Role of turn-over in active stress generation in a filament network

We study the effect of turnover of cross linkers, motors and filaments on the generation of a contractile stress in a network of filaments connected by passive crosslinkers and subjected to the forces exerted by molecular motors. We perform numerical simulations where filaments are treated as rigid rods and molecular motors move fast compared to the timescale of exchange of crosslinkers. We show that molecular motors create a contractile stress above a critical number of crosslinkers. When passive crosslinkers are allowed to turn over, the stress exerted by the network vanishes, due to the formation of clusters. When both filaments and passive crosslinkers turn over, clustering is prevented and the network reaches a dynamic contractile steady-state. A maximum stress is reached for an optimum ratio of the filament and crosslinker turnover rates.Comment: 17 pages, 8 figures, 5 supplementary movies (included in the source) In the latest version, appendices D and E have been added, text has been updated, Figure 2 has been corrected, and Figure 4 has been replaced by simulation results with higher precisio

The origin and architecture of existential indeterminates in Okinawan

In a number of languages, an indeterminate is combined with various particles to yield different indefinite pronouns. This has been called an indeterminate system (Kuroda 1965, Cheng 1991, Haspelmath 1997, Jayaseelan 2001). As Haspelmath (1997) and Jayaseelan (2001) observe, existential indeterminates are often built with disjunction markers. On the other hand, a disjunction particle and a question particle are often morphologically identical cross-linguistically (see Hagstrom 1998, Jayaseelan 2001). Thus, a question that I ask here is whether the alleged homophony between a disjunction marker and a marker that forms an existential quantifier is principled (Jayaseelan 2001, Szabolcsi et al. 2014) or coincidental (Haspelmath 1997, Cable 2010). In this paper, I argue that the observation about homophony is misguided and hence support Haspelmath’s hypothesis, based on the data obtained from my fieldwork on Okinawan, an endangered Ryukyuan language. I propose an analysis where existential indeterminates in Okinawan have a clausal structure of an embedded question and are derived by deletion

The Faculty of Language Integrates the Two Core Systems of Number

Only humans possess the faculty of language that allows an infinite array of hierarchically structured expressions (Hauser et al., 2002; Berwick and Chomsky, 2015). Similarly, humans have a capacity for infinite natural numbers, while all other species seem to lack such a capacity (Gelman and Gallistel, 1978; Dehaene, 1997). Thus, the origin of this numerical capacity and its relation to language have been of much interdisciplinary interest in developmental and behavioral psychology, cognitive neuroscience, and linguistics (Dehaene, 1997; Hauser et al., 2002; Pica et al., 2004). Hauser et al. (2002) and Chomsky (2008) hypothesize that a recursive generative operation that is central to the computational system of language (called Merge) can give rise to the successor function in a set-theoretic fashion, from which capacities for discretely infinite natural numbers may be derived. However, a careful look at two domains in language, grammatical number and numerals, reveals no trace of the successor function. Following behavioral and neuropsychological evidence that there are two core systems of number cognition innately available, a core system of representation of large, approximate numerical magnitudes and a core system of precise representation of distinct small numbers (Feigenson et al., 2004), I argue that grammatical number reflects the core system of precise representation of distinct small numbers alone. In contrast, numeral systems arise from integrating the pre-existing two core systems of number and the human language faculty. To the extent that my arguments are correct, linguistic representations of number, grammatical number, and numerals do not incorporate anything like the successor function

Sluicing cannot apply in-situ in Japanese

Ross (1969) proposed that sluicing in English is derived by wh- movement and deletion. The wh-movement analysis, however, is not straight- forward in wh-in-situ languages like Japanese. A number of studies argued that sluicing in Japanese is based on wh-cleft structure with much empirical evidence. More recently, however, Kimura (2010) and Abe (2015) have proposed an in-situ analysis of sluicing in Japanese, which deletes everything but a wh-phrase (and the Q-complementizer) in situ, without movement. In this paper, building on immobile elements, I will provide decisive evidence against the in-situ deletion analysis of sluicing and for the wh-cleft analysis of sluicing

Animacy hierarchy and case/agreement in Okinawan

In languages like Japanese and Okinawan, morphological evidence for agreement is scarce, which has led to the long-standing controversy as to its existence. In this article, I argue that while φ-agreement is not morphologically realized on the predicates in Okinawan, it is nevertheless indirectly detectable in the form of animacy agreement in differential case-marking

Relativization in Dàgáárè and its typological implications: Left-headed but internally-headed

This article examines in detail the syntax of relativization in Dàgáárè, a Mabia (Oti-Volta) language of the Gur branch in the Niger-Congo family. The main aims of our investigation are twofold. The first is to describe a cluster of typologically interesting syntactic features of relativization in Dàgáárè in the light of the fact that no detailed description exists in the literature. The second is to demonstrate that relative clauses in Dàgáárè are head-internal relative clauses (HIRCs), even though they are, on the surface, postnominal relative clauses, like those in English. Thus, they are not of the in-situ type of HIRC that is well known in the literature. We call this type of relative clause a left-headed HIRC. This type of relativization has rarely been noticed cross-linguistically in the previous literature and therefore is of considerable significance for general linguistics, linguistic typology, as well as theoretical linguistics. Evidence comes from coordination in possessor relativization and PP relativization. Our discovery shows that Universal Grammar allows left-headed HIRCs as an option in addition to the more familiar types: in-situ HIRCs and head-external relative clauses (HERCs). © 2009 Elsevier B.V. All rights reserved.postprin

Bare indeterminates in unconditionals

Indeterminates in Japanese have been studied extensively since Kuroda (1965) and all the previous works share the descriptive generalization that indeterminates must co-occur with overt quantificational particles such as ka and (de)mo. We present novel data indicating that the Japanese indeterminates are licensed "bare" without the presence of an overt particle to associate with. Conversely, we also point out data in which the mere presence of mo fails to license an indeterminate. We argue that our long-standing understanding of indeterminates has been misguided and that what truly licenses a bare indeterminate is a covert Q-morpheme. Our analysis that a covert Q-morpheme is the licensor of bare indeterminates departs from the traditional view that indeterminates require the overt licensing particle ka or (de)mo