37 research outputs found
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Analysis of prehistoric brown earth paleosols under the podzol soils of Exmoor, UK
The deforestation of the upland landscapes in southwest Britain during prehistory is an established archaeological narrative, documenting human impacts on the environment and questioning the relationship of prehistoric societies to the upland landscapes they inhabited. Allied to the paleoenvironmental analyses of pollen sequences, which have provided the evidence of this change, there has been some investigation of prehistoric paleosols fossilized under principally Bronze Age archaeological monuments. These analyses identified brown earth soils that were originally associated with temperate deciduous woodland, on occasion showing evidence of human impacts such as tilling. However, the number of analyses of these paleosols has been limited. This study presents the first analysis of a series of preâpodzol brown earth paleosols on Exmoor, UK, two of which are associated with colluvial soil erosion sediments before the formation of peat. This study indicates these paleosols are spatially extensive and have considerable potential to inform a more nuanced understanding of prehistoric human impacts on the upland environments of the earlyâmid Holocene and assess human agency in driving ecosystem change
Sub-arcsecond high sensitivity measurements of the DG~Tau jet with e-MERLIN
We present very high spatial resolution deep radio continuum observations at
5 GHz (6 cm) made with e-MERLIN of the young stars DG Tau A and B. Assuming it
is launched very close (~=1 au) from the star, our results suggest that the DG
Tau A outflow initially starts as a poorly focused wind and undergoes
significant collimation further along the jet (~=50 au). We derive jet
parameters for DG Tau A and find an initial jet opening angle of 86 degrees
within 2 au of the source, a mass-loss rate of 1.5x10^-8 solar masses/yr for
the ionised component of the jet, and the total ejection/accretion ratio to
range from 0.06-0.3. These results are in line with predictions from MHD
jet-launching theories.Comment: Accepted MNRAS Letter
Durrington Walls to West Amesbury by way of Stonehenge: a major transformation of the Holocene landscape
A new sequence of Holocene landscape change has been discovered through an investigation of sediment sequences, palaeosols, pollen and molluscan data discovered during the Stonehenge Riverside Project. The early post-glacial vegetational succession in the Avon valley at Durrington Walls was apparently slow and partial, with intermittent woodland modification and the opening-up of this landscape in the later Mesolithic and earlier Neolithic, though a strong element of pine lingered into the third millennium BC. There appears to have been a major hiatus around 2900 cal BC, coincident with the beginnings of demonstrable human activities at Durrington Walls, but slightly after activity started at Stonehenge. This was reflected in episodic increases in channel sedimentation and tree and shrub clearance, leading to a more open downland, with greater indications of anthropogenic activity, and an increasingly wet floodplain with sedges and alder along the riverâs edge. Nonetheless, a localized woodland cover remained in the vicinity of DurringtonWalls throughout the third and second millennia BC, perhaps on the higher parts of the downs, while stable grassland, with rendzina soils, predominated on the downland slopes, and alderâhazel carr woodland and sedges continued to fringe the wet floodplain. This evidence is strongly indicative of a stable and managed landscape in Neolithic and Bronze Age times. It is not until c 800â500 cal BC that this landscape was completely cleared, except for the marshy-sedge fringe of the floodplain, and that colluvial sedimentation began in earnest associated with increased arable agriculture, a situation that continued through Roman and historic times
Pre-Hispanic anthropogenic wetlands in the upper Ica drainage, south-central Andes: dating and context
Humans have engineered their environmentsthroughout the Holocene, especially in the constructionof hydraulic infrastructure. In many regions,however, this infrastructure is difficult to date, includingthe vestiges of water-management systems in theAndean highlands. Focusing on silt reservoirs in theupper Ica drainage, Peru, the authors use cores andradiocarbon dates to demonstrate the pre-Hispanicconstruction of walls to enhance and expand wetlandsfor camelid pasture. Interventions dated to the Incaperiod (AD 1400?1532) indicate an intensificationof investment in hydraulic infrastructure to expandproduction capacity in support of the state. Theresults are discussed in the context of the hydraulicstrategies of other states and empires.Fil: Lane, Kevin John. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Saavedra 15. Instituto de las Culturas. Universidad de Buenos Aires. Instituto de las Culturas; ArgentinaFil: Beresford Jones, David. Universitat Bonn; AlemaniaFil: Coll, Luis Vicente Javier. