Uniform Silicon Isotope Ratios Across the Milky Way Galaxy

We report the relative abundances of the three stable isotopes of silicon, $^{28}$Si, $^{29}$Si and $^{30}$Si, across the Galaxy using the $v = 0, J = 1 \to 0$ transition of silicon monoxide. The chosen sources represent a range in Galactocentric radii ($R_{\rm GC}$) from 0 to 9.8 kpc. The high spectral resolution and sensitivity afforded by the GBT permit isotope ratios to be corrected for optical depths. The optical-depth-corrected data indicate that the secondary-to-primary silicon isotope ratios $^{29}{\rm Si}/^{28}{\rm Si}$ and $^{30}{\rm Si}/^{28}{\rm Si}$ vary much less than predicted on the basis of other stable isotope ratio gradients across the Galaxy. Indeed, there is no detectable variation in Si isotope ratios with $R_{\rm GC}$. This lack of an isotope ratio gradient stands in stark contrast to the monotonically decreasing trend with $R_{\rm GC}$ exhibited by published secondary-to-primary oxygen isotope ratios. These results, when considered in the context of the expectations for chemical evolution, suggest that the reported oxygen isotope ratio trends, and perhaps that for carbon as well, require further investigation. The methods developed in this study for SiO isotopologue ratio measurements are equally applicable to Galactic oxygen, carbon and nitrogen isotope ratio measurements, and should prove useful for future observations of these isotope systems.Comment: 18 pages, 12 figures, 2 tables. Published in The Astrophysical Journal, Volume 839, Issue

The Effects of Private Self-Consciousness and Perspective Taking on Satisfaction in Close Relationships.

131 heterosexual student couples, aged 17–32 yrs, 30 of whom were married or engaged answered questions concerning themselves and their relationships. It was predicted that individual differences in private self-consciousness would be positively related to relationship satisfaction because of the greater self-disclosure resulting from that heightened self-attention. It was further predicted that individual differences in perspective taking would foster relationship satisfaction, independent of any influence of self-disclosure. Both expectations were confirmed. Scores on the private self-consciousness scale were predictive of reported self-disclosure, and self-disclosure was predictive of satisfaction in the relationship. Once the influence of self-disclosure was removed, no effect of self-consciousness on satisfaction remained. In contrast, after disclosure was controlled, perspective-taking scores were significantly related to satisfaction and were in fact unrelated to disclosure at all. Findings indicate that 2 personality characteristics having to do with habitual attention to behavioral tendencies, emotions, and motivations significantly enhance the quality of close heterosexual relationships in different ways

Heterogeneity in 12^{12}CO/13^{13}CO Ratios Toward Solar-Type Young Stellar Objects

This study reports an unusual heterogeneity in [$^{12}$C$^{16}$O]/[$^{13}$C$^{16}$O] abundance ratios of carbon monoxide observed in the gas phase toward seven ~ solar-mass YSOs and three dense foreground clouds in the nearby star-forming regions, Ophiuchus, Corona Australis, Orion, Vela and an isolated core, L43. Robust isotope ratios were derived using infrared absorption spectroscopy of the 4.7 $\mu$m fundamental and 2.3 $\mu$m overtone rovibrational bands of CO at very high resolution ($\lambda$/$\Delta$$\lambda\approx 95,000$), observed with the CRIRES spectrograph on the Very Large Telescope. We find [$^{12}$C$^{16}$O]/[$^{13}$C$^{16}$O] values ranging from ~ 85 to 165, significantly higher than those of the local interstellar medium (~ 65 to 69). These observations are evidence for isotopic heterogeneity in carbon reservoirs in solar-type YSO environments, and encourage the need for refined Galactic chemical evolution models to explain the $^{12}$C/$^{13}$C discrepancy between the solar system and local ISM. The oxygen isotope ratios are consistent with isotopologue-specific photodissociation by CO self-shielding toward the disks, VV CrA N and HL Tau, further substantiating models predicting CO self-shielding on disk surfaces. However, we find that CO self-shielding is an unlikely general explanation for the high [$^{12}$C$^{16}$O]/[$^{13}$C$^{16}$O] ratios observed in this study. Comparison of the solid CO against gas-phase [$^{12}$C$^{16}$O]/[$^{13}$C$^{16}$O] suggests that interactions between CO ice and gas reservoirs need to be further investigated as at least a partial explanation for the unusually high [$^{12}$C$^{16}$O]/[$^{13}$C$^{16}$O] observed.Comment: 16 pages, 14 figures, 7 tables. Accepted for publication in The Astrophysical Journa

