Sample Handling and Chemical Kinetics in an Acoustically Levitated Drop Microreactor

Accurate measurement of enzyme kinetics is an essential part of understanding the mechanisms of biochemical reactions. The typical means of studying such systems use stirred cuvettes, stopped-flow apparatus, microfluidic systems, or other small sample containers. These methods may prove to be problematic if reactants or products adsorb to or react with the container’s surface. As an alternative approach, we have developed an acoustically-levitated drop reactor eventually intended to study enzyme-catalyzed reaction kinetics related to free radical and oxidative stress chemistry. Microliter-scale droplet generation, reactant introduction, maintenance, and fluid removal are all important aspects in conducting reactions in a levitated drop. A three capillary bundle system has been developed to address these needs. We report kinetic measurements for both luminol chemiluminescence and the reaction of pyruvate with nicotinamide adenine dinucleotide, catalyzed by lactate dehydrogenase, to demonstrate the feasibility of using a levitated drop in conjunction with the developed capillary sample handling system as a microreactor

Maintaining the Environmental–Racial Order in Northern New Mexico

The environmental - racial order in northern New Mexico is maintained through a process of racial triangulation in which Anglos, Native Americans, and Hispanos are valued relative to one another along axes of environmental stewardship and victimization (Kim C J, 1999, "The racial triangulation of Asian Americans" Politics and Society 27 105 - 138). Both axes involve the juxtaposing of three long-standing images: (1) Spanish injustices to the Indians; (2) the inability of Mexicans to manage their land properly; and (3) Indians being preeminent environmental stewards. In contrast to Kim's formulation of racial triangulation, however, the axes also involve imagery that contradicts these images: the debauched, poverty-stricken Indian; and European culture as a despoiler of the environment. Also in contrast to Kim's formulation, racial triangulation can involve the creation of new identities. In the 1960s Hispano activists began claiming to be heirs to a hybrid culture that included elements of both Native American and Spanish cultures. While this claim to hybridity enabled the creation of new oppositional discourses, the reconciling of contradictory imagery by historicizing the discourses and by other means undermines the new Hispano oppositional discourses as well as Hispano identity itself Racial triangulation is thus a fluid and contested process in which identity formation and the interchange between predominant and oppositional discourses are constitutive of power relations. Contradictory imagery in the discourse facilitates the maintenance of the environmental - racial order, even as it enables subordinates to challenge their racialized positions and to effect change in the distribution of material wealth, rights, and privileges