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Far-UVC : the impact of optical filters on real-world deployment
Get PDFIn 2015, a study showed that Krypton-Chloride (KrCl) excimer lamps could induce erythema and basal layer DNA damage in human skin. Later studies found that filtering out longer wavelength emissions from these lamps resulted in no acute skin effects. However, there is a limited understanding of how much to reduce unwanted emissions and which wavelengths are important. Accurate spectral irradiance data is therefore crucial for safety, as variance in optical filtering significantly affects the weighted irradiance of a lamp. To simplify the risk assessment process for Far-UVC lamps, we highlight the usefulness of the lamp exposure limit (HLEL) and present this in the context of spectral emission data for 14 commercially available Far-UVC lamps. Our results demonstrate that relying solely on a radiometric measurement and a single-wavelength exposure limit at 222 nm could lead to over-exposure. The HLEL is a practical metric which can be utilized to determine the exposure time before reaching the exposure limit. It can also be used in the determination of the minimum ceiling height for compliance with standards like UL 8802. Manufacturers are urged to provide HLEL for their products; installers should adhere to HLEL; and standards and regulatory bodies should insist on this information in new guidance.Peer reviewe
HR 10 as seen by CHEOPS and TESS : revealing δ Scuti pulsations, granulation-like signal and hint for transients
Get PDFFunding: CHEOPS is an ESA mission in partnership with Switzerland with important contributions to the payload and the ground segment from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the United Kingdom. The CHEOPS Consortium would like to gratefully acknowledge the support received by all the agencies, offices, universities, and industries involved. Their flexibility and willingness to explore new approaches were essential to the success of this mission. This paper includes data collected by the TESS mission that are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA’s Science Mission directorate. We are grateful to V. Antoci for helpful comments. SJAJS has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 833925, project STAREX). VVG is an F.R.S-FNRS Research Associate. SS acknowledges the support from CNES, the Programme National de Planétologie (PNP), and the Programme National de Physique Stellaire (PNPS) of CNRS-INSU. GyMSz acknowledges the support of the Hungarian National Research, Development and Innovation Office (NKFIH) grant K-125015, a a PRODEX Experiment Agreement No. 4000137122, the Lendület LP2018-7/2021 grant of the Hungarian Academy of Science and the support of the city of Szombathely. ABr was supported by the SNSA. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project Four Aces. SH gratefully acknowledges CNES funding through the grant 837319. SGS acknowledges support from FCT through FCT contract nr. CEECIND/00826/2018 and POPH/FSE (EC). DG gratefully acknowledges financial support from the CRT foundation under Grant No. 2018.2323 “Gaseous or rocky? Unveiling the nature of small worlds”. SC acknowledges financial support from the Centre National d’Etudes Spatiales (CNES, France) and from the Agence Nationale de la Recherche (ANR, France) under grant ANR-17- CE31-0018, funding the INSIDE project. ACC and TW acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. YAl acknowledges the support of the Swiss National Fund under grant 200020_172746. We acknowledge support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grants ESP2016-80435-C2-1-R, ESP2016- 80435-C2-2-R, PGC2018-098153-B-C33, PGC2018-098153-B-C31, ESP2017- 87676-C5-1-R, MDM-2017-0737 Unidad de Excelencia Maria de MaeztuCentro de Astrobiología (INTA-CSIC), as well as the support of the Generalitat de Catalunya/CERCA programme. The MOC activities have been supported by the ESA contract No. 4000124370. SCCB acknowledges support from FCT through FCT contracts nr. IF/01312/2014/CP1215/CT0004. XB, SC, DG, MF and JL acknowledge their role as ESA-appointed CHEOPS science team members. LBo, VNa, IPa, GPi, RRa, GSc, VSi, and TZi acknowledge support from CHEOPS ASI-INAF agreement n. 2019-29-HH.0. ACC acknowledges support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1. PEC is funded by the Austrian Science Fund (FWF) Erwin Schroedinger Fellowship, program J4595-N. This project was supported by the CNES. The Belgian participation to CHEOPS has been supported by the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Program, and by the University of Liège through an ARC grant for Concerted Research Actions financed by the WalloniaBrussels Federation. LD is an F.R.S.-FNRS Postdoctoral Researcher. This work was supported by FCT – Fundação para a Ciência e a Tecnologia through national funds and by FEDER through COMPETE2020 – Programa Operacional Competitividade e Internacionalizacão by these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 and POCI01-0145-FEDER- 032113, PTDC/FIS-AST/28953/2017 and POCI-01-0145- FEDER-028953, PTDC/FIS-AST/28987/2017 and POCI-01-0145-FEDER028987, O.D.S.D. is supported in the form of work contract (DL 57/2016/CP1364/CT0004) funded by national funds through FCT. B-OD acknowledges support from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00046. MF and CMP gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19, 174/18). MG is an F.R.S.