284 research outputs found
The 46Ar(3He, d)47K direct reaction as a probe of the 46Ar proton wavefunction
Journal of Physics: Conference Series
PAPER • THE FOLLOWING ARTICLE ISOPEN ACCESS
The 46Ar(3He, d)47K direct reaction as a probe of the 46Ar proton wavefunction
D Brugnara1, A Gottardo1, M Assié2, D Mengoni3,4, A Lemasson5, E Clement5, F Flavigny6, D Ramos5, F Galtarossa2, A Matta6, V Girard-Alcindor2, M Babo2, D Bazzacco3, D Beaumel2, Y Blumenfeld2, S Bottoni7, U Datta8, G de Angelis1, G de France5, J Dudouet9, J Duenas10, A Goasduff1, E T Gregor1, F Hammache2, A Illana1, L Lalanne2, S Leblond11, I Lombardo12, N Marchini13, B Million7, F Recchia4, K Rezynkina3,4, M Rocchini13, J S Rojo14, M Siciliano11, J J Valiente-Dobón1, I Zanon1 and M Zielinska11 Hide full author list
Published under licence by IOP Publishing Ltd
Journal of Physics: Conference Series, Volume 2586, 28th International Nuclear Physics Conference (INPC 2022) 11/09/2022 - 16/09/2022 Cape Town, South Africa
Citation D Brugnara et al 2023 J. Phys.: Conf. Ser. 2586 012073
DOI 10.1088/1742-6596/2586/1/012073
DownloadArticle PDF
References
Download PDF
Article metrics
17 Total downloads
MathJax
Turn on MathJax
Share this article
Share this content via email
Share on Facebook (opens new window)
Share on Twitter (opens new window)
Share on Mendeley (opens new window)
Article and author information
Abstract
The discrepancy between shell-model calculations and intermediate-energy Coulomb excitation measurements in 46Ar still stands as an unsolved puzzle in understanding the N = 28 shell evolution. This phenomenon has significant relevance considering the remarkable achievements of the shell model and the SDPF-U interaction in the region which is able to predict the fading of the N = 28 shell gap in neutron-rich 44S. Recent measurements narrowed down this discrepancy to an overestimation of the proton amplitude to the quadrupole transition matrix element. The current work aims to propose a different perspective on the puzzle, by studying a direct proton-transfer reaction on 46Ar as a means to directly probe the proton wavefunction of the ground state this isotope. By measuring the amount of l = 0 transfer to the ground state (1/2+) of 47K with respect to the l = 2 to the first excited state (3/2+), we aim to gain insight into the ground state proton wavefunction of 46Ar. We will present a brief description of the experiment performed at the SPIRAL1 facility in GANIL (France). The experimental apparatus allowed a full reconstruction of the two-body reaction thanks to the combination of AGATA, VAMOS, MUGAST, CATS2, and HECTO
Perspectives on the measurement of competitive double gamma decay with the AGATA tracking array
The double-gamma decay is a second order electromagnetic process where two photons are emitted simultaneously. It is characterized by low branching ratios, making its measurement interesting both theoretically and also experimentally. Although this process has been already observed in the past, a recent publication claimed its observation in competition with the single gamma decay.
A measurement of this process with the AGATA spectrometer (Advanced GAmma Tracking Array) will deliver more detailed results. A test of feasibility of this challenging measurement has been performed through GEANT4 simulations of the decay of the 137Ba isotope. Particular emphasis is placed on the tracking algorithm which allows to reconstruct a scattering gamma-ray event based on the position and energy of every interaction point within the AGATA germanium detector
Oxidative damage and erythrocyte membrane transport abnormalities in thalassemias
Oxidative damage induced by free globin chains has been implicated in the pathogenesis of the membrane abnormalities observed in alpha and beta thalassemia. We have evaluated transport of Na+ and K+ in erythrocytes of patients with thalassemias as well as in two experimental models that use normal human red blood cells, one for alpha thalassemia (methylhydrazine treatment, alpha thalassemia like) and one for beta thalassemia (phenylhydrazine treatment, beta thalassemia like). With the exception of the Na-K pump, similar alterations in membrane transport were observed in thalassemia and thalassemia-like erythrocytes. These were: increased K-Cl cotransport, Na-Li countertransport and reduced Na-K-Cl cotransport. The Na-K pump was reduced in thalassemia-like cells, whereas it was increased in severe alpha thalassemia and in beta thalassemia cells. The increased K-Cl cotransport activity could be observed in light and dense fractions of beta-thalassemic cells. K-Cl cotransport in thalassemic and thalassemia-like erythrocytes was partially inhibited by [(dihydro-indenyl) oxy] alkanoic acid and completely abolished by dithiothreitol. Thus, oxidative damage represents an important factor in the increased activity of the K-Cl cotransport observed in thalassemias, and of the K+ loss observed in beta-thalassemia erythrocytes
Influence of warming and atmospheric circulation changes on multidecadal European flood variability
