Dynamics of Delta/Notch signaling on endomesoderm segregation in the sea urchin embryo.

Endomesoderm is the common progenitor of endoderm and mesoderm early in the development of many animals. In the sea urchin embryo, the Delta/Notch pathway is necessary for the diversification of this tissue, as are two early transcription factors, Gcm and FoxA, which are expressed in mesoderm and endoderm, respectively. Here, we provide a detailed lineage analysis of the cleavages leading to endomesoderm segregation, and examine the expression patterns and the regulatory relationships of three known regulators of this cell fate dichotomy in the context of the lineages. We observed that endomesoderm segregation first occurs at hatched blastula stage. Prior to this stage, Gcm and FoxA are co-expressed in the same cells, whereas at hatching these genes are detected in two distinct cell populations. Gcm remains expressed in the most vegetal endomesoderm descendant cells, while FoxA is downregulated in those cells and activated in the above neighboring cells. Initially, Delta is expressed exclusively in the micromeres, where it is necessary for the most vegetal endomesoderm cell descendants to express Gcm and become mesoderm. Our experiments show a requirement for a continuous Delta input for more than two cleavages (or about 2.5 hours) before Gcm expression continues in those cells independently of further Delta input. Thus, this study provides new insights into the timing mechanisms and the molecular dynamics of endomesoderm segregation during sea urchin embryogenesis and into the mode of action of the Delta/Notch pathway in mediating mesoderm fate.

Contracting Freedom: Governance and East Indian Indenture in the British Atlantic, 1838-1917

This is a dissertation about identity and governance, and how they are mutually constituted. Between 1838 and 1917, the British brought approximately half a million East Indian laborers to the Atlantic to work on sugar plantations. The dissertation argues that contrary to previous historiographical assumptions, indentured East Indians were an amorphous mass of people drawn from various regions of British India. They were brought together not by their innate "Indian-ness" upon their arrival in the Caribbean, but by the common experience of indenture recruitment, transportation and plantation life. Ideas of innate "Indian-ness" were products of an imperial discourse that emerged from and shaped official approaches to governing East Indians in the Atlantic. Government officials and planters promoted visions of East Indians as "primitive" subjects who engaged in child marriage and wife murder. Officials mobilized ideas about gender to sustain racialized stereotypes of East Indian subjects. East Indian women were thought to be promiscuous, and East Indian men were violent and depraved (especially in response to East Indian women's promiscuity). By pointing to these stereotypes about East Indians, government officials and planters could highlight the promise of indenture as a civilizing mechanism. This dissertation links the study of governance and subject formation to complicate ideas of colonial rule as static. It uncovers how colonial processes evolved to handle the challenges posed by migrant populations.

The primary architects of indenture, Caribbean governments, the British Colonial Office, and planters hoped that East Indian indentured laborers would form a stable and easily-governed labor force. They anticipated that the presence of these laborers would undermine the demands of Afro-Creole workers for higher wages and shorter working hours. Indenture, however, was controversial among British liberals who saw it as potentially hindering the creation of a free labor market, and abolitionists who also feared that indenture was a new form of slavery. Using court records, newspapers, legislative documents, bureaucratic correspondence, memoirs, novels, and travel accounts from archives and libraries in Britain, Guyana, and Trinidad and Tobago, this dissertation explores how indenture was envisioned and constantly re-envisioned in response to its critics. It chronicles how the struggles between the planter class and the colonial state for authority over indentured laborers affected the way that indenture functioned in the British Atlantic. In addition to focusing on indenture's official origins, this dissertation examines the actions of East Indian indentured subjects as they are recorded in the imperial archive to explore how these people experienced indenture.

Indenture contracts were central to the justification of indenture and to the creation of a pliable labor force in the Atlantic. According to English common law, only free parties could enter into contracts. Indenture contracts limited the period of indenture and affirmed that laborers would be remunerated for their labor. While the architects of indenture pointed to contracts as evidence that indenture was not slavery, contracts in reality prevented laborers from participating in the free labor market and kept the wages of indentured laborers low. Further, in late nineteenth-century Britain, contracts were civil matters. In the British Atlantic, indentured laborers who violated the terms of their contracts faced criminal trials and their associated punishments such as imprisonment and hard labor. Officials used indenture contracts to exploit the labor and limit the mobility of indentured laborers in a manner that was reminiscent of slavery but that instead established indentured laborers as subjects with limited rights. The dissertation chronicles how indenture contracts spawned a complex inter-imperial bureaucracy in British India, Britain, and the Caribbean that was responsible for the transportation and governance of East Indian indentured laborers overseas.

