Bonding Lexan and sapphire to form high-pressure, flame-resistant window

Flammable materials have been studied in normal gravity and microgravity for many years. Photography plays a major role in the study of the combustion process giving a permanent visual record that can be analyzed. When these studies are extended to manned spacecraft, safety becomes a primary concern. The need for a high-pressure, flame-resistant, shatter-resistant window permitting photographic recording of combustion experiments in manned spacecraft prompted the development of a method for bonding Lexan and sapphire. Materials that resist shattering (e.g., Lexan) are not compatible with combustion experiments; the material loses strength at combustion temperatures. Sapphire is compatible with combustion temperatures in oxygen-enriched atmospheres but is subject to shattering. Combining the two materials results in a shatter-resistant, flame-resistant window. Combustion in microgravity produces a low-visibility flame; however, flame propagation and flame characteristics are readily visible as long as there is no deterioration of the image. Since an air gap between the Lexan and the sapphire would reduce transmission, a method was developed for bonding these unlike materials to minimize light loss

Do Borders Matter? Soviet economic Reform after the Coup

macroeconomics, Soviet, borders, economic reform

Economic Feasibility of Ethanol Production from Sweet Sorghum Juice in Texas

The economic feasibility of producing ethanol from sweet sorghum juice is projected using Monte Carlo simulation models to estimate the price ethanol plants will likely have to pay for sweet sorghum and the uncertain returns for ethanol plants. Ethanol plants in high yielding regions will likely generate returns on assets of 11%-12% and in low yield areas the returns on assets will be less than 10%.Sweet Sorghum, Ethanol, Monte Carlo Simulation, Agribusiness, Agricultural Finance, Crop Production/Industries, Farm Management, Risk and Uncertainty, D20 G10 D81 C15,

Heating the outer heliosphere by pickup protons

There is a growing body of literature that demonstrates the ability of a turbulent cascade within the solar wind to heat the thermal protons. Several sources of energy are required to accomplish the observed heating. Wind shear and shocks originating with the multiple source of wind plasma heat the wind inside ∽AU. However, beyond this distance little is left of these sources and all that remains is the energy injected into the plasma by the pickup of newborn protons originating from interstellar neutrals. Recent advances in the theory of wave excitation by the newborn protons allows us to return to the published heating theory and remove a previously unexplained parameterization of the heating due to pickup protons. Furthermore, recent observational evidence suggests that large-scale correlations between the wind speed and the proton temperature exist into the distant outer heliosphere that motivate an attempt to connect the two within the structure of the heating theory

Highly Collimated Jets and Wide-Angle Outflows in HH46/47: New Evidence from Spitzer IR Images

We present new details of the structure and morphology of the jets and outflows in HH46/47 as seen in Spitzer infrared images from IRAC and MIPS, reprocessed using the ``HiRes'' deconvolution technique. HiRes improves the visualization of spatial morphology by enhancing resolution (to sub-arcsec levels in IRAC bands) and removing the contaminating side lobes from bright sources. In addition to sharper views of previously reported bow shocks, we have detected: (i) the sharply-delineated cavity walls of the wide-angle biconical outflow, seen in scattered light on both sides of the protostar, (ii) several very narrow jet features at distances 400 AU to 0.1 pc from the star, and, (iii) compact emissions at MIPS 24 micron coincident with the jet heads, tracing the hottest atomic/ionic gas in the bow shocks.Comment: 11 pages, 4 Figures, Accepted for publication in ApJ(Letters

