103,113 research outputs found
Markers of sulfadoxine-pyrimethamine-resistant Plasmodium falciparum in placenta and circulation of pregnant women
No full textPlacental sequestration of Plasmodium falciparum in pregnancy may impair the usefulness of molecular markers of sulfadoxine-pyrimethamine resistance. In 300 infected, delivering women, the concordance of PCR-restriction fragment length polymorphism-derived parasite resistance alleles in matched samples from placenta and circulation was 83 to 98%. Sulfadoxine-pyrimethamine resistance typing in peripheral blood is reasonably representative of P. falciparum infecting pregnant women.Frank P. Mockenhaupt, George Bedu-Addo, Claudia Junge, Lena Hommerich, Teunis A. Eggelte, and Ulrich Bienzl
Outcomes of starting first-line antiretroviral therapy in hepatitis B virus/HIV-coinfected patients in Ghana
No full textObjectives: HIV/hepatitis B virus (HBV) coinfection is common in Ghana, where first-line antiretroviral therapy (ART) comprises lamivudine with zidovudine or stavudine and nevirapine or efavirenz. Little is known about ART outcomes in the context of coinfection. This study evaluated outcomes of ART among HIV/HBV-coinfected Ghanaians, focusing on locally available parameters. Patients and methods: An observational study comparing clinical and virological outcomes in HIV-infected individuals who were either hepatitis B surface antigen (HBsAg) positive or HBsAg negative was conducted over 36 months. Clinical events, hepatic transaminases, CD4 count and body mass index (BMI) were evaluated among 143 HBsAg-positive and 228 HBsAg-negative patients. In a random subset of HBsAg-positive patients, HBV-DNA levels and polymerase sequences were analysed. Results: Comparing HBsAg-positive and HBsAg-negative patients, 44/143 (30.8%) and 83/228 (36.4%) defaulted follow-up, 15/143 (10.5%) and 30/228 (13.2%) experienced a new clinical event, and 8/143 (5.6%) and 11/228 (4.8%) discontinued their initial regimen, respectively. Transaminase levels were higher in HBsAg-positive patients, although elevations were low grade. HBV coinfection was associated with an adjusted 2.04 (95% CI 0.59-3.49) cells/mm. 3/month smaller CD4 cell increase; there was no significant effect on BMI changes. After a median of 9 months of ART, 64/66 (97.0%) patients showed detectable HBV-DNA (median 3.3 log. 10 IU/mL; IQR 2.6-6.2); 12/53 (22.6%) of these showed lamivudine-associated resistance mutations. Conclusions: HIV/HBV-coinfected Ghanaians tolerated first-line ART well, but experienced blunted CD4 cell responses. There was evidence of ongoing HBV replication, mild but persistent transaminase elevations and emerging lamivudine resistance in a proportion of treated patients, indicating the potential for progressive liver damag
Caribbean-Scottish Relations. Colonial & Contemporary Inscriptions in History, Language & Literature
No full textThis book focuses on the historical, cultural and literary representations of various aspects of this complicated interconnection: Anim-Addo’s on family history, Covi’s on identities in African-Caribbean literature, Pollard’s on Jamaican history and language, and Sassi’s on Scottish literature.
They discuss pivotal figures such as Mary Seacole, Charles and Hugh Mulzac, and texts by Walter Scott, Robert Louis
Stevenson, James Robertson, and anonymous Author of Marly, and
by Una Marson, Claude McKay, Olive Senior, Jamaica Kincaid,
and Nourbese Philip among others; they give voice to Juliana Mulzac through (auto)biography and to numerous people through interviews and acts of re-memorying.
