Les sables de Fontainebleau: a natural quartz reference sample and its characterisation

Fundamental studies on luminescence production in natural quartz require samples which can be studied by groups of laboratories using complementary methods. In the framework of a European collaboration studying quartz luminescence, a sample originating from the Fontainebleau Sandstone Formation in France was selected for characterisation and distribution to establish a starting point for interlaboratory work. Here we report on the preparation and characterisation work undertaken before distribution with the aim of ensuring that each laboratory received comparable material. Material was purified to enrich the quartz concentration, followed by mineralogical screening by SEM and ICP-MS analyses. Luminescence screening measurements were undertaken at a single laboratory (SUERC) to verify the suitability of the sample for use within the study, and to establish the level of homogeneity of subsamples prepared for distribution. The sample underwent minimal non-chemical pre-treatment by multiple cycles of magnetic separation and annealing. SEM analysis showed that the sample consists mainly of SiO2. The luminescence characterisation confirmed a dose sensitivity of ca. 22,000–160,000 cts K−1 Gy−1 per 260– 290 grains for the 110◦C UV TL peak, well developed low (here: 100–300◦C) temperature (pre-dose) TL signals and high OSL sensitivities. The grain to grain OSL response varies by more than one order of magnitude. No significant IRSL signal was observed. In summary, the results from luminescence characterisation confirm the suitability of the sample for the luminescence experiments envisaged and have established a basis for comparability in studies conducted by a network of laboratories

Datación del recinto murado calcolítico de Las Mesas (La Fuente, España)

El yacimiento amurallado de media hectárea de Las Mesas se ubica en la margen oeste del río Guadiana (La Fuente, Badajoz, España). El análisis de la cultura material recuperada en prospecciones de superficie remite a un arco cronológico que va desde el Neolítico Final (ca. 3600-2900 AC) a la Edad del Cobre (III milenio AC). Las excavaciones han revelado una muralla polibastionada y un espacio habitacional en el centro del asentamiento con tres fases de uso, diferentes áreas funcionales y un hoyo votivo adscrito a la segunda fase. En un hoyo ritual efectuado en la segunda fase se ha recuperado una cornamenta de cérvido que ha sido datado mediante AMS-14C. Se analizaron por Luminiscencia Ópticamente Estimulada (OSL) muestras de un nivel de uso de suelo asignado a la segunda fase (UE-9/10) y de la base de un horno asociado a la primera fase (UE- 18). Se aplicó un procedimiento de Dosis Única Regenerativa (SAR) sobre la fracción de granos de cuarzo de 90-160 μm. Se efectuó también un análisis de 7 muestras tomadas de la estratigrafía para determinar las variaciones de la conducta luminiscente y la edad relativa a través de la secuencia estratigráfica en muestras polimi- nerales mediante luminiscencia estimulada infrarojaópticamente y térmicamente (IRSl, OSL, TSL). La datación y el perfil luminiscente indican que el nivel superior (UE-1B) pertenecería probablemente al Bronce Final (ca. 1000 AC), pero que el resto de la secuencia estratigráfica se corresponde con una ocupación del