58 research outputs found

    Urinary excretion of prostaglandins and electrolytes in developing children

    Get PDF
    Urinary excretion of prostaglandins and electrolytes in developing children. A longitudinal study of the urinary excretion of prostaglandins (PG's) E and Fα was performed in 55 healthy children aged from 1 to 114 months. In addition, the urinary PG's and electrolytes were studied in 6 children with Bartier's syndrome before and after an oral treatment with indomethacin. In normal children, both urinary PGE and PGFα increased with age, more markedly before 24 months of age. During this period, a positive and significant correlation was found with the urinary osmolality (r = 0.61, N = 16, P < 0.05 for PGE; r = 0.82, N = 16, P < 0.001 for PGFα). At every age, the urinary PG's were related to the potassium excretion (r = 0.68, N = 55, P < 0.001 for PGE; r = 0.65, N = 55, P < 0.001 for PGFα) but not to the natriuresis. In children with Bartter's syndrome, the increased urinary excretion of PGE, PGFα and potassium was found to be consistently reduced after indomethacin treatment when the natriuresis was either decreased or increased after treatment. These results suggest that the renal PG's might play a role in the control of potassium excretion by the kidney. In addition, the determination of normal values in different age groups appears necessary for an accurate interpretation of the urinary PG's.Excrétion des prostaglandines urinaires et des électrolytes au cours du développement de l'enfant. L'élimination urinaire des prostaglandines (PG's) E et Fα a été étudiée chez 55 enfants normaux âgés de 1 à 114 mois ainsi que chez 6 enfants présentant un syndrome de Bartter, avant et après traitement par l'indométacine. Chez l'enfant normal, l'excrétion urinaire des PGE et PGFα augmente progressivement avec l'âge, surtout durant les 24 premiers mois de la vie où elle apparaît significativement corrélée à l'osmolalité urinaire (r = 0,61, N = 16, P < 0.05 pour PGE; r = 0.82, N = 16, P < 0.001 pour PGFα. Chez l'ensemble des 55 enfants normaux, elle n'apparaît pas liée à la natriurèse alors qu'elle est significativement corrélée à la kaliurèse (r = 0.68, N = 55, P < 0.001 pour PGE; r = 0.65, N = 55, P < 0.001 pour PGFα). Chez les enfants présentant un syndrome de Bartter, l'élimination urinaire des PGE et PGFα ainsi que la kaliurèse diminuent toujours sous indometacine alors que la natriurèse est soit diminuée, soit augmentée. Ces résultats suggèrent que les PG's rénales pourraient participer au contrôle de l'excrétion du potassium par le rein. Par ailleurs, il apparaît indispensable de se référer à des valeurs normales déterminées chez des sujets correctement appariés quant à l'age pour pouvoir interpréter d'une manière correcte les dosages urinaires

    Search for 22Na in novae supported by a novel method for measuring femtosecond nuclear lifetimes

    Get PDF
    Classical novae are thermonuclear explosions in stellar binary systems, and important sources of 26Al and 22Na. While ¿ rays from the decay of the former radioisotope have been observed throughout the Galaxy, 22Na remains untraceable. Its half-life (2.6 yr) would allow the observation of its 1.275 MeV ¿-ray line from a cosmic source. However, the prediction of such an observation requires good knowledge of its nucleosynthesis. The 22Na(p,¿¿)23Mg reaction remains the only source of large uncertainty about the amount of 22Na ejected. Its rate is dominated by a single resonance on the short-lived state at 7785.0(7) keV in 23Mg. Here, we propose a combined analysis of particle-particle correlations and velocity-difference profiles to measure femtosecond nuclear lifetimes. The application of this method to the study of the 23Mg states, places strong limits on the amount of 22Na produced in novae and constrains its detectability with future space-borne observatories.Postprint (published version

    Study of the neutron-rich region in the vicinity of 208Pb via multinucleon transfer reactions

    Get PDF
    The multinucleon transfer reaction mechanism was employed to populate isotopes around the doubly- magic 208 Pb nucleus. We used an unstable 94 Rb beam on 208 Pb targets of different thickness. Transfer channels were studied via the fragment-γ and γ-γ coincidences, by using MINIBALL γ spectrometer coupled to a particle detector. Gamma transitions associated to the different Pb isotopes, populated by the neutron transfers, are discussed in terms of excitation energy and spin. Fragment angular distributions were extracted, andcompared with the reaction model

    Consensus Guidelines for Advancing Coral Holobiont Genome and Specimen Voucher Deposition

