The biosynthesis of Abscisic acid

This work is the first investigation into the biosynthesis of abscisic acid. Green tomato fruit were injected with a solution of either the potassium salt of (±)-[2- 14 c] mevalonic acid in O.05M phosphate buffer, pH 7.3, containing 10% ethanol, or {±)-[2- 14 C] mevalonic acid in ethanol. Radioactivity was detected in material which co-chromatographed with authentic abscisic acid and the authentic derivatives of abscisic acid. This material exhibited the highly characteristic spectral properties of (+)-abscisic acid. Similar results were obtained when (t)-[2- l4 c] mevalonic acid was supplied to avocado fruit preparations. The results of this work have been published in the Biochemical Journal, Vol.ll2, p.547-548 (1969). Many analogues of abscisic acid have been synthesised at Shell Research Limited, Woodstock Agricultural Research Centre, and their growth inhibitory activity assessed. The strong inhibitory activity of (+)-5-(l',2'~epoxy-2' ,6',6'-trimethylcyclohexyl)-3- methylpenta-cis-2-trans-4-dienoic acid (epoxide) on plant growth was of particular interest since the compound has the same carbon skeleton and similar substitution to abscisic acid. To discover whether this compound was active per se or because it was converted to abscisic acid the (±)-[2- 14 C] labelled material was synthesised and injected, as an ethanol solution, into tomato fruit. Epoxide was converted to abscisic acid in 1.8% yield (3.6% of one enantiomer if only one is utilized) and 15% of the abscisic acid was derived from the precursor. The 2-trans isomer was not converted to abscisic acid. Neither epoxide nor its 2-trans isomer were converted to abscisic acid in boiled tomato fruit. Treatment of epoxide with dilute mineral acid produced the 1',2'-dihydroxy derivative. The 1',2'-dihydroxy derivative was not converted to abscisic acid in tomato fruit. Wright and Hiron (1969) reported that the abscisic acid concentration in wheat leaves increased 40-fold during the first 4 hours of wilting. It was found that this increase was caused by synthesis of abscisic acid rather than by its release from a conjugate or a precursor. This was shown by the increased incorporation of [2- 3 H] mevalonic acid into abscisic acid by wilted wheat shoots in comparison with turgid shoots which had absorbed equal amounts of [2- 3 H] mevalonic acid. When (+)-[2-14C] labelled epoxide was supplied, larger amounts of labelled material were again incorporated into abscisic acid by wilted plants. The incorporation of [14C] epoxide into abscisic acid shows that the carbon skeleton of the epoxide becomes the carbon skeleton of abscisic acid. The fate of the epoxy oxygen was also investigated with wilting wheat because any [18o] containing abscisic acid formed during the experiment would not be diluted by a large pool of endogenous [16o] material. (+)- [1’2’-18o] epoxide was converted to abscisic acid, the oxygen of the l',2'-epoxy group became the tertiary hydroxyl of abscisic acid and the conversion was quantitative. For the [18ᴏ] to be retained the C-l'-oxygen bond must remain intact and epimerization at C-l' is not possible. It follows that only one enantiomer of the epoxide is converted into abscisic acid: that one in which the I' ,2'-epoxy group is on the same side of the six-membered ring as the hydroxyl group in abscisic acid. The results of this work have been published in the Biochemical Journal, VOl.119, p.727-734 (1970). The 1',4'-diols of synthetic abscisic acid were found to inhibit the growth of a number of plants (private communication, Mr. R. Leach and Dr M. Anderson) although they were less potent than abscisic acid. The demonstration of the conversion of the epoxide into (+)-abscisic acid which entails the introduction of a 4'-keto-group, and which by analogy with similar oxidations (Murphy and West, 1969) probably takes place by a hydroxylation, suggested that plants were able to oxidise the 4'-hydroxy group in the l',4'-diols of abscisic acid to a 4' ketone. The abscisic acid produced would then account for the observed growth inhibitory activity of the l',4'-diols. (±)-[2- 14 C]- cis-1’, -l' ,4' and trans-l',4' diols of abscisic acid are both converted to abscisic acid by wilted and turgid wheat shoots. The abscisic acid recovered showed a preponderance of the unnatural (-) enantiomer. The unreacted cis-1’, 4'-diol which was recovered from the tissues also showed an excess of the (-) enantiomer, unreacted trans-I' ,4'-diol which was recovered from the tissue lacked optical activity and is presumed to be a racemic mixture