Massive Quiescent Cores in Orion. -- II. Core Mass Function

We have surveyed submillimeter continuum emission from relatively quiescent regions in the Orion molecular cloud to determine how the core mass function in a high mass star forming region compares to the stellar initial mass function. Such studies are important for understanding the evolution of cores to stars, and for comparison to formation processes in high and low mass star forming regions. We used the SHARC II camera on the Caltech Submillimeter Observatory telescope to obtain 350 \micron data having angular resolution of about 9 arcsec, which corresponds to 0.02 pc at the distance of Orion. Our analysis combining dust continuum and spectral line data defines a sample of 51 Orion molecular cores with masses ranging from 0.1 \Ms to 46 \Ms and a mean mass of 9.8 \Ms, which is one order of magnitude higher than the value found in typical low mass star forming regions, such as Taurus. The majority of these cores cannot be supported by thermal pressure or turbulence, and are probably supercritical.They are thus likely precursors of protostars. The core mass function for the Orion quiescent cores can be fitted by a power law with an index equal to -0.85$\pm$0.21. This is significantly flatter than the Salpeter initial mass function and is also flatter than the core mass function found in low and intermediate star forming regions. Thus, it is likely that environmental processes play a role in shaping the stellar IMF later in the evolution of dense cores and the formation of stars in such regions.Comment: 30 pages, 10 figures, accepted by Ap

Developmental Origin of Oligodendrocyte Lineage Cells Determines Response to Demyelination and Susceptibility to Age-Associated Functional Decline.

Oligodendrocyte progenitors (OPs) arise from distinct ventral and dorsal domains within the ventricular germinal zones of the embryonic CNS. The functional significance, if any, of these different populations is not known. Using dual-color reporter mice to distinguish ventrally and dorsally derived OPs, we show that, in response to focal demyelination of the young adult spinal cord or corpus callosum, dorsally derived OPs undergo enhanced proliferation, recruitment, and differentiation as compared with their ventral counterparts, making a proportionally larger contribution to remyelination. However, with increasing age (up to 13 months), the dorsally derived OPs become less able to differentiate into mature oligodendrocytes. Comparison of dorsally and ventrally derived OPs in culture revealed inherent differences in their migration and differentiation capacities. Therefore, the responsiveness of OPs to demyelination, their contribution to remyelination, and their susceptibility to age-associated functional decline are markedly dependent on their developmental site of origin in the developing neural tube.A.H.C. was funded by a Wellcome Trust Integrated Training Fellowship (096384/Z/11/Z). Work in R.J.M.F.’s laboratory was funded by The UK Multiple Sclerosis Society (941) and by a core support grant from the Wellcome Trust and MRC to the Wellcome Trust – Medical Research Council Cambridge Stem Cell Institute. Work in W.D.R.’s laboratory was funded by the Medical Research Council (G0800575), the Wellcome Trust (WT100269AIA), and the European Research Council (293544).This is the final version of the article. It first appeared from Cell Press via http://dx.doi.org/10.1016/j.celrep.2016.03.06

Median eminence myelin continuously turns over in adult mice

OBJECTIVE: Oligodendrocyte progenitor cell differentiation is regulated by nutritional signals in the adult median eminence (ME), but the consequences on local myelination are unknown. The aim of this study was to characterize myelin plasticity in the ME of adult mice in health or in response to chronic nutritional challenge and determine its relevance to the regulation of energy balance. METHODS: We assessed new oligodendrocyte (OL) and myelin generation and stability in the ME of healthy adult male mice using bromodeoxyuridine labelling and genetic fate mapping tools. We evaluated the contribution of microglia to ME myelin plasticity in PLX5622-treated C57BL/6J mice and in Pdgfra-Cre/ERT2;R26R-eYFP;Myrffl/fl mice, where adult oligodendrogenesis is blunted. Next, we investigated how high-fat feeding or caloric restriction impact ME OL lineage progression and myelination. Finally, we characterized the functional relevance of adult oligodendrogenesis on energy balance regulation. RESULTS: We show that myelinating OLs are continuously and rapidly generated in the adult ME. Paradoxically, OL number and myelin amounts remain remarkably stable in the adult ME. In fact, the high rate of new OL and myelin generation in the ME is offset by continuous turnover of both. We show that microglia are required for continuous OL and myelin production, and that ME myelin plasticity regulates the recruitment of local immune cells. Finally, we provide evidence that ME myelination is regulated by the body's energetic status and demonstrate that ME OL and myelin plasticity are required for the regulation of energy balance and hypothalamic leptin sensitivity. CONCLUSIONS: This study identifies a new mechanism modulating leptin sensitivity and the central control of energy balance and uncovers a previously unappreciated form of structural plasticity in the ME