How to Track Protists in Three Dimensions

We present an apparatus optimized for tracking swimming microorganisms in the size range 10-1000 microns, in three dimensions (3D), far from surfaces, and with negligible background convective fluid motion. CCD cameras attached to two long working distance microscopes synchronously image the sample from two perpendicular directions, with narrowband dark-field or bright-field illumination chosen to avoid triggering a phototactic response. The images from the two cameras can be combined to yield 3D tracks of the organism. Using additional, highly directional broad-spectrum illumination with millisecond timing control the phototactic trajectories in 3D of organisms ranging from Chlamydomonas to Volvox can be studied in detail. Surface-mediated hydrodynamic interactions can also be investigated without convective interference. Minimal modifications to the apparatus allow for studies of chemotaxis and other taxes.Comment: 8 pages, 7 figure

Decomposing the Great Trade Collapse: Products, Prices, and Quantities in the 2008-2009 Crisis

We identify a new set of stylized facts on the 2008-2009 trade collapse that we hope can be used to shed light on the importance of demand and supply-side factors in explaining the fall in trade. In particular, we decompose the fall in international trade into product entry and exit, price changes, and quantity changes for imports by Brazil, the European Union, Indonesia, and the United States. When we aggregate across all products, most of the countries analyzed experienced a decline in new products, a rise in product exit, and falls in quantity for product lines that continued to be traded. The evidence suggests that the intensive rather than extensive margin mattered the most, consistent with studies of other countries and previous recessionary periods. On average, quantities declined and prices fell. However, these average effects mask enormous differences across different products. Price declines were driven primarily by commodities. Within manufacturing, while most quantity changes were negative, in most cases price changes moved in the opposite direction. Consequently, within manufacturing, there is some evidence consistent with the hypothesis that supply side frictions played a role. For the United States, price increases were most significant in sectors which are typically credit constrained

Temporally disordered Ising models

We present a study of the influence of different types of disorder on systems in the Ising universality class by employing both a dynamical field theory approach and extensive Monte Carlo simulations. We reproduce some well known results for the case of quenched disorder (random temperature and random field), and analyze the effect of four different types of time-dependent disorder scarcely studied so far in the literature. Some of them are of obvious experimental and theoretical relevance (as for example, globally fluctuating temperatures or random fields). All the predictions coming from our field theoretical analysis are fully confirmed by extensive simulations in two and three dimensions, and novel qualitatively different, non-Ising transitions are reported. Possible experimental setups designed to explore the described phenomenologies are also briefly discussed.Comment: Submitted to Phys. Rev. E. Rapid Comm. 4 page

Early Ballet in the United States: The Importance of Florence Rogge, Choreographer

Radio City Music Hall, the first building completed in the complex known as Rockefeller City, premiered its inaugural performance on December 27, 1932. The initial vision of John D. Rockefeller, Jr. was to build the Hall into a center that showcased the accomplishments of American innovation through advanced engineering, art, and culture. The Hall represented newness. During the worst years of the Great Depression, newness represented optimism and hope for a better economic future for the country. An integral component included in all stage shows at the Music Hall was the Radio City Music Hall Ballet Company. Florence Rogge, the Artistic Director and Choreographer of the company, presented innovation that served to further propel Rockefeller\u27s initial vision by uplifting the people through fantasy, performing arts, and entertainment. Ballet also represented newness in the United States. Rogge successfully introduced and shaped a new aesthetic of ballet for American audiences, who were unfamiliar with ballet. The focus of this thesis is to examine the progression of early ballet in the United States. In order to understand the importance of Florence Rogge\u27s contributions to ballet, an analysis includes archival research and the oral histories of five members of the Radio City Music Hall Ballet Company from 1944-1958

Selection strategies for marker-assisted background selection with chromosome-wise SSR multiplexes in pseudo-backcross programs for grapevine breeding

Organizing SSR markers located on one chromosome into PCR multiplexes has the potential to reduce the costs of marker analysis. The optimal selection strategies for such chromosome-wise multiplexes have not yet been investigated. We investigated with computer simulations three different selection strategies for gene introgression with a pseudo-backcross scheme and a marker density of one marker every 10 cM. Selecting individuals with the highest number of chromosomes carrying V. vinifera alleles at all background marker loci reduced the number of required multiplexes by 7.24-7.87 % in generations pBC4-pBC6 for population sizes nt = 150-300 individuals per pseudo-backcross generation.

The Role of Bacteria and Pattern Recognition Receptors in GvHD

Graft-versus-Host Disease (GvHD) is the most serious complication of allogeneic stem cell transplantation (SCT) and results from an activation of donor lymphocytes by recipient antigen-presenting cells (APCs). For a long time, it has been postulated that the intestinal microflora and endotoxin exert a crucial step in this APC activation, as there is early and severe gastrointestinal damage induced by pretransplant conditioning. With the detailed description of pathogen-associated molecular patterns and pathogen recognition receptors single nucleotide polymorphisms of TLRs and especially NOD2 have been identified as potential risk factors of GvHD and transplant related complications thus further supporting the crucial role of innate immunity in SCT, related complications. Gastrointestinal decontamination and neutralization of endotoxin have been used to interfere with this early axis of activation with some success but more specific approaches of modulation of innate immunity are needed for further improvement of clinical outcome

Communication and Group Perception: Extending the `Saying is Believing' Effect

The saying-is-believing (SIB) effect occurs when tailoring a message to suit an audience influences a communicator's subsequent memories and impressions about the communication topic. Previous studies were restricted to one-person audiences and individuals as the communication topic. The present studies explored the SIB effect with multiple-person audiences and groups as the communication topic. In Study 1, the SIB effect occurred with a 1-person, but not a 3-person, audience. In Study 2, the SIB effect occurred with a 3-person audience when the audience explicitly validated communicators' messages. These findings demonstrate the generalizability of the SIB effect to group contexts, provide further evidence for a shared reality interpretation of this effect, and suggest a potentially important mechanism underlying stereotype development

Moduli spaces of toric manifolds

We construct a distance on the moduli space of symplectic toric manifolds of dimension four. Then we study some basic topological properties of this space, in particular, path-connectedness, compactness, and completeness. The construction of the distance is related to the Duistermaat-Heckman measure and the Hausdorff metric. While the moduli space, its topology and metric, may be constructed in any dimension, the tools we use in the proofs are four-dimensional, and hence so is our main result.Comment: To appear in Geometriae Dedicata, minor changes to previous version, 19 pages, 6 figure