of reducing the effects of signal distortion, and shown that such a system has the potential to reduce the bit-error-rate in the digitized version of the analogue electrical signal derived from an optical data stream by a substantial margin over existing techniques

Star-forming Galaxies in the 'Redshift Desert'

We describe results of optical and near-IR observations of a large spectroscopic sample of star-forming galaxies photometrically-selected to lie in the redshift range 1.4 < z < 2.5, often called the ``redshift desert'' because of historical difficulty in obtaining spectroscopic redshifts in this range. We show that the former ``redshift desert'' is now very much open to observation.Comment: 10 pages, 6 figures, to appear in the Proceedings of the ESO/USM/MPE Workshop on "Multiwavelength Mapping of Galaxy Formation and Evolution", eds. R. Bender and A. Renzin

K3-fibered Calabi-Yau threefolds I, the twist map

A construction of Calabi-Yaus as quotients of products of lower-dimensional spaces in the context of weighted hypersurfaces is discussed, including desingularisation. The construction leads to Calabi-Yaus which have a fiber structure, in particular one case has K3 surfaces as fibers. These Calabi-Yaus are of some interest in connection with Type II -heterotic string dualities in dimension 4. A section at the end of the paper summarises this for the non-expert mathematician.Comment: 31 pages LaTeX, 11pt, 2 figures. To appear in International Journal of Mathematics. On the web at http://personal-homepages.mis.mpg.de/bhunt/preprints.html , #

Neural circuit mechanisms of post–traumatic epilepsy

Traumatic brain injury (TBI) greatly increases the risk for a number of mental health problems and is one of the most common causes of medically intractable epilepsy in humans. Several models of TBI have been developed to investigate the relationship between trauma, seizures, and epilepsy-related changes in neural circuit function. These studies have shown that the brain initiates immediate neuronal and glial responses following an injury, usually leading to significant cell loss in areas of the injured brain. Over time, long-term changes in the organization of neural circuits, particularly in neocortex and hippocampus, lead to an imbalance between excitatory and inhibitory neurotransmission and increased risk for spontaneous seizures. These include alterations to inhibitory interneurons and formation of new, excessive recurrent excitatory synaptic connectivity. Here, we review in vivo models of TBI as well as key cellular mechanisms of synaptic reorganization associated with post-traumatic epilepsy (PTE). The potential role of inflammation and increased blood–brain barrier permeability in the pathophysiology of PTE is also discussed. A better understanding of mechanisms that promote the generation of epileptic activity versus those that promote compensatory brain repair and functional recovery should aid development of successful new therapies for PTE

Processingâ Dependent Microstructure of AgClâ CsAgCl2 Eutectic Photonic Crystals

Directional solidification of a eutectic melt allows control over the resultant eutectic microstructure, which in turn impacts both the mechanical and optical properties of the material. These selfâ organized phaseâ separated eutectic materials can be tuned to have periodicities from tens of micrometers down to nanometers. Furthermore, the two phases possess differences in their refractive index leading to interesting optical properties that can be tailored within the visible to infrared wavelength regime. It is found the binary salt eutectic AgClâ CsAgCl2 system forms a rod microstructure with sample draw rates up to 0.2 mm sâ 1 which transitions to a lamellar microstructure at draw rates greater than 0.36 mm sâ 1. Heatâ transfer simulations reveal a draw rateâ dependent direction of motion of the solidification front, which for a range of draw rates requires nucleation of the minority solid phase at the sample wall. Phaseâ field modeling indicates that the initial eutectic structure at the sample boundary, either rod or lamellar, dictates the bulk eutectic morphology. These samples contain submicrometer periodicities which coupled with their optical transparency results in them exhibiting draw rateâ dependent nearâ IR reflectance peaks consistent with stop bands for 2D hexagonal (rod) and 1D planar (lamellar) photonic crystals.The eutectic composition of the molten salts AgCl and CsCl exhibits a microstructural transition from rod to lamellar upon varying the draw rates controlled by directional solidification. This transition is dominated by the initial formation at the surface of either the rod or lamellar structure. The resultant eutectic microstructures have optical properties consistent with their being 2D and 1D photonic crystals.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145412/1/adom201701316.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145412/2/adom201701316_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145412/3/adom201701316-sup-0001-S1.pd

Accessing elite nurses for research: reflections on the theoretical and practical issues of telephone interviewing

Elite groups are interesting as they frequently are powerful (in terms of position, knowledge and influence) and enjoy considerable authority. It is important, therefore, to involve them in research concerned with understanding social contexts and processes. This is particularly pertinent in healthcare, where considerable strategic development and change are features of everyday practice that may be guided or perceived as being guided, by elites. This paper evolved from a study investigating the availability and role of nurses whose remit involved leading nursing research and development within acute NHS Trusts in two health regions in Southern England. The study design included telephone interviews with Directors of Nursing Services during which time the researchers engaged in a reflective analysis of their experiences of conducting research with an `elite' group. Important issues identified were the role of gatekeepers, engagement with elites and the use of the telephone interview method in this context. The paper examines these issues and makes a case for involving executive nurses in further research. The paper also offers strategies to help researchers design and implement telephone interview studies successfully to maximise access to the views and experiences of `hard to reach groups', such as elites, while minimising the associated disruption

Sexual dimorphism of human vallate papillae: an in vivo study of normative morphology

The perimeters of vallate papillae (VP) house approximately half of the taste buds on the human tongue. However, little information exists regarding perimeter measurements of VP. Likewise, great diversity exists among reports of the number of VP and diameter of VP, in general. The research presents an analysis of the perimeters, counts, and diameters of VP in vivo. Endoscopic examination was performed on 79 individuals (40 females, 39 males) between 18 and 26 years of age. A total of 583 VP were counted, 565 of which were able to be measured. Data revealed a statistically significant difference between male and female VP count (t(75.6) = 4.5; p = 0.00003). Females had, on average, 2.22 more VP than males. Males were found to have larger mean VP diameter per person and mean VP perimeter per person than females (t(58.9) = –2.4; p = 0.021 and t(59.3) = –2.4; p = 0.019, respectively). The report demonstrates that VP are sexually dimorphic at the gross anatomical level