Multi-Wavelength Properties of Barred Galaxies in the Local Universe. I: Virgo Cluster

We study in detail how the barred galaxy fraction varies as a function of luminosity, HI gas mass, morphology and color in the Virgo cluster in order to provide a well defined, statistically robust measurement of the bar fraction in the local universe spanning a wide range in luminosity (factor of ~100) and HI gas mass. We combine multiple public data-sets (UKIDSS near-infrared imaging, ALFALFA HI gas masses, GOLDMine photometry). After excluding highly inclined systems, we define three samples where galaxies are selected by their B-band luminosity, H-band luminosity, and HI gas mass. We visually assign bars using the high resolution H-band imaging from UKIDSS. When all morphologies are included, the barred fraction is ~17-24% while for morphologically selected discs, we find that the barred fraction in Virgo is ~29-34%: it does not depend strongly on how the sample is defined and does not show variations with luminosity or HI gas mass. The barred fraction depends most strongly on the morphological composition of the sample: when the disc populations are separated into lenticulars (S0--S0/a), early-type spirals (Sa--Sb), and late-type spirals (Sbc--Sm), we find that the early-type spirals have a higher barred fraction (~45-50%) compared to the lenticulars and late-type spirals (~22-36%). This difference may be due to the higher baryon fraction of early-type discs which makes them more susceptible to bar instabilities. We do not find any evidence of barred galaxies being preferentially blue.Comment: 13 pages, 14 figures. Submitted to Ap

Phase diagram of two dimensional electron gas in a perpendicular magnetic field around Landau level filling factors \nu=1 and \nu=3

The measured melting curve $T_{m}(\nu)$ between the crystal and liquid phases is analyzed using thermodynamics to extract the change of magnetization $\Delta M$ as a function of the Landau level filling factor \ $\nu,$ near $\nu=1$. \ An explanation of $\Delta M$($\nu)$ is proposed \ in terms of Skyrmions. \ Near $\nu=3$, a Wigner crystal is the most probable solid phase, experiments excluding Skyrmions.Comment: 5 pages, 4 figure

Temperature influence on the carbon isotopic composition of Orbulina universa and Globigerina bulloides (planktonic foraminifera)

Laboratory experiments with the planktonic foraminifera Orbulina universa (symbiotic) and Globigerina bulloides (nonsymbiotic) were used to examine the effects of temperature, irradiance (symbiont photosynthesis), [CO32-], [HPO42-], and ontogeny on shell d13C values. In ambient seawater ([CO32-] = 171 mmol kg-1), the d13C of O. universa shells grown under low light (LL) levels is insensitive to temperature and records the d13C value of seawater TCO2. In contrast, the d13C of high light (HL) shells increases ~0.4‰ across 15-25°C (+0.050‰/°C). This suggests that the d13C enrichment due to symbiont photosynthetic activity is temperature-dependent. A comparison of HL O. universa grown in elevated [CO32-] seawater with ambient specimens shows that temperature does not affect the slope of the d13C/[CO32-] relationship previously described [Spero et al., 1997]. The d13C of G. bulloides shells decreases across the 15-24°C temperature range and d13C:temperature slopes decrease with increasing shell size (-0.13, -0.10, and -0.09‰/°C in 11- 12-, and 13-chambered shells, respectively). The pattern of lower d13C values at higher temperatures likely results from the incorporation of more respired CO2 into the shell at higher metabolic rates. The d13C of HL O. universa increases with increased seawater [HPO42-]