IVOA Recommendation: IVOA Identifiers Version 1.12

An IVOA Identifier is a globally unique name for a resource. This name can be used to retrieve a unique description of the resource from an IVOA-compliant registry. This document describes the syntax for IVOA identifiers as well as how they are created. An IVOA identifier has two separable components that can appear in two equivalent formats: an XML-tagged form and a URI-compliant form. The syntax has been defined to encourage global-uniqueness naturally and to maximize the freedom of resource providers to control the character content of an identifier

The VISTA Science Archive

We describe the VISTA Science Archive (VSA) and its first public release of data from five of the six VISTA Public Surveys. The VSA exists to support the VISTA Surveys through their lifecycle: the VISTA Public Survey consortia can use it during their quality control assessment of survey data products before submission to the ESO Science Archive Facility (ESO SAF); it supports their exploitation of survey data prior to its publication through the ESO SAF; and, subsequently, it provides the wider community with survey science exploitation tools that complement the data product repository functionality of the ESO SAF. This paper has been written in conjunction with the first public release of public survey data through the VSA and is designed to help its users understand the data products available and how the functionality of the VSA supports their varied science goals. We describe the design of the database and outline the database-driven curation processes that take data from nightly pipeline-processed and calibrated FITS files to create science-ready survey datasets. Much of this design, and the codebase implementing it, derives from our earlier WFCAM Science Archive (WSA), so this paper concentrates on the VISTA-specific aspects and on improvements made to the system in the light of experience gained in operating the WSA.Comment: 22 pages, 16 figures. Minor edits to fonts and typos after sub-editting. Published in A&

Isotopic and zooarchaeological approaches towards understanding aquatic resource use in human economies and animal management in the prehistoric Scottish North Atlantic Islands

Despite being surrounded by aquatic resources, the Prehistoric populations of the North Atlantic Islands have a complex history of aquatic resource that until now has been little understood. Specifically the changing importance and uses of aquatic resources through time, and the role of aquatic resources in the management of animals in prehistory requires further attention. This paper presents results of faunal isotopic analysis in combination with existing human isotopic evidence and zooarchaeological datasets from Neolithic, Bronze Age and Iron Age sites in the Western Isles (also known as the Outer Hebrides) and Orkney to explore the importance of aquatic resources in the lives of these prehistory populations. In Orkney coastal grazing was an important aspect in the management of sheep throughout prehistory, whereas in the Western Isles this was only evident in the Bronze Age. Aquatic protein was also used in the management of pigs in the Western Isles during the Middle Iron Age. There is little evidence of humans consuming aquatic resources in the Neolithic, and only minor evidence of consumption in the Bronze Age. During the Iron Age aquatic resources become more important in the diet of humans. The Prehistoric Atlantic Islanders of Scotland had a complex and dynamic relationship with aquatic resources, especially in the role of animal management that changed throughout the course of prehistory.The authorswould like to express thanks to NERC for funding this research (Grant number NE/F021054/1, PI Richard Evershed), and the NERC Life Sciences Mass Spectrometry Facility in East Kilbride (EK158- 03/10) for their financial assistance with the analytical researc

A morphometric system to distinguish sheep and goat postcranial bones.

