A long-term VLBA monitoring campaign of the v=1, J=1-0 SiO masers toward TX Cam - I. Morphology and Shock Waves

We present the latest and final version of the movie of the SiO masers toward the Mira variable TX Cam. The new version consists of 112 frames (78 successfully reduced epochs) with data covering almost three complete stellar cycles between 24 May 1997 to 25 January 2002, observed with the VLBA. In this paper we examine the global morphology, kinematics and variability of the masering zone. The morphology of the emission is confined in a structure that usually resembles a ring or an ellipse, with occasional deviations due to localised phenomena. The ring appears to be contracting and expanding, although for the first cycle contraction is not observed. The width and outer boundary of the masering zone follow the stellar pulsation. Our data seem to be consistent with a shock being created once per stellar cycle at maximum that propagates with a velocity of ~7 km/s. The difference in velocities along different axes strongly suggests that the outflow in TX Cam is bipolar. The contribution of projection is examined and our results are compared with the latest theoretical model

Theoretical Investigation of Internal Rotation Barriers of 4-(Dimethylaminocinnamaldehyde)

Theoretical study on 4-dimethylaminocinnamaldehyde was done analyzing the barriers of rotation and interpretation of its Raman spectrum. B3LYP Density functional with basis sets up to 6-31G ** with additional f and d functions on C, N, O, and H respectively, calculations were performed. Results indicate trans conformation of the molecule had the lowest energy. Vibrational modes of interest were noted around 500, 1192, 1263, 1316, 1547, and 1608 cm-1. Observed strong enhancement at noted frequencies can be further studied in determining the molecule with other subatomic particles (Ag colloids)

Theoretical Studies of Several Small-Ring Precursors to (+)-JQ1

We present the results of DFT(B3LYP) calculations on several precursors to (+)-JQ1 using an accurate basis set, including a report of conformational analysis, thermochemistry, optimized geometries and electrostatic potentials, and calculated IR and Raman spectra. Species include (I)1H-1,4-diazepin-2(3H)-imine, (II) 9H-[1,2,4]triazolo[4,3-a][1,4]diazepine, (III) 6H-thieno[3,2-f][1,2,4]triazolo[4,3a][1,4]diazepine, and (IV) 4-(4-chlorophenyl)-6H-thieno[3,2f][1,2,4]triazolo[4,3-a][1,4]diazepine. Studies are also reported on monobrominated (II)-(IV) substituted at the chiral center of the seven member ring, including a comparison of the energetics of equatorial versus axial bromination of the parent precursor. Implications with regard to the larger structure of (+)-JQ1 are discussed

Theoretical Study of the Pseudomonic and Monic Acids

The drug Mupirocin has shown positive effects against both Gram-negative and Gram-positive bacteria with varying levels of success. It has been shown to be effective against Methicillin-Resistant Staphylococcus Aureas (MRSA) as a topical treatment in high concentrations. Mupirocin is comprised of pseudomonic acids. The monic acids are structurally similar to the pseudomonic acids and thus function as a good model to better understand the chemical characteristics of the drug. This work presents results of DFT (B3LYP) calculations with an accurate basis set on monic acid A and related species with focus on internal rotation barriers, optimal geometries, IR and Raman spectra, and electrostatic potentials to identify the differences between the monic and pseudomonic acids with an eye towards potential antibacterial treatments

Psychology ethics down under: A survey of student subject pools in Australia

A survey of the 37 psychology departments offering courses accredited by the Australian Psychological Society yielded a 92% response rate. Sixty-eight percent of departments employed students as research subjects, with larger departments being more likely to do so. Most of these departments drew their student subject pools from introductory courses. Student research participation was strictly voluntary in 57% of these departments, whereas 43% of the departments have failed to comply with normally accepted ethical standards. It is of great concern that institutional ethics committees apparently continue to condone, or fail to act against, unethical research practices. Although these committees have a duty of care to all subjects, the final responsibility for conducting research in an ethical manner lies with the individual researcher

VLBI Astrometry of the Stellar Image of U Herculis, Amplified by the 1667 OH Maser

The OH 1667 MHz maser in the circumstellar shell around the Mira variable U Herculis has been observed with the NRAO Very Long Baseline Array (VLBA) at 6 epochs, spread over 4 years. Using phase referencing techniques the position of the most blue-shifted maser spot was monitored with respect to two extra-galactic radio sources. The absolute radio positions of the maser can be compared with the stellar optical position measured by the Hipparcos satellite to 15 mas accuracy. This confirms the model in which one of the maser spots corresponds to the stellar continuum, amplified by the maser. The stellar proper motion and the annual parallax (5.3 +/- 2.1 mas) were measured.Comment: 6 pages, 4 figures; to be published in A&

The Most Detailed Picture Yet of an Embedded High-mass YSO

High-mass star formation is not well understood chiefly because examples are deeply embedded, relatively distant, and crowded with sources of emission. Using VLA and VLBA observations of water and SiO maser emission, we have mapped in detail the structure and proper motion of material 20-500 AU from the closest high-mass YSO, radio source-I in the Orion KL region. We observe streams of material driven in a rotating, wide angle, bipolar wind from the surface of an edge-on accretion disk. The example of source-I provides strong evidence that high-mass star formation proceeds via accretionComment: typo corrected and word added to abstract 6 pages including 4 B&W figures. To appear in the Proceeding of IAU Symposium 221, Star Formation at High Angular Resolution, Editors M. Burton, R. Jayawardhana & T. Bourke, Astronomical Society of the Pacifi