Evaluation of X-ray Fluorescence Spectroscopy as a Tool for Element Analysis in Pea Seeds

X-ray fluorescence spectroscopy (XRF) is a powerful analytical tool for the determination of elemental composition of diverse materials. The principal aim of this study was to evaluate and characterize the utility and reliability of synchrotron-based XRF for use in element analysis of field pea seeds for quantification of macro- (K and Ca) and micro- (Mn, Fe, Cu, Zn, Se) elements. Pea seed samples were ground into fine flour and pellets were prepared to collect XRF peak intensities. Seventy-three pea seed samples were selected to cover the expected concentration ranges for each element for developing calibration curves by correlating the results from atomic absorption spectroscopy (AAS) reference method and XRF peak intensities. For all the calibration curves R2 values were above 0.8 except for K (0.5). XRF results were validated by a systematic comparison with data obtained from AAS on a set of 80 additional and independent pea seed samples (Validation Set). Element concentrations were also predicted using the fundamental parameter approach collectively for 153 samples. Limit of detection was calculated as low as 0.016 mg/kg for Se and 9.54 mg/kg for K. For Mn, Cu, Zn, Se, the XRF method was found to be not statistically different from AAS method at 95% confidence interval; furthermore, the bias between the methods was not significantly different from 0. Relative standard deviation (RSD) was less than 26% in XRF and range of recovery 75-165% for different elements. For the lower energy elements K and Ca, significant negative bias was observed (statistically different from 0) indicating underprediction by XRF method. The intercepts of the validation curve were -1460.3 and -61.27 for K and Ca respectively. Similar results were obtained with the fundamental parameter approach except for Fe for which significant bias of ~6 mg/kg was calculated. The intercept of validation curves was found to be not significantly different from 0 and B (the slope) was found to be not significantly different from 1. This leads to the conclusion that the results obtained using XRF and AAS were statistically not different from AAS method at 95% confidence interval. This study demonstrated that the XRF technique is a fast and reliable tool for element analysis, particularly for high energy elements and does not produce waste and requires no chemical reagents

Evaluation of synchrotron based x-ray fluorescence spectroscopy for quantification of minerals in pea seeds

Non-Peer Reviewe

Zonal Safety and Particular Risk Analysis for Early Aircraft Design using Parametric Geometric Modelling

Safety assessment is paramount in aircraft design. For unconventional aircraft or aircraft with novel propulsion or system architectures or technologies, it is critical to investigate safety as early as possible in the design process to eliminate unfeasible aircraft configurations and system architectures. In this context, the Zonal Safety Analysis (ZSA) and the Particular Risk Analysis (PRA) that evaluate the safety aspects from an aircraft configuration and system placement perspective are essential to perform early. These analyses require a three-dimensional (3D) model of the aircraft and systems and substantial manual effort, limiting the ability to perform rapid iterations required to support design space exploration and, eventually, multidisciplinary design optimization. To analyze many aircraft configurations and system architectures, parametric 3D modelling, ZSA, and PRA require automation. This thesis reviews the methodologies for performing the ZSA and PRA from a systems point of view and proposes a novel methodology for semi-automated conceptual-level ZSA and PRA (CZSA and CPRA) implemented using Python and OpenVSP. As part of CZSA, automated aircraft 3D modelling, parametric zone definition, and zone-component interaction analysis methods are developed that are supported by a manually prepared database of safety-driven best practices. The CPRA involves parametric modelling of particular risk threat zones for trajectory-based PRAs and automated detection of system components in these zones. The effectiveness of the proposed approach is demonstrated with case studies for conventional and unconventional aircraft designs and novel system technologies. The presented work is a step towards integrating system safety analysis into multidisciplinary analysis and optimization environments, thus increasing conceptual design maturity and reducing development time

Does Gender or Religion Contribute to the Risk of COVID-19 in Hospital Doctors?

