420 research outputs found

    Heavy mineral stratigraphy of the Unayzah Formation and Basal Khuff Clastics (Carboniferous to Permian) of Central Saudi Arabia

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    A study of heavy mineral assemblages in the Unayzah Reservoir sandstones of central Saudi Arabia has identified successive changes in provenance signature. These define four heavy mineral units that are of regional extent and largely coincident with the four main depositional units defined by previous authors: Unayzah C, Unayzah B, Unayzah A and the Basal Khuff Clastics. Sandstone bodies with anomalous mineral signatures also occur, however, especially within the Unayzah B Member. These are attributed to local supply of sand from pre-Unayzah Paleozoic sandstones exposed on the Central Arabian Arch and on intrabasinal highs. The stratigraphic changes in mineralogy reflect successive developments in the geography and climate of the region and in the pattern of sand sourcing and transport. The Unayzah C sands and the majority of Unayzah B sands were derived from the south but whereas the southerly derived Unayzah C sands appear to have been derived from pre-existing mature sandstones, those of Unayzah B were sourced from a wider range of rock types including crystalline basement. This contrast is interpreted as indicating that a significant hiatus may separate the two units. The Unayzah B sands are also characterised by the common presence of apatite, indicating that the source rocks were relatively unweathered. This observation is compatible with the glacial origin attributed to many of the Unayzah B sediments. A further change in provenance signature takes place at the base the newly recognised ‘un-named middle Unayzah member’, equivalent to the base of Unayzah A of previous authors. This is associated with the onset of red-bed sedimentation throughout the area. Unayzah A sedimentation was terminated by a fall in sea level that led to the formation of a widespread unconformity and to the development of deeply incised valleys along the western basin margin. In most of the study area this unconformity corresponds to the base of the Khuff Formation, but in the east of the area, where the succession is more complete, it is believed to occur within the Unayzah Formation, at a level equivalent to the base of the Upper Gharif Member of Oman. By identifying lateral and vertical changes in sand provenance, heavy mineral analysis provides an important additional tool in the stratigraphic analysis of the Permian sandstone succession of Saudi Arabia, both at the regional scale and wand at the scale of individual reservoir sandstone successions

    Development of a biomarker for penconazole: a human oral dosing study and a survey of UK residents’ exposure

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    Penconazole is a widely used fungicide in the UK; however, to date, there have been no peer-reviewed publications reporting human metabolism, excretion or biological monitoring data. The objectives of this study were to i) develop a robust analytical method, ii) determine biomarker levels in volunteers exposed to penconazole, and, finally, to iii) measure the metabolites in samples collected as part of a large investigation of rural residents’ exposure. An LC-MS/MS method was developed for penconazole and two oxidative metabolites. Three volunteers received a single oral dose of 0.03 mg/kg body weight and timed urine samples were collected and analysed. The volunteer study demonstrated that both penconazole-OH and penconazole-COOH are excreted in humans following an oral dose and are viable biomarkers. Excretion is rapid with a half-life of less than four hours. Mean recovery of the administered dose was 47% (range 33%–54%) in urine treated with glucuronidase to hydrolyse any conjugates. The results from the residents’ study showed that levels of penconazole-COOH in this population were low with >80% below the limit of detection. Future sampling strategies that include both end of exposure and next day urine samples, as well as contextual data about the route and time of exposure, are recommended

    Oakleaf: an S locus-linked mutation of Primula vulgaris that affects leaf and flower development

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    •In Primula vulgaris outcrossing is promoted through reciprocal herkogamy with insect-mediated cross-pollination between pin and thrum form flowers. Development of heteromorphic flowers is coordinated by genes at the S locus. To underpin construction of a genetic map facilitating isolation of these S locus genes, we have characterised Oakleaf, a novel S locus-linked mutant phenotype. •We combine phenotypic observation of flower and leaf development, with classical genetic analysis and next-generation sequencing to address the molecular basis of Oakleaf. •Oakleaf is a dominant mutation that affects both leaf and flower development; plants produce distinctive lobed leaves, with occasional ectopic meristems on the veins. This phenotype is reminiscent of overexpression of Class I KNOX-homeodomain transcription factors. We describe the structure and expression of all eight P. vulgaris PvKNOX genes in both wild-type and Oakleaf plants, and present comparative transcriptome analysis of leaves and flowers from Oakleaf and wild-type plants. •Oakleaf provides a new phenotypic marker for genetic analysis of the Primula S locus. We show that none of the Class I PvKNOX genes are strongly upregulated in Oakleaf leaves and flowers, and identify cohorts of 507 upregulated and 314 downregulated genes in the Oakleaf mutant

    Popular music, psychogeography, place identity and tourism: The case of Sheffield

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    Tourism and cultural agencies in some English provincial cities are promoting their popular music ‘heritage’ and, in some cases, contemporary musicians through the packaging of trails, sites, ‘iconic’ venues and festivals. This article focuses on Sheffield, a ‘post-industrial’ northern English city which is drawing on its associations with musicians past and present in seeking to attract tourists. This article is based on interviews with, among others, recording artists, promoters, producers and venue managers, along with reflective observational and documentary data. Theoretical remarks are made on the representations of popular musicians through cultural tourism strategies, programmes and products and also on the ways in which musicians convey a ‘psychogeographical’ sense of place in the ‘soundscape’ of the city

    The views of older women towards mammographic screening: a qualitative and quantitative study

