Mars Encounters cause fresh surfaces on some near-Earth asteroids

All airless bodies are subject to the space environment, and spectral differences between asteroids and meteorites suggest many asteroids become weathered on very short (<1My) timescales. The spectra of some asteroids, particularly Q-types, indicate surfaces that appear young and fresh, implying they have been recently been exposed. Previous work found that Earth encounters were the dominant freshening mechanism and could be responsible for all near-Earth object (NEO) Q-types. In this work we increase the known NEO Q-type sample of by a factor of three. We present the orbital distributions of 64 Q-type near-Earth asteroids, and seek to determine the dominant mechanisms for refreshing their surfaces. Our sample reveals two important results: i) the relatively steady fraction of Q-types with increasing semi-major axis and ii) the existence of Q-type near-Earth asteroids with Minimum Orbit Intersection Distances (MOID) that do not have orbit solutions that cross Earth. Both of these are evidence that Earth-crossing is not the only scenario by which NEO Q-types are freshened. The high Earth-MOID asteroids represent 10% of the Q-type population and all are in Amor orbits. While surface refreshing could also be caused by Main Belt collisions or mass shedding from YORP spinup, all high Earth-MOID Q-types have the possibility of encounters with Mars indicating Mars could be responsible for a significant fraction of NEOs with fresh surfaces.Comment: Accepted for publication in Icarus -- 14 pages, 8 figures, 1 table, 2 appendice

X-ray Lightcurves from Realistic Polar Cap Models: Inclined Pulsar Magnetospheres and Multipole Fields

Thermal X-ray emission from rotation-powered pulsars is believed to originate from localized "hotspots" on the stellar surface occurring where large-scale currents from the magnetosphere return to heat the atmosphere. Lightcurve modeling has primarily been limited to simple models, such as circular antipodal emitting regions with constant temperature. We calculate more realistic temperature distributions within the polar caps, taking advantage of recent advances in magnetospheric theory, and we consider their effect on the predicted lightcurves. The emitting regions are non-circular even for a pure dipole magnetic field, and the inclusion of an aligned magnetic quadrupole moment introduces a north-south asymmetry. As the aligned quadrupole moment is increased, one hotspot grows in size before becoming a thin ring surrounding the star. For the pure dipole case, moving to the more realistic model changes the lightcurves by $5-10\%$ for millisecond pulsars, helping to quantify the systematic uncertainty present in current dipolar models. Including the quadrupole gives considerable freedom in generating more complex lightcurves. We explore whether these simple dipole+quadrupole models can account for the qualitative features of the lightcurve of PSR J0437$-$4715.Comment: 12 pages, 9 figure

A High Resolution View of Galactic Centers: Arp 220 and M31.

Ph.D. Thesis. University of Hawaiʻi at Mānoa 2017

Expression, Purification, and Characterization of the Mast Cell Proteases Chymase and Cathepsin G.

Human mast cells have been associated with wound healing, allergies, inflammation, and defense against pathogens and have been detected in tissues close to blood vessels especially in the areas between the inside of the body and the external environment, such as the skin, lungs, digestive tract, mouth, and nose. Previous studies have shown that mast cells contain large granules filled with histamine, heparin, cytokines, eicosanoids, and the serine proteases, tryptase, Chymase, and cathepsin G (CatG). These proteases are stored and released from mast-cell granules upon activation by antigen binding to IgE immunoglobulins on the cell surface or by direct injury. In this study, chymase and CatG were expressed as active enzymes in the yeast Pichia pastoris by homologous recombination of the cDNA coding for the mature active proteases into the Pichia genome. Methanol induction resulted in the secretion of active enzyme into the Pichia growth media and increasing levels of enzyme were detected in the media for 5 days. Cells that secreted the highest levels of activity were selected by kinetic assay. Active chymase was purified from the culture media with a 22% yield of activity by a simple two-step procedure that involved hydrophobic-interaction chromatography followed by affinity chromatography on immobilized heparin. The major peak from the heparin column contained a single band of 30.6 kDa on SDS/PAGE. The purified recombinant human chymase was 96% active and the yield was 2.2 mg/l of growth media. Active CatG was partially purified from culture media using an ultrafiltration. Mass Spectroscopy (Maldi-Tof) data confirmed that the major protein band was CatG, resulting in the first active human CatG to be produced recombinantly. Additionally, the partially purified enzyme was active against both chymotrypsin and trypsin substrates, and its reaction with inhibitors was consistent with CatG. Although the protein yields were low, these results confirm that CatG was recombinantly expressed

