A SPIRED\texttt{SPIRED} code for the reconstruction of spin distribution

In Nuclear Magnetic Resonance (NMR), it is of crucial importance to have an accurate knowledge of the sample probability distribution corresponding to inhomogeneities of the magnetic fields. An accurate identification of the sample distribution requires a set of experimental data that is sufficiently rich to extract all fundamental information. These data depend strongly on the control fields (and their number) used experimentally. In this work, we present and analyze a greedy reconstruction algorithm, and provide the corresponding $\texttt{SPIRED}$ code, for the computation of a set of control functions allowing the generation of data that are appropriate for the accurate reconstruction of a sample distribution. In particular, the focus is on NMR and the Bloch system with inhomogeneities in the magnetic fields in all spatial directions. Numerical examples illustrate this general study.Comment: 31 pages, 6 figure

Unmet challenges in septoplasty-nordic studies from a uniform healthcare and geographical area

PurposeNasal septoplasty is one of the most common surgical procedures in otorhinolaryngology and optimising both patient selection and the surgery is a challenge. The Nordic countries have similar public healthcare systems and comparable populations in terms of size. MethodsThis is a review of studies of outcome and predictors related to septoplasty from Denmark, Finland, Norway and Sweden, published during the last decade. The aim of this review was to identify areas in need of further research to meet the challenges of septoplasty in the Nordic countries with reference to international data. ResultsPostoperative patient satisfaction at 6-12 months was reported in around 2/3 of the patients and well in line with international data. Patients with more severe symptoms had a higher chance of improvement. Lack of standardisation in patient selection, surgical methods and skills, and follow up procedures, still makes it difficult to explain the 25% failure rate in septoplasty surgery. ConclusionThis review of the Nordic studies from the last decade shows that septoplasty in general is effective in relieving nasal obstruction. There is a need for studies addressing the standardisation of diagnostic tools and algorithms and the systematic and continuous implementation of follow-up of the surgical results at both departmental and personal level. This includes an awareness of how surgical skills in septoplasty are obtained and maintained.Peer reviewe

The paranasal sinuses are focus for colonisation and chronic biofilm lung infection in CF patients

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Isotopic constraints on nitrogen transformation rates in the deep sedimentary marine biosphere

Author Posting. © American Geophysical Union,2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Isotopic constraints on nitrogen transformation rates in the deep sedimentary marine biosphere. Global Biogeochemical Cycles, 32, (2018):1688–1702., doi: 10.1029/2018GB005948.Little is known about the nature of microbial community activity contributing to the cycling of nitrogen in organic-poor sediments underlying the expansive oligotrophic ocean gyres. Here we use pore water concentrations and stable N and O isotope measurements of nitrate and nitrite to constrain rates of nitrogen cycling processes over a 34-m profile from the deep North Atlantic spanning fully oxic to anoxic conditions. Using a 1-D reaction-diffusion model to predict the distribution of nitrogen cycling rates, results converge on two distinct scenarios: (1) an exceptionally high degree of coupling between nitrite oxidation and nitrate reduction near the top of the anoxic zone or (2) an unusually large N isotope effect (~60‰) for nitrate reduction that is decoupled from the corresponding O isotope effect, which is possibly explained by enzyme-level interconversion between nitrite and nitrate.Samples analyzed for this study were collected during the final expedition of the RV Knorr, KN223. The expedition would not have been possible without the captain and crew of the RV Knorr and the efforts of the shipboard science party. We would like to acknowledge Robert Pockalny for planning and facilitating the expedition. Inorganic geochemistry sample collection, processing, and analysis were performed shipboard by Arthur Spivack,Dennis Graham, Chloe Anderson, Emily Estes, Kira Homola, Claire McKinley, Theodore Present, and Justine Sauvage. Coring capabilities were provided by the Oregon State University and Woods Hole Oceanographic Institute Coring Facilities, directed and funded by the U. S. National Science Foundation (NSF) Ship Facilities Program. The cored materials and discrete samples from the expedition are curated and stored by the Marine Geological Samples Laboratory at the University of Rhode Island, codirected by Rebecca Robinson and Katherine Kelly and funded by the NSF Ocean Sciences Division. The nutrient and isotope data from pore waters in this study will be available at The Biological and Chemical Data Management Office (https://www.bcodmo.org/project/567401). This project was partially funded by an NSF CDEBI postdoctoral fellowship to C. Buchwald. Portions of this material are based upon work supported while R. W. M. was serving at the National Science Foundation.2019-04-1

