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"One of the Four": Anne Vallayer-Coster and the Social Implications of Still Life Painting
No full textResearch paper submitted to American University in partial fulfillment of the Degree of Master of Arts; approved as non-thesis optio
Leon Bakst's Set Design: Modern Classicism
No full textResearch paper submitted to American University in partial fulfillment of the Degree of Master of Arts; approved as non-thesis optio
Extent with modification: Leg patterning in the Beetle Tribolium castaneum and the evolution of serial homologs
No full textPublished in: G3: GENES, GENOMES, GENETICS February 1, 2012 vol. 2 no. 2 235-248.Serial homologs are similar structures that develop at different positions within a body plan. These structures share some, but not all, aspects of developmental patterning, and their evolution is thought to be constrained by shared, pleiotropic gene functions. Here we describe the functions of 17 developmental genes during metamorphic development of the legs in the red flour beetle, Tribolium castaneum. This study provides informative comparisons between appendage development in Drosophila melanogaster and T. castaneum, between embryonic and adult development in T. castaneum, and between the development of serially homologous appendages. The leg gap genes Distal-less and dachshund are conserved in function. Notch signaling, the zinc-finger transcription factors related to odd-skipped, and bric-à-brac have conserved functions in promoting joint development. homothorax knockdown alters the identity of proximal leg segments but does not reduce growth. Lim1 is required for intermediate leg development but not distal tarsus and pretarsus development as in D. melanogaster. Development of the tarsus requires decapentaplegic, rotund, spineless, abrupt, and bric-à-brac and the EGF ligand encoded by Keren. Metathoracic legs of T. castaneum have four tarsomeres, whereas other legs have five. Patterns of gene activity in the tarsus suggest that patterning in the middle of the tarsal region, not the proximal- or distal-most areas, is responsible for this difference in segment number. Through comparisons with other recent studies of T. castaneum appendage development, we test hypotheses for the modularity or interdependence of development during evolution of serial homologs
Scandinavian Women Artists in the Modern Era: High Art, Folk Art, and National Identity
No full textResearch paper submitted to American University in partial fulfillment of the Degree of Master of Arts; approved as non-thesis optio
Podcasting as public media: the future of U.S. news, public affairs and educational podcasts
No full textUptown /Downtown: The Ashcan School, John Sloan and the Image of Women in New York City
No full textResearch paper submitted to American University in partial fulfillment of the Degree of Master of Arts; approved as non-thesis optio
Size structure and geographic variation in chemical resistance of sea fan corals Gorgonia ventalina to a fungal pathogen
No full textPublished in: Mar. Ecol. Prog. Ser., 2002, Vol. 231, pp. 139-150.Despite the intense impact of diseases on tropical marine communities, little is known
about mechanisms of resistance to disease or the role of disease as a selective factor in these commu-
nities. Spatial variation in chemical resistance of Gorgonia ventalina (sea fan coral) to the fungus
Aspergillus sydowii was investigated by sampling G. ventalina populations in the Florida Keys, USA,
and San Salvador, Bahamas. A. sydowii is the causative agent in aspergillosis, a fungal disease
affecting G. ventalina throughout the Caribbean. Using field census and experimental inoculation,
this study examines if sea fan chemical extracts provide resistance to disease caused by A. sydowii
and the potential role of disease as a selective force in shaping the chemical defenses of sea fan
populations. Chemical resistance against A. sydowii was assessed with a fungal growth assay. Higher
anti-fungal activity of small versus large fans observed in field sampling and increased disease sever-
ity in mature versus young fans in inoculation studies support the hypothesis that resistance
decreases with increasing fan age. This result is also consistent with patterns predicted by the opti-
mal defense theory and growth-differentiation balance hypotheses in plant studies. Anti-fungal
activity of large sea fans increased upon inoculation, consistent with the hypothesis of inducible resis-
tance. Anti-fungal activity of sea fan extracts from the Florida Keys and Bahamas did vary signifi-
cantly with site and was negatively correlated with fan height and extract concentration (mg extract
per g dry coral weight). Anti-fungal activity did not correlate significantly with disease status in a
multiple regression model. The mean anti-fungal activity of sea fans varied significantly among
Florida Keys but not among San Salvador sites, nor between Florida Keys and San Salvador sites. Dis-
ease pressure was not correlated with anti-fungal activity across sites, as would be expected under a
simple resistance-selection model. A simple mean resistance-selection model may not be appropriate
in relatively open marine systems in which environmental induction may obscure natural selection.
However, the coefficient of variation in anti-fungal activity among sites is negatively correlated with
disease pressure, consistent with the hypothesis that A. sydowii imposes detectable directional selec-
tion and eliminates susceptible individuals from sites with high disease pressure
2010-14 A theory of unstructured bargaining using distribution-valued solution concepts
No full textDepartment of Economics, Working Paper Series, no. 2010-14. 22 pages.In experiments it is typically found that many joint utility outcomes arise in any given
unstructured bargaining game. This suggests using a positive unstructured bargaining
concept that maps a bargaining game to a probability distribution over outcomes rather
than to a single outcome. We show how to “translate” Nash’s bargaining axioms to
apply to such distributional bargaining concepts. We then prove that a subset of those
axioms forces the distribution over outcomes to be a power-law. Unlike Nash’s original
result, our result holds even if the feasible set is finite. When the feasible set is convex
and comprehensive, the mode of the power law distribution is the Harsanyi bargaining
solution, and if we require symmetry it is the Nash bargaining solution. However in general
these modes of the joint utility distribution are not Bayes-optimal predictions for the joint
uitlity, nor are the bargains corresponding to those outcomes the most likely bargains. We
then show how an external regulator can use distributional solution concepts to optimally
design an unstructured bargaining scenario. Throughout we demonstrate our analysis in
computational experiments involving flight rerouting negotiations in the National Airspace
System
The Eagle as a symbol of power and divinity in the New World: Some elements drawn from Colonial Mexico
No full textResearch paper submitted to American University in partial fulfillment of the Degree of Master of Arts; approved as non-thesis optio
