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The Galloway Hoard: Why are there textiles in a Viking Age Hoard
No full textDr Susanna Harris will be speaking about her work on the Textiles of the Galloway Hoard. Susanna will be talking about her analysis and research of the textile components of this spectacular discovery, drawing on her AHRC funded project – in collaboration with the National Museum of Scotland – Unwrapping the Galloway Hoard
Current status of the cryopreservation of embryogenic material of woody species.
No full textCryopreservation, or the storage at liquid nitrogen temperatures (-196°C), of embryogenic cells or somatic embryos allows their long-term conservation without loss of their embryogenic capacity. During the last decade, protocols for cryopreservation of embryogenic material of woody species have been increasing in number and importance. However, despite the large experimental evidence proved in thousands of embryogenic lines, the application for the large-scale conservation of embryogenic material in cryobanks is still limited. Cryopreservation facilitates the management of embryogenic lines, reducing costs and time spent on their maintenance, thus limiting the risk of the appearance of somaclonal variation or contamination. Somatic embryogenesis in combination with cryopreservation is especially useful to preserve the juvenility of lines while the corresponding clones are being field-tested. Hence, when tree performance has been evaluated, selected varieties can be propagated from the cryostock. The traditional method of slow cooling or techniques based on vitrification are mostly applied procedures. For example, slow cooling methods are widely applied to conserve embryogenic lines of conifers. Desiccation based procedures, although simpler, have been applied in a smaller number of species. Genetic stability of the cryopreserved material is supported by multiloci PCR-derived markers in most of the assayed species, whereas DNA methylation status assays showed that cryopreservation might induce some changes that were also observed after prolonged subculture of the embryogenic lines. This article reviews the cryopreservation of embryogenic cultures in conifers, fruit species, deciduous forest species and palms, including a description of the different cryopreservation procedures and the analysis of their genetic stability after storage in liquid nitrogen
Assessing above and belowground recovery from ammonium sulfate addition and wildfire in a lowland heath: mycorrhizal fungi as potential indicators.
No full textAtmospheric pollution containing soil‐nitrifying ammonium sulfate ((NH₄)₂SO₄) affects semi‐natural ecosystems worldwide. Long‐term additions of (NH₄)₂SO₄ to nitrogen (N)‐limited habitats, including heathlands, increase climate stress affecting recovery from wildfires. Although heathland vegetation largely depends on ericoid mycorrhizal fungi (ErM) to access soil N, we lack detailed understanding of how prolonged exposure to (NH₄)₂SO₄ may alter ErM community composition and host plants' reliance on fungal partners following wildfire and affect recovery. Simulation of atmospheric pollution ((NH₄)₂SO₄) occurred bi‐weekly for 5 years after a 2006 wildfire in a UK heathland. Ten years after treatments ceased, we measured vegetation structure, lichen and lichen photobiont composition, soil characteristics, ErM colonization, ErM diversity in roots and soil, and assessed ErM potential as novel recovery indicators. Heather height and density, and moss groundcover, were greater in N‐enriched plots. Lichen community indices showed significant treatment effects, but without differences in photobionts. Soil pH and Mg were significantly lower in treated plots while soil cation exchange capacity was significantly higher. There were no detectable differences in ErM composition and keystone ErM taxa between control and treated plots. Soil carbon stock measures were variable. Our results indicate atmospheric pollution following fire can have significant lingering effects above‐ and belowground. ErM diversity and root colonization were not assessed in the original N‐addition experiment; we advocate for their inclusion in future studies as an integral part of the recovery assessment toolkit. We show that mycorrhizal fungi diversity is a viable ecological tool and summarize key steps for ErM identification
A new species of the Marlierea group (Myrcia sect. Aulomyrcia, Myrtaceae) from the cacao region of Bahia, Brazil.
