164 research outputs found

    The Forum of European Geological Surveys Geochemistry Task Group 1994-1996 inventory

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    The Forum of European Geological Surveys (FOREGS) includes representatives from 33 European countries and is responsible for co-ordinating Geological Survey activities in Europe. The FOREGS Geochemistry Task Group was established in 1994 to develop a strategy for the preparation of European geochemical maps following the recommendations of the International Geological Correlation Programme (IGCP) Project 259 ‘International Geochemical Mapping’ (now the International Union of Geological Sciences (IUGS) /International Association of Geochemistry and Cosmochemistry (IAGC) Working Group on Global Geochemical Baselines). The FOREGS geochemistry programme is aimed at preparing a standardised European geochemical baseline to IGCP-259 standards. The principal aims of this dataset will be for environmental purposes, as a baseline for the assessment of the extent and distribution of contaminated land in the context of variations in the natural geochemical background, but it will also have applications in resource assessment and for the development of policy for the sustainable management of metalliferous mineral and other resources. The first phase of the programme was the compilation of an inventory of geochemical data based on the results of a questionnaire completed by Geological Surveys and related organisations throughout the FOREGS community. The results show that the sample types which have been used most extensively are stream sediment (26% coverage), surface water (19% coverage) and soil (11% coverage). Stream sediments have been collected using a narrow range of mesh sizes (< 150–< 200 μm), but soil samples have been collected according to two different conventions: some surveys used a similar mesh size range to that used for stream sediments while others employed the < 1000 or < 2000 μm fractions traditionally used by soil surveys. Sample densities range from 1 sample per 0.5 km2 to 1 per 3500 km2. Various analytical methods have been used, but most of the available data have been calibrated using international reference materials, and data for the most important of the potentially harmful elements (PHEs) are available for most datasets. Systematic radiometric data are available for only a small proportion of Europe, a situation which compares very unfavourably with that in Australia, North America, the former Soviet Union and many developing countries. Recommendations are made for increasing the compatibility of geochemical methods between national geochemical surveys as a basis for the preparation of a series of European geochemical maps. The next stage of the FOREGS Geochemistry Task Group will be the collection of the Global Reference Network of samples against which to standardise national datasets according to the methods recommended in the final report of the IGCP 259 programme

    Arsenic and selenium

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    Arsenic (As) and selenium (Se) have become increasingly important in environmental geochemistry because of their significance to human health. Their concentrations vary markedly in the environment, partly in relation to geology and partly as a result of human activity. Some of the contamination evident today probably dates back to the first settled civilizations that used metals. This chapter outlines the main effects of arsenic and selenium on human and animal health, their abundance and distribution in the environment, sampling and analysis, and the main factors controlling their speciation and cycling. Such information should help to identify aquifers, water resources, and soils at risk from high concentrations of arsenic and selenium, and areas of selenium deficiency. Human activity has had, and is likely to continue to have, a major role in releasing arsenic and selenium from the geosphere and in perturbing the natural distribution of these and other elements over the Earth’s surface

    Black nightshades, Solanum nigrum L. and related species

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    The black nightshades (Solanum nigrum and related species in sect. Solanum) are worldwide weeds of arable land, gardens, rubbish tips, soils rich in nitrogen, in moderately light and warm situations which occur from sea to montane levels. They are, however, also widely used as leafy herbs and vegetables, as a source of fruit and for various medicinal purposes. Therefore, human consumption of their leaves and fruits as food is widespread, particularly in Africa and SE Asia. Unfortunately, there is widespread confusion over the precise identification of the taxa involved, especially in those areas in which the species are most commonly used as food sources. This monograph attempts to identify the species related to the black nightshade more accurately, by providing an identification key, descriptions of the taxa most widely reported to be of dietary and/or ethnobotanical use in various Asian, African and Indonesian countries, listing some of the many vernacular names used for the species, recording precise uses of the various species and presenting some information on their genetic resources. Two appendices are included listing (1) research contacts and centres of research, and (2) gene banks maintaining collections. (Abstract © CAB ABSTRACTS, CAB International

    Cat's whiskers Cleome gynandra L.

