University of Nevada, Reno

About: University of Nevada, Reno is a education organization based out in Reno, Nevada, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 13561 authors who have published 28217 publications receiving 882002 citations. The organization is also known as: University of Nevada & Nevada State University.

Double Mutants Deficient in Cytosolic and Thylakoid Ascorbate Peroxidase Reveal a Complex Mode of Interaction between Reactive Oxygen Species, Plant Development, and Response to Abiotic Stresses

Abstract: Reactive oxygen species (ROS) play a key signaling role in plants and are controlled in cells by a complex network of ROS metabolizing enzymes found in several different cellular compartments. To study how different ROS signals, generated in different cellular compartments, are integrated in cells, we generated a double mutant lacking thylakoid ascorbate peroxidase (tylapx) and cytosolic ascorbate peroxidase1 (apx1). Our analysis suggests that two different signals are generated in plants lacking cytosolic APX1 or tylAPX. The lack of a chloroplastic hydrogen peroxide removal enzyme triggers a specific signal in cells that results in enhanced tolerance to heat stress, whereas the lack of a cytosolic hydrogen peroxide removal enzyme triggers a different signal, which results in stunted growth and enhanced sensitivity to oxidative stress. When the two signals are coactivated in cells (i.e. tylapx/apx1), a new response is detected, suggesting that the integration of the two different signals results in a new signal that manifests in late flowering, low protein oxidation during light stress, and enhanced accumulation of anthocyanins. Our results demonstrate a high degree of plasticity in ROS signaling in Arabidopsis (Arabidopsis thaliana) and suggest the existence of redundant pathways for ROS protection that compensate for the lack of classical ROS removal enzymes such as cytosolic and chloroplastic APXs. Further investigation of the enhanced heat tolerance in plants lacking tylAPX, using mutants deficient in chloroplast-to-nuclei retrograde signaling, suggests the existence of a chloroplast-generated stress signal that enhances basal thermotolerance in plants.

Neural correlates of genetically abnormal social cognition in Williams syndrome

Abstract: Williams-Beuren syndrome (WBS), caused by a microdeletion of approximately 21 genes on chromosome 7q11.23, is characterized by unique hypersociability combined with increased non-social anxiety. Using functional neuroimaging, we found reduced amygdala activation in individuals with WBS for threatening faces but increased activation for threatening scenes, relative to matched normal controls. Activation and interactions of prefrontal regions linked to amygdala, especially orbitofrontal cortex, were abnormal, suggesting a genetically controlled neural circuitry for regulating human social behavior.

Assessing the dynamic capabilities view: spare change, everyone?

Abstract: Why do some firms succeed in a dynamic competitive environment when others fail? Recently, concepts and models addressing this question have increasingly clustered around the dynamic capabilities view (DCV). Citation counts suggest that the DCV is the new touchstone firm-based performance-focused theory (Teece et al. [1997], for example, had received 1180 citations in the ISI Web of Knowledge as of June 2008), and case studies of innovative firms such as IDEO (Hargadon and Sutton, 1997) have fueled interest. We take a step back to assess the ability of the DCV to explain successful change with logical consistency, conceptual clarity and empirical rigor, criteria suggested by Laudan (1977). Such an assessment is important not only because of the DCV’s popularity, but also because of the theoretical and practical significance of the issues it addresses. While the arguably static resource-based view (RBV) emphasizes the value of resources, the DCV addresses the need to explain changes in valuable resources, e.g. the erosion of asset stocks (Dierickx and Cool, 1989) and the changes in asset values (Miller and Shamsie, 1996). The DCV also addresses a practical need to understand how firms can change effectively, given perceptions that many competitive environments now change at increasing rates, and that firms have difficulty changing successfully (Beer and Nohria, 2000; Strebel, 1996). Our assessment identifies four major problems that limit the potential contribution of the DCV: (1) unclear value-added relative to existing concepts; (2) lack of a coherent theoretical foundation; (3) weak empirical support; and (4) unclear practical implications. Although potentially interrelated, each problem presents different difficulties and raises different questions.