Runaway and walkaway stars from the ONC with Gaia DR2

Theory predicts that we should find fast, ejected (runaway) stars of all masses around dense, young star-forming regions. $N$-body simulations show that the number and distribution of these ejected stars could be used to constrain the initial spatial and kinematic substructure of the regions. We search for runaway and slower walkaway stars within 100 pc of the Orion Nebula Cluster (ONC) using $Gaia$ DR2 astrometry and photometry. We compare our findings to predictions for the number and velocity distributions of runaway stars from simulations that we run for 4 Myr with initial conditions tailored to the ONC. In $Gaia$ DR2, we find 31 runaway and 54 walkaway candidates based on proper motion, but not all of these are viable candidates in three dimensions. About 40 per cent are missing radial velocities, but we can trace back 9 3D-runaways and 24 3D-walkaways to the ONC, all of which are low/intermediate-mass (<8 M$_{\odot}$). Our simulations show that the number of runaways within 100 pc decreases the older a region is (as they quickly travel beyond this boundary), whereas the number of walkaways increases up to 3 Myr. We find fewer walkaways in $Gaia$ DR2 than the maximum suggested from our simulations, which may be due to observational incompleteness. However, the number of $Gaia$ DR2 runaways agrees with the number from our simulations during an age of $\sim$1.3-2.4 Myr, allowing us to confirm existing age estimates for the ONC (and potentially other star-forming regions) using runaway stars.Comment: 19 pages, 7 figures, accepted for publication in MNRA

Trophic Transfer of Arsenic from an Aquatic Insect to Terrestrial Insect Predators.

The movement of energy and nutrients from aquatic to terrestrial ecosystems can be substantial, and emergent aquatic insects can serve as biovectors not only for nutrients, but also for contaminants present in the aquatic environment. The terrestrial predators Tenodera aridifolia sinensis (Mantodea: Mantidae) and Tidarren haemorrhoidale (Araneae: Theridiidae) and the aquatic predator Buenoa scimitra (Hemiptera: Notonectidae) were chosen to evaluate the efficacy of arsenic transfer between aquatic and terrestrial environments. Culex tarsalis larvae were reared in either control water or water containing 1000 µg l(-1) arsenic. Adults that emerged from the control and arsenic treatments were fed to the terrestrial predators, and fourth instar larvae were fed to the aquatic predator reared in control or arsenic contaminated water. Tenodera a. sinensis fed arsenic-treated Cx. tarsalis accumulated 658±130 ng g(-1) of arsenic. There was no significant difference between control and arsenic-fed T. haemorrhoidale (range 142-290 ng g(-1)). Buenoa scimitra accumulated 5120±406 ng g(-1) of arsenic when exposed to arsenic-fed Cx. tarsalis and reared in water containing 1000 µg l(-1) arsenic. There was no significant difference between controls or arsenic-fed B. scimitra that were not exposed to water-borne arsenic, indicating that for this species environmental exposure was more important in accumulation than strictly dietary arsenic. These results indicate that transfer to terrestrial predators may play an important role in arsenic cycling, which would be particularly true during periods of mass emergence of potential insect biovectors. Trophic transfer within the aquatic environment may still occur with secondary predation, or in predators with different feeding strategies

Isotopic enrichment of planetary systems from Asymptotic Giant Branch stars

Short-lived radioisotopes, in particular 26-Al and 60-Fe, are thought to contribute to the internal heating of the Earth, but are significantly more abundant in the Solar System compared to the Interstellar Medium. The presence of their decay products in the oldest Solar System objects argues for their inclusion in the Sun's protoplanetary disc almost immediately after the star formation event that formed the Sun. Various scenarios have been proposed for their delivery to the Solar System, usually involving one or more core-collapse supernovae of massive stars. An alternative scenario involves the young Sun encountering an evolved Asymptotic Giant Branch (AGB) star. AGBs were previously discounted as a viable enrichment scenario for the Solar System due to the presumed low probability of an encounter between an old, evolved star and a young pre-main sequence star. We report the discovery in Gaia data of an interloping AGB star in the star-forming region NGC2264, demonstrating that old, evolved stars can encounter young forming planetary systems. We use simulations to calculate the yields of 26-Al and 60-Fe from AGBs and their contribution to the long-term geophysical heating of a planet, and find that these are comfortably within the range previously calculated for the Solar System.Comment: 8 pages, 4 figures, accepted for publication in ApJ

