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We argue against a purely semantic account of the Unique Path Constraint (Goldberg, Adele. 1991. It can't go down the chimney up: Paths and the English resultative. In Proceedings of the seventeenth annual meeting of the Berkeley Linguistics Society, 368–378.), i.e., the constraint that there can only be one result state in a single clause, and in favor of a syntactic restriction regarding event structure. We propose, following Mateu, Jaume & Víctor Acedo-Matellán. 2012. The manner/result complementarity revisited: A syntactic approach. In M. Cristina Cuervo & Yves Roberge (eds.), The end of argument structure? Syntax and semantics, 209–228. New York: Academic Press, that structurally there can only be one result predicate per clause since the little v head selects for one result predicate as its complement. In order to make our claim, we provide novel data that violate the Unique Path Constraint defined as a semantic constraint. Further, we analyze examples that at first blush pose a problem for the present account as they appear to involve two result phrases, e.g., shot him dead off the horse. We argue, however, that the second result phrase is not syntactically a result, but rather constitutes a case of what Acedo-Matellán, Víctor, Josep Ausensi, Josep Maria Fontana & Cristina Real-Puigdollers. forthcoming. Old Spanish resultatives as low depictives. In Chad L. Howe, Timothy Gupton, Margaret Renwick & Pilar Chamorro (eds.), Open romance linguistics 1. Selected papers from the 49th linguistic symposium on romance languages. Berlin: Language Science Press have called low depictives, which join the syntactic derivation through a low applicative head. [ABSTRACT FROM AUTHOR]

We study a central problem in algorithmic mechanism design: constructing truthful mechanisms for welfare maximization in combinatorial auctions with submodular bidders. Dobzinski, Nisan, and Schapira provided the first mechanism that guarantees a nontrivial approximation ratio of O(log²m) [STOC'06, ACM, New York, 2006, pp. 644-652], where m is the number of items. This approximation ratio was subsequently improved to O(logmlog logm) [S. Dobzinski, APPROX'07, Springer, Berlin, 2007, pp. 89-103] and then to O(logm) [P. Krysta and B. Vöcking, ICALP'12, Springer, Heidelberg, 2012, pp. 636-647]. In this paper we develop the first mechanism that breaks the logarithmic barrier. Specifically, the mechanism provides an approximation ratio of O(√logm). Similarly to previous constructions, our mechanism uses polynomially many value and demand queries and, in fact, provides the same approximation ratio for the larger class of XOS (also known as fractionally subadditive) valuations. We also develop a computationally efficient implementation of the mechanism for combinatorial auctions with budget additive bidders. Although, in general, computing a demand query is NP-hard for budget additive valuations, we observe that the specific form of demand queries that our mechanism uses can be efficiently computed when bidders are budget additive. [ABSTRACT FROM AUTHOR]

• Strong economy, large population and rapid urbanizationare three basic conditions to open a subway. • It is best for thefirst subway line to be straightto connect the city center and suburbs. • A stronger correlation between line length and t urban population did emerge as the lines grew. • The length of the subway lines in the first year was related to the built-up area of the city. The number of metro lines increases every year, with most new projects being located in developing countries. Metro construction costs a huge amount of money, and it is, therefore, worthwhile to consider if the decisions related to and direction of metro construction are justified. Adopting a historical perspective, this paper selects nine global cities that constructed metro systems prior to 1913. It considers the economic and social background at their time of opening and summarizes the optimal conditions for their opening. It compares and analyzes the location, form and length of the lines in the first year, and, taking Berlin, London, New York and Paris as examples, looks into the relationship between the urban land and the expansion of the metro network. This provides insights into the key characteristics of early line networks that will help other cities to reconsider the construction of their own metros and in the future, this will help to prevent blind development. [ABSTRACT FROM AUTHOR]