-FNRS Senior Research Associate. KGI is the ESA CHEOPS Project Scientist and is responsible for the ESA CHEOPS Guest Observers Programme. She does not participate in, or contribute to, the definition of the Guaranteed Time Programme of the CHEOPS mission through which observations described in this paper have been taken, nor to any aspect of target selection for the programme. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. ML acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. PM acknowledges support from STFC research grant number ST/M001040/1. This work was also partially supported by a grant from the Simons Foundation (PI Queloz, grant number 327127). IRI acknowledges support from the Spanish Ministry of Science and Innovation and the European Regional Development Fund through grant PGC2018-098153-B- C33, as well as the support of the Generalitat de Catalunya/CERCA programme. NAW acknowledges UKSA grant ST/R004838/1.Context . HR 10 has only recently been identified as a binary system. Previously thought to be an A-type shell star, it appears that both components are fast-rotating A-type stars, each presenting a circumstellar envelope. Although showing complex photometric variability, spectroscopic observations of the metallic absorption lines reveal variation explained by the binarity, but not indicative of debris-disc inhomogeneities or sublimating exocomets. On the other hand, the properties of the two stars make them potential δ Scuti pulsators. Aims . The system has been observed in two sectors by the TESS satellite, and was the target of three observing visits by CHEOPS. Thanks to these new data, we aim to further characterise the stellar properties of the two components. In particular, we aim to decipher the extent to which the photometric variability can be attributed to a stellar origin. In complement, we searched in the lightcurves for transient-type events that could reveal debris discs or exocomets. Methods . We analysed the photometric variability of both the TESS and CHEOPS datasets in detail. We first performed a frequency analysis to identify and list all the periodic signals that may be related to stellar oscillations or surface variability. The signals identified as resulting from the stellar variability were then removed from the lightcurves in order to search for transient events in the residuals. Results . We report the detection of δ Scuti pulsations in both the TESS and CHEOPS data, but we cannot definitively identify which of the components is the pulsating star. In both datasets, we find flicker noise with the characteristics of a stellar granulation signal. However, it remains difficult to firmly attribute it to actual stellar granulation from convection, given the very thin surface convective zones predicted for both stars. Finally, we report probable detection of transient events in the CHEOPS data, without clear evidence of their origin.Peer reviewe
Navigating the nexus of elections, technology and democracy amid escalating disinformation and misinformation challenges in Kenya
Get PDFDespite Kenya’s transformative and progressive 2010 Constitution, it is still grappling with a hybrid democracy, displaying both authoritarian and democratic traits. Scholars attribute this status to several factors, with a prominent one being the domination of the political order and wielding of political power by a few individuals and families with historical ties to patronage networks and informal power structures. The persisting issues of electoral fraud, widespread corruption, media harassment, weak rule of law and governance challenges further contribute to the hybrid democracy status. While the 2010 Constitution aims to restructure the state and enhance democratic institutions, the transition process is considered incomplete, especially since the judiciary’s role of judicial review is mostly faced with the difficult task of countering democratic regression. Moreover, critical institutions such as the Independent Electoral and Boundaries Commission (IEBC) have faced criticism due to corruption scandals and perceptions of partisanship, eroding public trust in their ability to oversee fair elections effectively
Landscape influences bat suppression of pine processionary moth : implications for pest management
Get PDFFunding: This work was funded by FCT – Fundação para a Ciência e a Tecnologia, Portugal, under the Project BatPine AAC/02/SAICT/2017/31731 and CE3C (UIDB/00329/2020) – DOI: 10.54499/UIDB/00329/2020. FCT also funded Ana Margarida Augusto (PD/BD/150555/2019). Tiago Marques and Soraia Pereira acknowledge partial support from CEAUL (funded by FCT – DOI: 10.54499/UIDB/00006/2020).Bats provide important ecosystem services, particularly in agriculture, yet integrating bat management into conservation plans remains challenging. Some landscape features considerably influence bat presence, diversity, and ecosystem service provision. Understanding the relationship between landscape structure, composition, pest suppression, and ecosystem services is crucial. We modelled areas where bats most effectively suppress pine processionary moths (Thaumetopoea pityocampa), considering landscape characteristics to predict ecosystem services and optimise pest suppression in Serra da Estrela, Portugal. Faecal samples collected during fieldwork were analysed for pine processionary moth presence