Ageing and senescence remain among the most intriguing questions in biology. Saccharomyces cerevisiae has become well established as a fertile model system for the investigation of ageing. Remarkable conservation has been found to exist between interventions extending lifespan in higher animals and yeast – genetic, chemical, and nutritional – suggesting a network of common regulatory pathways controlling large-scale shifts in gene expression involved in senescence. While it has been proposed that epigenetic regulation controls these shifts, evidence remains incomplete. To address this question, novel longevity mutants were isolated in S. cerevisiae using a purpose-designed high-precision screen based on ageing culture outgrowth. A novel long-lived mutant in uncharacterised gene YDR026C was discovered and found to participate in a pathway distinct from TOR signalling, but share epistasis with the histone deacetylase SIR2Δ, a well established regulator of replicative longevity and rDNA maintenance. Through equilibrium density centrifugal separation of culture subpopulations, SIR2Δ and Ydr026cΔ cultures were found to demonstrate reduced and improved maintenance of post-diauxic quiescence respectively, previously shown to underlie chronological survival in strains including snf1Δ. Development of a quantified TUNEL-based assay for genome fragmentation indicated early apoptotic-like behaviour in the SIR2Δ strain. Microdissection experiments and sectored-colony assays of strains containing an rDNA-embedded ADE2 reporter determined that Ydr026cΔ cells also exhibit extended replicative lifespan, and reduced recombination at the rDNA spacer region hotspot, abrogated in SIR2Δ strains. SIR2Δ is well established to repress RNA polymerase II-derived transcripts in the rDNA spacer region, including IGS1-R. Northern analysis determined Ydr026c also silences transcription in the spacer, possibly through preventing termination of the main rRNA transcript, interfering with IGS1-R expression. By transformation with a vector overexpressing IGS1-R, partial reconstitution of the SIR2Δ phenotype was observed, including rDNA hyperrecombination, shortened replicative longevity, and higher-order chromatin structure restoration. These data suggests a model whereby non-coding rDNA spacer transcripts epigenetically determine rDNA maintenance through recombination, leading to physiological phenotypes of replicative and chronological ageing.

The purpose of the study is to determine what degree of relationship exists between chronological age and performance in the first grade.

The problem of this study was to determine the relationship between chronological age and reading achievement and between chronological age and personality development in school children.

This bachelor thesis examines changes in the spatial organization of iron production sites and charcoal pits, in the county of Dalarna during the period 1-1050AD. The purpose is to try to gain an understanding, about how the spatial changes reflect changes in the importance of the iron production in the iron age society, by discussing the iron production and its importance through a biographical perspective. 14C dates of 81 iron production sites and 32 charcoal pits have been analyzed in GIS. The analysis indicates that the early iron production sites, before 550AD, were in close connection with graves, while the later sites, mainly during the Viking age, had a close connection to waterways. This change could reflect a transition in the importance of the iron production, in the iron age society. During the early phase, the importance was mainly seen from the symbolical aspects of the iron production, while during the later phase, it was mainly seen from the economic aspects. The analysis also indicates a change in the spatial organization of the charcoal pits, during the later part of the iron age. During the period 790-1000AD they were positioned in close connection to the iron production sites, and after 1000AD, they were instead positioned in close connection to the water ways. This change could indicate a change in the functional organization of the iron productions process. The charcoal started to get shipped along the waterways to iron production sites, instead of positioning the charcoal pits close to the iron production sites. Not all the iron production sites were however located at rational economical positions in the landscape, during the later phase. At certain locations, iron was produced during a long period of the iron age, even though the locations had no connection to the waterways. This could indicate that some sites had special meanings, which stretched far back in time. In other words, their own biographies.

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No description available.

No / This paper presents new chronological data applied to the problem of providing a date for the construction of a prehistoric building, with a case study from the Old Scatness Broch, Shetland. The innovative methodology employed utilises the combination of radiocarbon and optically stimulated luminescence (OSL) dates with the archaeological information, which includes the stratigraphic relationships of sampled deposits, context information, and evidence relating to the formation of the deposit. This paper discusses the scientific validity of the dates produced, and the advantages that the methodology employed at this site offers for archaeological interpretation. The combined dating evidence suggests that the broch at Old Scatness is earlier than the conventionally accepted dates for broch construction. More broadly it shows the value of integration of the specialists at the planning stages of the excavation. The application of a Bayesian statistical model to the sequences of dates allowed investigation of the robustness of the dates within the stratigraphic sequences, as well as increasing the resolution of the resulting chronology. In addition, the value of utilising multiple dating techniques on the same deposit was demonstrated, as this allowed different dated events to be directly compared as well as issues relating to the formation of the sampled deposit. This in turn impacted on the chronological significance of the resulting dating evidence, and therefore the confidence that could be placed in the results.

