Rare Earth Element Partition Coefficients from Enstatite/Melt Synthesis Experiments

Enstatite (En(80)Fs(19)Wo(01)) was synthesized from a hypersthene normative basaltic melt doped at the same time with La, Ce, Nd, Sm, Eu, Dy, Er, Yb and Lu. The rare earth element concentrations were measured in both the basaltic glass and the enstatite. Rare earth element concentrations in the glass were determined by electron microprobe analysis with uncertainties less than two percent relative. Rare earth element concentrations in enstatite were determined by secondary ion mass spectrometry with uncertainties less than five percent relative. The resulting rare earth element partition signature for enstatite is similar to previous calculated and composite low-Ca pigeonite signatures, but is better defined and differs in several details. The partition coefficients are consistent with crystal structural constraints

Activity-based protein profiling of the hepatitis C virus replication in Huh-7 hepatoma cells using a non-directed active site probe

<p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) poses a growing threat to global health as it often leads to serious liver diseases and is one of the primary causes for liver transplantation. Currently, no vaccines are available to prevent HCV infection and clinical treatments have limited success. Since HCV has a small proteome, it relies on many host cell proteins to complete its life cycle. In this study, we used a non-directed phenyl sulfonate ester probe (PS4≡) to selectively target a broad range of enzyme families that show differential activity during HCV replication in Huh-7 cells.</p> <p>Results</p> <p>The PS4≡ probe successfully targeted 19 active proteins in nine distinct protein families, some that were predominantly labeled <it>in situ </it>compared to the <it>in vitro </it>labeled cell homogenate. Nine proteins revealed altered activity levels during HCV replication. Some candidates identified, such as heat shock 70 kDa protein 8 (or HSP70 cognate), have been shown to influence viral release and abundance of cellular lipid droplets. Other differentially active PS4≡ targets, such as electron transfer flavoprotein alpha, protein disulfide isomerase A5, and nuclear distribution gene C homolog, constitute novel proteins that potentially mediate HCV propagation.</p> <p>Conclusions</p> <p>These findings demonstrate the practicality and versatility of non-directed activity-based protein profiling (ABPP) to complement directed methods and accelerate the discovery of altered protein activities associated with pathological states such as HCV replication. Collectively, these results highlight the ability of <it>in situ </it>ABPP approaches to facilitate the identification of enzymes that are either predominantly or exclusively labeled in living cells. Several of these differentially active enzymes represent possible HCV-host interactions that could be targeted for diagnostic or therapeutic purposes.</p

A qualitative examination of women\u27s self-presentation and social physique anxiety during injury rehabilitation

Objective To understand women\u27s self-presentation experiences in the rehabilitation setting, and their attitudes and preferences toward the social and physical features of the rehabilitation environment. Design Qualitative study. Setting Outpatient physiotherapy clinic. Participants Ten women (age 18 to 64) with high social physique anxiety (Social Physique Anxiety Scale score ≥25) referred for physiotherapy following acute injury. Main outcome measures Semi-structured interviews were conducted prior to commencement of treatment, and again after a third treatment session. Results Participants experienced extensive self-presentational concerns that were intensified due to the nature of the physiotherapy environment. The women reported that their self-presentational anxiety did not diminish over time, and was related to others’ negative perceptions regarding their physical appearance and inability to perform exercises as well as expected. The presence of men or younger women in the clinic was identified as a barrier to appointment attendance, along with open concept clinic settings, which were associated with the most potential for evaluation. Mirrors and windows in the physiotherapy clinic were highlighted as anxiety provoking. The women suggested that they would feel apprehensive about advocating for themselves if they felt uncomfortable with the area in which they were receiving treatment, and instead used avoidance coping strategies (e.g., hiding behind equipment, preventing eye contact) to manage their anxiety. Conclusions Physique-anxious women experience extensive self-presentational concerns in the rehabilitation environment, which could affect treatment adherence. Modifying the treatment setting, providing protective self-presentational strategies such as positive self-talk, and open patient–therapist communication could be implemented to help mitigate these concerns

