The Bounds of Possibility

2021 ◽  
Author(s):  
Cian Dorr ◽  
John Hawthorne ◽  
Juhani Yli-Vakkuri
Keyword(s):  
Modal Logic ◽  
Higher Order ◽  
Full Length ◽  
Entry Point ◽  
Material Objects ◽  
Gothic Novel ◽  
Fine Grained ◽  
Rigorous Treatment ◽  
Familiar Objects

This book didn’t have to consist of exactly the sentences that it in fact contains: any one of its sentences could have been very different. But it could not have consisted of an entirely different collection of sentences, such as to make it a gothic novel or a treatise on wine-tasting. Other familiar objects are similarly capable of being moderately different, but not radically different, in various respects. But there are puzzling arguments which threaten these apparently obvious judgments, exploiting the fact that an appropriate sequence of small differences can add up to a radical difference. This book presents the first full-length treatment of these puzzles, using them as an entry point to a broad range of metaphysical questions about possibility, necessity, and identity. It introduces tools of higher-order modal logic which enable a rigorous treatment of the puzzles, and develops a strategy for resolving them based on a plenitudinous ontology of material objects, which induces fine-grained variability in the reference of words like ‘book’.

scholarly journals Distinct Mechanism for the Formation of the Ribonucleoprotein Complex of Tomato Spotted Wilt Virus

2017 ◽  
Vol 91 (23) ◽  
Author(s):  
Yu Guo ◽  
Baocheng Liu ◽  
Zhenzhen Ding ◽  
Guobang Li ◽  
Meizi Liu ◽  
...  
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Higher Order ◽  
The Body ◽  
Full Length ◽  
Content Type ◽  
Ribonucleoprotein Complex ◽  
Tomato Spotted Wilt ◽  
Distinct Mechanism ◽  
C Terminus ◽  
Wilt Virus

ABSTRACT The Tomato spotted wilt virus (TSWV) belongs to the Tospovirus genus of the Bunyaviridae family and represents the sole plant-infecting group within bunyavirus. TSWV encodes a nucleocapsid protein (N) which encapsidates the RNA genome to form a ribonucleoprotein complex (RNP). In addition, the N has multiple roles during the infection of plant cells. Here, we report the crystal structure of the full-length TSWV N. The N features a body domain consisting of an N-lobe and a C-lobe. These lobes clamp a positively charged groove which may constitute the RNA binding site. Furthermore, the body domains are flanked by N- and C-terminal arms which mediate homotypic interactions to the neighboring subunits, resulting in a ring-shaped N trimer. Interestingly, the C terminus of one protomer forms an additional interaction with the protomer of an adjacent trimer in the crystal, which may constitute a higher-order oligomerization contact. In this way, this study provides insights into the structure and trimeric assembly of TSWV N, which help to explain previous functional findings, but also suggests distinct N interactions within a higher-order RNP. IMPORTANCE TSWV is one of the most devastating plant pathogens that cause severe diseases in numerous agronomic and ornamental crops worldwide. TSWV is also the prototypic member of the Tospovirus genus, which is the sole group of plant-infecting viruses in the bunyavirus family. This study determined the structure of full-length TSWV N in an oligomeric state. The structural observations explain previously identified biological properties of TSWV N. Most importantly, the additional homotypic interaction between the C terminus of one protomer with another protomer indicates that there is a distinct mechanism of RNP formation in the bunyavirus family, thereby enhancing the current knowledge of negative-sense single-stranded RNA virus-encoded N. TSWV N is the last remaining representative N with an unknown structure in the bunyavirus family. Combined with previous studies, the structure of TSWV N helps to build a complete picture of the bunyavirus-encoded N family and reveals a close evolutionary relationship between orthobunyavirus, phlebovirus, hantavirus, and tospovirus.