This webpage details and provides the research study conducted in the United Kingdom through online surveys focusing on the relationship between healthcare workplace prevention efforts, COVID-19 risks, religious identity, and gender. The research study focuses on healthcare workers, primarily hospital doctors and mental health doctors. A PDF of the entire study is available on the webpage

Diagnostic accuracy of seismocardiography compared with electrocardiography for the anatomic and physiologic diagnosis of coronary artery disease during exercise testing

A multicenter study was performed to compare the diagnostic accuracy of a new technique, Seismocardiography, with that of electrocardiography for physiologically and anatomically significant ischemic coronary artery disease (CAD) during exercise stress testing.Five participating centers enrolled 129 patients who had simultaneous seismocardiograms and 12-lead electrocardiograms at the time of their exercise treadmill stress tests. Two different definitions of CAD were used: anatomic and physiologically significant disease. The presence of anatomically significant CAD (>=50% diameter stenosis) was documented by coronary angiography. Physiologically significant CAD was defined as present in the same 129 patients when coronary arteriography (>=50% diameter stenosis) and thallium-201 scintigraphy (defect on initial postexercise images) were both abnormal. Seismocardiography had a significantly better sensitivity for detecting anatomic CAD than did electrocardiography (73 vs 48%; p Seismocardiography significantly improved sensitivity for the detection of anatomic and physiologic CAD. It is easy to perform and may be a clinically useful adjunct in exercise stress testing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30956/1/0000628.pd

Pharmacokinetics and Dosing of Levofloxacin in Children Treated for Active or Latent Multidrug-resistant Tuberculosis, Federated States of Micronesia and Republic of the Marshall Islands

In the Federated States of Micronesia (FSM) and then the Republic of the Marshall Islands (RMI), levofloxacin pharmacokinetics (PK) were studied in children receiving directly observed once-daily regimens (10 mg/kg, age >5 years; 15–20 mg/kg, age ≤5 years) for either multidrug-resistant tuberculosis (MDR TB) disease or latent infection after MDR TB exposure, to inform future dosing strategies

Nutritional Status of Under-five Children Living in an Informal Urban Settlement in Nairobi, Kenya

Malnutrition in sub-Saharan Africa contributes to high rates of childhood morbidity and mortality. However, little information on the nutritional status of children is available from informal settlements. During the period of post-election violence in Kenya during December 2007-March 2008, food shortages were widespread within informal settlements in Nairobi. To investigate whether food insecurity due to post-election violence resulted in high prevalence of acute and chronic malnutrition in children, a nutritional survey was undertaken among children aged 6-59 months within two villages in Kibera, where the Kenya Medical Research Institute/Centers for Disease Control and Prevention conducts population-based surveillance for infectious disease syndromes. During 25 March-4 April 2008, a structured questionnaire was administered to caregivers of 1,310 children identified through surveillance system databases to obtain information on household demographics, food availability, and child-feeding practices. Anthropometric measurements were recorded on all participating children. Indices were reported in z-scores and compared with the World Health Organization (WHO) 2005 reference population to determine the nutritional status of children. Data were analyzed using the Anthro software of WHO and the SAS. Stunting was found in 47.0% of the children; 11.8% were underweight, and 2.6% were wasted. Severe stunting was found in 23.4% of the children; severe underweight in 3.1%, and severe wasting in 0.6%. Children aged 36-47 months had the highest prevalence (58.0%) of stunting while the highest prevalence (4.1%) of wasting was in children aged 6-11 months. Boys were more stunted than girls (p<0.01), and older children were significantly (p<0.0001) stunted compared to younger children. In the third year of life, girls were more likely than boys to be wasted (p<0.01). The high prevalence of chronic malnutrition suggests that stunting is a sustained problem within this urban informal settlement, not specifically resulting from the relatively brief political crisis. The predominance of stunting in older children indicates failure in growth and development during the first two years of life. Food programmes in Kenya have traditionally focused on rural areas and refugee camps. The findings of the study suggest that tackling childhood stunting is a high priority, and there should be fostered efforts to ensure that malnutrition-prevention strategies include the urban poor