Yes / In the context of unanswered questions about the nature and development of the Late Neolithic in Orkney, we present a summary of research up to 2015 on the major site at the Ness of Brodgar, Mainland Orkney, concentrating on the impressive buildings. Finding sufficient samples for radiocarbon dating was a considerable challenge. There are indications from both features and finds of activity predating the main set of buildings exposed so far by excavation. Forty-six dates on 39 samples are presented and are interpreted in a formal chronological framework. Two models are presented, reflecting different possible readings of the sequence. Both indicate that piered architecture was in use by the thirtieth century cal BC and that the massive Structure 10, not the first building in the sequence, was also in existence by the thirtieth century cal BC. Activity associated with piered architecture came to an end (in Model 2) around 2800 cal BC. Midden and rubble infill followed. After an appreciable interval, the hearth at the centre of Structure 10 was last used around 2500 cal BC, perhaps the only activity in an otherwise abandoned site. The remains of some 400 or more cattle were deposited over the ruins of Structure 10: in Model 2, in the mid-twenty-fifth century cal BC, but in Model 1 in the late twenty-fourth or twenty-third century cal BC. The chronologies invite comparison with the near-neighbour of Barnhouse, in use from the later thirty-second to the earlier twenty-ninth century cal BC, and the Stones of Stenness, probably erected by the thirtieth century cal BC. The Ness, including Structure 10, appears to have outlasted Barnhouse, but probably did not endure as long in its primary form as previously envisaged. The decay and decommissioning of the Ness may have coincided with the further development of the sacred landscape around it; but precise chronologies for other sites in the surrounding landscape are urgently required. The spectacular feasting remains of several hundred cattle deposited above Structure 10 may belong to a radically changing world, coinciding (in Model 2) with the appearance of Beakers nationally, but it was arguably the by now mythic status of that building which drew people back to it. / We are very grateful to many institutions and individuals, in particular: Ness of Brodgar Trust, Foundation for World Health, Orkney Islands Council, University of the Highlands and Islands, Orkney Archaeology Society, American Friends of the Ness of Brodgar, Northlink, Talisman- Sinopec, Hiscox Insurance, Historic Environment Scotland, and numerous other supporters and volunteers; Mark Edmonds, Ann MacSween, Colin Richards, and Alison Sheridan for encouragement, advice, and critical comments on an earlier draft of this article; three anonymous referees for their comments; and Kirsty Harding for help with the figures. Dating and modelling have been supported by a European Research Council Advanced Investigator Grant (295412), The Times of Their Lives (www.totl.eu), led by Alasdair Whittle and Alex Bayliss.

No

Yes / Ceramic containers, intentionally deposited into wetlands, offer detailed insights into Early Neolithic culinary practices. Additionally, they are key for ascertaining the Neolithisation process in Denmark since they appear to form a typo-chronological sequence. Here, we use a combination of organic residue analysis (ORA) of pottery alongside Bayesian chronological modelling of the radiocarbon dates obtained on these vessels to explore the initial stages of votive deposition in wetlands, a practice that stretches from the Mesolithic to the onset of Christianity in Northern Europe. We consider 34 Early-Middle Neolithic (c. 3900–2350 cal BC) ‘bog pots’ from Denmark, of which 20 have ORA data, and 26 have been dated directly. Carbonised surface residues and absorbed lipids from powdered sherds were analysed using a combination of bulk carbon and nitrogen stable isotope analysis, gas chromatography-mass spectrometry (GC–MS) and GC-combustion-isotope ratio MS (GC-C-IRMS). The molecular and isotopic compositions of the analysed samples revealed the presence of aquatic, ruminant carcass and dairy fats as well as plant waxes with the majority containing mixtures thereof. Dairy fats were present from the onset of the Funnel Beaker culture, whilst aquatic foods, prevalent at the close of the preceding Mesolithic period, continued to be processed in pottery for the following thousand years. / UK Arts and Humanities Research Board Grant B/RG/AN1717/APN14658 (to O.E.C.) and the UK Arts and Humanities Research Council Grant AH/E008232/1 (to C.P.H and O.E.C.) for funding this research. H.K.R. acknowledges the British Academy for funding during the preparation of the manuscript.