No full textSearch and Seize: Partisan Publishers and Press Controls in Thomason’s London
No full textThe Thomason collection is recognised as being vital for exploring the dramatic developments in print culture that accompanied the English Revolution, not least those that were made possible by the collapse of press censorship in 1641. Less widely appreciated is that it also sheds valuable light upon the attempts that were subsequently made to reimpose some kind of press oversight. This essay explores a range of unique items that Thomason preserved, which reveal his fascination with, and intimate knowledge of, developments in the print trade, not least as recorded by his annotations on specific items. What emerges is a picture of the complex political machinations that surrounded cheap print during the revolutionary decades, and deeper understanding of the kinds of engagement and activism with which stationers became involved. As such, it highlights the possibilities that exist for integrating the history of print culture into the wider political history of the age
Repeated upslope biome shifts in Saxifraga during late-Cenozoic climate cooling.
No full textMountains are among the most biodiverse places on Earth, and plant lineages that inhabit them have some of the highest speciation rates ever recorded. Plant diversity within the alpine zone - the elevation above which trees cannot grow—contributes significantly to overall diversity within mountain systems, but the origins of alpine plant diversity are poorly understood. Here, we quantify the processes that generate alpine plant diversity and their changing dynamics through time in (Saxifragaceae), an angiosperm genus that occurs predominantly in mountain systems. We present a time-calibrated molecular phylogenetic tree for the genus that is inferred from 329 low-copy nuclear loci and incorporates 73% (407) of known species. We show that upslope biome shifts into the alpine zone are considerably more prevalent than dispersal of alpine specialists between regions, and that the rate of upslope biome shifts increased markedly in the last 5 Myr, a timeframe concordant with a cooling and fluctuating climate that is likely to have increased the extent of the alpine zone. Furthermore, alpine zone specialists have lower speciation rates than generalists that occur inside and outside the alpine zone, and major speciation rate increases within significantly pre-date increased rates of upslope biome shifts. Specialisation to the alpine zone is not therefore associated with speciation rate increases. Taken together, this study presents a quantified and broad scale perspective of processes underpinning alpine plant diversity
Reducing negative economic and equity implications associated with conserving 30% of the planet by 2030.
No full textAdvances in the characterisation and identification of mastic (Pistacia sp.) resin in archaeological samples by GC-QToF-MS
No full textA new analytical method based on GC-QToF-MS is proposed for the enhanced characterisation and identification of mastic ( sp.) resin in archaeological samples. New insights into the use of mastic in ancient Egypt are provided.
The optimisation and application of an analytical method based on gas chromatography coupled to quadrupole time-of-flight mass spectrometry (GC-QToF-MS) is proposed for the first time for the characterisation and identification of mastic ( sp.) resin in archaeological samples. The GC-QToF-MS method demonstrated higher sensitivity compared to single quadrupole GC-MS and enabled enhanced structural elucidation power to be exploited, particularly due to the high mass resolution and accuracy, the possibility to use standard and low ionisation energies as well as its tandem MS capabilities. The heat-induced degradation of the resin was also studied in open air conditions, showing that 28-norolean-17-en-3-one forms upon heating, but then progressively degrades. This makes it a reliable marker for heating of resin; however, the lack of detection does not imply that the resin was not heated. These observations were used to interpret the results of a large number of archaeological samples containing resin in different formulations, from various archaeological contexts and exposed to different environmental conditions. Lumps of relatively pure resin found in marine waterlogged conditions (Uluburun shipwreck, Turkey), residues on ceramics from Sai Island (Nubia, Sudan) as well as varnish and coating layers on Egyptian coffins from the collections of the British Museum (London, UK) and Fitzwilliam Museum (Cambridge, UK) were analysed to understand what the molecular profiles reveal about the use of the resin. The results showed that the resin was often mixed with a drying or semi-drying oil in ancient varnish formulations, thus suggesting that oil was used as a medium to dissolve the resin, which would have been impossible to apply as a layer using simple heat. These new observations significantly add to our understanding of ancient Egyptian technology and provide museum scientists and conservators with key information to accurately identify resin and preserve objects containing it
Cold War Scotland: new exhibition coming to National Museum of Scotland
No full textA new exhibition at the National Museum of Scotland, running from 13 July 2024, will explore Scotland’s critical position on the frontline of the Cold War