Future Directions in Physiochemical Modeling of the Thermodynamics of Polyelectrolyte Coacervates (PECs)

We review theories of polyelectrolyte (PE) coacervation, which is the spontaneous association of oppositely charged units of PEs and phase separation into a polymer-dense phase in aqueous solution. The simplest theories can be divided into “physics-based” and “chemistry-based” approaches. In the former, polyelectrolytes are treated as charged, long-chain, molecules, defined by charge level, chain length, and chain flexibility, but otherwise lacking chemical identity, with electrostatic interactions driving coacervation. The “chemistry-based” approaches focus on the local interactions between the species for which chemical identity is critical, and describe coacervation as the result of competitive local binding interactions of monomers and salts. In this article, we show how these approaches complement each other by presenting recent approaches that take both physical and chemical effects into account. Finally, we suggest future directions towards producing theories that are made quantitatively predictive by accounting for both long range electrostatic and local chemically specific interactions.

Experimental evidence supporting the overlapping distribution of core and exempt anaphors: Re-examination of long-distance bound caki-casin in Korean

The Korean anaphor caki-casin, which has been regarded as a local anaphor, has been shown to allow long-distance binding when local binding is not an option (Kim, Ji-Hye & James Yoon. 2009. Long-distance bound local anaphors in Korean: An empirical study of the Korean anaphor caki-casin. Lingua 119. 733–755). In this study, we examined the long-distance binding of caki-casin in domains where local binding is possible, and compare it with the long-distance binding of caki, the representative long-distance anaphor in Korean. Our investigation revealed that the availability of local binding does not rule out long-distance/exempt binding of caki-casin. The results imply that core and exempt binding may not be in complementary distribution, at least in Korean.

Binding of dsRNA by D. melanogaster Dicer-2 is substrate-dependent and regulated by Loquacious-PD

ABSTRACTDrosophila melanogaster Dicer-2 is a large, multidomain protein that cleaves double-stranded RNA (dsRNA) into small interfering RNAs in a terminus-dependent manner as part of the RNA interference pathway. We characterize the local binding environment involved in this substrate-selective molecular recognition event by monitoring the time-resolved photophysics of a cyanine dye linked to the dsRNA terminus. We observe substantial changes in the molecular rigidity and local freedom of motion of the probe as a function of distinct conformations of the biomolecular complex between Dicer-2 and dsRNA as a function of dsRNA termini, the presence of regulatory proteins, and the addition of a biochemical energy source (ATP) or a non-hydrolysable equivalent (ATP-γS). With a clustering analysis based solely on these molecular-scale measures of the local binding environment at the dsRNA terminus, we identify sub-populations of similar conformations that define distinct modes of molecular recognition which are correlated with biochemical activity. These observations reveal the important role of substrate-selective molecular recognition properties for proteins with multiple domains that can bind RNA, regulatory proteins, and cofactors.STATEMENT OF SIGNIFICANCEThe molecular-scale determinants of protein-RNA binding remain elusive, particularly when different subunits of a single protein confer specificity toward small structural differences of their RNA partners. An important case is that of Drosophila melanogaster Dicer-2, a critical component of the antiviral RNA interference response. Dicer-2 discriminates between double stranded RNA with blunt or 3’ overhang termini, a feature suggested to mediate recognition of “self” vs. “non-self” substrates. We study these interactions at the binding site with a fluorescent label at the RNA terminus, monitoring intramolecular and collective measures of flexibility to report on the local environment. Dicer-2 has distinct modes of molecular recognition which are regulated by accessory proteins and ATP, leading to different conformations and tuning biochemical activity.

Kokborok and the simple-complex reflexive distinction

This paper presents an in-depth investigation of the binding strategies in Kokborok and we will look more specifically how this sheds light on the theories of reflexivization. Kokborok, a Tibeto-Burman language spoken in Tripura, a state in the North-East of India, has two reflexives: sak sak ‘self self’ and sak baithaŋ ‘self self’. The form sak sak ‘self self’ conforms to Principle A of classic Binding Theory, blocking long-distance binding, but this does not hold true for sak baithaŋ allowing non-local binding. It is a well-established fact that some reflexives allow non-local binding, but it is generally assumed that this phenomenon is limited to a certain type of reflexive, morpho-syntactically ‘simple reflexives.’ The so-called ‘complex reflexives’ generally bar non-local binding, and the Kokborok reflexive sak baithaŋ seems an exception to that. This paper explores the uniqueness involved in the nature of anaphoric binding in Kokborok.

