Titanium honeycomb structure

A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks

In vitro culture with gemcitabine augments death receptor and NKG2D ligand expression on tumour cells

Much effort has been made to try to understand the relationship between chemotherapeutic treatment of cancer and the immune system. Whereas much of that focus has been on the direct effect of chemotherapy drugs on immune cells and the release of antigens and danger signals by malignant cells killed by chemotherapy, the effect of chemotherapy on cells surviving treatment has often been overlooked. In the present study, tumour cell lines: A549 (lung), HCT116 (colon) and MCF-7 (breast), were treated with various concentrations of the chemotherapeutic drugs cyclophosphamide, gemcitabine (GEM) and oxaliplatin (OXP) for 24 hours in vitro. In line with other reports, GEM and OXP upregulated expression of the death receptor CD95 (fas) on live cells even at sub-cytotoxic concentrations. Further investigation revealed that the increase in CD95 in response to GEM sensitised the cells to fas ligand treatment, was associated with increased phosphorylation of stress activated protein kinase/c-Jun N-terminal kinase and that other death receptors and activatory immune receptors were co-ordinately upregulated with CD95 in certain cell lines. The upregulation of death receptors and NKG2D ligands together on cells after chemotherapy suggest that although the cells have survived preliminary treatment with chemotherapy they may now be more susceptible to immune cell-mediated challenge. This re-enforces the idea that chemotherapy-immunotherapy combinations may be useful clinically and has implications for the make-up and scheduling of such treatments

Inferring Market Structure from Customer Response to Competing and Complementary Products

We consider customer influences on market structure, arguing that market structure should explain the extent to which any given set of market offerings are substitutes or complements. We describe recent additions to the market structure analysis literature and identify promising directions for new research in market structure analysis. Impressive advances in data collection, statistical methodology and information technology provide unique opportunities for researchers to build market structure tools that can assist “real-time” marketing decision-making.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46981/1/11002_2004_Article_5088105.pd

Mitochondrial calcium exchange links metabolism with the epigenome to control cellular differentiation.

Fibroblast to myofibroblast differentiation is crucial for the initial healing response but excessive myofibroblast activation leads to pathological fibrosis. Therefore, it is imperative to understand the mechanisms underlying myofibroblast formation. Here we report that mitochondrial calcium (mCa2+) signaling is a regulatory mechanism in myofibroblast differentiation and fibrosis. We demonstrate that fibrotic signaling alters gating of the mitochondrial calcium uniporter (mtCU) in a MICU1-dependent fashion to reduce mCa2+ uptake and induce coordinated changes in metabolism, i.e., increased glycolysis feeding anabolic pathways and glutaminolysis yielding increased α-ketoglutarate (αKG) bioavailability. mCa2+-dependent metabolic reprogramming leads to the activation of αKG-dependent histone demethylases, enhancing chromatin accessibility in loci specific to the myofibroblast gene program, resulting in differentiation. Our results uncover an important role for the mtCU beyond metabolic regulation and cell death and demonstrate that mCa2+ signaling regulates the epigenome to influence cellular differentiation

Mechanism for export of sediment-derived iron in an upwelling regime

Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 39 (2012): L03601, doi:10.1029/2011GL050366.Model simulations performed with a three-dimensional, high-resolution, process study ocean model of eastern boundary upwelling systems are used to describe a mechanism that efficiently transports sediment-derived dissolved iron offshore in the subsurface through the bottom boundary layer (BBL) during downwelling-favorable wind events. In the model, sediment-derived iron accumulates in the BBL on the outer shelf when the winds are upwelling-favorable. When the wind reverses, the iron-laden BBL is mixed into the water column and transported offshore along isopycnals that intersect the bottom. Depending on the frequency of wind reversal, between 10–50% of the shelf sediment-derived iron flux is exported offshore through this previously unidentified subsurface pathway. If this mechanism operates on all coastal upwelling regimes, the global export of sediment-derived iron to the open ocean would be equivalent to ten times larger than the estimated source of dissolved iron from aerosols.NSF supported this work.2012-08-1

The Orbiting Astrophysical Spectrometer In Space (OASIS)

The Orbiting Astrophysical Observatory In Space (OASIS) is an Advanced Concept currently under study at NASA as a mission for the next decade. The goal of the OASIS mission is to identify a local site or sites where galactic cosmic rays (GCR) originate and are accelerated. The mission will also allow GCR data to be used to investigate how elements are made and distributed in the galaxy and to improve our understanding of supernovae and the nucleosynthesis of the heavy elements. OASIS consists of two instruments that provide complementary data on the location and nature of the source(s) through investigating the composition of ultra-heavy nuclei ( ) and the energy spectrum of electrons. In particular OASIS will measure the relative abundances in the actinide group ( ) to determine the age of the -process material in GCRs. The presence of young r-process material would indicate that GCRs are a sample of the interstellar medium in OB associations. OASIS will measure the electron spectrum to 10 TeV. The energy where this spectrum ends will tell us the distance to the nearest GCR source(s). OASIS will look for spectral features and anisotropy in the high energy electron spectrum that are expected to appear when only a few of the nearest astrophysical sources can contribute to the electron flux. Spectral features may also suggest dark matter decay products. We anticipate that these measurements will lead to the identification of the nearest cosmic ray electron source and provide a crucial test of the OB association model for the origin of GCR nuclei

Self-Excited Vibration of Statically Unloaded Pads in Tilting-Pad Journal Bearings

load characteristics are satisfactory if ^m«0.66ap, but these pads do not have tendencies to loose their stability