Rank differences for overpartitions

In 1954, Atkin and Swinnerton-Dyer proved Dyson's conjectures on the rank of a partition by establishing formulas for the generating functions for rank differences in arithmetic progressions. In this paper, we prove formulas for the generating functions for rank differences for overpartitions. These are in terms of modular functions and generalized Lambert series.Comment: 17 pages, final version, accepted for publication in the Quarterly Journal of Mathematic

Empirical essays on finance and development

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2009.Cataloged from PDF version of thesis.Includes bibliographical references.The central focus of this dissertation is the role of financial instruments, in particular insurance and credit, in economic development. Motivated by the observation that exposure to the risk of extreme weather conditions may constrain investment by subsistence farmers and lead to inefficient production choices, the first chapter evaluates whether insuring farmers against such risks alters resource allocation decisions. In particular I consider the effects of a Mexican government disaster relief program with insurance-like features. The results, based on a regression discontinuity design, indicate that insurance against losses arising from natural disasters changes how rural households invest in their farms. Insured farmers utilize more expensive capital inputs and adopt different technologies. Additionally, the insurance changes labor supply patterns. Notably, members of insured households are approximately 10% more likely to migrate internationally. Additional results, that the program matters most when the returns to migration are more unpredictable, are consistent with a model where insurance obviates the need for precautionary savings, allowing households to finance international migration. Turning from insurance to the role of access to credit in furthering development, the second chapter considers how interest rate ceilings affected investment in agricultural capital and the tenure status of farms in the nineteenth century United States. Using within state variation in usury laws, I find that more restrictive laws lead to an economically meaningful reduction in agricultural investment.(cont.) Additionally, the results pertaining to the tenure status of farms indicate that exacting usury laws reduce the share of owner-operated farms. This effect is especially pronounced for small farms, which is consistent with the notion that interest rate limits ration small-scale, risky farmers out of the credit market. To overcome the issue of omitted factors which may affect both legislation and agricultural outcomes, I employ an instrumental variables strategy. By isolating variation in usury laws associated with the historical presence of religious bodies, this study provides evidence of a causal channel from more permissive interest rate ceilings to greater agricultural investment and a more egalitarian ownership structure of agricultural land. The third chapter departs from the more narrow focus on the provision of financial services and addresses a question of relevance to development economics in general. In particular, this chapter, which is joint work with Abhijit Banerjee, Esther Duflo and Raghabendra Chattopadhyay, evaluates how well various systems for identifying and targeting assistance to the poorest of the poor actually identify the poorest. Firstly, we consider the methods used to identify households eligible for participation in assistance programs administered by the Indian government. Secondly, we evaluate Participatory Rural Appraisals (PRAs) as a mechanism to identify exceptionally poor households. Finally, we investigate whether additional verification of information gathered in PRAs improves targeting.(cont.) For each method of targeting, we examine whether the households identified by that process are more disadvantaged according to several measures of economic well-being than households which were not identified. We conclude that PRAs and PRAs coupled with additional verification successfully identify a population which is measurably poorer in various respects, especially those which are more readily observed. The standard government procedures, however, do not appear to target the very poorest for assistance. Based on this sample, households targeted for government assistance are observationally equivalent to those that are not.by Jeremy Place Shapiro.Ph.D

Can Tetrahymena thermophila help us better understand the activity of proto-oncogenes and their associated gene regulation?

Nearly all of us have been affected by cancer, a deadly disease that has its roots in mitotic dysregulation. Proto-oncogenes, or regulated growth genes, are present in all eukaryotic cells. In many tumors, the regulatory elements that allow for homeostatic growth have been silenced or lost to mutations, resulting in pathological overgrowth of cells. Tetrahymena thermophila are free-living eukaryotic unicellular organisms that generally reproduce asexually via mitosis. Our previous studies have shown that these organisms appear to express homologues of the proto-oncogene, Ras, and its signaling partner, Raf. The Ras/Raf uncoupler BAY-293 reduces mitotic signaling in this organism, apparently by decreasing gene expression as indicated by the increased level of histone acetylation seen with drug treatment. Another proto-oncogene involved in vertebrate mitotic signaling is the tyrosine phosphatase SHP2, encoded by the gene PTPN11. This protein is instrumental in recruiting a number of pathways involved in mitosis and differentiation, including the Ras/Raf pathway. BLAST searches of the Tetrahymena Genome Database using the SHP2 sequence indicate a high likelihood that Tetrahymena have a SHP2 homolog, making this an intriguing target for drug study. We hypothesized that inhibiting SHP2 would reduce mitosis in Tetrahymena; however, the SHP2 inhibitor PHPS significantly increased cell division in this organism while decreasing histone acetylation. PHPS increased levels of tyrosine phosphorylation and nucleolar activity in Tetrahymena; the distribution of phosphorylation throughout the cell was also affected. In summary, we see that while the Ras homolog in Tetrahymena affects mitosis in a manner that is similar to vertebrates, the SHP2 homolog does not. Therefore, Tetrahymena would be a useful model system in which to study drugs that affect the Ras/Raf portion of growth factor signaling

Student Recital (April 26, 2012)