    Get PDF
    Coral research is being ushered into the genomic era. To fully capitalize on the potential discoveries from this genomic revolution, the rapidly increasing number of high-quality genomes requires effective pairing with rigorous taxonomic characterizations of specimens and the contextualization of their ecological relevance. However, to date there is no formal framework that genomicists, taxonomists, and coral scientists can collectively use to systematically acquire and link these data. Spurred by the recently announced “Coral symbiosis sensitivity to environmental change hub” under the “Aquatic Symbiosis Genomics Project” - a collaboration between the Wellcome Sanger Institute and the Gordon and Betty Moore Foundation to generate gold-standard genome sequences for coral animal hosts and their associated Symbiodiniaceae microalgae (among the sequencing of many other symbiotic aquatic species) - we outline consensus guidelines to reconcile different types of data. The metaorganism nature of the coral holobiont provides a particular challenge in this context and is a key factor to consider for developing a framework to consolidate genomic, taxonomic, and ecological (meta)data. Ideally, genomic data should be accompanied by taxonomic references, i.e., skeletal vouchers as formal morphological references for corals and strain specimens in the case of microalgal and bacterial symbionts (cultured isolates). However, exhaustive taxonomic characterization of all coral holobiont member species is currently not feasible simply because we do not have a comprehensive understanding of all the organisms that constitute the coral holobiont. Nevertheless, guidelines on minimal, recommended, and ideal-case descriptions for the major coral holobiont constituents (coral animal, Symbiodiniaceae microalgae, and prokaryotes) will undoubtedly help in future referencing and will facilitate comparative studies. We hope that the guidelines outlined here, which we will adhere to as part of the Aquatic Symbiosis Genomics Project sub-hub focused on coral symbioses, will be useful to a broader community and their implementation will facilitate cross- and meta-data comparisons and analyses.CV acknowledges funding from the German Research Foundation (DFG), grants 433042944 and 458901010. Open Access publication fees are covered by an institutional agreement of the University of Konstanz

    Search for 22^{22}Na in novae supported by a novel method for measuring femtosecond nuclear lifetimes

    Get PDF
    Classical novae are thermonuclear explosions in stellar binary systems, and important sources of 26^{26}Al and 22^{22}Na. While gamma rays from the decay of the former radioisotope have been observed throughout the Galaxy, 22^{22}Na remains untraceable. The half-life of 22^{22}Na (2.6 yr) would allow the observation of its 1.275 MeV gamma-ray line from a cosmic source. However, the prediction of such an observation requires good knowledge of the nuclear reactions involved in the production and destruction of this nucleus. The 22^{22}Na(p,γp,\gamma)23^{23}Mg reaction remains the only source of large uncertainty about the amount of 22^{22}Na ejected. Its rate is dominated by a single resonance on the short-lived state at 7785.0(7) keV in 23^{23}Mg. In the present work, a combined analysis of particle-particle correlations and velocity-difference profiles is proposed to measure femtosecond nuclear lifetimes. The application of this novel method to the study of the 23^{23}Mg states, combining magnetic and highly-segmented tracking gamma-ray spectrometers, places strong limits on the amount of 22^{22}Na produced in novae, explains its non-observation to date in gamma rays (flux < 2.5x10410^{-4} ph/(cm2^2s)), and constrains its detectability with future space-borne observatories.Comment: 18 pages, 3 figures, 1 tabl

    A Multi-Objective Decision Framework for Lifecycle Investment

    Get PDF
    In this paper we propose a multi-objective decision framework for lifecycle investment choice. Instead of optimizing individual strategies with respect to a single-valued objective, we suggest evaluation of classes of strategies in terms of the quality of the tradeoffs that they provide. The proposed framework takes inspiration from psychological theories which, on the one hand, assert that humans analyze risky choice situations in terms of several competing factors, and, on the other hand, recognize that attribute overload is detrimental to decision making. In particular, we use SP/A (security-potential/aspiration) theory as developed by Lopes and co-authors. The proposed approach is illustrated in a simple lifecycle model. As decision factors, we consider (a) the contribution paid, (b) the ambition level (targeted level of retirement income), and (c) the guarantee level (a level of retirement income that will be achieved with high probability). In terms of the tradeoffs generated between these indices, we compare a class of traditional lifecycle strategies, defined in terms of a glide path, with a class of so called collar strategies

    Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

    Get PDF
    © 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

    Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

    Get PDF
    Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide

    The mutable nature of particle-core excitations with spin in the one-valence-proton nucleus ¹³³Sb

    Get PDF
    The γ-ray decay of excited states of the one-valence-proton nucleus ¹³³Sb has been studied using cold-neutron induced fission of ²³⁵U and ²⁴¹Pu targets, during the EXILL campaign at the ILL reactor in Grenoble. By using a highly efficient HPGe array, coincidences between γ-rays prompt with the fission event and those delayed up to several tens of microseconds were investigated, allowing to observe, for the first time, high-spin excited states above the 16.6 μs isomer. Lifetimes analysis, performed by fast-timing techniques with LaBr₃(Ce) scintillators, revealed a difference of almost two orders of magnitude in B(M1) strength for transitions between positive-parity medium-spin yrast states. The data are interpreted by a newly developed microscopic model which takes into account couplings between core excitations (both collective and non-collective) of the doubly magic nucleus ¹³²Sn and the valence proton, using the Skyrme effective interaction in a consistent way. The results point to a fast change in the nature of particle-core excitations with increasing spin
    corecore