Percolation experiment across a 10-year-old interface between Opalinus Clay and Portland concrete

An interface sample between Portland concrete and Opalinus Clay with a contact time of 10 years recovered from a field experiment was investigated by SEM-EDX and X-ray CT. The concrete side showed a large chloride ingress from the claystone alongside a decalcification and an opening of the porosity. Additional XRD, TGA and leaching experiments of the concrete at few centimetres (∼5 cm) away from the interface confirmed the chloride ingress. The interface was then subjected to a long-term percolation experiment accompanied with repeated X-ray CT-scans. Injection of synthetic claystone pore water proceeded into the claystone-part of the sample, and through the concrete part, whereby the outflow was continuously sampled. The bedding joints that were partially desaturated rapidly saturated, while hydraulic conductivity steadily decreased to values similar to unaltered claystone. The analysis of the exfiltrating aliquots shed light on the advective/diffusive properties of water transport and multi-component solute transport

Micro-X-ray diffraction and chemical mapping of aged interfaces between cement pastes and Opalinus Clay

The safety of a geological repository designed for deep storage of nuclear waste rests on the long-lived isolation properties of the geological environment and the engineered barrier system. To study the chemical and physical behaviour of cementitious/clayey interfaces, such interfaces have been collected during repeat sampling campaigns of the CI Experiment (Cement-Clay Interaction Experiment) at the Mont Terri rock laboratory (St. Ursanne, Switzerland, www.mont-terri.ch) over the last decade. This study focuses on the advanced analysis by µ-XRD mapping to locate and identify the mineral phases on each side of the interface. The hydrates as portlandite, ettringite and C-S-H present in the Portland cement (PC) were dissolved in contact with the Opalinus Clay (OPA) up to different depths (~0.2 mm for portlandite; ~1 mm for ettringite; completely depleted for C-S-H up to 0.1 mm and less visible on a 1-mm-depth) while the ettringite from ESDRED (a low-pH cement type) seems to be destabilized to a larger depth ( ≥ 3 mm ). In contrast to former studies, calcite could not be clearly observed at the interface PC - OPA but was well developed at the interface ESDRED - OPA. The extent of reaction after 10 years is very small in both cases, and dissolution of clay minerals remains below detection. The identification of mineral phases involved in reactions facilitates the understanding of the processes, thus, will help to improve the reactive transport models used to simulate the evolution over long times

Is science communication its own field?

The present comment examines to what extent science communication has attained the status of an academic discipline and a distinct research field, as opposed to the common view that science communication is merely a sub-discipline of media studies, sociology of science or history of science. Against this background, the authors of this comment chart the progress science communication has made as an emerging subject over the last 50 years in terms of a number of measures. Although discussions are still ongoing about the elements that must be present to constitute a legitimate disciplinary field, we show here that science communication meets four key elements that constitute an analytical framework to classify academic disciplines: the presence of a community; a history of inquiry; a mode of inquiry that defines how data is collected; and the existence of a communications network

Neurotropism and behavioral changes associated with Zika infection in the vector Aedes aegypti

Understanding Zika virus infection dynamics is essential, as its recent emergence revealed possible devastating neuropathologies in humans, thus causing a major threat to public health worldwide. Recent research allowed breakthrough in our understanding of the virus and host pathogenesis; however, little is known on its impact on its main vector, Aedes aegypti. Here we show how Zika virus targets Aedes aegypti’s neurons and induces changes in its behavior. Results are compared to dengue virus, another flavivirus, which triggers a different pattern of behavioral changes. We used microelectrode array technology to record electrical spiking activity of mosquito primary neurons post infections and discovered that only Zika virus causes an increase in spiking activity of the neuronal network. Confocal microscopy also revealed an increase in synapse connections for Zika virus-infected neuronal networks. Interestingly, the results also showed that mosquito responds to infection by overexpressing glutamate regulatory genes while maintaining virus levels. This neuro-excitation, possibly via glutamate, could contribute to the observed behavioral changes in Zika virus-infected Aedes aegypti females. This study reveals the importance of virus-vector interaction in arbovirus neurotropism, in humans and vector. However, it appears that the consequences differ in the two hosts, with neuropathology in human host, while behavioral changes in the mosquito vector that may be advantageous to the virus

Living with Volcan Tungurahua: the dynamics of vulnerability during prolonged volcanic activity

For the people that live around many of the world’s volcanos, the effects of eruptive activity on livelihoods and wellbeing are seldom experienced as a one-off event. Not only do volcanos commonly enter long-lived phases of activity, during which the physical hazards they create alter in characteristics, but the way exposure to such hazards generates impacts on society and shapes responses by people and institutions also modifies and evolves. Within this dynamic process, the behaviour of the volcano provides a framing, but social, economic and political changes interact to shape unfolding patterns of vulnerability. The research presented in this paper explored this complexity of impact and social change for the case of Volcan Tungurahua in Ecuador, which has been in eruptive phase since 1999. Focussing on the people who live in different areas around the volcano, the study used interview and survey evidence to examine changing knowledge about eruptions and how people have experienced the effects of the volcano over time on their economic livelihoods, mobility, residence patterns, and access to services and infrastructure. Crucially, this meant recognising that the existence of a threat from hazards had societal implications, regardless of whether or not the volcano is actually in a state of high activity. These implications played out differently for different sections of the neighbouring population, with the strongest contrast emerging between the rural and urban populations, though the complexity of the case defies a simple binary comparison. The research underlines the importance of building a longitudinal element into analysis

Pandem-icons — exploring the characteristics of highly visible scientists during the Covid-19 pandemic

The Covid-19 pandemic escalated demand for scientific explanations and guidance, creating opportunities for scientists to become publicly visible. In this study, we compared characteristics of visible scientists during the first year of the Covid-19 pandemic (January to December 2020) across 16 countries. We find that the scientists who became visible largely matched socio-cultural criteria that have characterised visible scientists in the past (e.g., age, gender, credibility, public image, involvement in controversies). However, there were limited tendencies that scientists commented outside their areas of expertise. We conclude that the unusual circumstances created by Covid-19 did not change the phenomenon of visible scientists in significant way

Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model