Search for Magnetic Monopoles Trapped in Matter

There have been many searches for magnetic monopoles in flight, but few for monopoles in matter. We have searched for magnetic monopoles in meteorites, schists, ferromanganese nodules, iron ores and other materials. The detector was a superconducting induction coil connected to a SQUID (Superconducting Quantum Interference Device) with a room temperature bore 15 cm in diameter. We tested a total of more than 331 kg of material including 112 kg of meteorites. We found no monopole and conclude the overall monopole/nucleon ratio in the samples is $<1.2 \times 10^{-29}$ with a 90\% confidence level.Comment: 6 pages, rev tex, no figure

Four Poynting Theorems

The Poynting vector is an invaluable tool for analysing electromagnetic problems. However, even a rigorous stress-energy tensor approach can still leave us with the question: is it best defined as \Vec{E} \cross \Vec{H} or as \Vec{D} \cross \Vec{B}? Typical electromagnetic treatments provide yet another perspective: they regard \Vec{E} \cross \Vec{B} as the appropriate definition, because \Vec{E} and \Vec{B} are taken to be the fundamental electromagnetic fields. The astute reader will even notice the fourth possible combination of fields: i.e. \Vec{D} \cross \Vec{H}. Faced with this diverse selection, we have decided to treat each possible flux vector on its merits, deriving its associated energy continuity equation but applying minimal restrictions to the allowed host media. We then discuss each form, and how it represents the response of the medium. Finally, we derive a propagation equation for each flux vector using a directional fields approach; a useful result which enables further interpretation of each flux and its interaction with the medium.Comment: 8 pages. Updated slightly from EJP versio

In-Depth Assessment of the Palladium-Catalyzed Fluorination of Five-Membered Heteroaryl Bromides

A thorough investigation of the challenging Pd-catalyzed fluorination of five-membered heteroaryl bromides is presented. Crystallographic studies and density functional theory (DFT) calculations suggest that the challenging step of this transformation is C–F reductive elimination of five-membered heteroaryl fluorides from Pd(II) complexes. On the basis of these studies, we have found that various heteroaryl bromides bearing phenyl groups in the ortho position can be effectively fluorinated under catalytic conditions. Highly activated 2-bromoazoles, such as 8-bromocaffeine, are also viable substrates for this reaction.National Institutes of Health (U.S.) (GM46059)National Science Foundation (U.S.) (Predoctoral Fellowship 2010094243)Amgen Inc

The age of Wolfe Creek meteorite crater (Kandimalal), Western Australia

Wolfe Creek crater lies in northwestern Australia at the edge of the Great Sandy Desert. Together with Meteor Crater, it is one of the two largest craters on Earth from which meteorite fragments have been recovered. The age of the impact is poorly constrained and unpublished data places the event at about 300,000 years ago. In comparison, Meteor Crater is well constrained by exposure dating. In this paper, we present new ages for Wolfe Creek Crater from exposure dating using the cosmogenic nuclides 10Be and 26Al, together with optically stimulated luminescence ages (OSL) on sand from a site created by the impact. We also present a new topographic survey of the crater using photogrammetry. The exposure ages range from ~86 to 128 ka. The OSL ages indicate that the age of the impact is most likely to be ~120 ka with a maximum age of 137 ka. Considering the geomorphic setting, the most likely age of the crater is 120 ± 9 ka. Last, we review the age of Meteor Crater in Arizona. Changes in production rates and scaling factors since the original dating work revise the impact age to 61.1 ± 4.8 ka, or ~20% older than previously reported