Aerospace vehicle

A dual structure aerospace vehicle is described which has an aeroshell structure and an internally disposed separable and reusable integral tank/thrust structure. The tank/thrust structure is inuslated for cryogenic fuels and the cavity within aeroshell is insulated from the tank/thrust structure. An internal support ring within the cavity serves as an attachment for lugs on the tank/thrust structure via double hinges. The aft end of tank/thrust structure is provided with rocket engines and exit nozzles with a trunnion supporting the tank/thrust structure within the aeroshell

A two-species stage-structured model for West Nile virus transmission

We develop a host–vector model of West Nile virus (WNV) transmission that incorporates multiple avian host species as well as host stage-structure (juvenile and adult stages), allowing for both species-specific and stage-specific biting rates of vectors on hosts. We use this ordinary differential equation model to explore WNV transmission dynamics that occur between vectors and multiple structured host populations as a result of heterogeneous biting rates on species and/or life stages. Our analysis shows that increased exposure of juvenile hosts generally results in larger outbreaks of WNV infectious vectors when compared to differential host species exposure. We also find that increased juvenile exposure is an important mechanism for determining the effect of species diversity on the disease risk of a community

Aluminum ion-containing polyimide adhesives

A meta-oriented aromatic diamine is reacted with an aromatic dianhydride and an aluminum compound in the presence of a water or lower alkanol miscible ether solvent to produce an intermediate polyamic acid. The polyamic acid is then converted to the thermally stable, metal ion-filled polyimide by heating in the temperature range of 300 C to produce a flexible, high temperature adhesive

The role of merchandise exports to Mexico in the pattern of Texas employment

In 1987, Texas exported $25 billion worth of merchandise to foreign countries. Twenty-six percent, or$6.5 billion, of those exports went south to Mexico. By 1994, Texas merchandise exports to Mexico had grown to more than $18.5 billion per year (in 1987 constant dollars). Texas merchandise exports to Mexico (in real terms) have grown more than 10 percent a year for six of the last seven years. ; Using input-output analysis, Kelly George and Lori Taylor find that merchandise exports to Mexico, while representing only about 5 percent of Texas output, have grown in ways that have substantially influenced the composition of the state's economy. The authors attribute a small portion of the state's overall job gains since 1987 to rising merchandise exports to Mexico but find that almost all Texas employment growth in high-tech manufacturing sectors stems from trade with Mexico.Employment (Economic theory) ; Exports ; Mexico ; Texas

Mechanical and spectroscopic properties of metal-containing polyimides

The incorporation of specific metal ions into polyimides is described. Detailed studies have included various compounds of copper, lithium, and palladium as dopants. Addition of the metal during polymerization or after formation of the polyamic acid precedes the thermal imidization step. With many dianhydride-diamine-dopant combinations high quality variously colored films are produced. Many metal doped films exhibit (1) improved high temperature adhesive properties, (2) increased electrical conductivity, (3) excellent thermal stability, (4) improved acid/base resistance, (5) increased modulus in flexible films and (6) excellent high temperature tensile strength. X-ray photo-electron spectroscopic study of these films suggests that many of the additives undergo chemical modification during thermal imidization. Palladium dopants appear to be partially reduced to the metallic state, while lithium and copper dopants are probably converted to their oxides. Ion etching experiments with Auger electron spectroscopy monitoring are discussed

IVOA Recommendation: SAMP - Simple Application Messaging Protocol Version 1.3

SAMP is a messaging protocol that enables astronomy software tools to interoperate and communicate. IVOA members have recognised that building a monolithic tool that attempts to fulfil all the requirements of all users is impractical, and it is a better use of our limited resources to enable individual tools to work together better. One element of this is defining common file formats for the exchange of data between different applications. Another important component is a messaging system that enables the applications to share data and take advantage of each other's functionality. SAMP builds on the success of a prior messaging protocol, PLASTIC, which has been in use since 2006 in over a dozen astronomy applications and has proven popular with users and developers. It is also intended to form a framework for more general messaging requirements

Crystal structure of human IPS-1/MAVS/VISA/Cardif caspase activation recruitment domain

Background: IPS-1/MAVS/VISA/Cardif is an adaptor protein that plays a crucial role in the induction of interferons in response to viral infection. In the initial stage of the intracellular antiviral response two RNA helicases, retinoic acid inducible gene-I (RIG-I) and melanoma differentiation-association gene 5 (MDA5), are independently able to bind viral RNA in the cytoplasm. The 62 kDa protein IPS-1/MAVS/VISA/Cardif contains an N-terminal caspase activation and recruitment (CARD) domain that associates with the CARD regions of RIG-I and MDA5, ultimately leading to the induction of type I interferons. As a first step towards understanding the molecular basis of this important adaptor protein we have undertaken structural studies of the IPS-1 MAVS/VISA/Cardif CARD region. Results: The crystal structure of human IPS-1/MAVS/VISA/Cardif CARD has been determined to 2.1 angstrom resolution. The protein was expressed and crystallized as a maltose-binding protein (MBP) fusion protein. The MBP and IPS-1 components each form a distinct domain within the structure. IPS-1/MAVS/VISA/Cardif CARD adopts a characteristic six-helix bundle with a Greek-key topology and, in common with a number of other known CARD structures, contains two major polar surfaces on opposite sides of the molecule. One face has a surface-exposed, disordered tryptophan residue that may explain the poor solubility of untagged expression constructs. Conclusion: The IPS-1/MAVS/VISA/Cardif CARD domain adopts the classic CARD fold with an asymmetric surface charge distribution that is typical of CARD domains involved in homotypic protein-protein interactions. The location of the two polar areas on IPS-1/MAVS/VISA/Cardif CARD suggest possible types of associations that this domain makes with the two CARD domains of MDA5 or RIG-I. The N-terminal CARD domains of RIG-I and MDA5 share greatest sequence similarity with IPS-1/MAVS/VISA/Cardif CARD and this has allowed modelling of their structures. These models show a very different charge profile for the equivalent surfaces compared to IPS-1/MAVS/VISA/Cardif CARD.Publisher PDFPeer reviewe

Quantized Electric Multipole Insulators

In this article we extend the celebrated Berry-phase formulation of electric polarization in crystals to higher electric multipole moments. We determine the necessary conditions under which, and minimal models in which, the quadrupole and octupole moments are topologically quantized electromagnetic observables. Such systems exhibit gapped boundaries that are themselves lower-dimensional topological phases. Furthermore, they manifest topologically protected corner states carrying fractional charge, i.e., fractionalization at the boundary of the boundary. To characterize these new insulating phases of matter, we introduce a new paradigm whereby `nested' Wilson loops give rise to a large number of new topological invariants that have been previously overlooked. We propose three realistic experimental implementations of this new topological behavior that can be immediately tested.Comment: Main text: 9 pages, 6 figures. Supplementary Material: 37 pages, 15 figures. Submitted on Jul 25, 201

Daze fasteners

A daze fastener system for connecting two or more structural elements wherein the structural elements and fastener parts have substantially different coefficient of thermal expansion physical property characteristics is employed in this invention. By providing frusto-conical abutting surfaces between the structural elements and fastener parts any differences in thermal expansion/contraction between the parts is translated to sliding motion and avoids deleterious thermal stresses in the connection. An essential feature for isotropic homogeneous material connections is that at least two sets of mating surfaces are required wherein each set of mating surfaces have line element extensions that pass through a common point