The Influence of Exercise Empowerment on Life Stress

Background: Psychological stress – when an individual perceives that the environment exceeds their ability to meet the demands placed on them - is common in college students and exercise, and specifically instructional physical activity courses, is frequently cited as a one method of stress reduction. Objective: Determine any relationship between exercise empowerment and perceived life stress for those participating in instructional physical activity courses (IPAC). Methods: All undergraduate students (n = 3388) enrolled in IPAC in 15-week IPAC at a large university were surveyed on perceived life stress (PSS), empowerment in exercise (EES), and specific demographic variables. Results: 944 of 3388 enrolled students (Nov. 2015, April 2016) completed the survey. The data revealed GPA (p \u3c 0.002), sex (p \u3c 0.000), and EES (p \u3c 0.001) showed differences for PSS. It was determined that EES, sex, and GPA predicted PSS differently for students according to their year in college. Conclusions: For freshman and seniors, sex and lower GPA were a stronger predictor of PSS with no mitigating effect of exercise empowerment. For sophomores and juniors the level of life stress was lower at higher levels of exercise empowerment. These findings support a complex relationship between exercise empowerment and life stress. While exercise is cited as a method for stress reduction the relationship between exercise empowerment and life stress for college-aged students is not as straightforward as it may seem

Development and characterization of bispecific proteins for targeted drug and gene delivery systems

Active targeting, based on antibodies and molecules that direct effector molecules and carriers to specific cells and tissues, have been extensively investigated in various therapeutic applications including cancer and gene therapy. Indeed, antibodies or antibody fragments are often covalently coupled onto the surface of nanoparticles or viral vectors. However, their conjugation frequently results in premature clearance of the drug and gene carriers as well as reduced vector titers and stability, thereby greatly limiting efficacy. To address these challenges, I explored the use of bispecific fusion proteins (BFP) and bispecific antibodies (bsAb) to enhance cell-specific delivery of drug and gene carriers to tumor cells in vitro and in vivo. In this dissertation, I first explored a two-step targeting approach termed pretargeting that decouples targeting specificity from carrier circulation kinetics and stability. Specifically, pretargeting relies on bsAb or BFP that can bind both selected epitopes on target cells and subsequently administered effector molecules (ie. nanoparticles and lentiviruses). I utilized quantitative approaches and systematic analyses to (1) evaluate interactions between pretargeting BFP and nanoparticles on the cell surface that maximizes internalization of nanoparticles into target cells, and (2) determine the bsAb format that enhances tumor accumulation of pretargeted PEGylated nanoparticles. I also investigated (3) the use of bsAb coupled with engineered lentiviral vectors for efficient targeted gene delivery capable of facilitating long-term gene integration of the therapeutic genes of interest. My results indicated that density of BFP on the cell surface can effectively limit internalization of pretargeted nanoparticles, underscoring the need to carefully tune BFP dosing for intracellular delivery. I also found that multivalency and elimination of FcRn recycling are both critical in maximizing pretargeting efficiency of PEGylated nanoparticles. Finally, I showed that the specificity of targeted viral gene delivery was enhanced by decreasing binding to off-target cells and coupling the lentiviral vectors with bsAb for selective targeting. The methodologies and overall findings described here inform future studies of antibody-cell receptor interactions and effective nanoparticle and viral vector targeting strategies.Doctor of Philosoph

A Thematic Analysis of Study Abroad Programs in Community College Institutions in the U.S.

The following study focuses on community colleges and the textual website materials they present regarding study abroad programs in order to illuminate the congruence between the overall community college mission of accessibility and the information presented on their study abroad websites. The text was evaluated by utilizing a thematic analysis coupled with multiple case studies and then further examined through the theoretical lenses of academic capitalism, institutional isomorphism, and universalism. The analysis of the text indicated that institutions are offering these programs for a combination of reasons, including institutional legitimacy, institutional revenue, and attempted student accessibility. The most significant deduction made from analysis was the lack of congruence between the overall community college mission of accessibility and information institutions present on their study abroad websites as it relates to scholarships, financial aid, diversity, and inclusion. These findings provide significant implication for further studies regarding how community colleges can seek to increase accessibility for students to study abroad programs as related to diversity and inclusion

Undergraduate Research Journal, Volume 14

Table of Contents: The Myth of Chechen Radical Islam / by Jonathan Parker (p.1-8) -- Genre and the Perception of Massacre... / by Lauren Ferguson (p.9-18) -- Sentinel of Liberty: Captain America on the Home Front in WWII / by Carolyn McNamara (p.19-34) -- Embracing Myth in Mrs. Dalloway / by Aza Pace (p.35-48) -- Cannibalism and Witchcraft in The Tempest / by Kenneth F. Harlock (p.49-62) -- Evolutionary Game Models of Optimal Nuclear Weapons Strategies / by Christina Kent (p.63-82) -- Optimization for a Bio-Impedance Measurement System / by Matthew Normayle (p.83-94)Senate of College Council

Dark Borders: Film Noir and American Citizenship, by Jonathan Auerbach

Over the past few decades, many scholars of film noir have displayed a certain repetition compulsion, often proclaiming as their starting standpoint the very incongruity of defining film noir as a genre because of its resistance to being labelled as such. Part of this identity crisis in noir studies has roots in the origins of the term “noir”, a label that was retroactively applied by French critic Nino Frank in 1946 to a cycle of North American films that bore a striking resemblance to the série noire, a collection of hard-boiled detective thrillers published in France and authored by pulp writers like Dashiell Hammett and Raymond Chandler (Silver and Ursini 83)