Logophoricity and Locality: A View from French Anaphors

In many unrelated languages, the same anaphor is either subject to Condition A of the binding theory, or exempt from it but with specific interpretive properties. On the basis of French data and crosslinguistic comparisons, I first show that such exempt anaphors must be anteceded by logophoric centers. Elaborating on but modifying Sells 1987 , I provide specific tests to argue that these logophoric antecedents can be classified into two kinds of perspective centers, attitude holders and empathy loci, thus reducing logophoricity to mental perspective. Next, I propose to derive the logophoricity of exempt anaphors from the following hypothesis: seemingly exempt anaphors are in fact bound by silent logophoric pronouns introduced by syntactically represented logophoric operators within their local domain. Crucially, this hypothesis, which is independently supported by exhaustive coreference constraints on locally cooccurring exempt anaphors, also accounts for their apparent exemption from Condition A, reanalyzed here as local binding by a silent logophoric binder.

Translating local binding energy to a device effective one

While nonfullerene acceptors based organic photovoltaics reaching high power conversion efficiency, their binding energy is 150–500 meV. Here there is a model considering disorder and entropy that able to quantitatively explain this controversy.

Long distance binding option for the Mandarin Chinese reflexive taziji

Contradicting prevailing claims in the literature, we report experimental evidence showing that the Chinese reflexive taziji has both local and long-distance binding options. We per-formed a series of formal judgment experiments manipulating the gender feature of the potential antecedents such that they matched or mismatched the anaphor’s gender using a bi-clausal structure with an argument reflexive in the embedded clause (e.g., Name1-says-Name2-Verb-taziji). Participants were asked to choose the antecedent of the anaphor (antecedent choice task) and also to judge the acceptability of the sentence (acceptability judgment task). Results showed that the reflexive taziji had both long-distance and local binding options, although the local binding option was preferred. Also, the pattern was replicated for the original examples taken from a widely used Chinese syntax textbook (Huang et al. 2009), contra the judgments reported there. We discuss the implications of this study from both theoretical and methodological perspectives.

Intrasentential binding and extrasentential binding in child and adult Korean

This article investigates the binding properties of the Korean reflexive caki. Korean caki allows a local antecedent, a long-distance sentence-internal antecedent, and (unusually) an extrasentential antecedent. Two experiments were conducted with Korean-speaking child participants (mean age = 5;8; age range = 5;1–6;4) and adult controls. The first tested local binding versus long-distance intrasentential binding, and the second tested extrasentential binding. The results show, first, that the children allowed both a local and a long-distance antecedent for caki, with a preference for the long-distance reading (counter to many claims that children show a robust preference for local antecedents crosslinguistically). Second, the children allowed caki to refer to an antecedent in a preceding sentence. These results indicate that, at an early stage, Korean children have acquired adult-like knowledge of the complex properties of caki, including what might be considered the computationally taxing option of extrasentential binding.

Anaphor binding

Scandinavian has a reflexive pronoun and a reflexive possessive for the 3rd person, and a reciprocal pronoun for all persons. Regular binding domains are finite and non-finite clauses, small clauses, and noun phrases with a verbal content and a genitive ‘agent’. There are also less expected binding relations within NPs, possibly involving an invisible binder. Within VP an indirect object may bind a direct object. Even non-c-commanding binders within VP do exist. Non-local binding into small clauses and infinitival clauses is frequent. Some varieties, especially Norwegian, also allow long distance binding, i.e. binding into finite subordinate clauses. At this point, there is a great deal of variation in acceptability, and definite rules are hard to identify.

Processing possessives in translation between unequal systems. An exploratory study

The present paper reports on results of two translation experiments conducted with eye tracking and keylogging. Norwegian and Danish professional and student translators have each translated a small English news text into their L1. The texts include possessives in different syntactic environments which affect choice between a reflexive and an irreflexive form in the targets. While native speakers are expected to make uniform choices which conform to regularities on local and non-local binding principles in Danish and Norwegian, we find disparate solutions among the participants in both groups. The study compares final products with process data, both in terms of edits and in terms of temporal measures indicative of translation effort. Results show a considerable amount of hesitation on choice in all non-finite clause constructions, although more so among students than among professionals. Questions of translation effects versus an unstable locality principle is taken up in the final discussion.