A Purdue Community Partner: The Hartford Hub of Lower Lincoln

The Hartford Hub is a community center located in downtown Lafayette. The Hub is a unique opportunity for community members and Purdue students to get involved locally. The Hartford Hub was created to support the Lafayette community members and help residents connect and build meaningful relationships. Faith Development Corporation created the Hub as well as the North End Community Center to create a space for residents to gather and use as they need. The Hartford Hub is located in the Lower Lincoln neighborhood, a high turnover neighborhood with mostly rental properties. The goal of the Hub was to unite the residents and hopefully enrich lives through supportive connection. Many services that the Hub offers include support for local children as well as older community members. The Hub houses the monthly neighborhood association meeting, where residents meet to discuss community issues. In addition, the Hub hosts weekly homework time where volunteers support the urban youth by helping them with homework, or other educational exercises. Beyond scheduled programming, the Hub is open for community members to use and features a basketball court and outdoor park. Purdue students can easily get involved at The Hartford Hub by taking specific honors course, or joining the Ware Research Group. They can also volunteer at the Hub as they are available. Homework time is the main way to help out, but there are other events such as block parties or social gathering where volunteers are needed. The Hub is always looking for new volunteers to interact with the community in many different ways. The Hub offers Purdue students a unique opportunity to impact the youth of Lafayette and interact with the local community

The Eccentric Kozai-Lidov Mechanism as the Cause of Exocomet Transits of KIC 8462852

KIC 8462852 is a star in the Kepler field that exhibits almost unique behaviour. The deep, irregular and aperiodic dips in its light curve have been interpreted as the breakup of a large exocomet on a highly eccentric orbit whose post-disruption material obscures the star. It is hypothesised that a nearby M-dwarf, recently confirmed to be bound to the system, could be exciting planetesimals in a source belt to high eccentricities if its orbit is highly misaligned with the belt: an effect known as the 'Eccentric Kozai-Lidov Mechanism'. To quantify how often this effect is expected to occur, this paper presents a Monte Carlo model of wide binary stars with embedded, misaligned planetesimal belts. These belts collisionally erode over time until they are excited to high eccentricities on secular timescales by a companion star if its orbit is sufficiently misaligned. The large planetesimals then produce an observable dimming signature in the light curve for a set period of time which may or may not overlap with similar events. The model finds that, for dimming events that persist for 100 yr, the most likely companion stars are located at $10^2 - 10^4$ au, the most likely belts are at $10^2-10^3$ au and the system age is most likely to be $10^2 - 10^3$ Myr. However, the probability of observing one or more stars exhibiting this phenomenon in the Kepler field is $1.3 \times 10^{-3}$, such that it is unlikely this mechanism is driving the observations of KIC 8462852.Comment: 23 pages, 24 figures and 2 tables. This is a pre-copyedited, author-produced PDF of an article accepted for publication in MNRAS following peer revie

Performance and loads data from a hover test of a 0.658-scale V-22 rotor and wing

A hover test of a 0.658-scale model of a V-22 rotor and wing was conducted at the Outdoor Aerodynamic Research Facility at Ames Research Center. The primary objectives of the test were to obtain accurate measurements of the hover performance of the rotor system, and to measure the aerodynamic interactions between the rotor and wing. Data were acquired for rotor tip Mach numbers ranging from 0.1 to 0.73. This report presents data on rotor performance, rotor-wake downwash velocities, rotor system loads, wing forces and moments, and wing surface pressures

From RNA-seq reads to differential expression results

Many methods and tools are available for preprocessing high-throughput RNA sequencing data and detecting differential expression

System Analysis Applied to Autonomy: Application to High-Altitude Long-Endurance Remotely Operated Aircraft

Maturation of intelligent systems technologies and their incorporation into aerial platforms are dictating the development of new analysis tools and incorporation of such tools into existing system analysis methodologies in order to fully capture the trade-offs of autonomy on vehicle and mission success. A first-order "system analysis of autonomy" methodology is outlined in this paper. Further, this analysis methodology is subsequently applied to notional high-altitude long-endurance (HALE) aerial vehicle missions