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    Cat's whiskers (Cleome gynandra) grows as a weed in most tropical countries, but is a semi-cultivated, popular tropical leafy vegetable in many parts of sub-Saharan Africa especially in most countries in eastern and southern Africa. This book presents information on its genetic resources in a series of chapters on the following topics: taxonomy, botany, origin and centre of diversity, properties and uses, characterization, evaluation and conservation, breeding, production, ecology, agronomy, and limitations, prospects and research needs. An appendix details researchers and institutions working on indigenous leafy vegetables in sub-Saharan Africa. (Abstract © CAB ABSTRACTS, CAB International

    A global geochemical database for environmental and resource management : recommendations for International Geochemical Mapping, final report of IGCP Project 259

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    Research conducted since 1988 as part of the International Geochemical Mapping (IGM) project has confirmed that the presently available data concerning the geochemical composition of the Earth’s surface are substantially incomplete and internally inconsistent. Many of the older data sets have serious deficiencies and do not meet basic requirements for establishing the range of natural geochemical background values. As a result of natural geological and environmental processes, element abundances in natural materials can vary by several orders of magnitude within short distances. These variations are inadequately documented and their existence is often overlooked in the setting of public policy. A high quality geochemical database is pertinent to a wide range of investigations in the earth and life sciences, and should be considered as an essential component of environmental knowledge. Detailed information about the natural variability of the geochemical background is pertinent to administrative and legal issues as much as to scientific research. Sustainable long-term management of environmental and mineral resources is dependent upon a comprehensive and reliable database. The International Geosphere-Biosphere Program on Global Change requires information on current conditions. Important aspects of change cannot be measured, or their consequences anticipated, unless the present composition of the earth’s surface materials is known. The International Geochemical Mapping project, which was endorsed in 1988 as a contribution to the IGBP (IGBP, 1989), is a multi-stage project established to consider how best to provide quantitative data to portray the geochemical diversity of the earth’s land surface. Participants in IGCP 259 have undertaken a comprehensive review of methods of regional and national geochemical mapping and examined the results obtained. Many problems have been identified and a variety of solutions discussed. Field and laboratory research has been carried out. The resulting recommendations are contained in this report. They are directed towards geochemists and those institutions, which have a mandate for providing an earth science and/or environmental database

    Low-temperature concentration of tellurium and gold in continental red bed successions

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    Acknowledgements This research was supported by NERC grants (NE/L001764/1, NE/M010953/1). We are grateful to J. Still and A. Sandison for technical support and to the gypsum mines and C. Brolley for access and sampling. Critical comments from Cristiana Ciobanu, Eric Gloaguen and Georges Calas are gratefully acknowledged. The authors have no conflicts of interest to declare.Peer reviewedPublisher PD

    Accessing elite nurses for research: reflections on the theoretical and practical issues of telephone interviewing

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    Elite groups are interesting as they frequently are powerful (in terms of position, knowledge and influence) and enjoy considerable authority. It is important, therefore, to involve them in research concerned with understanding social contexts and processes. This is particularly pertinent in healthcare, where considerable strategic development and change are features of everyday practice that may be guided or perceived as being guided, by elites. This paper evolved from a study investigating the availability and role of nurses whose remit involved leading nursing research and development within acute NHS Trusts in two health regions in Southern England. The study design included telephone interviews with Directors of Nursing Services during which time the researchers engaged in a reflective analysis of their experiences of conducting research with an `elite' group. Important issues identified were the role of gatekeepers, engagement with elites and the use of the telephone interview method in this context. The paper examines these issues and makes a case for involving executive nurses in further research. The paper also offers strategies to help researchers design and implement telephone interview studies successfully to maximise access to the views and experiences of `hard to reach groups', such as elites, while minimising the associated disruption

