85 research outputs found

    Metabolic responses to arsenite in rice seedlings that differed in grain arsenic concentration

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    © Crop Science Society of America. Arsenic (As) occurs naturally in the environment, and is present in all edible and nonedible plant tissues. Plants have multiple mechanisms to prevent plant injury by heavy metals such as As. These same mechanisms could be used to reduce accumulation of As in rice (Oryza sativa L.) grains. From previous study of 1765 international rice accessions, specific accessions were identified as having exceptionally high grain As concentrations (grain As accumulators) and others low grain As (grain As excluders). This study investigated As uptake, transport, and metabolism in six previously identified lines to determine which physiological responses, if any, were associated with accumulation or exclusion of As in grains. Hydroponically grown seedlings were treated with 0 (controls) or 100 mM arsenite [As(III)], and then whole seedlings were analyzed for concentrations of As plus key compounds involved in heavy metal metabolism. Both grain accumulators and grain excluders actively concentrated As within their roots, and both groups had 10-fold higher As concentrations in roots than leaves. In response to As(III), roots of both grain excluders and grain accumulators increased in cysteine and phytochelatin (PC) production, which suggests PC sequestration of As. In contrast, only grain excluders doubled in leaf glutathione (GSH) concentration by 72 h after As(III) addition. Because PC concentrations remained constant in leaves, it appears that the additional leaf GSH in the grain excluders was not used to produce more PC but may instead be forming As-GSH adducts, which also aid in As sequestration

    Web Vulnerability Study of Online Pharmacy Sites

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    Consumers are increasingly using online pharmacies, but these sites may not provide an adequate level of security with the consumers’ personal data. There is a gap in this research addressing the problems of security vulnerabilities in this industry. The objective is to identify the level of web application security vulnerabilities in online pharmacies and the common types of flaws, thus expanding on prior studies. Technical, managerial and legal recommendations on how to mitigate security issues are presented. The proposed four-step method first consists of choosing an online testing tool. The next steps involve choosing a list of 60 online pharmacy sites to test, and then running the software analysis to compile a list of flaws. Finally, an in-depth analysis is performed on the types of web application vulnerabilities. The majority of sites had serious vulnerabilities, with the majority of flaws being cross-site scripting or old versions of software that have not been updated. A method is proposed for the securing of web pharmacy sites, using a multi-phased approach of technical and managerial techniques together with a thorough understanding of national legal requirements for securing systems

    Geomorphological context and formation history of Cloggs Cave: What was the cave like when people inhabited it?

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    New research undertaken at Cloggs Cave, in the foothills of the Australian Alps, employed an integrated geological-geomorphological-archaeological approach with manifold dating methods and fine resolution LiDAR 3D mapping. Long-standing questions about the site’s chronostratigraphy (e.g. the exact relationship between basal megafaunal deposits and archaeological layers), sedimentation processes and geomorphic changes were resolved. The cave’s formation history was reconstructed to understand its changing morphology and morphogenic processes, and to clarify how these processes shaped the cave’s deposits. Key findings include the identification of: 1) the geomorphological processes that caused the lateral juxtaposition of 52,000 year-old megafaunal and later occupational layers; 2) the existence of one and possibly two (now-buried) palaeo-entrance(s) that enabled now-extinct megafauna and extant large fauna to enter the cave, most likely via a free-roaming passage rather than a pit drop; 3) morphological changes to the cave during the time of the Old People, including the timing of changes to the inclination of palaeo-surfaces; and 4) modifications to stalactites, crushing of calcite formations for the manufacture of powder, construction of a stone arrangement, and movement of large limestone blocks by the Old People. Ultimately, these findings demonstrate that to properly understand what Cloggs Cave was like when the Old People visited the site requires the construction of a narrative that spans some 400 million years and the development of an approach capable of integrating the many scales and processes (e.g. geological, geomorphological, archaeological) that configured to shape the site

    A Comparative Study on Three Analytical Methods for the Determination of the Neurotoxin BMAA in Cyanobacteria