The Exceptionally Luminous Type Ia Supernova 2007If

SN 2007if was the third over-luminous Type Ia supernova (SN Ia) detected after 2003fg and 2006gz. We present the photometric and spectroscopic observations of the SN and its host by ROTSE-III, HET, and Keck. From the H a line identified in the host spectra, we determine a redshift of 0.0736. At this distance, the SN reached an absolute magnitude of -20.4, brighter than any other SNe Ia ever observed. If the source of luminosity is radioactive decay, a large amount of radioactive nickel (similar to 1.5 M(circle dot)) is required to power the peak luminosity, more than can be produced realistically in a Chandrasekhar mass progenitor. Low expansion velocity, similar to that of 2003fg, is also measured around the maximum light. The observations may suggest that SN 2007if was from a massive white dwarf progenitor, plausibly exploding with mass well beyond 1.4 M(circle dot). Alternatively, we investigate circumstellar interaction that may contribute to the excess luminosity.NASA NNX-08AN25G, NNX-08AV63GNSF AST-0707769, PHY-0801007Australian Research CouncilUniversity of New South WalesUniversity of TexasUniversity of MichiganAstronom

A qualitative examination of women's self-presentation and social physique anxiety during injury rehabilitation

Objective To understand women\u27s self-presentation experiences in the rehabilitation setting, and their attitudes and preferences toward the social and physical features of the rehabilitation environment. Design Qualitative study. Setting Outpatient physiotherapy clinic. Participants Ten women (age 18 to 64) with high social physique anxiety (Social Physique Anxiety Scale score ≥25) referred for physiotherapy following acute injury. Main outcome measures Semi-structured interviews were conducted prior to commencement of treatment, and again after a third treatment session. Results Participants experienced extensive self-presentational concerns that were intensified due to the nature of the physiotherapy environment. The women reported that their self-presentational anxiety did not diminish over time, and was related to others’ negative perceptions regarding their physical appearance and inability to perform exercises as well as expected. The presence of men or younger women in the clinic was identified as a barrier to appointment attendance, along with open concept clinic settings, which were associated with the most potential for evaluation. Mirrors and windows in the physiotherapy clinic were highlighted as anxiety provoking. The women suggested that they would feel apprehensive about advocating for themselves if they felt uncomfortable with the area in which they were receiving treatment, and instead used avoidance coping strategies (e.g., hiding behind equipment, preventing eye contact) to manage their anxiety. Conclusions Physique-anxious women experience extensive self-presentational concerns in the rehabilitation environment, which could affect treatment adherence. Modifying the treatment setting, providing protective self-presentational strategies such as positive self-talk, and open patient–therapist communication could be implemented to help mitigate these concerns

Process for Making Single-Domain Magnetite Crystals

A process for making chemically pure, single-domain magnetite crystals substantially free of structural defects has been invented as a byproduct of research into the origin of globules in a meteorite found in Antarctica and believed to have originated on Mars. The globules in the meteorite comprise layers of mixed (Mg, Fe, and Ca) carbonates, magnetite, and iron sulfides. Since the discovery of the meteorite was announced in August 1996, scientists have debated whether the globules are of biological origin or were formed from inorganic materials by processes that could have taken place on Mars. While the research that led to the present invention has not provided a definitive conclusion concerning the origin of the globules, it has shown that globules of a different but related chemically layered structure can be grown from inorganic ingredients in a multistep precipitation process. As described in more detail below, the present invention comprises the multistep precipitation process plus a subsequent heat treatment. The multistep precipitation process was demonstrated in a laboratory experiment on the growth of submicron ankerite crystals, overgrown by submicron siderite and pyrite crystals, overgrown by submicron magnesite crystals, overgrown by submicron siderite and pyrite. In each step, chloride salts of appropriate cations (Ca, Fe, and Mg) were dissolved in deoxygenated, CO2- saturated water. NaHCO3 was added as a pH buffer while CO2 was passed continuously through the solution. A 15-mL aliquot of the resulting solution was transferred into each of several 20 mL, poly(tetrafluoroethylene)-lined hydrothermal pressure vessels. The vessels were closed in a CO2 atmosphere, then transferred into an oven at a temperature of 150 C. After a predetermined time, the hydrothermal vessels were removed from the oven and quenched in a freezer. Supernatant solutions were decanted, and carbonate precipitates were washed free of soluble salts by repeated decantations with deionized water

Dynamical chiral symmetry breaking and confinement with an infrared-vanishing gluon propagator?

