932 research outputs found
Chemical diffusion of fluorine in melts in the system Na2OAl2O3SiO2
The volatilization of fluorine from three melts in the system Na2OAl2O3SiO2 has been investigated at 1 atm pressure and 1200â1400°C. The melts chosen have base compositions corresponding to albite, jadeite and a peraluminous melt with 75 mole % SiO2. Melt spheres were suspended from platinum loops in a vertical tube furnace in a flow of oxygen gas, then quenched, sectioned and analysed by electron microprobe. The microprobe scans indicate that transport of fluorine to the melt-vapor interface is by binary, concentration-independent interdiffusion of fluorine and oxygen. FO interdiffusivity increases in the order albite < peraluminous < jadeite. There is no simple reciprocal relationship between FO interdiffusivity and melt viscosity. Comparison with data on high-pressure interdiffusivity of fluorine and oxygen in jadeite melt indicates that FO interdiffusivity increases with pressure from 0.001 to 10 kbar while the activation energy remains unchanged.
Fluorine chemical diffusivity in albite melt is substantially lower than H2O chemical diffusivity in obsidian melts suggesting that different diffusive mechanisms are responsible for the transport of F and H2O in igneous melts. Fluorine diffuses in albite melt via an anionic exchange with oxygen whereas water probably diffuses in obsidian melt via an alkali exchange mechanism
Assessing availability of European plant protection product data: an example evaluating basic area treated
Besides the benefits of plant protection products (PPPs) for agricultural production, there is an increasing acknowledgement of the associated potential environmental risks. Here, we examine the feasibility of summarizing the extent of PPP usage at the country level, using Ireland as a case study, as well as at the European level. We used the area over which PPPs are applied (basic area) as an example variable that is relevant to initially assess the geographic extent of environmental risk. In Irish agricultural systems, which are primarily grass-based, herbicides fluroxypyr and glyphosate are the most widely applied active substances (ASs) in terms of basic area, followed by the fungicides chlorothalonil and prothioconazole that are closely associated with arable crops. Although all EU countries are subject to Regulation (EC) No 1185/2009, which sets the obligation of PPP usage data reporting at the national level, we only found usable data that met our criteria for Estonia, Germany, Finland, and Spain (4 of 30 countries reviewed). Overall, the most widely applied fungicide and herbicide in terms of basic area were prothioconazole (20%, 7% and 5% of national cultivated areas of Germany, Estonia and Ireland) and glyphosate (11%, 8% and 5% of national cultivated areas of Spain, Estonia and Ireland) respectively, although evaluations using application frequency may result in the observation of different trends. Several recommendations are proposed to tackle current data gaps and deficiencies in accessibility and usability of pesticide usage data across the EU in order to better inform environmental risk assessment and promote evidence-based policymaking.Publishe
National First Peoples Gathering on Climate Change
Our purpose in hosting the National First Peoples Gathering on Climate Change (the Gathering) was to celebrate, learn from and enhance First Peoples-led climate action. We set out to strengthen kinships, cultural identity and well-being, and to strengthen caring for Country by using both Indigenous and scientific knowledge. The Gathering supported this overall purpose through five aims:⢠Bring Traditional Owners together to share with one another about climate change ⢠Share scientific information in a form useful for Traditional Owners⢠Identify options for policy to respond to climate change ⢠Provide tangible information to take back to communities⢠Highlight First Peoplesâ climate change actions. 110 Traditional Owners from across Australia attended the Gathering
Autonomy of Nations and Indigenous Peoples and the Environmental Release of Genetically Engineered Animals with Gene Drives
This article contends that the environmental release of genetically engineered (GE) animals with heritable traits that are patented will present a challenge to the efforts of nations and indigenous peoples to engage in selfâdetermination. The environmental release of such animals has been proposed on the grounds that they could function as public health tools or as solutions to the problem of agricultural insect pests. This article brings into focus two politicalâeconomicâlegal problems that would arise with the environmental release of such organisms. To address those challenges, it is proposed that nations considering the environmental release of GE animals must take into account the underlying circumstances and policy failures that motivate arguments for the use of the modified animals. Moreover, countries must recognize that the UN International Covenant on Civil and Political Rights and the UN International Covenant on Economic, Social and Cultural Rights place on them an obligation to ensure that GE animals with patented heritable traits are not released without the substantive consent of the nations or indigenous peoples that could be affected
