Dust, Ice, and Gas in Time (DIGIT) Herschel Observations of GSS30-IRS1 in Ophiuchus

As a part of the "Dust, Ice, and Gas In Time" (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d = 120 pc), with Herschel/Photodetector Array Camera and Spectrometer. More than 70 lines were detected within a wavelength range from 50 to 200 mu m, including CO, H2O, OH, and two atomic [O I] lines at 63 and 145 mu m. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field (ISRF), is also detected at 158 mu m. All lines, except [O I] and [C II], are detected only at the central spaxel of 9 ''.4 x 9 ''.4. The [O I] emissions are extended along a NE-SW orientation, and the [C II] line is detected over all spaxels, indicative of an external photodissociation region. The total [C II] intensity around GSS30 reveals that the far-ultraviolet radiation field is in the range of 3 to 20 G(0), where G(0) is in units of the Habing Field, 1.6 x 10(-3) erg cm(-2) s(-1). This enhanced external radiation field heats the envelope of GSS30-IRS1, causing the continuum emission to be extended, unlike the molecular emission. The best-fit continuum model of GSS30-IRS1 with the physical structure including flared disk, envelope, and outflow shows that the internal luminosity is 10 L-circle dot, and the region is externally heated by a radiation field enhanced by a factor of 130 compared to the standard local ISRF.NASANational Research Foundation of Korea (NRF) - Ministry of Education of the Korean government NRF-2012R1A1A2044689National Research Foundation (NRF) - Ministry of Education of KoreaAstronom

Superconducting transition of a two-dimensional Josephson junction array in weak magnetic fields

The superconducting transition of a two-dimensional (2D) Josephson junction array exposed to weak magnetic fields has been studied experimentally. Resistance measurements reveal a superconducting-resistive phase boundary in serious disagreement with the theoretical and numerical expectations. Critical scaling analyses of the $IV$ characteristics indicate contrary to the expectations that the superconducting-to-resistive transition in weak magnetic fields is associated with a melting transition of magnetic-field-induced vortices directly from a pinned-solid phase to a liquid phase. The expected depinning transition of vortices from a pinned-solid phase to an intermediate floating-solid phase was not observed. We discuss effects of the disorder-induced random pinning potential on phase transitions of vortices in a 2D Josephson junction array.Comment: 9 pages, 7 figures (EPS+JPG format), RevTeX

Identifying the Substrate Specificities of SENP1 and SENP2 in Recognition of Sumoylated Thymine-DNA Glycosylase

SUMO is an essential post-translational protein modification regulated in part by the activity of a family of SUMO-specific proteases known as SENPs. Mammalian cells express six different SENPs with essential and non-redundant functions. The molecular mechanisms that determine the substrate specificities of individual SENPs and their unique functions, however, remain unknown. Thymine-DNA glycosylase (TDG) is an important enzyme that recognizes and repairs G/U and G/T mismatches in the genome during the initial stages of base excision repair (BER), and this role is critical in genome integrity and also DNA demethylation. TDG is sumoylated in vivo and we are interested in exploring the functional importance and regulation of its modification. We previously found that SENP1 preferentially deconjugates sumoylated TDG in vivo, compared with SENP2, and that specificity is determined by the SENP1 catalytic domain (cSENP1). Here, we have used in vitro studies to further explore this specificity by comparing the activities of the SENP1 and SENP2 catalytic domains using multiple substrates, including AMC, RanGAP1 and TDG. Because TDG contains a SUMO interaction motif (SIM) that affects its modification in vivo, we hypothesized that non-covalent, intramolecular SUMO-SIM interactions impede TDG deconjugation. We also hypothesized that the cSENP1 is more efficient at disrupting the TDG SIM-SUMO interaction, thus explaining specificity. To test these hypotheses, we measured deconjugation rates of cSENP1 and cSENP2 over time for SUMO-modified RanGAP1, wild type and SIM mutant TDG. Our result supported a role for SIM binding in impeding deconjugation, and also revealed interesting and unique substrate specificities for both cSENP1 and cSENP2

The Effects of Game Players’ Social Intelligence on Social Support and Psychosocial Problem Factors in a 2-Wave Longitudinal Study

Although digital gaming may be considered a social medium, no prior study has investigated how young players’ social intelligence affects their psychosocial problems (aggression, depression, loneliness, and stress) and social functioning (relationships with parents and peers). The primary aim of this study was to investigate the relations between social intelligence and psychosocial outcomes. Using data from 1364 online game players in Korea, we conducted a 2-wave longitudinal study at 6-month intervals for tracking the same person. The findings indicated that level of social intelligence was negatively related with all measures of adverse emotions and positively related with relationships with parents and peers over time. The findings and implications are discussed