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    Purpose: Mammographic screening has improved breast cancer survival in the screened age group. This improved survival has not been seen in older women (>70 years) where screening uptake is low. This study explores the views, knowledge and attitudes of older women towards screening. Methods: Women (>70) were interviewed about breast screening. Interview findings informed the development of a questionnaire which was sent to 1000 women (>70) to quantify their views regarding screening. Results: Twenty-six women were interviewed and a questionnaire designed. The questionnaire response rate was 48.3% (479/992). Over half (52.9%, 241/456) of respondents were unaware they could request mammography by voluntary self-referral and were unaware of how to arrange this. Most (81.5% 383/470) had not attended breast screening since turning 70. Most (75.6%, 343/454) felt screening was beneficial and would attend if invited. Most, (90.1%, 412/457) felt screening should be offered to all women regardless of age or health. Conclusions: There is a lack of knowledge about screening in older women. The majority felt that invitation to screening should be extended to the older age group regardless of age or health. The current under-utilised system of voluntary self referral is not supported by older women

    Engaging with community researchers for exposure science: lessons learned from a pesticide biomonitoring study

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    A major challenge in biomonitoring studies with members of the general public is ensuring their continued involvement throughout the necessary length of the research. The paper presents evidence on the use of community researchers, recruited from local study areas, as a mechanism for ensuring effective recruitment and retention of farmer and resident participants for a pesticides biomonitoring study. The evidence presented suggests that community researchers' abilities to build and sustain trusting relationships with participants enhanced the rigour of the study as a result of their on-the-ground responsiveness and flexibility resulting in data collection beyond targets expected

    Integration of genetic and physical maps of the Primula vulgaris S locus and localization by chromosome in situ hybridization

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    •Heteromorphic flower development in Primula is controlled by the S locus. The S locus genes, which control anther position, pistil length and pollen size in pin and thrum flowers, have not yet been characterized. We have integrated S-linked genes, marker sequences and mutant phenotypes to create a map of the P. vulgaris S locus region that will facilitate the identification of key S locus genes. We have generated, sequenced and annotated BAC sequences spanning the S locus, and identified its chromosomal location. •We have employed a combination of classical genetics and three-point crosses with molecular genetic analysis of recombinants to generate the map. We have characterized this region by Illumina sequencing and bioinformatic analysis, together with chromosome in situ hybridization. •We present an integrated genetic and physical map across the P. vulgaris S locus flanked by phenotypic and DNA sequence markers. BAC contigs encompass a 1.5-Mb genomic region with 1 Mb of sequence containing 82 S-linked genes anchored to overlapping BACs. The S locus is located close to the centromere of the largest metacentric chromosome pair. •These data will facilitate the identification of the genes that orchestrate heterostyly in Primula and enable evolutionary analyses of the S locus

    Weight gain, overweight, and obesity: determinants and health outcomes from the Australian Longitudinal Study on Women’s Health

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    Recent estimates suggest that 35.3\ua0% of adult Australians are overweight and a further 27.5\ua0% are obese. The Australian Longitudinal Study on Women's Health (ALSWH) is a prospective study of women's health that commenced in Australia in 1996. The study recruited approximately 40,000 women in three birth cohorts, 1973-1978, 1946-1951 and 1921-1926, who have since been followed up approximately every three years using self-report surveys. Six surveys have been completed to date. This review aims to describe the changes in weight and weight status over time in the three ALSWH cohorts, and to review and summarise the published findings to date relating to the determinants and health consequences of weight gain, overweight and obesity. Future plans for the ALSWH include on-going surveys for all cohorts, with a seventh survey in 2013-2015, and establishment of a new cohort of women born in 1990-1995, which is currently being recruited

    Risks to Birds Traded for African Traditional Medicine: A Quantitative Assessment

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    Few regional or continent-wide assessments of bird use for traditional medicine have been attempted anywhere in the world. Africa has the highest known diversity of bird species used for this purpose. This study assesses the vulnerability of 354 bird species used for traditional medicine in 25 African countries, from 205 genera, 70 families, and 25 orders. The orders most represented were Passeriformes (107 species), Falconiformes (45 species), and Coraciiformes (24 species), and the families Accipitridae (37 species), Ardeidae (15 species), and Bucerotidae (12 species). The Barn owl (Tyto alba) was the most widely sold species (seven countries). The similarity of avifaunal orders traded is high (analogous to ‘‘morphospecies’’, and using Sørensen’s index), which suggests opportunities for a common understanding of cultural factors driving demand. The highest similarity was between bird orders sold in markets of Benin vs. Burkina Faso (90%), but even bird orders sold in two geographically separated countries (Benin vs. South Africa and Nigeria vs. South Africa) were 87% and 81% similar, respectively. Rabinowitz’s ‘‘7 forms of rarity’’ model, used to group species according to commonness or rarity, indicated that 24% of traded bird species are very common, locally abundant in several habitats, and occur over a large geographical area, but 10% are rare, occur in low numbers in specific habitats, and over a small geographical area. The order with the highest proportion of rare species was the Musophagiformes. An analysis of species mass (as a proxy for size) indicated that large and/or conspicuous species tend to be targeted by harvesters for the traditional medicine trade. Furthermore, based on cluster analyses for species groups of similar risk, vultures, hornbills, and other large avifauna, such as bustards, are most threatened by selective harvesting and should be prioritised for conservation action.University of the Witwatersrand SPARC Prestigious and URC Postdoctoral Fellowships; National Research Foundatio
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