The Asteropyginae Delo, 1935 is a group of phacopid trilobites in the family Acastidae Delo, 1935 that has served as the focus for several studies due to their distinctive morphologies and diversity. However, despite an interest in these characteristic morphologies, there have been no studies that have examined this group using morphometric techniques. Our investigation utilized both geometric morphometric and elliptical Fourier methods to quantify the morphology of cephalic sclerites of asteropyginid specimens representing wide taxonomic sampling of the clade. We constructed a phylomorphospace that shows temporal and spatial patterns of phenotypic evolution within the framework of a novel tip-dated phylogenetic tree generated using Bayesian inference. We recovered similar patterns in disparity regardless of the morphometric approach. Both analyses illustrated a marked expansion into morphospace throughout the temporal range of the clade, peaking in disparity in the Emsian and with European taxa exhibiting the highest disparity in glabellar morphospace. Additionally, glabellar shape showed low phylogenetic signal and no major patterns in phylomorphospace. This study highlights the utility of employing different methodologies to quantitatively explore the disparity of fossil taxa. It also illustrates some of the patterns of morphological change occurring during one of the final and major evolutionary radiations within Phacopida.

Sharks have a long and rich fossil record that consists predominantly of isolated teeth due to the poorly mineralized cartilaginous skeleton. Tiger sharks (Galeocerdo), which represent apex predators in modern oceans, have a known fossil record extending back into the early Eocene (ca. 56 Ma) and comprise 22 recognized extinct and one extant species to date. However, many of the fossil species remain dubious, resulting in a still unresolved evolutionary history of the tiger shark genus. Here, we present a revision of the fossil record of Galeocerdo by examining the morphological diversity and disparity of teeth in deep time. We use landmark-based geometric morphometrics to quantify tooth shapes and qualitative morphological characters for species discrimination. Employing this combined approach on fossil and extant tiger shark teeth, our results only support six species to represent valid taxa. Furthermore, the disparity analysis revealed that diversity and disparity are not implicitly correlated and that Galeocerdo retained a relatively high dental disparity since the Miocene despite its decrease from four to one species. With this study, we demonstrate that the combined approach of quantitative geometric morphometric techniques and qualitative morphological comparisons on isolated shark teeth provides a useful tool to distinguish between species with highly similar tooth morphologies.

The bottom of the pyramid (BoP) consists of 1.4 billion people living less than 1.25 USD per day. Fulfilling unmet needs of BoP people involves the design of products as a main activity. Designing products for the BoP faces two main problems. First, there is a general lack of understanding of the needs of users and second, traditional design methods may be limited in addressing the BoP context. Frugal innovation is positioned as a very interesting approach with the potential to adequately respond to the design challenges of the products for the BoP. However, studies in engineering design based on frugal innovation are still limited. In response to these issues, through an analysis and review of the literature, an exploratory mapping of the proposals in frugal innovation and the characteristics of the BoP was conducted. On the basis of the results, this paper defines a set of eight frugal criteria design and an identification of three dimensions that characterize a BoP context and two roles of BoP people. Finally, an association of BoP dimensions and roles with the key criteria of frugal design is proposed.

Vanadium dioxide (VO2) displays a well-known metal-insulator (MI) transition at a temperature of 68°C. In this study we use terahertz time-domain spectroscopy (THz-TDS) to investigate the optical properties of VO2 thin films in the vicinity of the MI transition temperature in the frequency range 0.1 – 1.5 THz. We observe the interesting effect that the phase of the transmitted THz field through the conducting VO2 film is delayed in comparison to the phase of the same THz signal transmitted through the insulating VO2 film. This is in contrast to the expected behavior of a homogeneous, conducting film. This observation shows that even at temperatures significantly above the transition temperature, the formation of a homogeneous, conducting film is incomplete. We demonstrate that effective-medium theory (EMT) in combination with a Drude model accounting for the conductivity of metallic domains formed in the VO2 film accounts for all our observations. We show that the Maxwell-Garnett EMT is consistent with our observations, whereas the Bruggeman EMT fails to account for our observations.

We have fabricated ordered arrays of gold nanocrystals on FIB-processed silicon substrates using electroless deposition. We have also fabricated ordered arrays of silver nanocrystals on silicon with diameters 40–60 nm separated by 180 nm center-to-center, using pulsed-laser deposition (PLD) to deposit silver on the substrate. The metal nanocrystal arrays are characterized using SEM as well as AFM and energy dispersive x-ray (EDX) analysis. AFM confirms particle sizes measured in SEM, and EDX analysis demonstrates that Ag preferentially clusters at sites that have been damaged by the ion beam. These results suggest that the FIB-PLD combination can be used to create ordered arrays of Ag nanocrystals with diameters of 10 nm or less.