An early warning risk prediction tool (RECAP-V1) for patients diagnosed with COVID-19: the protocol for a statistical analysis plan
Background: Since the start of the Covid-19 pandemic efforts have been made to develop early warning risk scores to help clinicians decide which patient is likely to deteriorate and require hospitalisation. The RECAP (Remote COVID Assessment in Primary Care) study investigates the predictive risk of hospitalisation, deterioration, and death of patients with confirmed COVID-19, based on a set of parameters chosen through a Delphi process done by clinicians. The study aims to use rich data collected remotely through the use of electronic data templates integrated in the electronic health systems of a number of general practices across the UK to construct accurate predictive models that will use pre-existing conditions and monitoring data of a patientâs clinical parameters such as blood oxygen saturation to make reliable predictions as to the patientâs risk of hospital admission, deterioration, and death. Objective: We outline the statistical methods to build the prediction model to be used in the prioritisation of patients in the primary care setting. The statistical analysis plan for the RECAP study includes as primary outcome the development and validation of the RECAP-V1 prediction model. Such prediction model will be adapted as a three-category risk score split into red (high risk), amber (medium risk), and green (low risk) for any patient with suspected covid-19. The model will predict risk of deterioration, hospitalisation, and death. Methods: After the data has been collected, we will assess the degree of missingness and use a combination of traditional data imputation using multiple imputation by chained equations, as well as more novel machine learning approaches to impute the missing data for the final analysis. For predictive model development we will use multiple logistic regressions to construct the model on a training dataset, as well as validating the model on an independent dataset. The model will also be applied for multiple different datasets to assess both its performance in different patient groups, and applicability for different methods of data collection. Results: As of 5th of May 2021 we have recruited 2280 patients for the main dataset for model development, as well as a further 1741 patients for the validation dataset. Final analysis will commence as soon as data for 2880 are collected. Conclusions: We believe that the methodology for the development of the RECAP V1 prediction model as well as the risk score will provide clinicians with a statistically robust tool to help prioritise Covid-19 patients. Clinical Trial: Trial registration number: NCT0443504
What items should be included in an early warning score for remote assessment of suspected COVID-19? qualitative and Delphi study
Background To develop items for an early warning score (RECAP: REmote COVID-19 Assessment in Primary Care) for patients with suspected COVID-19 who need escalation to next level of care. Methods The study was based in UK primary healthcare. The mixed-methods design included rapid review, Delphi panel, interviews, focus groups and software development. Participants were 112 primary care clinicians and 50 patients recovered from COVID-19, recruited through social media, patient groups and snowballing. Using rapid literature review, we identified signs and symptoms which are commoner in severe COVID-19. Building a preliminary set of items from these, we ran four rounds of an online Delphi panel with 72 clinicians, the last incorporating fictional vignettes, collating data on R software. We refined the items iteratively in response to quantitative and qualitative feedback. Items in the penultimate round were checked against narrative interviews with 50 COVID-19 patients. We required, for each item, at least 80% clinician agreement on relevance, wording and cut-off values, and that the item addressed issues and concerns raised by patients. In focus groups, 40 clinicians suggested further refinements and discussed workability of the instrument in relation to local resources and care pathways. This informed design of an electronic template for primary care systems. Results The prevalidation RECAP-V0 comprises a red flag alert box and 10 assessment items: pulse, shortness of breath or respiratory rate, trajectory of breathlessness, pulse oximeter reading (with brief exercise test if appropriate) or symptoms suggestive of hypoxia, temperature or fever symptoms, duration of symptoms, muscle aches, new confusion, shielded list and known risk factors for poor outcome. It is not yet known how sensitive or specific it is. Conclusions Items on RECAP-V0 align strongly with published evidence, clinical judgement and patient experience. The validation phase of this study is ongoing. Trial registration number NCT04435041
Osseous metaplasia in an ulcerating tubular adenoma of the colon: a case report
