background and aims: celery mosaic virus (cemv) is one of the causal agents of viral diseases in celery (apium graveolens). cemv is a member of the potyvirus genus in potyviridae family. the virus is naturally transmitted by aphids in a non-persistent manner. during growing season 2006-2007 viral disease symptoms were observed in celery fields grown in tehran province (bage daneshkade, mohamads...

The induction of somatic embryo development in cell cultures of alfalfa (Medicago sativa), celery (Apium graveolens), and lettuce (Lactuca sativa) was compared for 2,4-dichlorophenoxy-acetic acid (2,4-D) and various phenoxy acid growth regulators. Tests using a series of straight chain extensions to the phenoxy acid side chain indicate that phenoxybutanoic acid is active, whereas the phenoxypro...

By providing incentives for sellers to act in a trustworthy manner, reputation mechanisms in many online environments can mitigate moral-hazard problems when particular buyers and sellers interact infrequently. However, these mechanisms rely on buyers sharing their private information about sellers with the community, and thus may suffer from too little feedback when its provision is costly. In...

2007-4085/© 2016 Sociedad Mexicana de Urología. Publicado por Masson Doyma México S.A. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/). *Corresponding author at: División de Urología, Hospital General «Dr. Manuel Gea González», Secretaría de Salud. Calzada de Tlalpan 4800. Col. Sección XVI. CP: 14080. México, Distrito Federal. Tel...

In this paper, we examine how a seller sells a product/service with a positive consumption externality, and customers are uncertain about the product’s/service’s value. Because early adopters learn this value, we consider the customers’ intrinsic signaling incentives and positive feedback effects. Anticipating this, the seller commits to provide price discounts to the followers, and charges the...