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    The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) has been considered a serious health threat because of its putative role in multiple neurodegenerative diseases. First reports on BMAA concentrations in cyanobacteria were alarming: nearly all cyanobacteria were assumed to contain high BMAA concentrations, implying ubiquitous exposure. Recent studies however question this presence of high BMAA concentrations in cyanobacteria. To assess the real risk of BMAA to human health, this discrepancy must be resolved. We therefore tested whether the differences found could be caused by the analytical methods used in different studies. Eight cyanobacterial samples and two control samples were analyzed by three commonly used methods: HPLC-FLD analysis and LC-MS/MS analysis of both derivatized and underivatized samples. In line with published results, HPLC-FLD detected relatively high BMAA concentrations in some cyanobacterial samples, while both LC-MS/MS methods only detected BMAA in the positive control (cycad seed sarcotesta). Because we could eliminate the use of different samples and treatments as causal factors, we demonstrate that the observed differences were caused by the analytical methods. We conclude that HPLC-FLD overestimated BMAA concentrations in some cyanobacterial samples due to its low selectivity and propose that BMAA might be present in (some) cyanobacteria, but in the low µg/g or ng/g range instead of the high µg/g range as sometimes reported before. We therefore recommend to use only selective and sensitive analytical methods like LC-MS/MS for BMAA analysis. Although possibly present in low concentrations in cyanobacteria, BMAA can still form a health risk. Recent evidence on BMAA accumulation in aquatic food chains suggests human exposure through consumption of fish and shellfish which expectedly exceeds exposure through cyanobacteria

    Characterising the nature of primary care patient safety incident reports in the England and Wales National Reporting and Learning System: a mixed-methods agenda-setting study for general practice

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    Background There is an emerging interest in the inadvertent harm caused to patients by the provision of primary health-care services. To date (up to 2015), there has been limited research interest and few policy directives focused on patient safety in primary care. In 2003, a major investment was made in the National Reporting and Learning System to better understand patient safety incidents occurring in England and Wales. This is now the largest repository of patient safety incidents in the world. Over 40,000 safety incident reports have arisen from general practice. These have never been systematically analysed, and a key challenge to exploiting these data has been the largely unstructured, free-text data. Aims To characterise the nature and range of incidents reported from general practice in England and Wales (2005–13) in order to identify the most frequent and most harmful patient safety incidents, and relevant contributory issues, to inform recommendations for improving the safety of primary care provision in key strategic areas. Methods We undertook a cross-sectional mixed-methods evaluation of general practice patient safety incident reports. We developed our own classification (coding) system using an iterative approach to describe the incident, contributory factors and incident outcomes. Exploratory data analysis methods with subsequent thematic analysis was undertaken to identify the most harmful and most frequent incident types, and the underlying contributory themes. The study team discussed quantitative and qualitative analyses, and vignette examples, to propose recommendations for practice. Main findings We have identified considerable variation in reporting culture across England and Wales between organisations. Two-thirds of all reports did not describe explicit reasons about why an incident occurred. Diagnosis- and assessment-related incidents described the highest proportion of harm to patients; over three-quarters of these reports (79%) described a harmful outcome, and half of the total reports described serious harm or death (n = 366, 50%). Nine hundred and ninety-six reports described serious harm or death of a patient. Four main contributory themes underpinned serious harm- and death-related incidents: (1) communication errors in the referral and discharge of patients; (2) physician decision-making; (3) unfamiliar symptom presentation and inadequate administration delaying cancer diagnoses; and (4) delayed management or mismanagement following failures to recognise signs of clinical (medical, surgical and mental health) deterioration. Conclusions Although there are recognised limitations of safety-reporting system data, this study has generated hypotheses, through an inductive process, that now require development and testing through future research and improvement efforts in clinical practice. Cross-cutting priority recommendations include maximising opportunities to learn from patient safety incidents; building information technology infrastructure to enable details of all health-care encounters to be recorded in one system; developing and testing methods to identify and manage vulnerable patients at risk of deterioration, unscheduled hospital admission or readmission following discharge from hospital; and identifying ways patients, parents and carers can help prevent safety incidents. Further work must now involve a wider characterisation of reports contributed by the rest of the primary care disciplines (pharmacy, midwifery, health visiting, nursing and dentistry), include scoping reviews to identify interventions and improvement initiatives that address priority recommendations, and continue to advance the methods used to generate learning from safety reports
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