The apiary discovered in Stratum V at Tel Reḥov in 2005–2007 remains unique in the archaeology of the ancient Near East. Here the authors briefly summarize the data previously published in this journal and add results of new studies, mainly concerning the identification of ancient charred bees trapped in burnt honeycombs found in the hives. Measurements of two wings and one leg, and statistical work based on existing database of modern subspecies, are inconsistent with the Syrian subspecies local to Israel (Apis meliferra syriaca), but were found to be similar to the Anatolian bee (Apis meliferra anatoliaca). We discuss the implications of this result, suggesting trade relations with southern Anatolia. The authors suggest that the beeswax was perhaps related to the copper-based metallurgical industry that entailed casting in the lost wax method, at a time when the copper trade based on the Arabah mines was at its peak.
The collective properties of ordered ensembles of anisotropically shaped nanoparticles depend on the morphology of organization. Here, we describe the utilization of block copolymer micelles to bias the natural packing tendency of semiconductor nanorods and organize them into circularly arranged superstructures. These structures are formed as a result of competition between the segregation tendency of the nanorods in solution and in the polymer melt; when the nanorods are highly compatible with the solvent but prefer to segregate in the melt to the core-forming block, they migrate during annealing toward the core–corona interface, and their superstructure is, thus, templated by the shape of the micelle. The nanorods, in turn, exhibit surfactant-like behavior and protect the micelles from coalescence during annealing. Lastly, the influence of the attributes of the micelles on nanorod organization is also studied. The circular nanorod arrangements and the insights gained in this study add to a growing list of possibilities for organizing metal and semiconductor nanorods that can be achieved using rational design.
Supramolecular polymers are based on noncovalent interactions, which impart unique properties such as dynamic behavior, concentration-dependent degree of polymerization, and environmental responsiveness. While linear supramolecular polymers are ubiquitous and have been extensively studied, branched polymers that are based exclusively on supramolecular interactions are much less abundant, and a fundamental understanding of their molecular-level structure is still lacking. We report on the preparation of branched, all-supramolecular polymers based on a combination of a bisureidotoluene building block [N,N′-2,4-bis((2-ethylhexyl)ureido)toluene (EHUT)], which is associated with four-point hydrogen bonding, and three anionic co-monomers featuring one, two, or three sulfonate groups. The co-monomers were designed to serve as a chain stopper, a bifunctional linear comonomer, and a branch point. Whereas combination of EHUT with the singly functionalized co-monomer led to linear supramolecular chains, diffusion and viscosity data indicate that branched supramolecular polymers were obtained when EHUT was combined not only with the triply functionalized molecules but also with the doubly functionalized molecules. Theoretical analysis based on an adaptation of Flory’s theory of branched polymers suggests that in both cases, the interaction of certain EHUT units with the multiply functionalized co-monomers converted these EHUT units into branch points, which led to substantially reduced viscosities in these systems. The insights gained from this study enable tuning the properties of supramolecular polymers not only by concentration and temperature but also by introducing appropriately designed molecular additives. This may lead to the development of sophisticated smart materials.
During the height of the COVID-19 pandemic, teachers around the globe had been forced to move their teaching to full-time online, remote teaching. In this study, we aimed at understanding teacher burnout during COVID-19. We conducted a survey among 399 teachers at the peak of a prolonged physical school closure. Teachers reported experiencing more burnout during (vs. before) the COVID-19 pandemic. Contributing factors to this burnout were high family work conflict and low online teaching proficiency. Burnout was associated with lower work-related wellbeing: Lower work commitment, and higher turnover intentions. It was also associated with lower psychological wellbeing: More depressive and anxiety symptoms, and lower subjective wellbeing. Approach (but not avoid) coping strategies served as a protective factor against the burnout-turnover intentions association. We conclude with recommendations on how to mitigate teacher burnout, thereby contributing to teacher wellbeing.