Adagio and Allegro, Op. 70 / Robert Schumann Susan Blazejewski, viola Prelude in C minor, BWV 847 / Johann Sebastian Bach Important Event, Op. 15, No. 6 / Robert Schumann Carl Hollant, piano Sonatina for Trombone and Piano / Bryan Kelly Agitato Daniel Hatchfield, trombone Carl Hollant, piano Suite No. 1 in E minor, BWV 996 / J. S. Bach Prelude Jeremy Place, guitar Sonata in a minor, BWV 1013 / J. S. Bach Allemande Amethyst Lambert, flute Pie Jesu from Requiem in D minor, Op. 48 / Gabriel Fauré Mi Choe, soprano Sonata No. 3, Op. 1, No. 12, HWV 370 / George Frideric Handel arr. Sigurd Rascher Adagio Allegro Mackenzie Leahy, alto saxophone Fantasia / Sylvius Leopold Weiss Nicholas Rice, guitarhttps://vc.bridgew.edu/student_concerts/1020/thumbnail.jp

Student Recital (December 12, 2012)

What Good Would the Moon Be / Kurt Weill Jordan Ennis, soprano Concerto / Nikolai Rimsky-Korsakov Andante Cantabile Sage Lewis, trombone Du bist wie eine Blume, Op. 25, No. 24 / Robert Schumann Long Time Ago / Aaron Copland Richard Moran, tenor Estudios Sencillos / Leo Brouwer Five Studies / Fredric Hand Nolan Driscoll, guitar Study No. 7 in A minor / Matteo Carcassi Jeremy Place, guitar Concerto no. 3 in G, K. 216 / Wolfgang Amadeus Mozart Allegro Carla Mason, violin Etude No. 14 in D Major / M. Carcassi Etude No. 1 in E minor / Heitor Villa-Lobos James Davidson, guitar Prelude No. 4 / H. Villa-Lobos Mark Gavin, guitar Bois Epais / Jean-Baptiste Lully The Call / Ralph Vaughan Williams Justine Smigel, mezzo-soprano Allegro, Op. 20 / Joseph Hector Fiocco Gail Colombo, violin Improvisation II et III pour Saxophone Alto Seul / Ryo Noda III Chelsea Fisk, alto saxophonehttps://vc.bridgew.edu/student_concerts/1034/thumbnail.jp

Acute RyR1 Ca2+ leak enhances NADH-linked mitochondrial respiratory capacity

Sustained ryanodine receptor (RyR) Ca2+ leak is associated with pathological conditions such as heart failure or skeletal muscle weakness. We report that a single session of sprint interval training (SIT), but not of moderate intensity continuous training (MICT), triggers RyR1 protein oxidation and nitrosylation leading to calstabin1 dissociation in healthy human muscle and in in vitro SIT models (simulated SIT or S-SIT). This is accompanied by decreased sarcoplasmic reticulum Ca2+ content, increased levels of mitochondrial oxidative phosphorylation proteins, supercomplex formation and enhanced NADH-linked mitochondrial respiratory capacity. Mechanistically, (S-)SIT increases mitochondrial Ca2+ uptake in mouse myotubes and muscle fibres, and decreases pyruvate dehydrogenase phosphorylation in human muscle and mouse myotubes. Countering Ca2+ leak or preventing mitochondrial Ca2+ uptake blunts S-SIT-induced adaptations, a result supported by proteomic analyses. Here we show that triggering acute transient Ca2+ leak through RyR1 in healthy muscle may contribute to the multiple health promoting benefits of exercise

The Public Repository of Xenografts enables discovery and randomized phase II-like trials in mice

More than 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publicly available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment, called the Public Repository of Xenografts (PRoXe). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional, and proteomic biomarkers in both treatment-naive and relapsed/refractory disease

Student Recital: Jeremy Place (April 23, 2015)

Now, O now I needs must part / John Dowland Go crystal tears A shepherd in a shade Piano Sonata no. 11 in A Major, K. 331 / Wolfgang Amadeus Mozart Rondo alla Turca (arr. Four Bridges) Jeremy Place, mandolin Greg Ferreira, guitar Ben Marshall, banjo Russell Hermansen, bass Mountain Songs / Robert Beaser Barbara Allen Brian Strange, dobro The House Carpenter Greg Ferreira, mandolin Fair and Tender Ladies Angela Maloney, soprano Cindy Terry Doyon, flutehttps://vc.bridgew.edu/student_concerts/1086/thumbnail.jp

Student Guitar Recital (March 21, 2014)

Fantasy No. 7 / John Dowland Jeremy Place Homenaje (Pour le tombeau de Claude Debussy) / Manuel de Falla Estudio brillante de Alard / Francisco Tárrega Mark Gavin Cello Suite No. 3 in C Major, BWV 1009 / Johann Sebastian Bach Prelude Allamande Bourée Jeremy Place El Decameron Negro / Leo Brouwer El arpa de guerrero La huida de los amantes pour el valle de los ecos Mark Gavin Sonata in A Major / Frederico Moreno-Torroba Allegretto Andante Allegro Jeremy Place Douze etudes / Heitor Villa-Lobos Lent-Poco meno-Animé Animé-Più mosso-a tempo primo-Un peu plus animé Mark Gavinhttps://vc.bridgew.edu/student_concerts/1059/thumbnail.jp

Student Recital: Tim Prosser, Jeremy Place, Eric George (December 5, 2013)

Lute Suite in E minor, BWV 996 / Johann Sebastian Bach Prelude and Fugue Tim Prosser, guitar Fantasy No. 7 / John Dowland Jeremy Place, guitar No. 6 / Fred Albright Eric George, snare drumhttps://vc.bridgew.edu/student_concerts/1051/thumbnail.jp