Transgenerational Effects of Early Life Starvation on Growth, Reproduction, and Stress Resistance in Caenorhabditis elegans.

Starvation during early development can have lasting effects that influence organismal fitness and disease risk. We characterized the long-term phenotypic consequences of starvation during early larval development in Caenorhabditis elegans to determine potential fitness effects and develop it as a model for mechanistic studies. We varied the amount of time that larvae were developmentally arrested by starvation after hatching ("L1 arrest"). Worms recovering from extended starvation grew slowly, taking longer to become reproductive, and were smaller as adults. Fecundity was also reduced, with the smallest individuals most severely affected. Feeding behavior was impaired, possibly contributing to deficits in growth and reproduction. Previously starved larvae were more sensitive to subsequent starvation, suggesting decreased fitness even in poor conditions. We discovered that smaller larvae are more resistant to heat, but this correlation does not require passage through L1 arrest. The progeny of starved animals were also adversely affected: Embryo quality was diminished, incidence of males was increased, progeny were smaller, and their brood size was reduced. However, the progeny and grandprogeny of starved larvae were more resistant to starvation. In addition, the progeny, grandprogeny, and great-grandprogeny were more resistant to heat, suggesting epigenetic inheritance of acquired resistance to starvation and heat. Notably, such resistance was inherited exclusively from individuals most severely affected by starvation in the first generation, suggesting an evolutionary bet-hedging strategy. In summary, our results demonstrate that starvation affects a variety of life-history traits in the exposed animals and their descendants, some presumably reflecting fitness costs but others potentially adaptive.

Biogeography in deep time - What do phylogenetics, geology, and paleoclimate tell us about early platyrrhine evolution?

Molecular data have converged on a consensus about the genus-level phylogeny of extant platyrrhine monkeys, but for most extinct taxa and certainly for those older than the Pleistocene we must rely upon morphological evidence from fossils. This raises the question as to how well anatomical data mirror molecular phylogenies and how best to deal with discrepancies between the molecular and morphological data as we seek to extend our phylogenies to the placement of fossil taxa. Here I present parsimony-based phylogenetic analyses of extant and fossil platyrrhines based on an anatomical dataset of 399 dental characters and osteological features of the cranium and postcranium. I sample 16 extant taxa (one from each platyrrhine genus) and 20 extinct taxa of platyrrhines. The tree structure is constrained with a "molecular scaffold" of extant species as implemented in maximum parsimony using PAUP with the molecular-based 'backbone' approach. The data set encompasses most of the known extinct species of platyrrhines, ranging in age from latest Oligocene (∼26 Ma) to the Recent. The tree is rooted with extant catarrhines, and Late Eocene and Early Oligocene African anthropoids. Among the more interesting patterns to emerge are: (1) known early platyrrhines from the Late Oligocene through Early Miocene (26-16.5Ma) represent only stem platyrrhine taxa; (2) representatives of the three living platyrrhine families first occur between 15.7 Ma and 13.5 Ma; and (3) recently extinct primates from the Greater Antilles (Cuba, Jamaica, Hispaniola) are sister to the clade of extant platyrrhines and may have diverged in the Early Miocene. It is probable that the crown platyrrhine clade did not originate before about 20-24 Ma, a conclusion consistent with the phylogenetic analysis of fossil taxa presented here and with recent molecular clock estimates. The following biogeographic scenario is consistent with the phylogenetic findings and climatic and geologic evidence: Tropical South America has been a center for platyrrhine diversification since platyrrhines arrived on the continent in the middle Cenozoic. Platyrrhines dispersed from tropical South America to Patagonia at ∼25-24 Ma via a "Paraná Portal" through eastern South America across a retreating Paranense Sea. Phylogenetic bracketing suggests Antillean primates arrived via a sweepstakes route or island chain from northern South America in the Early Miocene, not via a proposed land bridge or island chain (GAARlandia) in the Early Oligocene (∼34 Ma). Patagonian and Antillean platyrrhines went extinct without leaving living descendants, the former at the end of the Early Miocene and the latter within the past six thousand years. Molecular evidence suggests crown platyrrhines arrived in Central America by crossing an intermittent connection through the Isthmus of Panama at or after 3.5Ma. Any more ancient Central American primates, should they be discovered, are unlikely to have given rise to the extant Central American taxa in situ.