We study a model Dyson-Schwinger equation for the quark propagator closed using an {\it Ansatz} for the gluon propagator of the form \mbox{$D(q) \sim q^2/[(q^2)^2 + b^4]$} and two {\it Ans\"{a}tze} for the quark-gluon vertex: the minimal Ball-Chiu and the modified form suggested by Curtis and Pennington. Using the quark condensate as an order parameter, we find that there is a critical value of $b=b_c$ such that the model does not support dynamical chiral symmetry breaking for $b>b_c$. We discuss and apply a confinement test which suggests that, for all values of $b$, the quark propagator in the model {\bf is not} confining. Together these results suggest that this Ansatz for the gluon propagator is inadequate as a model since it does not yield the expected behaviour of QCD.Comment: 21 Pages including 4 PostScript figures uuencoded at the end of the file. Replacement: slight changes of wording and emphasis. ADP-93-215/T133, ANL-PHY-7599-TH-93, FSU-SCRI-93-108, REVTEX 3.

Angiogenic Factors Stimulate Growth of Adult Neural Stem Cells

The ability to grow a uniform cell type from the adult central nervous system (CNS) is valuable for developing cell therapies and new strategies for drug discovery. The adult mammalian brain is a source of neural stem cells (NSC) found in both neurogenic and non-neurogenic zones but difficulties in culturing these hinders their use as research tools.Here we show that NSCs can be efficiently grown in adherent cell cultures when angiogenic signals are included in the medium. These signals include both anti-angiogenic factors (the soluble form of the Notch receptor ligand, Dll4) and pro-angiogenic factors (the Tie-2 receptor ligand, Angiopoietin 2). These treatments support the self renewal state of cultured NSCs and expression of the transcription factor Hes3, which also identifies the cancer stem cell population in human tumors. In an organotypic slice model, angiogenic factors maintain vascular structure and increase the density of dopamine neuron processes.We demonstrate new properties of adult NSCs and a method to generate efficient adult NSC cultures from various central nervous system areas. These findings will help establish cellular models relevant to cancer and regeneration

The Early Optical Afterglow of GRB 030418 and Progenitor Mass Loss

The ROTSE-IIIa telescope and the SSO 40 inch (1.0 m) telescope, both located at Siding Spring Observatory, imaged the early-time afterglow of GRB 030418. In this report, we present observations of the early afterglow, first detected by the ROTSE-IIIa telescope 211 s after the start of the burst and only 76 s after the end of the gamma-ray activity. We detect optical emission that rises for ∼600 s, slowly varies around R = 17.3 mag for ∼1400 s, and then fades as a power law of index α = -1.36. Additionally, the ROTSE-IIIb telescope, located at McDonald Observatory, imaged the early-time afterglow of GRB 030723. The behavior of this light curve was qualitatively similar to that of GRB 030418, but 2 mag dimmer. These two afterglows are dissimilar to other afterglows such as GRB 990123 and GRB 021211. We investigate whether or not the early afterglow can be attributed to a synchrotron break in a cooling synchrotron spectrum as it passes through the optical band, but we find that this model is unable to accurately describe the early light curve. We present a simple model for gamma-ray burst emission emerging from a wind medium surrounding a massive progenitor star. This model provides an effective description of the data and suggests that the rise of the afterglow can be ascribed to extinction in the local circumburst environment. In this interpretation, these events provide further evidence of the connection between gamma-ray bursts and the collapse of massive stars.This work has been supported by NASA grants NAG5- 5281 and F006794, NSF grants AST 01-19685 and 01-05221, the Australian Research Council, the University of New South Wales, and the University of Michigan. Work performed at LANL is supported by NASA SR&T through Department of Energy (DOE) contract W-7405-ENG-36 and through internal LDRD funding

Supernova / Acceleration Probe: A Satellite Experiment to Study the Nature of the Dark Energy

The Supernova / Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universe's expansion by performing a series of complementary systematics-controlled measurements. We describe a self-consistent reference mission design for building a Type Ia supernova Hubble diagram and for performing a wide-area weak gravitational lensing study. A 2-m wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high-efficiency low-resolution integral field spectrograph. The SNAP mission will obtain high-signal-to-noise calibrated light-curves and spectra for several thousand supernovae at redshifts between z=0.1 and 1.7. A wide-field survey covering one thousand square degrees resolves ~100 galaxies per square arcminute. If we assume we live in a cosmological-constant-dominated Universe, the matter density, dark energy density, and flatness of space can all be measured with SNAP supernova and weak-lensing measurements to a systematics-limited accuracy of 1%. For a flat universe, the density-to-pressure ratio of dark energy can be similarly measured to 5% for the present value w0 and ~0.1 for the time variation w'. The large survey area, depth, spatial resolution, time-sampling, and nine-band optical to NIR photometry will support additional independent and/or complementary dark-energy measurement approaches as well as a broad range of auxiliary science programs. (Abridged)Comment: 40 pages, 18 figures, submitted to PASP, http://snap.lbl.go