International audienceEuropean flood frequency and intensity change on a multidecadal scale. Floods were more frequent in the 19th (central Europe) and early 20th century (western Europe) than during the mid-20th century and again more frequent since the 1970s. The causes of this variability are not well understood and the relation to climate change is unclear. Palaeoclimate studies from the northern Alps suggest that past flood-rich periods coincided with cold periods. In contrast, some studies suggest that more floods might occur in a future, warming world. Here we address the contribution of atmospheric circulation and of warming to multidecadal flood variability. For this, we use long series of annual peak streamflow, daily weather data, reanalyses, and reconstructions. We show that both changes in atmospheric circulation and moisture content affected multidecadal changes of annual peak streamflow in central and western Europe over the past two centuries. We find that during the 19th and early 20th century, atmospheric circulation changes led to high peak values of moisture flux convergence. The circulation was more conducive to strong and long-lasting precipitation events than in the mid-20th century. These changes are also partly reflected in the seasonal mean circulation and reproduced in atmospheric model simulations, pointing to a possible role of oceanic variability. For the period after 1980, increasing moisture content in a warming atmosphere led to extremely high moisture flux convergence. Thus, the main atmospheric driver of flood variability changed from atmospheric circulation variability to water vapour increase.La fréquence et l'intensité des inondations en Europe changent à une échelle multidécennale. Les inondations étaient plus fréquentes au 19ème (Europe centrale) et au début du 20ème siècle (Europe occidentale) qu'au milieu du 20ème siècle et à nouveau plus fréquentes depuis les années 1970. Les causes de cette variabilité ne sont pas bien comprises et la relation avec le changement climatique n'est pas claire. Les études paléoclimatiques menées dans les Alpes du Nord suggèrent que les périodes passées riches en inondations coïncidaient avec des périodes froides. En revanche, certaines études suggèrent que davantage d'inondations pourraient se produire dans un monde futur en réchauffement. Nous abordons ici la contribution de la circulation atmosphérique et du réchauffement à la variabilité multidécennale des inondations. Pour cela, nous utilisons de longues séries de débit maximal annuel, des données météorologiques quotidiennes, des réanalyses et des reconstructions climatiques. Nous montrons que les changements de la circulation atmosphérique et du contenu en humidité ont affecté les changements multidécennaux du débit maximal annuel en Europe centrale et occidentale au cours des deux derniers siècles. Nous constatons qu'au cours du 19ème et du début du 20ème siècle, les changements de la circulation atmosphérique ont conduit à des valeurs de pointe élevées de convergence du flux d'humidité. La circulation était plus propice à des événements de précipitations forts et durables qu'au milieu du 20e siècle. Ces changements se reflètent également en partie dans la circulation moyenne saisonnière et sont reproduits dans les simulations des modèles atmosphériques, ce qui indique un rôle possible de la variabilité océanique. Pour la période après 1980, l'augmentation de la teneur en humidité dans une atmosphère qui se réchauffe a conduit à une convergence extrêmement élevée des flux d'humidité. Ainsi, le principal moteur atmosphérique de la variabilité des crues est passé de la variabilité de la circulation atmosphérique à l'augmentation de la vapeur d'eau
A roadmap to climate data rescue services
Quantitative approaches to climate risk management such as mapping or impact modelling rely on past meteorological data with daily or sub‐daily resolution, a large fraction of which have not yet been digitized. Over the last decade or so, a number of projects have contributed to the rescue of some of these data. Here we provide a summary of a survey we have undertaken of several meteorological and climate data rescue projects, in order to identify the needs of climate data rescue services. To make these efforts more sustainable, additional integrated activities are needed. We argue that meteorological and climate data rescue must be seen as a continuous, coordinated long‐term effort. Technical developments (e.g. data assimilation), new scientific questions (e.g. process understanding of extreme events) and new social (e.g. risk assessment, health) or economic (e.g. new renewable energy sources, agriculture and forestry, tourism, infrastructure, etc.) services are highlighting the immense value of data previously neglected or never considered. This continuous effort is currently undertaken by projects of various sizes, structure, funding and staffing, as well as by dedicated programmes, ranging from those within many national weather services down to “grassroots” initiatives. These activities are often not sufficiently coordinated, staffed, or funded at an international level and will benefit considerably from climate data rescue services being established within the Copernicus Climate Change Service (C3S) (https://climate.copernicus.eu/)
Centrifugal melt spinning of polyvinylpyrrolidone (PVP)/triacontene copolymer fibres