Imaginario Erótico Decolonial Kairibeafroxeri

La disertación no define un campo disciplinario, ni una construcción formal, ni una metodología que intente llegar a una verdad racional. Se desobedece la linealidad epistémica occidental y el enfoque en un tema específico. El manuscrito opta por navegar a través de rutas relacionales en conversación desde, con y entre varios saberes y experiencias personales, tribales y comunitarias. Localizamos el andar decolonial en un territorio expandido donde incorporamos una geo-­‐‑política trazada en la continuidad que ofrece la ancestralidad lingüística y cultural entre maya, seminole y loko, esta última conectada a la lengua madre arahuaca que se extiende desde la región amazónica del este de Los Andes, norte de Argentina y Paraguay desde 9000 A.C.

Al hilvanar experiencias y saberes otros, se establecen conexiones y rupturas más cercanas a los que entendimos como cosmos-­‐‑existencia y cosmoconvivencia en los imaginarios indígenas, afro y US latinxs. La disertación no podrá abarcar todas las rutas y encrucijadas que propician la decolonialidad del imaginario erótico kairibe, pero transito caminos sacbes desde donde los trazos de la memoria y la experiencia sanan la opresión colonial y nutren el andar del espíritu por los saberes inscritos en los relatos de creación indígenas y afro caribe, la oralidad de las lenguas maya yucateca y loko, la expresión de varixs creadores decoloniales, y las conversaciones e intercambios sociales con algunos de los miembros del proyecto decolonial.

A partir de la propuesta metodológica de Linda Tuhiwai Smith, en la cual se afirma que las metodologías indígenas son el resultado de la elaboración de un tejido, este manuscrito entrelaza una plataforma crítica, una encrucijada de saberes donde confluyen la variabilidad de los proyectos metodológicos propuesto por Tuhiwai Smith (1999), el pensamiento fronterizo de Gloria Anzaldúa (1987), la corpo-­‐‑política de Frantz Fanon (1987), la poética relacional de Edouard Glissant (1997), las pedagogía sagrada de Jacqui Alexander (2005), el desprendimiento, delinking de Walter D. Mignolo (2007), el poder erótico de Audre Lorde (1986), la transmodernidad de Enrique Dussel (2005) y la geopolítica del pensar propuesta por Catherine Walsh (2007).

Desde esta encrucijada de saberes, la disertación navega el racismo cognitivo eurocentrado, al mismo tiempo que efectúa el desligue epistémico y creativo hacia locaciones otras donde las experiencias y aprendizajes, conectados a las memorias ancestrales de lxs abuelxs, propician la decolonización del imaginario erótico kairibeafroxeri.

We Are the Ones We Have Been Waiting for: Pan-African Consciousness Raising and Organizing in the United States and Venezuela

We Are the Ones We Have Been Waiting for: Pan-African Consciousness Raising and Organizing in the United States and Venezuela, draws on fifteen months of field research accompanying organizers, participating in protests, planning/strategy meetings, state-run programs, academic conferences and everyday life in these two countries. Through comparative examination of the processes by which African Diaspora youth become radically politicized, this work deconstructs tendencies to deify political s/heroes of eras past by historicizing their ascent to political acclaim and centering the narratives of present youth leading movements for Black/African liberation across the Diaspora. I employ Manuel Callahan’s description of “encuentros”, “the disruption of despotic democracy and related white middle-class hegemony through the reconstruction of the collective subject”; “dialogue, insurgent learning, and convivial research that allows for a collective analysis and vision to emerge while affirming local struggles” to theorize the moments of encounter, specifically, the moments (in which) Black/African youth find themselves becoming politically radicalized and by what. I examine the ways in which Black/African youth organizing differs when responding to their perpetual victimization by neoliberal, genocidal state-politics in the US, and a Venezuelan state that has charged itself with the responsibility of radically improving the quality of life of all its citizens. Through comparative analysis, I suggest the vertical structures of “representative democracy” dominating the U.S. political climate remain unyielding to critical analyses of social stratification based on race, gender, and class as articulated by Black youth. Conversely, I contend that present Venezuelan attempts to construct and fortify more horizontal structures of “popular democracy” under what Hugo Chavez termed 21st Century Socialism, have resulted in social fissures, allowing for a more dynamic and hopeful negation between Afro-Venezuelan youth and the state.

