Excavations on the Lower Terrace, Site C, Tintagel Island 1990–94

1997 ◽  
Vol 77 ◽  
pp. 1-143 ◽  
Author(s):  
C.D. Morris ◽  
Rachel Harry
Keyword(s):  
Mathematical Modelling ◽  
Radiocarbon Dating ◽  
Clay Soil ◽  
Structural Phase ◽  
Environmental Sampling ◽  
Lower Terrace ◽  
Wide Range ◽  
Modelling Techniques ◽  
Terrace Site ◽  
Trees And Shrubs

This article reports excavations undertaken between 1990 and 1994 on a small cliff terrace, at Tintagel Island in Cornwall. This terrace (the Lower Terrace) lies below Site C (the Middle Terrace), where a building was excavated by Dr C.A.R. Radford in the 1930s. The remains uncovered on the Lower Terrace comprise several phases of ephemeral stone and turf structures with associated hearths, floor deposits and stakeholes. These are separated by periods of shillet (tiny flakes of slate in sandy clay soil) levelling. With the collapse of the last structure the terrace was buried by layers of scree and slate slip from the slope above. Artefact groups of fire-lighting stones, whetstones and worked flint and quartz were recovered predominantly from earlier phases, together with Romano-British Native pottery. Later phases mainly comprised sherds of Imported Mediterranean pottery (84 per cent of all finds) and slate disc pot lids. The results of an extensive programme of environmental sampling clarified that a wide range of probably locally growing trees and shrubs were exploited for fuel, as well as for wattles and larger posts and beams. Tiny burnt fragments of animal and some human bone were found scattered through a handful of deposits, but the material is probably residual. A programme of radiocarbon dating was possible with the availability of charcoal material from hearths and stakeholes. This programme, using innovative mathematical modelling techniques, produced three distinct date ranges of structural activity on the Lower Terrace: 395–460 cal AD for one of the earliest phases of hearths, floors and stakeholes pre-dating the occurrence of Imported pottery; 415–535 cal AD for a later structural phase with hearths and first occurrences of Imported and Native pottery together; and 560–670 cal AD for the latest and best surviving structure, with hearths, stakeholes and a large assemblage of Imported pottery.

The excavation of a medieval ring-ditch enclosure at Hayknowes Farm, Annan, Dumfries and Galloway

2001 ◽  
Vol 23 (2) ◽  
pp. 119-139
Author(s):  
R. A. GREGORY ◽  
D. W. HALL ◽  
D. W. SHIMWELL
Keyword(s):  
Radiocarbon Dating ◽  
Structural Phase ◽  
Morphological Characteristics ◽  
Internal Structures

Excavation at a crop-mark site found close to Annan, Dumfries and Galloway, revealed evidence of a ring-ditch containing a number of intriguing internal structures. Initially this was presumed to be a prehistoric monument, but pottery and radiocarbon dating, unexpectedly, indicated that the main structural phase of the site falls between the 11th-13th centuries AD. This suggests that a degree of caution is required when interpreting crop-mark sites on morphological characteristics alone. Moreover this excavation makes clear that morphological interpretation can have a constraining influence on excavation strategy, so caution is required when designing fieldwork programmes.

scholarly journals Conventional and Conservation Seedbed Preparation Systems for Wheat Planting in Silty-Clay Soil

2021 ◽  
Vol 13 (11) ◽  
pp. 6506
Author(s):  
Roberto Fanigliulo ◽  
Daniele Pochi ◽  
Pieranna Servadio
Keyword(s):  
Clay Soil ◽  
Conservation Tillage ◽  
Field Tests ◽  
Superficial Layer ◽  
Soil Tillage ◽  
Energy Requirements ◽  
Silty Clay ◽  
Wide Range ◽  
Seedbed Preparation ◽  
Silty Clay Soil

Conventional seedbed preparation is based on deep ploughing followed by lighter and finer secondary tillage of the superficial layer, normally performed by machines powered by the tractor’s Power Take-Off (PTO), which prepares the seedbed in a single pass. Conservation methods are based on a wide range of interventions, such as minimum or no-tillage, by means of machines with passive action working tools which require two or more passes The aim of this study was to assess both the power-energy requirements of conventional (power harrows and rotary tillers with different working width) and conservation implements (disks harrow and combined cultivator) and the soil tillage quality parameters, with reference to the capability of preparing an optimal seedbed for wheat planting. Field tests were carried out on flat, silty-clay soil, using instrumented tractors. The test results showed significant differences among the operative performances of the two typologies of machines powered by the tractor’s PTO: the fuel consumption, the power and the energy requirements of the rotary tillers are strongly higher than power harrows. However, the results also showed a decrease of these parameters proceeding from conventional to more conservation tillage implements. The better quality of seedbed was provided by the rotary tillers.

