Uranium isotopic composition can provide valuable information about the history and provenance of a nuclear material; therefore, uranium isotopic analyses are frequently made in the nuclear ...forensics, safeguards, and environmental monitoring communities. These measurements have always presented challenges due to the extreme variability in the relative abundance between the major (235U, 238U) and minor (233U, 234U, 236U) isotopes of uranium. The recently developed ATONA (Atto- to Nano-Amp) amplification system paired with Faraday cup detectors has a large dynamic range and low noise floor making it ideal for measuring uranium isotopic ratios in materials of both natural and anthropogenic origin. A wide variety of certified reference materials were analyzed to investigate the utility of the ATONA amplification system for determining uranium isotopic composition in samples ranging from depleted to highly enriched. The ATONA amplifiers provide nearly an order of magnitude improvement in external reproducibility over 1011 Ω amplifiers when measuring the minor 234U/238U ratio in isotopically natural and depleted samples and when paired with a secondary electron multiplier can measure very low relative abundance uranium isotopes (i.e., 236U).
Mitochondrial DNA copy number (mtDNA-CN) is a biomarker for mitochondrial dysfunction associated with several diseases. Previous genome-wide association studies (GWAS) have been performed to unravel ...underlying mechanisms of mtDNA-CN regulation. However, the identified gene regions explain only a small fraction of mtDNA-CN variability. Most of this data has been estimated from microarrays based on various pipelines. In the present study we aimed to (1) identify genetic loci for qPCR-measured mtDNA-CN from three studies (16,130 participants) using GWAS, (2) identify potential systematic differences between our qPCR derived mtDNA-CN measurements compared to the published microarray intensity-based estimates, and (3) disentangle the nuclear from mitochondrial regulation of the mtDNA-CN phenotype. We identified two genome-wide significant autosomal loci associated with qPCR-measured mtDNA-CN: at HBS1L (rs4895440, p = 3.39 × 10
) and GSDMA (rs56030650, p = 4.85 × 10
) genes. Moreover, 113/115 of the previously published SNPs identified by microarray-based analyses were significantly equivalent with our findings. In our study, the mitochondrial genome itself contributed only marginally to mtDNA-CN regulation as we only detected a single rare mitochondrial variant associated with mtDNA-CN. Furthermore, we incorporated mitochondrial haplogroups into our analyses to explore their potential impact on mtDNA-CN. However, our findings indicate that they do not exert any significant influence on our results.
In 2015 a geothermal exploration well was drilled on the island of Tutuila, American Samoa. The sample suite from the drill core provides 645 m of volcanic stratigraphy from a Samoan volcano, ...spanning 1.45 million years of volcanic history. In the Tutuila drill core, shield lavas with an EM2 (enriched mantle 2) signature are observed at depth, spanning 1.46 to 1.44 Ma. These are overlain by younger (1.35 to 1.17 Ma) shield lavas with a primordial “common” (focus zone) component interlayered with lavas that sample a depleted mantle component. Following ~1.15 Myr of volcanic quiescence, rejuvenated volcanism initiated at 24.3 ka and samples an EM1 (enriched mantle 1) component. The timing of the initiation of rejuvenated volcanism on Tutuila suggests that rejuvenated volcanism may be tectonically driven, as Samoan hotspot volcanoes approach the northern terminus of the Tonga Trench. This is consistent with a model where the timing of rejuvenated volcanism at Tutuila and at other Samoan volcanoes relates to their distance from the Tonga Trench. Notably, the Samoan rejuvenated lavas have EM1 isotopic compositions distinct from shield lavas that are geochemically similar to “petit spot” lavas erupted outboard of the Japan Trench and late stage lavas erupted at Christmas Island located outboard of the Sunda Trench. Therefore, like the Samoan rejuvenated lavas, petit spot volcanism in general appears to be related to tectonic uplift outboard of subduction zones, and existing geochemical data suggest that petit spots share similar EM1 isotopic signatures.
Key Points
Within the 645‐m Tutuila drill core we find isotopically heterogeneous lavas as well as several abrupt temporal and geochemical boundaries
The proximity of Samoan volcanoes to the Tonga Trench and geochronology are consistent with a tectonic influence on rejuvenated volcanism
The tectonic setting and isotopic signatures of the Samoan rejuvenated lavas link them to “petit spots” outboard of the Japan Trench
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Cs measurements were performed on a set of debris samples from the first nuclear test, Trinity. Debris from several locations around ground zero of the event were purified and analyzed ...for
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Cs by thermal ionization mass spectrometry (TIMS). The Cs-isotopic measurements presented here are the first high precision TIMS
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Cs measurements of trinitite from variable locations and cooling histories relative to ground zero. Our measurements show a large fractionation from the predicted fission yields, all with a relative enrichment in
137
Cs.
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Cs ratios indicate that condensation times varied between different debris forms, however they are not consistent with an unfractionated decay to Cs from independent fission products. Variations in
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Cs ratios are observed with relative distance from ground zero as well as
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Cs heterogeneities between different trinitite lithologies within a single sample.
Particulate isotopic analysis in nuclear forensics has developed rapidly during the past two decades due to technical advances in determining the isotopic composition of individual particles. This ...paper introduces basic statistical concepts that can be applied by analysts to understand the importance of statistical adequacy when interpretating particle data. While these basic statistical methods provide a useful point-of-entry to particle data analysis, more sophisticated statistical and modeling approaches are needed to extract maximal information from such datasets in the future.