This book inaugurates the project to remap history by accounting for the often paradoxical complexity of relations determined by imperial power; not only does it consider that which separates Scotland from the Caribbean, that which sets ‘Blackness’ apart from ‘Scottishness’, but it also accepts an investigation of that which brings these two geopolitical areas and ethnic groups together. The inquiry results in a multi-vocal discourse that deconstructs national narratives, unveils colonial inscriptions, and releases the creolised images and words that demand full citizenship in the representation of the Circum-Atlantic
Fabrication of nanostructures for photonic applications
No full textInternational audienceNanophotonics requires a very fine control over the size and shape of nanofeatures because they strongly affect all the types of light-matter interactions. The most efficient interactions occur when the light wavelength is resonant with the spectral response of the individual particles or with coupling between the particles if they are situated close enough from each other. We will discuss the fabrication of metal and dielectric metasurfaces using both individual and collective effects for photonic applications. All nanostructures were realized in our clean room facilities using nanofabrication tools such as electron beam lithography, magnetron sputtering or thermal evaporation and chemical or reactive ion etching. We will illustrate the discussion on nanofabrication process equipment available in the CINaM clean room PLANETE by new scientific results. First, nanostructured metasurfaces using plasmon resonances in individual gold discs were fabricated on glass substrates and were used for precise relative humidity sensing [1] and for the studies of interactions between water vapor and sooth aerosols [2] in collaboration with Benjamin Demirdjian (CINaM, Marseille). Localized plasmons in individual gold discs or more complex nanostructures organized in a periodic metamaterial lattices can also be resonantly coupled to a diffraction wave under certain excitation conditions [3]. Such a coupling leads to a drastic narrowing of plasmon resonance lineshapes in direct and ATR geometries observed by collaborators from two research groups leaded by Andrei Kabashin (LP3, Marseille) and by Alexander Grigorenko (Manchester). Such plasmonic surface lattice resonances are very promising for the improvement of performance of plasmonic biosensors [4]. Even more complex spiral antenna structures organized in metasurfaces were fabricated and studied in collaboration with the group of Jeong Weon Wu (EWHA University, Korea) in order to control vortex-charge dependent separation of structured light beams [5].The second type of nanostructures that we will discuss are individual silicon Mie resonators and all-dielectric metasurfaces obtained in collaboration with Institut Fresnel (Marseille) and Institut de NanoSciences de Paris. Such nanoparticles made of high-refractive index dielectric materials like silicon are known to efficiently scatter incident electromagnetic waves. Their optical spectra show several well pronounced peaks corresponding to electric and magnetic dipole and quadrupole moments resonantly induced in the particles by the incident light. For the visible and near-infrared spectral regions, the typical sizes of individual resonant silicon particles are situated in the range from 70 to 250 nm. These nanostructures were fabricated using electron beam lithography followed by wet chemical alkaline etching [6] or reactive ion etching [7].For the metasurfaces constituted by the individual particles, the distances between them should be large enough in order to avoid possible near-field coupling. For example, in collaboration with the group of Nicolas Bonod (Institut Fresnel, Marseille) we have fabricated the metasurfaces composed of amorphous silicon particles situated at distances larger than 1 µm providing vivid structural colors [6]. The relative strength of the electric and magnetic resonances can be easily tuned with the aspect ratio of the particle. This allowed us to create a large palette of colors when considering the same particle height and simply tuning the aspect ratio of the particle by varying the diameter [6,7].We also fabricated individual silicon monomers and dimers that were used to tailor the spontaneous emission of organic molecules. The monomer silicon optical nanoantennas were used by the groups leaded by Sébastien Bidault and Yannick de Wilde (Institut Langevin, Paris) to enhance the spontaneous emission rate and brightness of solid-state emitters [8]. Using scanning probe microscopy, they analyzed in three dimensions the near-field interaction between a 100 nm fluorescent nanosphere and silicon nanoantennas and demonstrated significant enhancement and inhibition of the fluorescence intensity depending on the size of the antennas and the distance between the near-field probe and monomer antennas. When the antennas are constituted of two silicon disks separated by a gap of several nanometers, fluorescence correlation spectroscopy and lifetime measurements performed in the group of Jérôme Wenger (Institut Fresnel, Marseille) demonstrate that the fluorescence intensity of dye molecules in the gap can be enhanced by more than two orders of magnitude [9]. These results confirm that all-silicon nanoantennas can be considered as a valid alternative to plasmonic devices. Finally, a metasurface composed of closely packed resonators has shown to be a very efficient antireflective coating in a large spectral range from the visible to the near infrared and it was fabricated by nanostructuring of monocrystalline silicon [10]. Angle resolved and polarized optical measurements performed in the group of Nicolas Bonod showed that the light reflection was remaining under 5% when averaged in the visible spectrum for both polarizations in a wide angular range. Light reflection remained almost insensitive to the light polarization even in oblique incidence.In conclusion, we show that common nanofabrication tools and processes (e-beam lithography, evaporation, sputtering, chemical and reactive ion etching) are well adapted for realization of objects for fundamental studies and for nanophotonic applications.[1] B. Demirdjian, F. Bedu, A. Ranguis, I. Ozerov, and C.R. Henry, “Water adsorption by a sensitive calibrated gold plasmonic nanosensor”, Langmuir 34, 5381 (2018)[2] B. Demirdjian, F. Bedu, A. Ranguis, I. Ozerov, A. Karapetyan, and C.R. Henry, “Indirect nanoplasmonic sensing to probe with a high sensitivity the interaction of atmospheric water with soot aerosols”, J. Phys. Chem. Lett. 6, 4148 (2015)[3] A. Danilov, G. Tselikov, F. Wu, V.K. Kravets, I. Ozerov, F. Bedu, A.N. Grigorenko and A.V. Kabashin, “Condition of excitation and sensitivity of diffractively-coupled surface lattice resonances over plasmonic nanoparticle arrays in ATR geometry”, Proc. SPIE, 10521, 1052109 (2018)[4] A. Danilov, G. Tselikov, F. Wu, V.K. Kravets, I. Ozerov, F. Bedu, A.N. Grigorenko and A.V. Kabashin, “Ultra-narrow surface lattice resonances in plasmonic metamaterial arrays for biosensing applications”, Biosensors and Bioelectronics 104, 102 (2018)[5] Y.U. Lee, I. Ozerov, F. Bedu, J.S. Kim, F. Fages, and J.W. Wu, “Extrinsic spin-and orbital-Hall effect in cyclic group symmetric metamaterial”, Proc. SPIE 9918, 991818 (2016)[6] J. Proust, F. Bedu, S. Chenot, I. Soumahoro, I. Ozerov, B. Gallas, R. Abdeddaim, and N. Bonod, “Chemical alkaline etching of silicon Mie particles”, Advanced Optical Materials 3, 1280 (2015)[7] J. Proust, F. Bedu, B. Gallas, I. Ozerov, and N. Bonod, “All-Dielectric Colored Metasurfaces with Silicon Mie Resonators,” ACS Nano 10, 7761 (2016)[8] D. Bouchet, M. Mivelle, J. Proust, B. Gallas, I. Ozerov, M.F. García-Parajó, A. Gulinatti, I. Rech, Y. de Wilde, N. Bonod, V. Krachmalnicoff, and S. Bidault, “Enhancement and Inhibition of Spontaneous Photon Emission by Resonant Silicon Nanoantennas,” Phys. Rev. Applied 6,064016 (2016)[9] R. Regmi, J. Berthelot, P.M. Winkler, M. Mivelle, J. Proust, F. Bedu, I. Ozerov, T. Begou, J. Lumeau, H. Rigneault, M.F. García-Parajó, S. Bidault, J. Wenger, and N. Bonod, “All-Dielectric silicon nanogap antennas to enhance the fluorescence of single molecules,” Nano Lett. 16, 5143 (2016)[10] J. Proust, A-L. Fehrembach, F. Bedu, I. Ozerov, and N. Bonod, “Optimized 2D array of thin silicon pillars for efficient antireflective coatings in the visible spectrum”, Scientific Reports 6, 24947 (2016
5G Aerial Component for IoT Support in Remote Rural Areas