The Influence of Intelligence and Other Factors on the Type of Punishment Administered to Children

This report is based on the answers given by twenty-five hundred children in certain Iowa public schools to a brief questionnaire viz: 1. Have you ever been punished at home? (underscore the right word) Yes, often; Seldom; Once only; Never. 2. How were you punished at home? By scolding; slapping; whipping; other ways -_______________________ 3. Have you ever been punished at school? Yes, often; Seldom; Only once; Never. 4. How were you punished at school? Scolding; Slapping; Keeping in; Whipping; Other ways ___________________ 5. If you were a parent or a teacher how would you punish a child? (underscore your choice of ways) Scolding; Take away playtime; No dinner; Send to bed early; Slapping; Whipping; _____________________ This study is concerned only with the answers to No. 2, - How were you punished at home? and the answers to No. 5 - The type of punishment the child would administer if he were a parent or a teacher

Alien Registration- Lockhart, H W E. (Fort Fairfield, Aroostook County)

https://digitalmaine.com/alien_docs/36500/thumbnail.jp

Referencing Sources of Molecular Spectroscopic Data in the Era of Data Science: Application to the HITRAN and AMBDAS Databases

The application described has been designed to create bibliographic entries in large databases with diverse sources automatically, which reduces both the frequency of mistakes and the workload for the administrators. This new system uniquely identifies each reference from its digital object identifier (DOI) and retrieves the corresponding bibliographic information from any of several online services, including the SAO/NASA Astrophysics Data Systems (ADS) and CrossRef APIs. Once parsed into a relational database, the software is able to produce bibliographies in any of several formats, including HTML and BibTeX, for use on websites or printed articles. The application is provided free-of-charge for general use by any scientific database. The power of this application is demonstrated when used to populate reference data for the HITRAN and AMBDAS databases as test cases. HITRAN contains data that is provided by researchers and collaborators throughout the spectroscopic community. These contributors are accredited for their contributions through the bibliography produced alongside the data returned by an online search in HITRAN. Prior to the work presented here, HITRAN and AMBDAS created these bibliographies manually, which is a tedious, time-consuming and error-prone process. The complete code for the new referencing system can be found at \url{https://github.com/hitranonline/refs}.Comment: 11 pages, 5 figures, already published online at https://doi.org/10.3390/atoms802001

Aging Effect on Foot Dynamics During Unexpected Slips

Slip-induced fall accidents have been recognized as a serious threat to the health of the elderly.The objective of the current study was to investigate the aging effect on the biomechanical reactions of both perturbed foot and unperturbed foot to the unexpected slips. Nineteen younger (mean age: 25.0 years old) and twenty-one older (mean age: 71.2 years old) adults were involved in a laboratory study,in which slippery surface was induced during walking without their awareness.The reactive responses of both slipping foot and unperturbed foot were quantified by optical motion capture system and force platforms.The results indicate a characteristic toe-touch strategy by the unperturbed foot after slip starts. Significant aging effects were found in touch down base of support created by the unperturbed foot. It was concluded that the unperturbed foot is important to facilitate successful recovery from unexpected. Specifically, in order to prevent age-related slip-induced falls, it is important for the unperturbed foot to create sufficient base of support in anterior-posterior direction and to control the base of support in media-lateral direction