Purdue University

About: Purdue University is a education organization based out in West Lafayette, Indiana, United States. It is known for research contribution in the topics: Population & Heat transfer. The organization has 73219 authors who have published 163563 publications receiving 5775236 citations. The organization is also known as: Purdue & Purdue-West Lafayette.

Multidrug Resistance–like Genes of Arabidopsis Required for Auxin Transport and Auxin-Mediated Development

Abstract: Arabidopsis possesses several genes related to the multidrug resistance (MDR) genes of animals, one of which, AtMDR1, was shown to be induced by the hormone auxin. Plants having mutations in AtMDR1 or its closest relative, AtPGP1, were isolated by a reverse genetic strategy. Auxin transport activity was greatly impaired in atmdr1 and atmdr1 atpgp1 double mutant plants. Epinastic cotyledons and reduced apical dominance were mutant phenotypes consistent with the disrupted basipetal flow of auxin. The auxin transport inhibitor 1-naphthylphthalamic acid was shown to bind tightly and specifically to AtMDR1 and AtPGP1 proteins. The results indicate that these two MDR-like genes of Arabidopsis encode 1-naphthylphthalamic acid binding proteins that are required for normal auxin distribution and auxin-mediated development.

Goodbye Pareto Principle, Hello Long Tail: The Effect of Search Costs on the Concentration of Product Sales

Abstract: Many markets have historically been dominated by a small number of best-selling products. The Pareto principle, also known as the 80/20 rule, describes this common pattern of sales concentration. However, information technology in general and Internet markets in particular have the potential to substantially increase the collective share of niche products, thereby creating a longer tail in the distribution of sales. This paper investigates the Internet's “long tail” phenomenon. By analyzing data collected from a multichannel retailer, it provides empirical evidence that the Internet channel exhibits a significantly less concentrated sales distribution when compared with traditional channels. Previous explanations for this result have focused on differences in product availability between channels. However, we demonstrate that the result survives even when the Internet and traditional channels share exactly the same product availability and prices. Instead, we find that consumers' usage of Internet search and discovery tools, such as recommendation engines, are associated with an increase the share of niche products. We conclude that the Internet's long tail is not solely due to the increase in product selection but may also partly reflect lower search costs on the Internet. If the relationships we uncover persist, the underlying trends in technology portend an ongoing shift in the distribution of product sales. This paper was accepted by Ramayya Krishnan, information systems.

Dominant Shareholders, Corporate Boards and Corporate Value: A Cross-Country Analysis

Abstract: We investigate the relation between corporate value and the proportion of the board made up of independent directors in 799 firms with a dominant shareholder across 22 countries. We find a positive relation, especially in countries with weak legal protection for shareholders. The findings suggest that a dominant shareholder, were he so inclined, could offset, at least in part, the documented value discount associated with weak country-level shareholder protection by appointing an 'independent' board. The cost to the dominant shareholder of doing so is the loss in perquisites associated with being a dominant shareholder. Thus, not all dominant shareholders will choose independent boards.

Structure of the Immature Dengue Virus at Low pH Primes Proteolytic Maturation

Abstract: Intracellular cleavage of immature flaviviruses is a critical step in assembly that generates the membrane fusion potential of the E glycoprotein. With cryo-electron microscopy we show that the immature dengue particles undergo a reversible conformational change at low pH that renders them accessible to furin cleavage. At a pH of 6.0, the E proteins are arranged in a herringbone pattern with the pr peptides docked onto the fusion loops, a configuration similar to that of the mature virion. After cleavage, the dissociation of pr is pH-dependent, suggesting that in the acidic environment of the trans-Golgi network pr is retained on the virion to prevent membrane fusion. These results suggest a mechanism by which flaviviruses are processed and stabilized in the host cell secretory pathway.