<p>Abstract</p> <p>Introduction</p> <p>Heterotopic bone is rarely found in the gastrointestinal tract. Here we report a rare case of metaplastic ossification within a benign ulcerating adenoma and review the literature concerning the aetiology.</p> <p>Case presentation</p> <p>A 63-year-old woman, who presented with a history of melaena, was found at colonoscopy to have a pedunculated ulcerating polyp. Histological examination demonstrated multiple areas of osseous metaplasia within the polyp stroma.</p> <p>Conclusion</p> <p>Heterotopic ossification in colonic adenomas is a particularly rare phenomenon, with the majority of cases occurring within malignant lesions. The suggested mechanisms for its aetiology still remain unclear.</p
Clinical implications of determination of safe surgical margins by using a combination of CT and 18FDG-positron emission tomography in soft tissue sarcoma
<p>Abstract</p> <p>Background</p> <p>To determine safe surgical margins for soft tissue sarcoma, it is essential to perform a general evaluation of the extent of tumor, responses to auxiliary therapy, and other factors preoperatively using multiple types of diagnostic imaging. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is a tool for diagnostic imaging that has recently spread rapidly in clinical use. At present, the roles played by FDG-PET/CT in determination of margins for surgical resection of sarcoma are unclear. The present study was undertaken to explore the roles of FDG-PET/CT in determination of surgical margins for soft tissue sarcoma and to examine whether PET can serve as a standard means for setting the margins of surgical resection during reduced surgery.</p> <p>Methods</p> <p>The study involved 7 patients with sarcoma who underwent surgery in our department and in whom evaluation with FDG-PET/CT was possible. Sarcoma was histologically rated as MFH in 6 cases and leiomyosarcoma in 1 case. In all cases, sarcoma was superficial (T1a or T2a). The tumor border was defined by contrast-enhanced MRI, and SUVs were measured at intervals of 1 cm over a 5-cm long area from the tumor border. Mapping of viable tumor cells was carried out on whole-mount sections of resected tissue, and SUVs were compared with histopathological findings.</p> <p>Results</p> <p>Preoperative maximum SUVs (SUV-max) of the tumor averaged 11.7 (range: 3.8-22.1). Mean SUV-max was 2.2 (range: 0.3-3.8) at 1 cm from the tumor border, 1.1 (0.85-1.47) at 2 cm, 0.83 (0.65-1.15) at 3 cm, 0.7 (0.42-0.95) at 4 cm, and 0.64 (0.45-0.82) at 5 cm. When resected tissue was mapped, tumor cells were absent in the areas where SUV-max was below 1.0.</p> <p>Conclusions</p> <p>Our findings suggest that a safe surgical margin free of viable tumor cells can be ensured if the SUV cut-off level is set at 1.0. FDG-PET/CT is promising as a diagnostic imaging technique for setting of safe minimal margins for surgical resection of soft tissue sarcoma.</p
Signatures of selection underpinning rapid coral adaptation to the worldâs warmest reefs
Coral populations in the worldâs warmest reefs, the Persian/Arabian Gulf (PAG), represent an ideal model system to understand the evolutionary response of coral populations to past and present environmental change and to identify genomic loci that contribute to elevated thermal tolerance. Here, we use population genomics of the brain coral Platygyra daedalea to show that corals in the PAG represent a distinct subpopulation that was established during the Holocene marine transgression, and identify selective sweeps in their genomes associated with thermal adaptation. We demonstrate the presence of positive and disruptive selection and provide evidence for selection of differentially methylated haplotypes. While demographic analyses suggest limited potential for genetic rescue of neighboring Indian Ocean reefs, the presence of putative targets of selection in corals outside of the PAG offers hope that loci associated with thermal tolerance may be present in the standing genetic variation
The Impact of Human Resource Practices on Actual and Perceived Organizational Performance in a Middle Eastern Emerging Market
This is a study centered on the impact of the specific set of HRM practices on organizational performance (OP) within an emerging-market setting. It seeks to explore which HR practices are most closely associated with better OP within the financial services industry in Jordan based on a survey of managers and the annual reports of the companies encompassed by the study. It was found that the only HR practice seen to consistently impact on OP was training; in other words, we did not encounter any recognizable "bundle" of HR practices that optimized OP across the sector. We argue that this reflects the weaker and more partially coupled nature of institutions in many emerging markets, which makes it difficult to generate the type of complementarities associated between regulation and practice in mature markets. It also reflects the limited transferability of perceived best practice models in the context of emerging-market settings. Although belied by objective firm performance data, many respondents believed that it was not only training but also the extensive usage of extrinsic incentives (pay and promotion) that would translate into superior results. This highlights the limitations of relying on managerial reported performance data in exploring the consequences of specific HR practices
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