Academically productive talk (APT) in classrooms has long been associated with significant gains in student learning and development. Yet, due to COVID-19 related restrictions, teachers around the world were forced to adapt their teaching to online, remote settings during the pandemic. In this investigation, we studied APT in junior high school during extended online, remote teaching spells. Specifically, we focused on the extent APT was a part of online teaching practices, what characterized teachers who tended to promote APT more in online, remote teaching, and associations between APT and teacher well-being, as well as student motivation and engagement. Findings from two survey studies (Study 1: 99 teachers, and 83 students; Study 2: 399 teachers) revealed the following patterns: Students and teachers agreed that APT was used to a lesser extent in remote, online classes, and associated with more interactive instructional formats (whole classroom discussion, peer group work, and questioning), but not with frontal teaching and individual task completion. Teachers with a higher sense of teaching self-efficacy, autonomous orientations, and higher empathy tended to promote APT in online, remote teaching more. More APT was associated with greater teachers’ work-related (i.e., lower burnout, more commitment to teaching, and lower turnover intentions) and psychological well-being (i.e., less depressive and anxiety symptoms, and higher subjective well-being). Finally, student experiences with APT in online, remote learning was positively associated with learning motivation and engagement. Theoretical and practical implications are discussed.
Research in the area of human information interaction (HII) typically represents viewpoints on debated topics in a binary fashion, as either against or in favor of a given topic (e.g., the feminist movement). This simple taxonomy, however, greatly reduces the latent richness of viewpoints and thereby limits the potential of research and practical applications in this field. Work in the communication sciences has already demonstrated that viewpoints can be represented in much more comprehensive ways, which could enable a deeper understanding of users’ interactions with debated topics online. For instance, a viewpoint’s stance usually has a degree of strength (e.g., mild or strong), and, even if two viewpoints support or oppose something to the same degree, they may use different logics of evaluation (i.e., underlying reasons). In this paper, we draw from communication science practice to propose a novel, two-dimensional way of representing viewpoints that incorporates a viewpoint’s stance degree as well as its logic of evaluation. We show in a case study of tweets on debated topics how our proposed viewpoint label can be obtained via crowdsourcing with acceptable reliability. By analyzing the resulting data set and conducting a user study, we further show that the two-dimensional viewpoint representation we propose allows for more meaningful analyses and diversification interventions compared to current approaches. Finally, we discuss what this novel viewpoint label implies for HII research and how obtaining it may be made cheaper in the future.
Smart windows are used to minimize overall indoor energy consumption for thermal regulation through the modulation of radiant and conducted heat. While the control of thermal radiation can be done effectively by various technologies such as electrochromic, thermochromic, photochromic, etc., the modulation of heat conduction through smart windows remains a very challenging problem to be solved. The main obstacles are the lack of an effective conduction pathway within a double-glazed window and the need for a reliable active thermal switching mechanism. In this work, we introduce a novel idea for modulating heat conduction through a smart window by building thermally conductive pathways via coatings together with a heat transfer switching channel. The thermal switch uses various FexOy-decorated carbon-based nanomaterials that can be turned ‘ON’ or ‘OFF’, thus modulating heat conduction through a window. By applying an external magnetic force, such carbon-based magnetic nanomaterials can be easily moved or aligned within the switching channel to modulate thermal conduction. In this work, FexOy-decorated carbon nanotubes (CNTs) and graphene are developed as a thermal conduction pathway, and a thermal heat switching mechanism is developed and proposed. The FexOy-decorated carbon nanotubes (CNTs) and graphene show excellent heat diffusivity as a thermal conduction pathway coating, through a 2 mm channel gap with a 40 mm distance from the heat source, whilst the thermal conduction switch proposed is shown to effectively modulate thermal conduction through it.
Soft lithography techniques have become leading mesoscale approaches for replicating topographic features in polymer films. So far, the modified polymer films formed by soft lithography only featured topographic heterogeneity. Here we demonstrate the application of soft lithography techniques to block copolymer films, and show that the preferential affinity of one of the blocks to the stamping material leads to chemical heterogeneity that corresponds to the topographic features. Detailed surface and structural characterization of the patterned films provided information on its three-dimensional structure, revealing insights on the domain reorganization that takes place in the block copolymer film concomitantly with topography formation. The formed structures were utilized for selective assembly of gold nanoparticles into hierarchical structures. The versatility of this combined nanofabrication/self-assembly approach was demonstrated by the assembly of two types of metallic nanoparticles into two different arrangements with full control over the location of each type of nanoparticles.
