This article focuses on an examination of the role of the state in the development of the informal economy. Using material from unstructured interviews, the authors analyse reasons for choosing ...illegal strategies to overcome formal barriers to entry into the gold- mining sector. They conclude that it is not so much the height of administrative barriers as the configuration of power relations which develops when the state treats some businesses favourably compared to others that comprises the fundamental reason for the development of informal economic practices.
To control G protein signaling in vivo, we have modified G protein-coupled receptors to respond exclusively to synthetic small molecule agonists and not to their natural agonist(s). These engineered ...receptors are designated RASSLs (receptor activated solely by a synthetic ligand). A prototype RASSL (Ro1) based on the Gi-coupled K opioid receptor was expressed in transgenic mice under the control of the tetracycline transactivator (tet) system. Activation of Ro1 expressed in the heart decreased heart rate by up to 80%, an expected effect of increased Gi signaling. Maximal heart rate changes occurred in less than 1 min, demonstrating the speed of this inducible signaling system. This Ro1-mediated slowing of heart rate was also subject to desensitization, which lasted more than 24 h. Both the initial effect on heart rate and the desensitization occurred, even though Ro1 is derived from a human opioid receptor not normally involved in heart rate control. In addition, the tet system was used to induce Ro1 expression in hepatocytes and salivary gland, where Gi signaling is known to control physiologic events such as proliferation and secretion. These studies demonstrate that a RASSL can be inducibly expressed in several mouse tissues and used in vivo to activate G protein signaling in a controllable fashion.
Focal adhesion kinase (FAK) integrates diverse signaling pathways to regulate proliferation, migration, and differentiation. Germline deletion of FAK in mice results in embryonic lethality with ...pronounced defects in vascular structure and integrity, implicating FAK as critical to the development and migration of vascular smooth muscle cells (SMCs). However, the precise function of FAK in SMCs remains elusive. Primary aortic SMCs from fakflox/flox mice were infected with Cre-expressing adenovirus, ablating FAK production. FAK deletion inhibited migration to platelet-derived growth factor (PDGF). While PDGF-induced membrane ruffling was FAK-independent, PDGF-induced polarization was reduced fivefold in FAK-depleted cells. The RhoA effector, Dia2, localized to focal adhesions in a FAK-dependent manner, and ablation of FAK attenuated myosin light chain phosphorylation. Finally, we detected a novel interaction between Dia2 and the Arp2/3 activator, cortactin. These data suggest that FAK may promote cell contraction and polarized migration toward PDGF by regulating distinct pools of RhoA activity.
Thesis (M.S.)--University of North Carolina at Chapel Hill, 2008.
Title from electronic title page (viewed Feb. 17, 2009). "... in partial fulfillment of the requirements for the degree of Master of ...Science in the Department of Pathology and Laboratory Medicine." Discipline: Pathology and Laboratory Medicine; Department/School: Medicine.
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