2D X-ray diffraction and molecular modelling of the crystalline structure of polyesters under uniaxial stress

2021 ◽  
pp. 096739112199822
Author(s):  
Ahmed I Abou-Kandil ◽  
Gerhard Goldbeck
Keyword(s):  
Crystalline Structure ◽  
Molecular Modelling ◽  
Three Dimensional ◽  
Uniaxial Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Modelling Techniques ◽  
Diffraction Patterns

Studying the crystalline structure of uniaxially and biaxially drawn polyesters is of great importance due to their wide range of applications. In this study, we shed some light on the behaviour of PET and PEN under uniaxial stress using experimental and molecular modelling techniques. Comparing experiment with modelling provides insights into polymer crystallisation with extended chains. Experimental x-ray diffraction patterns are reproduced by means of models of chains sliding along the c-axis leading to some loss of three-dimensional order, i.e. moving away from the condition of perfect register of the fully extended chains in triclinic crystals of both PET and PEN. This will help us understand the mechanism of polymer crystallisation under uniaxial stress and the appearance of mesophases in some cases as discussed herein.

Oligonychus coffeae. [Distribution map].

1963 ◽  
Author(s):  
Keyword(s):  
South Africa ◽  
Central America ◽  
West Indies ◽  
Pacific Islands ◽  
Distribution Map ◽  
Wide Range ◽  
Oligonychus Coffeae ◽  
Belgian Congo ◽  
Trees And Shrubs ◽  
New Distribution

Abstract A new distribution map is provided for Oligonychus coffeae (Nietn.) (Acarina, Tetranychidae) (Tea Red Spider). Hosts: Tea, coffee; wide range of trees and shrubs. Information is given on the geographical distribution in ASIA (excl. USSR), Burma, Ceylon, Formosa, India, Indo-China, Indonesia, Pakistan, USSR, AFRICA, Belgian Congo, Egypt, Ethiopia, Kenya, Mauritius, Nyasaland, Republic of South Africa, Tanganyika, AUSTRALASIA and PACIFIC ISLANDS, Australia, NORTH AMERICA, U.S.A., CENTRAL AMERICA and WEST INDIES, Costa Rica, SOUTH AMERICA, Colombia, Ecuador.

scholarly journals Reliability of Nitrogen Content (%N) and Carbon:Nitrogen Atomic Ratios (C:N) as Indicators of Collagen Preservation Suitable for Radiocarbon Dating

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 879-886 ◽  
Author(s):  
Fiona Brock ◽  
Rachel Wood ◽  
Thomas F G Higham ◽  
Peter Ditchfield ◽  
Alex Bayliss ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Radiocarbon Dating ◽  
Linear Regression Analysis ◽  
Atomic Weight ◽  
Animal Bones ◽  
Bone Powder ◽  
Wide Range ◽  
Pass Through ◽  
Percent Nitrogen

A recent study into prescreening techniques to identify bones suitable for radiocarbon dating from sites known for poor or variable preservation (Brock et al. 2007, 2010a) found that the percent nitrogen (%N) content of whole bone powder was the most reliable indicator of collagen preservation. Measurement of %N is rapid, requires little preparation or material, and is relatively cheap. The technique reduces the risk of needlessly sampling valuable archaeological objects, as well as saving time and money on their unsuccessful pretreatment prior to dating. This method of prescreening is now regularly used at the Oxford Radiocarbon Accelerator Unit (ORAU). In the original study, linear regression analysis of data from 100 bones from 12 Holocene sites across southern England showed that when 0.76% N was chosen as a threshold, 84% of bones were successfully identified as containing sufficient (i.e. >1%) or insufficient (i.e. <1%) collagen for dating. However, it has been observed that for older, Pleistocene bones the failure rate may be higher, possibly due to the presence of more degraded, short-chain proteins that pass through the ultrafilters used in pretreatment, resulting in lower yields. Here, we present linear regression analysis of data from nearly 600 human and animal bones, antlers, and teeth, from a wide range of contexts and ages, to determine whether the 0.76% threshold identified in the previous study is still applicable. The potential of carbon:nitrogen atomic weight ratios (C:N) of whole bone to predict collagen preservation is also discussed.

scholarly journals Fixel-based Analysis of Diffusion MRI: Methods, Applications, Challenges and Opportunities

2020 ◽  
Author(s):  
Thijs Dhollander ◽  
Adam Clemente ◽  
Mervyn Singh ◽  
Frederique Boonstra ◽  
Oren Civier ◽  
...  
Keyword(s):  
Diffusion Mri ◽  
State Of The Art ◽  
Specific Information ◽  
Analysis Framework ◽  
Wide Range ◽  
Challenges And Opportunities ◽  
P Diffusion ◽  
Modelling Techniques ◽  
The Rich