A relational modal logic for higher-order stateful ADTs

2010 ◽  
Vol 45 (1) ◽  
pp. 185-198 ◽  
Author(s):  
Derek Dreyer ◽  
Georg Neis ◽  
Andreas Rossberg ◽  
Lars Birkedal
Keyword(s):  
Modal Logic ◽  
Higher Order

Logical Tools

2021 ◽  
pp. 14-52
Author(s):  
Cian Dorr ◽  
John Hawthorne ◽  
Juhani Yli-Vakkuri
Keyword(s):  
Modal Logic ◽  
Possible Worlds ◽  
Higher Order ◽  
Order Logic ◽  
First Order Logic ◽  
First Order ◽  
System P

This chapter presents the system of classical higher-order modal logic which will be employed throughout this book. Nothing more than a passing familiarity with classical first-order logic and standard systems of modal logic is presupposed. We offer some general remarks about the kind of commitment involved in endorsing this logic, and motivate some of its more non-standard features. We also discuss how talk about possible worlds can be represented within the system.

scholarly journals Sterile Alpha Motif Domain-Mediated Self-Association Plays an Essential Role in Modulating the Activity of the Drosophila ETS Family Transcriptional Repressor Yan

2010 ◽  
Vol 30 (5) ◽  
pp. 1158-1170 ◽  
Author(s):  
Jie Zhang ◽  
Thomas G. W. Graham ◽  
Pavithra Vivekanand ◽  
Lauren Cote ◽  
Maureen Cetera ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Nuclear Export ◽  
Transcriptional Repressor ◽  
Higher Order ◽  
Full Length ◽  
Sterile Alpha Motif ◽  
Sam Domain ◽  
Rtk Signaling ◽  
Ets Family ◽  
Self Association

ABSTRACT The ETS family transcriptional repressor Yan is an important downstream target and effector of the receptor tyrosine kinase (RTK) signaling pathway in Drosophila melanogaster. Structural and biochemical studies have shown that the N-terminal sterile alpha motif (SAM) of Yan is able to self associate to form a helical polymeric structure in vitro, although the extent and functional significance of self-association of full-length Yan remain unclear. In this study, we demonstrated that full-length Yan self associates via its SAM domain to form higher-order complexes in living cells. Introduction of SAM domain missense mutations that restrict Yan to a monomeric state reduces Yan's transcriptional repression activity and impairs its function during embryonic and retinal development. Coexpression of combinations of SAM domain mutations that permit the formation of Yan dimers, but not higher-order oligomers, increases activity relative to that of monomeric Yan, but not to the level obtained with wild-type Yan. Mechanistically, self-association directly promotes transcriptional repression of target genes independent of its role in limiting mitogen-activated protein kinase (MAPK)-mediated phosphorylation and nuclear export of Yan. Thus, we propose that the formation of higher-order Yan oligomers contributes to proper repression of target gene expression and RTK signaling output in developing tissues.

scholarly journals The Glory of the Past and Geometrical Concurrency

10.29007/klcl ◽  
2018 ◽  
Author(s):  
Cristian Prisacariu
Keyword(s):  
Modal Logic ◽  
Geometric Model ◽  
Expressive Power ◽  
Geometrical Model ◽  
Geometrical Aspect ◽  
Fine Grained ◽  
The Past ◽  
Action Refinement ◽  
Higher Dimensional ◽  
Natural Way

This paper contributes to the general understanding of the "geometrical model of concurrency" that was named higher dimensional automata (HDAs) by Pratt and van Glabbeek. In particular we provide some understanding of the modal logics for such models and their expressive power in terms of the bisimulation that can be captured.The geometric model of concurrency is interesting from two main reasons: its generality and expressiveness, and the natural way in which autoconcurrency and action refinement are captured.Logics for this model, though, are not well investigated, where a simple, yet adequate, modal logic over HDAs was only recently introduced.As this modal logic, with two existential modalities, "during" and "after", captures only split bisimulation, which is rather low in the spectrum of van Glabbeek and Vaandrager, the immediate question was what small extension of this logic could capture the more fine-grained hereditary history preserving bisimulation (hh)?In response, the work in this paper provides several insights. One is the fact that the geometrical aspect of HDAs makes it possible to use for capturing the hh-bisimulation, a standard modal logic that does not employ event variables, opposed to the two logics (over less expressive models) that we compare with. The logic that we investigate here uses standard backward-looking modalities (i.e., past modalities) and extends the previously introduced logic (called HDML) that had only forward, action-labelled, modalities.Since the direct proofs are rather intricate, we try to understand better the above issues by introducing a related model that we call ST-configuration structures, which extend the configuration structures of van Glabbeek and Plotkin. We relate this model to HDAs, and redefine and prove the earlier results in the light of this new model. These offer a different view on why the past modalities and geometrical concurrency capture the hereditary history preserving bisimulation.Additional correlating insights are also gained.

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