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Saavedra 15. Instituto de las Culturas. Universidad de Buenos Aires. Instituto de las Culturas; ArgentinaFil: Marsh, Erik Johnson. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias BĂĄsicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias BĂĄsicas; ArgentinaFil: Scaife, Rob. University of Southampton; Reino UnidoFil: Greco Mainero, Mariano Catriel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias FĂsico MatemĂĄticas y Naturales; ArgentinaFil: Oros, Oliver Huaman. Ministerio de Cultura; PerĂșFil: Herrera, Alexander. Universidad de Los Andes; ColombiaFil: Grant Lett Brown, Jennifer Luisa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. SecretarĂa de Cultura de la NaciĂłn. DirecciĂłn Nacional de Cultura y Museos. Instituto Nacional de AntropologĂa y Pensamiento Latinoamericano; ArgentinaFil: French, Charles. University of Cambridge; Estados Unido
Early to Middle Bronze Age agricultural terraces in north-east England : morphology, dating and cultural implications
Terracing is found widely in the Mediterranean and in other hilly and mountainous regions of the world. Yet while archaeological attention to these âmundane' landscape features has grown, they remain understudied, particularly in Northern Europe. Here, the authors present a multidisciplinary study of terraces in the Breamish Valley, Northumberland. The results date their construction to the Early to Middle Bronze Age, when they were built by cutting back the hillside, stone clearance and wall construction. Environmental evidence points to their use for cereal cultivation. The authors suggest that the construction and use of these terraces formed part of an Early to Middle Bronze Age agricultural intensification, which may have been both demographically and culturally driven
Radio Continuum Surveys with Square Kilometre Array Pathfinders
In the lead-up to the Square Kilometre Array (SKA) project, several next-generation radio telescopes and upgrades are already being built around the world. These include APERTIF (The Netherlands), ASKAP (Australia), e-MERLIN (UK), VLA (USA), e-EVN (based in Europe), LOFAR (The Netherlands), MeerKAT (South Africa), and the Murchison Widefield Array. Each of these new instruments has different strengths, and coordination of surveys between them can help maximise the science from each of them. A radio continuum survey is being planned on each of them with the primary science objective of understanding the formation and evolution of galaxies over cosmic time, and the cosmological parameters and large-scale structures which drive it. In pursuit of this objective, the different teams are developing a variety of new techniques, and refining existing ones. To achieve these exciting scientific goals, many technical challenges must be addressed by the survey instruments. Given the limited resources of the global radio-astronomical community, it is essential that we pool our skills and knowledge. We do not have sufficient resources to enjoy the luxury of re-inventing wheels. We face significant challenges in calibration, imaging, source extraction and measurement, classification and cross-identification, redshift determination, stacking, and data-intensive research. As these instruments extend the observational parameters, we will face further unexpected challenges in calibration, imaging, and interpretation. If we are to realise the full scientific potential of these expensive instruments, it is essential that we devote enough resources and careful study to understanding the instrumental effects and how they will affect the data. We have established an SKA Radio Continuum Survey working group, whose prime role is to maximise science from these instruments by ensuring we share resources and expertise across the projects. Here we describe these projects, their science goals, and the technical challenges which are being addressed to maximise the science return
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Trends and variability in weather and atmospheric deposition at UK Environmental Change Network sites (1993â2012)
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Soil pollen analysis: a waning science?
Geoarchaeological research captures dimensions of the past at an unprecedented level of detail and multiple spatial and temporal scales. The record of the past held by soils and sediments is an archive for past environments, climate change, resource use, settlement lifeways, and societal development and resilience over time. When the McDonald Institute was established at Cambridge, geoarchaeology was one of the priority fields for a new research and teaching environment. An opportunity to develop the legacy of Charles McBurney was bestowed upon Charles French, whose âgeoarchaeology in actionâ approach has had an enormous impact in advancing knowledge, principles and practices across academic, teaching and professional sectors. Many journeys that began at Cambridge have since proliferated into dozens of inspired geoarchaeologies worldwide. This volume presents research and reflection from across the globe by colleagues in tribute to Charly, under whose leadership the Charles McBurney Laboratory became a beacon of geoarchaeology