Diffusion MRI has provided the neuroimaging community with a powerful tool to acquire in-vivo data sensitive to microstructural features of white matter, up to 3 orders of magnitude smaller than typical voxel sizes. The key to extracting such valuable information lies in complex modelling techniques, which form the link between the rich diffusion MRI data and various metrics related to the microstructural organisation. Over time, increasingly advanced techniques have been developed, up to the point where some diffusion MRI models can now provide access to properties specific to individual fibre populations in each voxel in the presence of multiple "crossing" fibre pathways. While highly valuable, such fibre-specific information poses unique challenges for typical image processing pipelines and statistical analysis. In this work, we review the "fixel-based analysis" (FBA) framework that implements bespoke solutions to this end, and has recently seen a stark increase in adoption for studies of both typical (healthy) populations as well as a wide range of clinical populations. We describe the main concepts related to fixel-based analyses, as well as the methods and specific steps involved in a state-of-the-art FBA pipeline, with a focus on providing researchers with practical advice on how to interpret results. We also include an overview of the scope of current fixel-based analysis studies (until August 2020), categorised across a broad range of neuroscientific domains, listing key design choices and summarising their main results and conclusions. Finally, we critically discuss several aspects and challenges involved with the fixel-based analysis framework, and outline some directions and future opportunities.

Parlatoria oleae. [Distribution map].

1962 ◽  
Author(s):  
Keyword(s):  
North America ◽  
South America ◽  
Geographical Distribution ◽  
Canary Islands ◽  
Stone Fruits ◽  
Distribution Map ◽  
Wide Range ◽  
Trees And Shrubs ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Parlatoria oleae (Colv.) (Homopt, Coccoidea) (Olive Scale). Hosts: Wide range of trees and shrubs, notably olives, apple, pear and stone fruits. Information is given on the geographical distribution in EUROPE (excl. USSR), Bulgaria, France, Greece, Italy, Lipari Islands, Sardinia, Spain, Yugoslavia, ASIA (excl. USSR), Afghanistan, Cyprus, India, Iraq, Israel, Jordan, Kashmir, Lebanon, Pakistan, Persia, Syria, Turkey, USSR, AFRICA, Algeria, Canary Islands, Egypt, Libya, Morocco, Sudan, Tunisia, NORTH AMERICA, U.S.A., SOUTH AMERICA, Argentina, Brazil.

Quadraspidiotus perniciosus. [Distribution map].

1986 ◽  
Author(s):  
Keyword(s):  
Central America ◽  
Distribution Map ◽  
San Jose ◽  
Jammu And Kashmir ◽  
Wide Range ◽  
Quadraspidiotus Perniciosus ◽  
San Jose Scale ◽  
Trees And Shrubs ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Quadraspidiotus perniciosus (Comstock) [Hemiptera: Diaspididae] San Jose scale, California scale Polyphagous, attacking most deciduous fruits (trees and shrubs) and a wide range of other trees and shrubs. Information is given on the geographical distribution in EUROPE, Austria, Bulgaria, Czechoslovakia, France, Germany, West Greece, Hungary, Italy, Poland, Portugal, Romania, Spain, Switzerland, Yugoslavia, USSR, Azerbaijan SSR, Georgian SSR, Kazakh SSR, Moldavian SSR, Tadzhik SSR, Ukrainian SSR, Uzbek SSR, Russian SFSR, AFRICA, Algeria, Canary Islands, Madeira, Zaire, South Africa, Zimbabwe, ASIA, Afghanistan, China, India, Iran, Iraq, Jammu and Kashmir, Japan, Korea, Nepal, Pakistan, Turkey, AUSTRALASIA, Australia, New Zealand, NORTH AMERICA, Canada, Mexico, USA, CENTRAL AMERICA and CARIBBEAN, Cuba, SOUTH AMERICA, Argentina, Bolivia, Brazil, Chile, Peru, Uruguay, Venezuela.

Nectria cinnabarina. [Descriptions of Fungi and Bacteria].

1977 ◽  
Author(s):  
C. Booth
Keyword(s):  
Hong Kong ◽  
New Zealand ◽  
Geographical Distribution ◽  
Woody Plants ◽  
Considerable Importance ◽  
Northern Europe ◽  
Wide Range ◽  
The World ◽  
Facultative Parasite ◽  
Trees And Shrubs

Abstract A description is provided for Nectria cinnabarina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Many species including Ribes and Robinia. This species occurs on conifers and on a wide range of broad-leaved trees and shrubs. DISEASE: Coral spot fungus. Evidence supports the view that this species is a facultative parasite of considerable importance on blackcurrants (48, 3063); it occurs as the cause of cankers of Robinia (54, 1020) and may attack many other woody plants (55, 655). GEOGRAPHICAL DISTRIBUTION: It is very common and widespread in Northern Europe and has frequently been reported from temperate parts of the world, USA, Canada, Australia and New Zealand, and also from India and Hong Kong. TRANSMISSION: Because of the slimy nature of the conidia and the fact that they form a hard crust in dry weather, wind is not considered as important as water in their dispersal. Even the ascospores appear to be extruded or discharged only in moist weather (Jorgensen, 1952). Entry is usually through wounds or dead buds (47, 1181; 48, 3063).

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