Human infection challenge in the pandemic era and beyond, HIC-Vac annual meeting report, 2022

HIC-Vac is an international network of researchers dedicated to developing human infection challenge studies to accelerate vaccine development against pathogens of high global impact. The HIC-Vac Annual Meeting (3rd and 4th November 2022) brought together stakeholders including researchers, ethicists, volunteers, policymakers, industry partners, and funders with a strong representation from low- and middle-income countries. The network enables sharing of research findings, especially in endemic regions. Discussions included pandemic preparedness and the role of human challenge to accelerate vaccine development during outbreak, with industry speakers emphasising the great utility of human challenge in vaccine development. Public consent, engagement, and participation in human challenge studies were addressed, along with the role of embedded social science and empirical studies to uncover social, ethical, and regulatory issues around human infection challenge studies. Study volunteers shared their experiences and motivations for participating in studies. This report summarises completed and ongoing human challenge studies across a variety of pathogens and demographics, and addresses other key issues discussed at the meeting

The evolution of language: a comparative review

For many years the evolution of language has been seen as a disreputable topic, mired in fanciful "just so stories" about language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language. I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species, from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language, and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the ‘‘descended larynx’ ’ of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny, discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our most distinctively human trait: language

Light trapping for solar cells using localised surface plasmons in self-assembled AG nanoparticles

Ag nanoparticle arrays, located on the front or rear surface of a Si solar cell, can provide effective lighttrapping via the excitation of localised surface plasmons. We identify key parameters in engineering random Ag nanoparticle arrays for optimum plasmonic light-trapping. We demonstrate that there is an asymmetry in scattering behaviour between particles located on the front and rear of a Si substrate, which we attribute to differences in the driving field at the position of the nanoparticles. Applying the design considerations presented, we report a relative photocurrent increase of 27% over the light trapping spectral region for thin c-Si solar cells incorporating a rearlocated self-assembled Ag nanoparticle array, constituting the largest reported enhancement due to plasmonic light trapping for such cells. Inclusion of a detached rear reflector behind these particles increases the photocurrent enhancement to 33%

Periodic silver nanoparticles fabricated with soft-stamp nanoimprint on silicon solar cells

The fabrication of periodic silver nanoparticle arrays has been successfully demonstrated by adapting nanoimprint lithography. This method has the advantage of good control on the size and shape of the particles and other advantages such as low fabrication cost, large coverage and robust process. In this study, we varied the Ag nanoparticle shape by a simple annealing process. The diameter to height ratio was varied from 1:0.3 to 1:1.7. We applied the periodic Ag nanoparticles on the front of a 2mm c-Si cell, which showed EQE enhancement over long wavelength region (750nm to 1100nm), but also reduction in the short wavelength region (380nm to 750nm). However, by putting the periodic Ag nanoparticles on the rear, the reduction in the short wavelength region is eliminated while still maintaining the enhanced EQE in the long wavelength region. A photocurrent increment of 11% over the spectral region is observed with an EQE enhancement of 300% at 1050nm

Contactless and Spatially Resolved Determination of Current-Voltage Curves in Perovskite Solar Cells via Photoluminescence

Early prediction of spatially resolved performance of perovskite solar cells (PSCs) is essential for process monitoring, control and fault diagnosis, and upscaling of this emerging technology. Herein, a fast, nonde structive, contactless imaging-based approach is developed to visualize the spatial distribution of possible light current density−voltage (pseudo-J−V) curves on finished and partly finished cells. This allows for the extraction of other critical spatially resolved properties including implied open-circuit voltage and pseudo-fill factor. The technique is applied to systematically investigate various degradation behaviors on PSCs including thermal stability, light soaking, and ambient air exposure. Finally, it is used to predict pseudo-J−V curves of various perovskite films with different compositions. These results demonstrate the significant value of this fast imaging technique for the research and development of PSCs ranging from material selection, process optimization, to degradation study