    Developing and evaluating threshold-based algorithms to detect drinking behavior in dairy cows using reticulorumen temperature

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    © 2019 American Dairy Science Association In this study, we assessed for the first time the use of a reticuloruminal temperature bolus and a thresholding method to detect drinking events and investigated different factors that can affect drinking behavior. First, we validated the detection of drinking events using 16 cows that received a reticuloruminal bolus. For this, we collected continuous drinking behavior data for 4 d using video recordings and ambient and water temperature for the same 4 d. After all the data were synchronized, we performed 2 threshold algorithms: a general-fixed threshold and a cow-day specific threshold algorithm. In the general-fixed threshold, a positive test was considered if the temperature of any cow fell below a fixed threshold; in the cow-day specific threshold, a positive test was considered when the temperature of specific cows fell below the threshold value deviations around the mean temperature of the cow for that day. The former was evaluated using a threshold varying between 35.7 and 39.5°C, and the latter using the formulaμ− [Formula presented] σ, where µ = mean of the temperature of each cow for one day, n = 1, 2, …, 20, and σ = standard deviation of the temperature of each cow on that day. The performance of the validation of detection using each of the threshold types was computed using different metrics, including overall accuracy, precision, recall (also known as sensitivity), F-score, positive predictive value, negative predictive value, false discovery rate, false omission rate, and Cohen's kappa statistic. The findings of the first study showed that the cow-day specific threshold of n = 10 performed better (true positives = 466; false positives = 167; false negatives = 165; true negatives = 8,416) than using a general-fixed threshold of 38.1°C (true positives = 449; false positives = 181; false negatives = 182; true negatives = 8,402). With the information gained in this first study, we investigated the different factors associated with temperature drop characteristics per cow: number of drops, mean amplitude of the drop, and mean recovery time. For this, we used data from 54 cows collected for almost 1 yr to build a mixed-effect multilevel model that included days in milk, parity, average monthly milk production, and ambient temperature as explanatory variables. Cow characteristics and ambient temperature had significant effects on drinking events. Our results provide a platform for automated monitoring of drinking behavior, which has potential value in prediction of health and welfare in dairy cattle

    In vitro collecting techniques for germplasm conservation

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    During the early 1980s, while searching for ways to more fully utilize the techniques of plant biotechnology, IPGRI (the International Plant Genetic Resources Institute, then the International Board of Plant Genetic Resources, IBPGR) suggested that germplasm be collected by means of in vitro methods. Between 1990 and today, research in this area has been performed by different groups, leading to the development and/or optimization of in vitro collecting techniques for various additional species including coconut, taro, tropical rainforest tree species and wild and endangered species. This technical bulletin comprises three separate parts. The first part (theoretical background to in vitro collecting), consists of three chapters regarding the rationale behind the development of in vitro collecting and its potential for the conservation of crops and wild or endangered species and the control of contamination, a critically important step which conditions the successful development of any in vitro collecting protocol. The second part (case studies) comprises nine chapters, each describing the work performed for the development of in vitro protocols for a particular species or group of species. The protocols described can be applied directly for collecting germplasm of any of the species concerned. However, circumstances will differ from one collecting mission to the next and it can be expected that these protocols will have to be adapted to these circumstances. Therefore, the aim of these chapters is to illustrate the range of protocols, from the simplest to the most sophisticated, which can be developed for in vitro collecting germplasm of a given species and to highlight the critical steps of such protocols. Such information should be used by the readers as a guide for the development of protocols for the species of their own interest. The last part (prospects) consists of a single chapter which analyses the future of in vitro collecting for improving the conservation and use of plant genetic resources. This technical bulletin includes references up to 2001. It includes both theoretical and practical aspects, aims to provide a resource for those wishing to understand the basic concepts of adapting plant tissue culture methods to field collecting
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