Space shuttle contamination due to backflow from control motor exhaust

Spacecraft contamination of the space shuttle orbiter and accompanying Spacelab payloads is studied. The scattering of molecules from the vernier engines and flash evaporator nozzle after impingement on the orbiter wing surfaces, and the backflow of molecules out of the flash evaporator nozzle plume flow field due to intermolecular collisions in the plume are the problems discussed. A method was formulated for dealing with these problems, and detailed results are given

Scotin, a novel p53-inducible proapoptotic protein located in the ER and the nuclear membrane

p53 is a transcription factor that induces growth arrest or apoptosis in response to cellular stress. To identify new p53-inducible proapoptotic genes, we compared, by differential display, the expression of genes in spleen or thymus of normal and p53 nullizygote mice after γ-irradiation of whole animals. We report the identification and characterization of human and mouse Scotin homologues, a novel gene directly transactivated by p53. The Scotin protein is localized to the ER and the nuclear membrane. Scotin can induce apoptosis in a caspase-dependent manner. Inhibition of endogenous Scotin expression increases resistance to p53-dependent apoptosis induced by DNA damage, suggesting that Scotin plays a role in p53-dependent apoptosis. The discovery of Scotin brings to light a role of the ER in p53-dependent apoptosis

Transport theory yields renormalization group equations

We show that dissipative transport and renormalization can be described in a single theoretical framework. The appropriate mathematical tool is the Nakajima-Zwanzig projection technique. We illustrate our result in the case of interacting quantum gases, where we use the Nakajima-Zwanzig approach to investigate the renormalization group flow of the effective two-body interaction.Comment: 11 pages REVTeX, twocolumn, no figures; revised version with additional examples, to appear in Phys. Rev.

Graph-Embedding Empowered Entity Retrieval

In this research, we improve upon the current state of the art in entity retrieval by re-ranking the result list using graph embeddings. The paper shows that graph embeddings are useful for entity-oriented search tasks. We demonstrate empirically that encoding information from the knowledge graph into (graph) embeddings contributes to a higher increase in effectiveness of entity retrieval results than using plain word embeddings. We analyze the impact of the accuracy of the entity linker on the overall retrieval effectiveness. Our analysis further deploys the cluster hypothesis to explain the observed advantages of graph embeddings over the more widely used word embeddings, for user tasks involving ranking entities

Comparing proxy rated quality of life of people living with dementia in care homes

Background: Improving quality of life (QOL) for people with dementia is a priority. In care homes, we often rely on proxy ratings from staff and family but we do not know if, or how, they differ in care homes. Methods: We compared 1056 pairs of staff and family DEMQOL-Proxy ratings from 86 care homes across England. We explored factors associated with ratings quantitatively using multilevel modelling and, qualitatively, through thematic analysis of 12 staff and 12 relative interviews. Results: Staff and family ratings were weakly correlated (ρs = 0.35). Median staff scores were higher than family's (104 v. 101; p < 0.001). Family were more likely than staff to rate resident QOL as ‘Poor’ (χ2 = 55.91, p < 0.001). Staff and family rated QOL higher when residents had fewer neuropsychiatric symptoms and severe dementia. Staff rated QOL higher in homes with lower staff:resident ratios and when staff were native English speakers. Family rated QOL higher when the resident had spent longer living in the care home and was a native English. Spouses rated residents’ QOL higher than other relatives. Qualitative results suggest differences arise because staff felt good care provided high QOL but families compared the present to the past. Family judgements centre on loss and are complicated by decisions about care home placement and their understandings of dementia. Conclusion: Proxy reports differ systematically between staff and family. Reports are influenced by the rater:staff and family may conceptualise QOL differently

Studies in synthetic carbonatite systems: Solidus relationships for CaO-MgO-CO_2-H_2O to 40 kbar and CaO-MgO-SiO_2-CO_2-H_2O to 10 kbar

The system CaO-MgO-SiO_2-CO_2-H_2O is an important model for many igneous and metamorphic processes, including the generation and differentiation of carbonatite and associated silicate magmas. We have experimentally established the vapor-saturated solidus for the system CaO-MgO-CO_2-H_2O from 595°C/1 kbar to <500°C/40 kbar, about 25°C lower than the corresponding temperatures for the CaO-CO_2-H_2O system. Brucite replaces periclase on the vapor-saturated solidus at about 750 bars pressure, remaining as the stable phase to pressures of at least 40 kbar; no dolomite or magnesite was encountered. At a pressure between 35 and 40 kbar, the assemblage portlandite + brucite + aragonite + vapor changes to one containing phase W, a previously unreported Ca-Mg carbonate. At 20 kbar, the vapor-saturated liquid contains at least 24 wt % H_2O. The vapor-saturated solidus for the system CaO-MgO-SiO_2-CO_2-H_2O ranges from 613°C/1 kbar to 565°C/10 kbar, experimentally indistinguishable from that for CaO-MgO-CO_2-H_2O, about 10°C lower than that for CaO-CO_2-H_2O, and about 25°C lower than that for CaO-SiO_2-CO_2-H_2O. In the quinary system, monticellite is replaced by dellaite and an unidentified silicate on the vapor-saturated solidus above 4.1 kbar. MgO-poor liquids are similar in composition to the magma from which the Magnet Cove calcite carbonatite crystallized. More magnesian magmas would produce dolomite at moderate depths, such as at Alnö Island

A possible mechanism of ultrafast amorphization in phase-change memory alloys: an ion slingshot from the crystalline to amorphous position

We propose that the driving force of an ultrafast crystalline-to-amorphous transition in phase-change memory alloys are strained bonds existing in the (metastable) crystalline phase. For the prototypical example of GST, we demonstrate that upon breaking of long Ge-Te bond by photoexcitation Ge ion shot from an octahedral crystalline to a tetrahedral amorphous position by the uncompensated force of strained short bonds. Subsequent lattice relaxation stabilizes the tetrahedral surroundings of the Ge atoms and ensures the long-term stability of the optically induced phase.Comment: 6 pages, 3 figure

Entangling flux qubits with a bipolar dynamic inductance

We propose a scheme to implement variable coupling between two flux qubits using the screening current response of a dc Superconducting QUantum Interference Device (SQUID). The coupling strength is adjusted by the current bias applied to the SQUID and can be varied continuously from positive to negative values, allowing cancellation of the direct mutual inductance between the qubits. We show that this variable coupling scheme permits efficient realization of universal quantum logic. The same SQUID can be used to determine the flux states of the qubits.Comment: 4 pages, 4 figure

Experimentally induced root mortality increased nitrous oxide emission from tropical forest soils

We conducted an experiment on sand and clay tropical forest soils to test the short‐term effect of root mortality on the soil‐atmosphere flux of nitrous oxide, nitric oxide, methane, and carbon dioxide. We induced root mortality by isolating blocks of land to 1 m using trenching and root exclusion screening. Gas fluxes were measured weekly for ten weeks following the trenching treatment. For nitrous oxide there was a highly significant increase in soil‐atmosphere flux over the ten weeks following treatment for trenched plots compared to control plots. N2O flux averaged 37.5 and 18.5 ng N cm−2 h−1 from clay trenched and control plots and 4.7 and 1.5 ng N cm−2 h−1 from sand trenched and control plots. In contrast, there was no effect for soil‐atmosphere flux of nitric oxide, carbon dioxide, or methane