Mount Carmel in the Commune: Promoting the Holy Land in Central Italy in the 13th and 14th Centuries

The Carmelite friars were the last of the major mendicant orders to be established in Italy. Originally an eremitical order, they arrived from the Holy Land in the 1240s, decades after other mendicant orders, such as the Franciscans and Dominicans, had constructed churches and cultivated patrons in the burgeoning urban centers of central Italy. In a religious market already saturated with friars, the Carmelites distinguished themselves by promoting their Holy Land provenance, eremitical values, and by developing an institutional history claiming to be descendants of the Old Testament prophet Elijah. By the end of the 13th century the order had constructed thriving churches and convents and leveraged itself into a prominent position in the religious community. My dissertation analyzes these early Carmelite churches and convents, as well as the friars’ interactions with patrons, civic governments, and the urban space they occupied. Through three primary case studies – the churches and convents of Pisa, Siena and Florence – I examine the Carmelites’ approach to art, architecture, and urban space as the order transformed its mission from one of solitary prayer to one of active ministry.

My central questions are these: To what degree did the Carmelites’ Holy Land provenance inform the art and architecture they created for their central Italian churches? And to what degree was their visual culture instead a reflection of the mendicant norms of the time?

I have sought to analyze the Carmelites at the institutional level, to determine how the order viewed itself and how it wanted its legacy to develop. I then seek to determine how and if the institutional model was utilized in the artistic and architectural production of the individual convents. The understanding of Carmelite art as a promotional tool for the identity of the order is not a new one, however my work is the first to consider deeply the order’s architectural aspirations. I also consider the order’s relationships with its de facto founding saint, the prophet Elijah, and its patron, the Virgin Mary, in a more comprehensive manner that situates the resultant visual culture into the contemporary theological and historical contexts.

A REPRESENTATIVE OUTSIDER AND THE INCLUSION OF THE OUTSIDER IN ACTS 8:26-40

In Luke’s two volumes, Luke is not interested only in Gentiles and those with high social status but also in the marginalized and those who are outsiders. This dissertation seeks to read Luke’s concern for outsiders and the theme of the inclusion of outsiders in the new kingdom of God in Luke’s narrative of the Ethiopian eunuch’s conversion in Acts 8:26-40. This paper examines the Ethiopian eunuch’s complex identity from the perspectives of the Greco-Roman world, Old Testament (LXX) allusions to the Elijah-Elisha narratives, and Luke’s interpretation of the Isaianic quotation of the Suffering Servant in Acts 8:32-33 (cf. Isaiah 53:7-8). This study pays close attention to the correlations between the theme of outsiders and three key characters in Acts 8:26-40: the Ethiopian eunuch, Philip, and the Suffering Servant. First, Luke depicts the Ethiopian eunuch as the consummate outsider—geographically, morally, socially, ethnically, and in terms of gender—and indicates that the eunuch represents other marginalized outsiders. The eunuch shows no one can prevent outsiders like him from inclusion in the kingdom of God. Second, Luke portrays Philip as a prophet, specifically a prophet like Elijah and Elisha. Philip emulates Elijah and Elisha by reaching out to the outsider (in this instance, the Ethiopian eunuch). Third, Luke presents the Isaianic Suffering Servant as a religious and social outsider and identifies the character with Jesus and the Ethiopian eunuch. The indescribable descendants of the Suffering Servant signify a universally inclusive messianic community and fulfill the outsiders’ inclusion within the people of God as Isaiah prophesied (Isaiah 56:3-8). This thesis finally suggests ways to read the story of the Ethiopian eunuch today and concludes that it is imperative to include those outsiders among us within the community of Jesus’s followers.