Polyvinylpyrrolidone/1-triacontene (PVP/TA) copolymer fibre webs produced by centrifugal melt spinning were studied to determine the influence of jet rotation speed on morphology and internal structure as well as their potential utility as adsorbent capture media for disperse dye effluents. Fibres were produced at 72 C with jet head rotation speeds from 7000 to 15,000 r min-1. The fibres were characterised by means of SEM, XRD and DSC. Adsorption behaviour was investigated by means of an isothermal bottle point adsorption study using a commercial disperse dye, Dianix AC-E. Through centrifugal spinning nanofibers and microfibers could be produced with individual fibres as fine as 200–300 nm and mean fibre diameters of ca. 1–2 lm. The PVP/TA fibres were mechanically brittle with characteristic brittle tensile fracture regions observed at the fibre ends. DSC and XRD analyses suggested that this brittleness was linked to the graft chain crystallisation where the PVP/TA was in the form of a radial brush copolymer. In this structure, the triacontene branches interlock and form small lateral crystals around an amorphous backbone. As an adsorbent, the PVP/TA fibres were found to adsorb 35.4 mg g-1 compared to a benchmark figure of 30.0 mg g-1 for a granular-activated carbon adsorbent under the same application conditions. PVP/TA is highly hydrophobic and adsorbs disperse dyes through the strong ‘‘hydrophobic bonding’’ interaction. Such fibrous assemblies may have applications in the targeted adsorption and separation of non-polar species from aqueous or polar environments
Central nervous system failure in melanoma patients: results of a randomised, multicentre phase 3 study of temozolomide- and dacarbazine- based regimens
Reconstruction of Lamb weather type series back to the eighteenth century
The Lamb weather type series is a subjective catalogue of daily atmospheric patterns and flow directions over the British Isles, covering the period 1861–1996. Based on synoptic maps, meteorologists have empirically classified surface pressure patterns over this area, which is a key area for the progression of Atlantic storm tracks towards Europe. We apply this classification to a set of daily pressure series from a few stations from western Europe, in order to reconstruct and to extend this daily weather type series back to 1781. We describe a statistical framework which provides, for each day, the weather types consistent enough with the observed pressure pattern, and their respective probability. Overall, this technique can correctly reconstruct almost 75% of the Lamb daily types, when simplified to the seven main weather types. The weather type series are described and compared to the original series for the winter season only. Since the low frequency variability of synoptic conditions is directly related to the North Atlantic Oscillation (NAO), we derive from the weather type series an NAO index for winter. An interesting feature is a larger multidecadal variability during the nineteenth century than during the twentieth century
Acidosis Activation of the Proton-Sensing GPR4 Receptor Stimulates Vascular Endothelial Cell Inflammatory Responses Revealed by Transcriptome Analysis
Acidic tissue microenvironment commonly exists in inflammatory diseases, tumors, ischemic organs, sickle cell disease, and many other pathological conditions due to hypoxia, glycolytic cell metabolism and deficient blood perfusion. However, the molecular mechanisms by which cells sense and respond to the acidic microenvironment are not well understood. GPR4 is a proton-sensing receptor expressed in endothelial cells and other cell types. The receptor is fully activated by acidic extracellular pH but exhibits lesser activity at the physiological pH 7.4 and minimal activity at more alkaline pH. To delineate the function and signaling pathways of GPR4 activation by acidosis in endothelial cells, we compared the global gene expression of the acidosis response in primary human umbilical vein endothelial cells (HUVEC) with varying level of GPR4. The results demonstrated that acidosis activation of GPR4 in HUVEC substantially increased the expression of a number of inflammatory genes such as chemokines, cytokines, adhesion molecules, NF-κB pathway genes, and prostaglandin-endoperoxidase synthase 2 (PTGS2 or COX-2) and stress response genes such as ATF3 and DDIT3 (CHOP). Similar GPR4-mediated acidosis induction of the inflammatory genes was also noted in other types of endothelial cells including human lung microvascular endothelial cells and pulmonary artery endothelial cells. Further analyses indicated that the NF-κB pathway was important for the acidosis/GPR4-induced inflammatory gene expression. Moreover, acidosis activation of GPR4 increased the adhesion of HUVEC to U937 monocytic cells under a flow condition. Importantly, treatment with a recently identified GPR4 antagonist significantly reduced the acidosis/GPR4-mediated endothelial cell inflammatory response. Taken together, these results show that activation of GPR4 by acidosis stimulates the expression of a wide range of inflammatory genes in endothelial cells. Such inflammatory response can be suppressed by GPR4 small molecule inhibitors and hold potential therapeutic value
- …