Essays in Corporate Finance

This dissertation consists of three chapters in corporate finance and private equity. Chapter 1, “Incentives of Private Equity General Partners from Future Fundraising”, co-authored with Ji-Woong Chung, Berk Sensoy and Michael Weisbach, studies the incentives of private equity general partners (GPs). Lifetime incomes of GPs are affected by their current funds’ performance not only directly, through carried interest profit-sharing provisions, but also indirectly by the effect of the current fund’s performance on GP’s abilities to raise capital for future funds. In the context of a rational learning model, which we show better matches the empirical relations between future fundraising and current performance than behavioral alternatives, we estimate that indirect pay for performance from future fundraising is of the same order of magnitude as direct pay for performance from carried interest. Consistent with the learning framework, indirect pay for performance is stronger when managerial abilities are more scalable and weaker when current performance is less informative about ability. Specifically, it is stronger for buyout funds than for venture capital funds, and declines in the sequence of a partnership’s funds. Total pay for performance in private equity is both considerably larger and much more heterogeneous than implied by the carried interest alone. Our framework can be adapted to estimate indirect pay for performance in other asset management settings. Uncertainty is ubiquitous in financial markets, and market participants form expectations and learn about parameters, which may be the ability of general partners or the quality of a firm’s governance structure. Assessing the quality of a firm\u27s governance is valuable, which might explain the recent growth of the governance industry. Yet, governance indices have been criticized by researchers and practitioners alike, mainly on the grounds of overlooking firms\u27 heterogeneity and their specific governance needs. Chapter 2, “D&O Insurance and IPO Performance: what can we learn from insurers?”, co-authored with Martin Boyer, provides new insights into the ability of directors’ and officers’ (D&O) insurers to price risk, and in particular risk related to governance characteristics. Therefore, learning by investors about governance quality could be facilitated by providing investors with a market-based assessment of governance as reflected in the D&O insurance premium. We investigate whether a firm’s D&O liability insurance contract at the time of the IPO is related to insured firms’ first year post-IPO performance. We find that insurers charge a higher premium per dollar of coverage to protect the directors and officers of firms that will subsequently have poor first year post-IPO stock performance. A higher price of coverage is also associated with a higher post-IPO volatility and lower Sharpe ratio. Our results are robust to various econometric specifications and suggest that even when the high level of information asymmetry inherent to the IPO context prevails, insurers have information about the firms’ prospects that should be valuable to outside investors. In Chapter 3, “A Learning-Based Approach to Evaluating Boards of Directors”, I develop a general framework based on a theoretical model of learning to assess how investors react to the appointment of new directors. Using predictions from a learning model, this chapter exploits the cross-sectional variation in the learning-induced decline in stock return volatility over director tenure to infer the marginal value of different kinds of directors. This new framework confirms prior empirical findings and documents new results. For example, directors joining better compensated boards have higher marginal value while the marginal value of a director joining an entrenched board is muted. Furthermore, the estimates imply that governance related uncertainty associated with the arrival of a new director accounts for 7% of return volatility, shedding light on the extent to which governance matters

A History of The Bracero Program as an Agent of Transnational Modernity in the 20th Century

The Bracero Program was an agreement devised between Mexico and the United States which provided a state-sanctioned avenue for Mexican men to work as contract laborers in the United States. It was originally intended to alleviate the World War II labor shortage in the United States, but would continue past the war until 1964. Its longevity was due to the central role it played in bringing Mexico and the United States into a modern, transnational relationship. I aim to examine the relationship between the two nations in two contexts: an historical-economic one, and an ethnographic one. These lenses are two sides of the same coin, in that they are both ways of viewing the change that modernity and transnationalism brought to Mexico and America. Keywords: Bracero Program, World War II, Mexican Immigration, Mexico-US Relations, American Labor Politics Part of the panel: Hidden Histories during WWIIModerator: Professor Richard Beyle

Fuzzy logic control for camera tracking system

A concept utilizing fuzzy theory has been developed for a camera tracking system to provide support for proximity operations and traffic management around the Space Station Freedom. Fuzzy sets and fuzzy logic based reasoning are used in a control system which utilizes images from a camera and generates required pan and tilt commands to track and maintain a moving target in the camera's field of view. This control system can be implemented on a fuzzy chip to provide an intelligent sensor for autonomous operations. Capabilities of the control system can be expanded to include approach, handover to other sensors, caution and warning messages

Mentoring trainee psychologists: learning from lived experience

Purpose – To examine service-users’ experiences of mentoring trainee clinical psychologists as part of an involvement initiative on a doctoral training course. Methodology – Seven service-users were paired with trainee clinical psychologists. Pairs met for one hour monthly over 6 months. Meetings were unstructured, lacked a formal agenda and were not evaluated academically. All seven mentors were interviewed. They were asked about positive and negative experiences, as well as about the support provided. Transcripts were subject to thematic analysis and themes were reviewed by mentors in a follow-up meeting. Findings - Overall, results demonstrate that service-users can be involved in training in a way that they find meaningful and contributes to their recovery. Seven themes were identified: Giving hope and optimism; making a difference; personal and professional development; the process; practicalities/ logistics; support (positives); support (areas for improvement). Practical implications – The importance of designing involvement initiatives in a way which implicitly supports service-user values was highlighted. Recommendations for designing effective support structures are given. Authors were also involved in the scheme which could have introduced bias. Originality/value – Research exploring service-users’ experiences of involvement in training health professionals is limited. This was the first study to explore in depth service users’ perspectives of involvement in a scheme such as the Mentoring Scheme. If initiatives are to seriously embrace the values of the service-user movement then seeking service-users’ perspectives is vital. Paper type: Research Pape

A Matter of Perspective: How Experience Shapes Preferences for Redistribution

We investigate in a laboratory experiment if the experience of economic failure or success shapes people’s preferences for redistribution beyond self-interest. Subjects generated a high or a low income either through a lottery or through an effort-based tournament. A sub-set of subjects could then redistribute the income of another sub-set of subjects. We find that individuals who lost the tournament (lottery) redistribute significantly more than all the other types of distributors when the inequality is generated by the tournament (lottery). The effect still holds when controlling for self-selection into different outcomes of the tournament and can be explained by in- or out-group bias and a self-serving bias in responsibility attribution. These findings have implications for public policies and for the design of compensation schemes in organizations