The role of tectonic uplift, climate, and vegetation in the long-term terrestrial phosphorous cycle

Phosphorus (P) is a crucial element for life and therefore for maintaining ecosystem productivity. Its local availability to the terrestrial biosphere results from the interaction between climate, tectonic uplift, atmospheric transport, and biotic cycling. Here we present a mathematical model that describes the terrestrial P-cycle in a simple but comprehensive way. The resulting dynamical system can be solved analytically for steady-state conditions, allowing us to test the sensitivity of the P-availability to the key parameters and processes. Given constant inputs, we find that humid ecosystems exhibit lower P availability due to higher runoff and losses, and that tectonic uplift is a fundamental constraint. In particular, we find that in humid ecosystems the biotic cycling seem essential to maintain long-term P-availability. The time-dependent P dynamics for the Franz Josef and Hawaii chronosequences show how tectonic uplift is an important constraint on ecosystem productivity, while hydroclimatic conditions control the P-losses and speed towards steady-state. The model also helps describe how, with limited uplift and atmospheric input, as in the case of the Amazon Basin, ecosystems must rely on mechanisms that enhance P-availability and retention. Our novel model has a limited number of parameters and can be easily integrated into global climate models to provide a representation of the response of the terrestrial biosphere to global change. © 2010 Author(s).

Police is Dead: On the Birth of Economism

Police is Dead is an historiographic analysis whose objective is to change the terms by which contemporary humanist scholarship assesses the phenomenon currently termed neoliberalism. It proceeds by building an archeology of legal thought in the United States that spans the nineteenth and twentieth centuries. My approach assumes that the decline of certain paradigms of political consciousness set historical conditions that enable the emergence of what is to follow. The particular historical form of political consciousness I seek to reintroduce to the present is what I call “police:” a counter-liberal way of understanding social relations that I claim has particular visibility within a legal archive, but that has been largely ignored by humanist theory on account of two tendencies: first, an over-valuation of liberalism as Western history’s master signifier; and second, inconsistent and selective attention to law as a cultural artifact. The first part of my dissertation reconstructs an anatomy of police through close studies of court opinions, legal treatises, and legal scholarship. I focus in particular on juridical descriptions of intimate relationality—which police configured as a public phenomenon—and slave society apologetics, which projected the notion of community as an affective and embodied structure. The second part of this dissertation demonstrates that the dissolution of police was critical to emergence of a paradigm I call economism: an originally progressive economic framework for understanding social relations that I argue developed at the nexus of law and economics at the turn of the twentieth century. Economism is a way of understanding sociality that collapses ontological distinctions between formally distinct political subjects—i.e., the state, the individual, the collective—by reducing them to the perspective of economic force. Insofar as it was taken up and reoriented by neoliberal theory, this paradigm has become a hegemonic form of political consciousness. This project concludes by encouraging a disarticulation of economism—insofar as it is a form of knowledge—from neoliberalism as its contemporary doctrinal manifestation. I suggest that this is one way progressive scholarship can think about moving forward in the development of economic knowledge, rather than desiring to move backwards to a time before the rise of neoliberalism. Disciplinarily, I aim to show that understanding the legal historiography informing our present moment is crucial to this task.

The Synthesis of Novel N-Heterocyclic Scaffolds and Diazirine-Based Molecular Tags

N-Heterocycles are ubiquitous in biologically active natural products and pharmaceuticals. Yet, new syntheses and modifications of N-heterocycles are continually of interest for the purposes of expanding chemical space, finding quicker synthetic routes, better pharmaceuticals, and even new handles for molecular labeling. There are several iterations of molecular labeling; the decision of where to place the label is as important as of which visualization technique to emphasize.

Piperidine and indole are two of the most widely distributed N-heterocycles and thus were targeted for synthesis, functionalization, and labeling. The major functionalization of these scaffolds should include a nitrogen atom, while the inclusion of other groups will expand the utility of the method. Towards this goal, ease of synthesis and elimination of step-wise transformations are of the utmost concern. Here, the concept of electrophilic amination can be utilized as a way of introducing complex secondary and tertiary amines with minimal operations.

Molecular tags should be on or adjacent to an N-heterocycle as they are normally the motifs implicated at the binding site of enzymes and receptors. The labeling techniques should be useful to a chemical biologist, but should also in theory be useful to the medical community. The two types of labeling that are of interest to a chemist and a physician would be positron emission tomography (PET) and magnetic resonance imaging (MRI).

Coincidentally, the 3-positions of both piperidine and indole are historically difficult to access and modify. However, using electrophilic amination techniques, 3-functionalized piperidines can be synthesized in good yields from unsaturated amines. In the same manner, 3-labeled piperidines can be obtained; the piperidines can either be labeled with an azide for biochemical research or an 18F for PET imaging research. The novel electrophiles, N-benzenesulfonyloxyamides, can be reacted with indole in one of two ways: 3-amidation or 1-amidomethylation, depending on the exact reaction conditions. Lastly, a novel, hyperpolarizable 15N2-labeled diazirine has been developed as an exogenous and versatile tag for use in magnetic resonance imaging.