Neolítico Final-Edad del Cobre. Siendo lo más probable que la ocupación del sitio tuviera lugar entre el 3300 y el 2900 AC. Se detectan vacíos de ocupación entre la fase I y II, y entre la fase II y la ocupación del Bronce Final (fase III). Indicando que el asentamiento fue abandonado y reocupado en dos ocasiones, una en la Edad del Cobre y una en el Bronce Final. La fecha de 4254 ± 45 BP (3010-2675 cal AC) obtenida mediante AMS-14C coincide con las fechas luminiscente de la fase II, apuntando que el hoyo fue excavado al principio de la fase II. Las fechas luminiscentes y radiocarbónicas combinadas muestran que el asentamiento de Las Mesas fue ocupado durante la colonización agrícola del territorio que tuvo lugar en el Neolítico Final, abandonado durante la Edad del Cobre y reocupado en el Bronce Final. Los vacíos poblacionales registrados podrían relacionarse con las evidencias de quemado y destrucción parcial de la muralla del asentamiento, y su posterior reconstrucción y consolidación.The site of Las Mesas is located in the west bank of the Guadajira river (La Fuente, Badajoz, Spain). It covers a half hectare and is enclosed by a stone wall. Previous assessments based on site surveys suggested a general chronological span from Late Neolithic period (ca. 3600- 2900 BC) through the Copper Age (3rd millennium BC). Excavations revealed a well-constructed wall with bastions and a domestic space at the centre of the site with three occupational phases. Several functional areas and a votive pit are ascribed to the second phase. A deer antler located in a re-cut ritual pit associated to the second phase was dated by AMS-14C. Samples from a living floor assigned to the second phase (SU- 9/10) and the basement of a kiln associated with the first phase (SU-18) was dated by optically stimulated luminescence (OSL) using the single aliquot regenerative dose (SAR) protocol on 90-160 μm quartz grains. Luminescence profiling analysis of 7 samples taken throughout the archaeological stratigraphy was used to assess variations in luminescence behaviour and relative age through the sequence, using infrared-, optically –and thermally– stimulated luminescence (IRSL, OSL, TSL) on poly-mineral and etched samples. Luminescence dating and profiling indicates that the upper archaeological layer (SU-1B) probably dates to the Late Bronze Age (ca. 1000 BC), but that the sediments in the remainder of this section accumulated during the late Neolithic-Copper Age: the site was most probably inhabited between 3300 and 2900 BC. There were gaps in occupation between the Late Neolithic-Cooper Age phases (I & II), and between the Late Neolithic-Cooper Age phases and Late Bronze Age phase (II & III), indicating that the site was abandoned and reoccupied twice. The AMS-14C date on deer antler of 4254 ± 45 BP (3010- 2675 cal BC) is consisten with the OSL results for phase II, indicating that the pit was excavated at the beginning of the second occupational phase. Combined OSL and AMS-14C dating shows that Las Mesas site was first occupied during Late Neolithic farming colonization, abandoned during the Copper Age and occupied again during the Late Bronze Age. The occupational gap recorded during the Copper Age relates to evidence for burning of the site and the partial destruction of the wall, followed by its reconstruction and consolidation