in bat diets. Lasso regression assessed spatial landscape variables to create an “optimal landscape” for predation. Landscape structure and composition influenced pest suppression differently, with the greatest impact within a 5000-m buffer. “Riparian edge” and “tree cover density” were key habitat structure variables supporting bat navigation and access to hunting areas, while “other forest” and “vineyard/orchard” areas were important composition variables. Optimising landscape composition involves incorporating diverse forest within agroforestry systems to enhance pest suppression by creating habitats reflecting bats' foraging preferences. We recommend strategies focusing on riparian edge conservation, selective canopy reduction, and promoting diverse forest compositions. These strategies aim to create mosaic landscapes balancing land uses, fostering optimal conditions for bat foraging. Our study shows edges provide the highest rates of bats-pine processionary moth interactions. However, caution is needed to avoid excessive fragmentation, which may reduce habitat suitability and increase pest presence before effective bat predation. A balanced approach, focusing on edge creation without over-fragmenting the landscape, is key to promoting sustainable pest management.Peer reviewe
Writing for justice, reading for absence
Get PDFConversing with Laura Shepherd in The Self and Other Stories, this essay considers accompaniment, embodiment, expertise, and representation through a care-infused lens. I present my readings of contentions in her book, and ask what it means to view position, power, and presence in writing. Through my reading, I present Shepherd’s vulnerability as a mode of writing justice, despite its absences.Peer reviewe
Context in memory is reconstructed, not encoded
Get PDFFunding: This paper is the result of work from the interdisciplinary Representing Memory project supported by Durham University’s Institute of Advanced Study (IAS). We also acknowledge the support of the Durham University IAS in awarding Fellowships to JA, AH & JS.Context has long been regarded as an important element of long-term memory, and episodic memory in particular. The ability to remember not only the object or focus of a memory but also contextual details allow us to reconstruct integrated representations of events. However, despite its prevalence in the memory literature, context remains difficult to define and identify, with different studies using context to refer to different sets of stimuli or concepts. These varying definitions of context have not prevented it from being a key element of many models of memory. Within these models, context is usually explicitly encoded as an element of an event and processed through different neural pathways to other elements of the event, such as objects. Here we challenge the notion that context in memory is encoded. We offer an alternative where context in memory takes a variety of forms depending on the question being asked. We propose events are simply encoded, but the focus of retrieval (object) and context are not defined until recall.Peer reviewe
A third player : Chinese linguistic and cultural influence at a UAE university
Get PDFAs part of China’s Belt and Road Initiative (BRI), a series of large-scale projects have been launched in the Arab Gulf due to its geopolitically strategic position. We examine the influence of Chinese as a third player, in addition to Arabic and English, in a UAE university educationscape together with Emirati students’ attitudes towards its influence. The study takes a case study approach, which employs open-ended questionnaires with university students (n = 40), semi-structured interviews with university students (n = 3) and a university Confucius Institute director and visual data from a walking ethnography of university social, learning, and online spaces. Data are analysed thematically via the lens of ‘Critical, Cultural Political Economy of Education’ (CCPEE), which brings together a range of concepts to interrogate globalising processes within an ‘education ensemble’. Key findings revealed a growing influence and awareness of Chinese language and culture in the UAE as well as generally positive attitudes towards such growth. There was, however, less interest in learning Chinese in comparison with other languages such as Korean and Turkish connected with soft power and media presence via dramas and music. Implications of the findings are discussed in relation to informing future language policy directions in the UAE.Peer reviewe
Monitoring soil erosion and vegetation pattern related to microclimatic conditions in Icelandic and Fennoscandian tundra
Get PDFThe Arctic tundra, a key regulator of the global carbon cycle that stores nearly half of the world's below-ground organic carbon, is increasingly threatened by soil erosion driven by climate change and anthropogenic activity. Topography moderates these impacts on small spatial scales by creating microclimates that shape biogeomorphological processes and the distribution of barren and vegetated areas. Seasonal variations further influence these dynamics, adding to the complexity of monitoring and assessing landscape resilience under growing environmental pressures.
This research addresses two key questions: How can we best monitor tundra environments? Where and how will different tundra environments respond to changing climatic conditions?