No full textThere is today a renewed interest in satellite communications. It is expected that many new systems will be operative in a short time. They will become part of the aerial component of 5G, also including high-altitude balloons and drones for focused coverages. The interest of this paper is to investigate a satellite 5G scenario for massive Machine Type communication (mMTC), where an intermediate layer of drones is used for collecting sensors data. We study an application where sensors are deployed in large rural (remote) areas for the timely detection of fire alarms (even if other types of measurements and alarms are possible). In this scenario, no terrestrial Internet connectivity is available so that drones are used to collect data from sensors and connect to a control station via satellite. A system architecture has been proposed and an analytical model has been adopted to characterize the mean delay to notify alarms from the field to the control center. This model takes shadowing and collisions effects into account. This study has been validated by means of simulations
PLANETE – Platform for micro and nanofabrication
No full textInternational audienceThe goal of this poster presentation is to give an overview of nanofabrication techniques commonly used for the realization of nanostructures in our micro and nanofabrication facilities. We focus on the process equipment available in the CINaM clean room. We will also present some recent scientific results in photonics obtained on plasmonics nano-arrays for molecular sensing (collaboration with B. Demirdjian’s group) [1] and on transition metal dichalcogenide structures showing a non-linear coupling between excitons and Mie scattering resonances in the visible and near infrared spectral regions (collaboration with G. Tselikov) [2]. We will also present the fabrication of nanocluster arrays used for detection of hidden features in the architecture of T-lymphocyte cells (collaboration with K. Sengupta’s group) [3]. Finally, we will present our recent results on fabrication of sharp silicon arrays to wound Caenorhabditis elegans worms (collaboration with J.J. Ewbank’s group) [4].All micro and nanostructures were obtained in our clean room facilities using nanofabrication tools such as optical and electron beam lithography, magnetron sputtering or thermal evaporation and chemical or reactive ion etching.The PLANETE platform is open to the regional scientific research community as well as to innovative companies carrying out research and development projects. All the cleanroom facilities and equipment are available to them to carry out their projects with technical assistance from the platform staff according to their needs.[1] B. Demirdjian, I. Ozerov, F. Bedu, A. Ranguis, and C.R. Henry, ACS Omega 6, 13398 (2021)[2] A.A. Popkova et al. Laser & Photonics Reviews 16, 2100604 (2022)[3] A. Nassereddine et al. Nano Letters 21, 5606 (2022)[3] J. Belougne, I. Ozerov, C. Caillard, F. Bedu, J.J. Ewbank, Scientific Reports 10, 3581 (2020
Peak power in obese and nonobese adolescents: effects of gender and braking force
No full textPURPOSE:The aim of this study was to determine the cycling peak power (CPP) of obese compared with nonobese adolescents and to identify possible effects of braking force (BF) and gender on CPP. To adjust for differences in body size, we used ratio standard and allometric model.
METHODS:Obese (26 girls, 18 boys) and nonobese (30 girls, 20 boys) adolescents participated. Fat-free mass (FFM) was determined by dual-energy x-ray absorptiometry (DEXA) in obese and by anthropometric method in nonobese groups. A force-velocity test was used to measure peak power (flywheel inertia included) for BF corresponding to applied load: 25, 50, and 75 g x kg(-1) body mass (BM). The highest peak power was defined as CPP.
RESULTS:CPP was independent of BF in nonobese adolescents but dependent in obese adolescents. The optimal braking load is approximately 6.5% FFM. Absolute CPP was higher in obese than nonobese adolescents. Related to BM, CPP was significantly lower in obese than nonobese adolescents, using the standard ratio or the allometric model. These differences disappeared when CPP was related to FFM. Multiple stepwise regression showed that FFM was the most important explanatory variable of the variance of CPP (72%) in obese and nonobese adolescents. No significant difference between obese and nonobese adolescents occurred when Fopt was related to FFM (standard or power function ratios used). There was no gender effect on CPP, and the manner of expressing CPP did not affect the results. However, girls showed a higher FFM-related Fopt than boys, using standard and power function ratios.
CONCLUSION:There was no significant difference between obese and nonobese girls and boys for anaerobic performance (CPP and Fopt) when FFM was taken into accoun
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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