A systematic review of adaption to climate change impacts in the aviation sector

The incremental changes and greater extremes of a changing climate will have operational, infrastructure and economic impacts for aviation. Given the criticality of aviation for global connectivity and mobility, it is vital that the sector understands and adequately adapts to these risks. This article presents a systematic review of the growing but somewhat dispersed academic literature on climate change impacts and adaptation in the aviation sector. Information was synthesised from 131 studies (published between January 2000 and November 2022) on eleven climate change effects and the associated impacts and potential adaptation measures. Six areas for action to address knowledge, awareness and implementation gaps were identified: (i) to broaden geographical coverage, particularly to address the current lack of studies addressing climate risks and responses in Central and South America, Africa and the Middle East; (ii) to extend knowledge of physical impacts; (iii) to address known-unknowns such as the risks associated with unprecedented or compound extreme events; (iv) to extend knowledge of adaptation including cost–benefit analysis and consideration of integrated mitigation and adaptation; (v) to identify and apply other relevant research; and (vi) for sector bodies to support and facilitate collaboration between researchers and practitioners to co-develop accessible user-oriented climate adaptation services

A deep X-ray observation of NGC 4258 and its surrounding field

We present a deep X-ray observation of the low-luminosity active galactic nucleus in NGC4258 (M106) using ASCA. The soft X-ray spectrum <2keV is dominated by thermal emission from optically-thin plasma with kT~0.5keV. The hard X-ray emission is clearly due to a power-law component with photon index Gamma=1.8 absorbed by a column density of N_H=8x10^22/cm^2. The power-law is readily identified with primary X-ray emission from the AGN central engine. We also clearly detect a narrow iron K-alpha emission line at 6.4keV. No broad component is detected. We suggest that the bulk of this narrow line comes from the accretion disk and, furthermore, that the power-law X-ray source which excites this line emission (which is typically identified with a disk corona) must be at least 100GM/c^2 in extent. This is in stark contrast to many higher-luminosity Seyfert galaxies which display a broad iron line indicating a small 10 GM/c^2 X-ray emitting region. It must be stressed that this study constrains the size of the X-ray emitting corona rather than the presence/absence of a radiatively efficient accretion disk in the innermost regions. If, instead, a substantial fraction of the observed narrow line originates from material not associated with the accretion disk, limits can be placed on the parameter space of possible allowed relativistically broad iron lines. By comparing our data with previous ASCA observations, we find marginal evidence for a change in absorbing column density through to the central engine, and good evidence for a change in the AGN flux.Comment: 11 pages, 9 postscript figures. Accepted for publication in Ap

RENEB accident simulation exercise

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested

Distribution and chronological framework for Iberian variscite mining and consumption at Pico Centeno, Encinasola, Spain

AMS radiocarbon and OSL dating, and profiling were used to directly delimit periods of variscite production at Pico CentenoMine 2. These resultswere integratedwith analysis of otherwell-dated periods of variscite production to establish an Iberian-wide chronological framework. Variscite production at Pico Centeno Mine 2 began at ~5200 BC, coincident with alpine jade production or Casa Montero Iberian flint production. Variscite was only used occasionally, together with other greenstones, during the 5th and 6th millennia BC. During the 4thmillenniumBC, variscite use began to increase to its apogee in the first half of 3rd millenniumBC when it appeared in nearly every Iberian burial site. This increase in variscite production and use coincided with decline in the popularity of alpine jade. By the end of the 3rd millennium BC, new resources began to be valued such as Asian and African Ivory, Baltic and Sicilian amber, and copper-based metal products. The variscite cycle thus started with the decline of jade in the 5th–4th millennium BC, and ended with the appearance of copper, ivory and extra-peninsular amber by the end of the 3rd millennium BC.info:eu-repo/semantics/publishedVersio

The conservation impacts of ecological disturbance : time-bound estimates of population loss and recovery for fauna affected by the 2019–2020 Australian megafires

Aim: After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019–2020 Australian megafires, we estimated population losses and recovery in fire-affected fauna, to inform conservation status assessments and management. Location: Temperate and subtropical Australia. Time period: 2019–2030 and beyond. Major taxa: Australian terrestrial and freshwater vertebrates; one invertebrate group. Methods: From > 1,050 fire-affected taxa, we selected 173 whose distributions substantially overlapped the fire extent. We estimated the proportion of each taxon’s distribution affected by fires, using fire severity and aquatic impact mapping, and new distribution mapping. Using expert elicitation informed by evidence of responses to previous wildfires, we estimated local population responses to fires of varying severity. We combined the spatial and elicitation data to estimate overall population loss and recovery trajectories, and thus indicate potential eligibility for listing as threatened, or uplisting, under Australian legislation. Results: We estimate that the 2019–2020 Australian megafires caused, or contributed to, population declines that make 70–82 taxa eligible for listing as threatened; and another 21–27 taxa eligible for uplisting. If so-listed, this represents a 22–26% increase in Australian statutory lists of threatened terrestrial and freshwater vertebrates and spiny crayfish, and uplisting for 8–10% of threatened taxa. Such changes would cause an abrupt worsening of underlying trajectories in vertebrates, as measured by Red List Indices. We predict that 54–88% of 173 assessed taxa will not recover to pre-fire population size within 10 years/three generations. Main conclusions: We suggest the 2019–2020 Australian megafires have worsened the conservation prospects for many species. Of the 91 taxa recommended for listing/uplisting consideration, 84 are now under formal review through national processes. Improving predictions about taxon vulnerability with empirical data on population responses, reducing the likelihood of future catastrophic events and mitigating their impacts on biodiversity, are critical. © 2022 The Authors. Global Ecology and Biogeography published by John Wiley & Sons Ltd. **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Diana Kuchinke” is provided in this record*