Fieldwork was conducted in Svalbarðshreppur, Iceland and Kilpisjärvi, Finland during the growing seasons of 2021-2023. Methods included remote sensing data from multispectral uncrewed aerial vehicle (UAV) surveys, optical satellites (Landsat, Sentinel-2, PlanetScope) and digital elevation models derived from UAV, aerial LiDAR (light detection and ranging) and ArcticDEM. Soil moisture and temperature sensors were deployed along mesotopographic transects, together with vegetation surveys, to provide ground-level information.
Findings revealed limitations of common satellite systems for soil erosion monitoring due to spectral confusion caused by shrub expansion. The Shannon Evenness Index was introduced to identify suitable spatial resolutions for environmental monitoring, revealing that a resolution of <3 m is necessary in Iceland to minimise excessive mixed pixels. Seasonal microclimatic conditions and topographic position influenced the distribution of land cover and plant structure. In summer, soil moisture impacted plant species richness and distribution, with increased water stress observed on ridge positions. In winter, snow cover duration (SCD), associated with thermal insulation and wind protection, was a determining factor on the distribution of barren and vegetated areas. In Finland, an SCD of approximately 155 days was identified as a tipping point, beyond which snow cover shifts from benefiting vegetation to suppressing it."The PhD was funded by the St Andrews World Leading Scholarship. The research visit and fieldwork conducted in Finland was funded by the Scottish Alliance for Geoscience, Environment & Society (SAGES) Saltire Award (2022). Santander Research Mobility award supported a field trip to Iceland (2022). Smaller grant schemes from Scottish Arctic Network (ScAN) and SAGES provided financial support for conferences."--Fundin
Reclaiming heaven from history : a theological critique of Martin Hägglund's This Life
Get PDFMartin Hägglund's This Life offers an incisive critique of Christian visions of eternal life. Theological responses to Hägglund emphasize the ‘worldly’ nature of heaven over-against overly Platonic, ‘otherworldly’ accounts of everlasting life. In contrast, I suggest Hägglund's critique fails to grapple with theocentric forms of creaturely consummation qualitatively distinct from mundane life. I critique Hägglund's ‘suspicious’ reading of Augustine and CS Lewis, and, in dialogue with Michael Rosen, suggest his account of what makes finite life meaningful participates in an early modern movement from heaven to ‘historical immortality’. Hägglund thinks heaven is not desirable, yet when interpreted in the foregoing terms, this is the precise objection I direct at his account of ‘historical immortality’.Peer reviewe
Haven or hell? A perspective on the ecology of offshore oil and gas platforms
Get PDFFunding: NH and DMP were supported by NERC-INSITE funding project FuECoMMS (NE/T010800/1). This work was also funded by Chevron Grant number: NDC-AP-001) through its Anchor Partnership with the UK National Decommissioning Centre.Offshore oil and gas platforms (OGP) have been installed worldwide and initially with limited consideration given to the nature of their positive or negative long-term interactions with the natural marine habitats. However, as OGP reach the end of their useful life, with many being decommissioned and removed, it is timely to review the growing evidence of the association of marine biota with OGP to provide a summary and synthesis for policy makers and to give insight to decisions in increasingly crowded marine spatial plans. In the last decade, there has been rapid increase in studies concerning the ecological role of OGP. This research reveals strong contextual difference between platforms in different geographical regions, but all OGP add to local biodiversity particularly where hard substrata are introduced to areas dominated by depositional (mud and sand) habitats. This includes the attraction and increased productivity of fish, sessile invertebrates, and algae while also affecting change in the benthic habitats beneath platforms. There also evidence of the OGP changing local hydrodynamics conditions with effects on phytoplankton and local scour. In terms of the biota associated with OGP, water depth is a major driver of community type across systems. This study emphasises that while knowledge of OGP communities and species has improved, there are still significant knowledge gaps that may prevent the most environmentally beneficial decisions being made around decommissioning. There are few studies following the effect of decommissioning (topping, toppling, or removal) on the ecology of the systems as they change with time (longitudinal research) for the decommissioning event. There is also a need for more studies comparing the biodiversity and functionality of OGP system to artificial and natural reefs and habitats to better understand the ecological cost-benefit of decommissioning scenarios. Finally, commercial data is often unavailable and even when available, surveys are often conducted using varied methodology that prevents comparative analysis. By imposing/agreeing standards and sharing data around the ecological cost-benefit of decommissioning strategies, improve policy guidance concerning OGP planning, and management might emerge.Peer reviewe
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