Multivalent Molecular Motors for Surface Attachment

Moleculaire motoren zijn een unieke groep fotoresponsieve organische verbindingen die in staat zijn licht energie om te zetten in repetitieve unidirectionele rotationele beweging.Een belangrijke uitdaging in het ontwikkelen van lichtgestuurde systemen gebaseerd op motoren is gebruik te maken van de collectieve roterende beweging om een interactie aan te gaan met macro-objecten op een dynamische manier. Echter, de roterende beweging van moleculaire motor wordt overweldigd door Browniaanse beweging wanneer de moleculen in oplossing zijn. Motoren beperken tot oppervlaktes zou de Browniaanse beweging kunnen onderdrukken en zodoende is het mogelijk om de relatieve rotatie van één deel van het molecuul ten opzichte van het andere, om te zetten in absolute rotatie van de rotor ten opzichte van het oppervlak. Er zijn twee manieren om motoren op een oppervlak te bevestigen: azimutaal en altitudinaal. In de azimutale oriëntatie staat de as van rotatie loodrecht op het oppervlak, terwijl in de altitudinale oriëntatie de as evenwijdig is aan het oppervlak.De juiste assemblage van motoren op oppervlakken met behoud van hun roterende beweging is uitermate uitdagend en van grote betekenis voor het benutten van de collectieve beweging om arbeid te verrichten. Het verhinderen van interferentie effecten, de oriëntatie ten opzichte van het oppervlak, de wijze van bevestiging, de afstand tot het oppervlak, de rigiditeit van de verankeringsgroepen, en de bepakkingsdichtheid van de rotor groepen zijn allemaal fundamentele kwesties die overwogen en aangepakt dienen te worden om zodoende nieuwe, op motoren gebaseerde, aan het oppervlak gebonden systemen te maken voor dynamische nanoschaal toepassingen.Molecular motors are a unique group of photoresponsive organic molecules that are able to convert light energy into repetitive unidirectional rotary motion which is controlled by the stereogenic center in the rotor moiety.A key challenge in developing photo driven systems based on molecular motors is to exploit their collective rotary motion in order to interact with external, micro- or macro objects in a dynamic manner. However, the rotary motion of molecular motors is overwhelmed by Brownian motion while the molecules are in solution. Confining molecular motors to surfaces could inhibit Brownian motion and hence the relative rotation of one part of the molecule with respect to the other could be converted to absolute rotation of the rotor relative to the surface.When molecular motors are attached to the surface, two kinds of orientations could be envisioned: azimuthal and altitudinal. In the azimuthal orientation the axis of rotation is perpendicular to the surface, while in the altitudinal orientation it is parallel to the surface.The proper assembly of light-driven molecular motors on surfaces while retaining their rotary motion is particularly challenging and of great importance for harnessing their collective motion to perform work. To avoid interference effects, orientation with respect to surface, mode of attachment (number of legs), distance from the surface, rigidity of anchoring groups, and packing density of the rotor moieties are all basic issues to be considered and addressed for the successful construction of new surface-bound systems based on molecular motors for dynamic nanoscale applications

Towards Dynamic Control of Wettability by Using Functionalized Altitudinal Molecular Motors on Solid Surfaces

We report the synthesis of altitudinal molecular motors that contain functional groups in their rotor part. In an approach to achieve dynamic control over the properties of solid surfaces, a hydrophobic perfluorobutyl chain and a relatively hydrophilic cyano group were introduced to the rotor part of the motors. Molecular motors were attached to quartz surfa-ces by using interfacial 1,3-dipolar cycloadditions. To test the effect of the functional groups on the rotary motion, photochemical and thermal isomerization studies of the motors were per-formed both in solution and when attached to the surface. We found that the substituents have no significant effect on the thermal and photochemical processes, and the functionalized motors preserved their rotary function both in solution and on a quartz surface. Preliminary results on the influence of the functional groups on surface wettability are also described

ZARA: Improving Few-Shot Self-Rationalization for Small Language Models

Language models (LMs) that jointly generate end-task answers as well as free-text rationales are known as self-rationalization models. Recent works demonstrate great performance gain for self-rationalization by few-shot prompting LMs with rationale-augmented exemplars. However, the ability to benefit from explanations only emerges with large-scale LMs, which have poor accessibility. In this work, we explore the less-studied setting of leveraging explanations for small LMs to improve few-shot self-rationalization. We first revisit the relationship between rationales and answers. Inspired by the implicit mental process of how human beings assess explanations, we present a novel approach, Zero-shot Augmentation of Rationale-Answer pairs (ZARA), to automatically construct pseudo-parallel data for self-training by reducing the problem of plausibility judgement to natural language inference. Experimental results show ZARA achieves SOTA performance on the FEB benchmark, for both the task accuracy and the explanation metric. In addition, we conduct human and quantitative evaluation validating ZARA's ability to automatically identify plausible and accurate rationale-answer pairs.Comment: Accepted as a long paper at EMNLP Findings 202

Transactive Memory System, Job Competence and Individual Performance

The purpose of this paper is to understand important variables that impact individual performance within a team. This will enhance knowledge management within a team context and facilitate competence development of individuals. This research proposes and examines a multi-level model which elaborates how transactive memory system and job competence (i.e., technology competence and teamwork competence) affect individual performance. An empirical study was conducted with 19 teams of television news reporters, with 211 valid survey responses. Hierarchical linear modeling was applied to analyze the data. The result indicated that transactive memory system and technology competence helped to improve a reporter’s job performance. Furthermore, the relationships were fully mediated by teamwork competence. Our findings thus suggest teamwork competence is the core. Neither technology competence nor transactive memory system will necessarily translate directly into enhanced individual performance. Therefore, for organizational investment on transactive memory system and digital technologies to take effect, management should help develop the employee’s teamwork competence

SiGeo: Sub-One-Shot NAS via Information Theory and Geometry of Loss Landscape

Neural Architecture Search (NAS) has become a widely used tool for automating neural network design. While one-shot NAS methods have successfully reduced computational requirements, they often require extensive training. On the other hand, zero-shot NAS utilizes training-free proxies to evaluate a candidate architecture's test performance but has two limitations: (1) inability to use the information gained as a network improves with training and (2) unreliable performance, particularly in complex domains like RecSys, due to the multi-modal data inputs and complex architecture configurations. To synthesize the benefits of both methods, we introduce a "sub-one-shot" paradigm that serves as a bridge between zero-shot and one-shot NAS. In sub-one-shot NAS, the supernet is trained using only a small subset of the training data, a phase we refer to as "warm-up." Within this framework, we present SiGeo, a proxy founded on a novel theoretical framework that connects the supernet warm-up with the efficacy of the proxy. Extensive experiments have shown that SiGeo, with the benefit of warm-up, consistently outperforms state-of-the-art NAS proxies on various established NAS benchmarks. When a supernet is warmed up, it can achieve comparable performance to weight-sharing one-shot NAS methods, but with a significant reduction ($\sim 60$\%) in computational costs.Comment: 24 pages, 7 figure