Distinguishing between the bones of sheep and goat is a notorious challenge in zooarchaeology. Several methodological contributions have been published at different times and by various people to facilitate this task, largely relying on a macro-morphological approach. This is now routinely adopted by zooarchaeologists but, although it certainly has its value, has also been shown to have limitations. Morphological discriminant criteria can vary in different populations and correct identification is highly dependent upon a researcher's experience, availability of appropriate reference collections, and many other factors that are difficult to quantify. There is therefore a need to establish a more objective system, susceptible to scrutiny. In order to fulfil such a requirement, this paper offers a comprehensive morphometric method for the identification of sheep and goat postcranial bones, using a sample of more than 150 modern skeletons as a basis, and building on previous pioneering work. The proposed method is based on measurements-some newly created, others previously published-and its use is recommended in combination with the more traditional morphological approach. Measurement ratios, used to translate morphological traits into biometrical attributes, are demonstrated to have substantial diagnostic potential, with the vast majority of specimens correctly assigned to species. The efficacy of the new method is also tested with Discriminant Analysis, which provides a successful verification of the biometrical indices, a statistical means to select the most promising measurements, and an additional line of analysis to be used in conjunction with the others

A morphometric system to distinguish sheep and goat postcranial bones.

Distinguishing between the bones of sheep and goat is a notorious challenge in zooarchaeology. Several methodological contributions have been published at different times and by various people to facilitate this task, largely relying on a macro-morphological approach. This is now routinely adopted by zooarchaeologists but, although it certainly has its value, has also been shown to have limitations. Morphological discriminant criteria can vary in different populations and correct identification is highly dependent upon a researcher's experience, availability of appropriate reference collections, and many other factors that are difficult to quantify. There is therefore a need to establish a more objective system, susceptible to scrutiny. In order to fulfil such a requirement, this paper offers a comprehensive morphometric method for the identification of sheep and goat postcranial bones, using a sample of more than 150 modern skeletons as a basis, and building on previous pioneering work. The proposed method is based on measurements-some newly created, others previously published-and its use is recommended in combination with the more traditional morphological approach. Measurement ratios, used to translate morphological traits into biometrical attributes, are demonstrated to have substantial diagnostic potential, with the vast majority of specimens correctly assigned to species. The efficacy of the new method is also tested with Discriminant Analysis, which provides a successful verification of the biometrical indices, a statistical means to select the most promising measurements, and an additional line of analysis to be used in conjunction with the others

Dead or alive?: investigating long-distance transport of live fallow deer and their body parts in antiquity

The extent to which breeding populations of fallow deer were established in Roman Europe has been obscured by the possibility that the skeletal remains of the species, in particular Dama foot bones and antlers, were traded over long distances as objects in their own right. This paper sets out to refine our understanding of the evidence for the transportation of living and dead fallow deer in Iron Age and Roman Europe. To achieve this, museum archives containing purportedly early examples of Dama antler were searched, with available specimens sampled for carbon, nitrogen and strontium isotope analyses, and compared with data for archaeological fallow deer from across Europe. Importantly, the resulting isotope values can be interpreted in light of new modern baseline data for fallow deer presented here. Together these multi-isotope results for modern and archaeological fallow deer provide a more critical perspective on the transportation of fallow deer and their body parts in antiquity

Data sharing reveals complexity in the westward spread of domestic animals across Neolithic Turkey

This study presents the results of a major data integration project bringing together primary archaeozoological data for over 200,000 faunal specimens excavated from seventeen sites in Turkey spanning the Epipaleolithic through Chalcolithic periods, c. 18,000-4,000 cal BC, in order to document the initial westward spread of domestic livestock across Neolithic central and western Turkey. From these shared datasets we demonstrate that the westward expansion of Neolithic subsistence technologies combined multiple routes and pulses but did not involve a set 'package' comprising all four livestock species including sheep, goat, cattle and pig. Instead, Neolithic animal economies in the study regions are shown to be more diverse than deduced previously using quantitatively more limited datasets. Moreover, during the transition to agro-pastoral economies interactions between domestic stock and local wild fauna continued. Through publication of datasets with Open Context (opencontext.org), this project emphasizes the benefits of data sharing and web-based dissemination of large primary data sets for exploring major questions in archaeology (Alternative Language Abstract S1)