Bioassay monitoring is an important capability for any facility that works with significant amounts of radioactive material. The speed at which these analyses can be made is critical in the event of ...a potential exposure. In this study, we present a new method that facilitates the rapid separation of uranium from a urine matrix for assay and isotopic determination by inductively coupled plasma mass spectrometry. This method is validated with archived urine samples that were previously analyzed using established, more time consuming methods. The sources of uncertainty for uranium assay and isotopic measurements are modelled using the Monte Carlo method to better understand the precision and accuracy of this method at the limit of quantification.
In this study, data from thirteen laboratories from around the world are presented for a successful certification of uranium isotope ratios in uranium ore concentrate (UOC) certified reference ...materials from the National Research Council Canada. Different mass spectrometric measurement principles (including SF‐ICP‐MS, quadruple ICP‐MS, TIMS, MC‐ICP‐MS, SIMS and AMS) and measurement procedures were employed. In general, data from all sources exhibit good consistency with TIMS and MC‐ICP‐MS showing superior performance. The three candidate UOC CRMs (UCLO‐1, UCHI‐1 and UPER‐1) have natural uranium isotope ratios with certified values of 0.5304(7) × 10−4, 0.5475(2) × 10−4 and 0.5361(4) × 10−4 for n(234U)/n(238U) and 0.007 2563(13), 0.007 2563(10) and 0.007 2542(11) for n(235U)/n(238U), respectively, with expanded uncertainty (k = 2) applicable to the last digit of the value given in the parentheses. Information values for n(236U)/n(238U) in these three CRMs, measured by AMS, are also provided: 10 × 10−12, 200 × 10−12 and 22 × 10−12. The uncertainties of the proposed certified values of uranium isotope ratios in UOC CRMs are superior to available reference materials, and the values of n(234U)/n(238U) and n(236U)/n(238U) show significant variation among the three CRMs.
Key Points
Collaboration involving 13 international laboratories employing different mass spectrometric measurement principles (SF‐ICP‐MS, Q‐ICP‐MS, TIMS, MC‐ICP‐MS, SIMS, AMS) and measurement procedures.
Successful certification of uranium isotope ratios in uranium ore concentrate CRMs UCHI‐1, UCLO‐1 and UPER‐1 from the National Research Council Canada.
Suitable for validation of methods used for uranium isotope ratio measurements.
Buprenorphine is an effective medication for the treatment of opioid use disorder. However, the traditional method of buprenorphine induction requires a period of abstinence and the development of at ...least moderate withdrawal, which can be barriers in starting treatment. We present the case of a hospitalized patient with opioid use disorder using unregulated fentanyl, who underwent a transdermal buprenorphine induction over 48 hours to initiate sublingual buprenorphine/naloxone on the third day. The patient experienced minimal levels of withdrawal and did not experience precipitated withdrawal. The ease of use of this novel induction method over previously published induction protocols can greatly improve the accessibility of buprenorphine for patients and healthcare staff.
Here, in this study, data from thirteen laboratories from around the world are presented for a successful certification of uranium isotope ratios in uranium ore concentrate (UOC) certified reference ...materials from the National Research Council Canada. Different mass spectrometric measurement principles (including SF-ICP-MS, quadruple ICP-MS, TIMS, MC-ICP-MS, SIMS and AMS) and measurement procedures were employed. In general, data from all sources exhibit good consistency with TIMS and MC-ICP-MS showing superior performance. The three candidate UOC CRMs (UCLO-1, UCHI-1 and UPER-1) have natural uranium isotope ratios with certified values of 0.5304(7) x 10-4, 0.5475(2) x 10-4 and 0.5361(4) x 10-4 for n(234U)/n(238U) and 0.007 2563(13), 0.007 2563(10) and 0.007 2542(11) for n(235U)/n(238U), respectively, with expanded uncertainty (k = 2) applicable to the last digit of the value given in the parentheses. Information values for n(236U)/n(238U) in these three CRMs, measured by AMS, are also provided: 10 x 10-12, 200 x 10-12 and 22 x 10-12. The uncertainties of the proposed certified values of uranium isotope ratios in UOC CRMs are superior to available reference materials, and the values of n(234U)/n(238U) and n(236U)/n(238U) show significant variation among the three CRMs.
Lord Rodger of Earlsferry was a distinguished judge and scholar. He was a Justice of the Supreme Court of the United Kingdom and the author of many high quality law journal articles and two books. ...Written in memory of Lord Rodger, this book contains forty-seven chapters by Lord Rodger's friends and colleagues from the UK and Europe. The chapters reflect Lord Rodger's role as a leading judge and also his wide-ranging academic interests including Roman law, Scots law, legal history, and a miscellany of other topics. The contributors to this volume are leading academics or judges, and a particularly notable feature is the nine chapters written by Supreme Court justices. As the highest judges in the UK they provide a unique insight into the work of the Supreme Court, as well as Lord Rodger's work in the Court. The book also includes the memorial tributes to Lord Rodger which explain his remarkable legal career, including his roles as Lord Advocate (Senior Law Officer of Scotland) Lord President of the Court of Session, Lord of Appeal in Ordinary and, finally, Justice of the UK Supreme Court. The chapters include personal reminiscences of Lord Rodger, helping the reader to understand why he was so highly regarded and why his untimely death has dealt such a devastating blow to law in the UK.
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