Human immunodeficiency virus type-1 (HIV-1) continues to evolve in presence of broadly neutralizing antibodies more than ten years after infection.

BACKGROUND: The evolution of HIV-1 and its immune escape to autologous neutralizing antibodies (Nabs) during the acute/early phases of infection have been analyzed in depth in many studies. In contrast, little is known about neither the long-term evolution of the virus in patients who developed broadly Nabs (bNabs) or the mechanism of escape in presence of these bNabs. RESULTS: We have studied the viral population infecting a long term non progressor HIV-1 infected patient who had developed broadly neutralizing antibodies toward all tier 2/3 viruses (6 clades) tested, 9 years after infection, and was then followed up over 7 years. The autologous neutralization titers of the sequential sera toward env variants representative of the viral population significantly increased during the follow-up period. The most resistant pseudotyped virus was identified at the last visit suggesting that it represented a late emerging escape variant. We identified 5 amino acids substitutions that appeared associated with escape to broadly neutralizing antibodies. They were V319I/S, R/K355T, R/W429G, Q460E and G/T463E, in V3, C3 and V5 regions. CONCLUSION: This study showed that HIV-1 may continue to evolve in presence of both broadly neutralizing antibodies and increasing autologous neutralizing activity more than 10 years post-infection

Continuous evolution of HIV-1 more than ten years after infection in an elite neutralizer

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Comparison of two types of 60 GHz photonic millimeter-wave generation and distribution of a 3 Gb/s OFDM signal

International audienceWe demonstrate and compare experimentally two set-ups achieving very high data rate (3 Gbps) wireless transmission in the 60 GHz window, both using Radio-over-Fiber (RoF) for reach extension with OFDM signal compliant to the IEEE 802.15.3.c pre-standard

Transmission Quality Measurement of Two Types of 60 GHz Millimeter-Wave Generation and Distribution Systems

International audienceIn this paper, we demonstrate and compare experimentally two techniques achieving very high-data-rates (> 1 Gb/s) wireless transmission in the 60 GHz window using radio over fiber (RoF) for reach extension. The first RoF link is based on a 10 GHz vertical-cavity surface-emitting laser and uses a multimode fiber. The radio signal is transported on an intermediate frequency of 4.5 GHz and electrically upconverted to 60 GHz after the optical link. The second uses an optical frequency upconversion from 4.5 to 60 GHz by direct modulation of a mode-locked Fabry-PEacuterot laser whose self-pulsating frequency is 54.8 GHz before transmission over a single-mode fiber. For both techniques, two different types of modulation were tested. The first one was an on-off keying at 1.5 Gb/s and the second one was an orthogonal frequency-division multiplexing-QPSK signal compliant to the IEEE 802.15.3.c prestandard (3.03 Gb/s). Radio propagation performance is also reported

Low loss coatings for the VIRGO large mirrors

présentée par L. PinardThe goal of the VIRGO program is to build a giant Michelson type interferometer (3 kilometer long arms) to detect gravitational waves. Large optical components (350 mm in diameter), having extremely low loss at 1064 nm, are needed. Today, the Ion beam Sputtering is the only deposition technique able to produce optical components with such performances. Consequently, a large ion beam sputtering deposition system was built to coat large optics up to 700 mm in diameter. The performances of this coater are described in term of layer uniformity on large scale and optical losses (absorption and scattering characterization). The VIRGO interferometer needs six main mirrors. The first set was ready in June 2002 and its installation is in progress on the VIRGO site (Italy). The optical performances of this first set are discussed. The requirements at 1064 nm are all satisfied. Indeed, the absorption level is close to 1 ppm (part per million), the scattering is lower than 5 ppm and the R.M.S. wavefront of these optics is lower than 8 nm on 150 mm in diameter. Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the mirrors (thermal noise reduction)

High Peak Power, Narrow RF Linewidth Asymmetrical Cladding Quantum-Dash Mode-Locked Lasers

International audienceIn this paper, we report the development of an asymmetrical cladding single-section InAs/InP quantum-dash mode-locked laser (MLL). The asymmetrical cladding structure allows us to decrease the internal losses and to increase the optical eigenmode mode size. We have measured continuous-wave power superior to 400 mW and RF linewidth as narrow as 300 Hz for passive modelocking. We have compressed the optical signal using the dispersion of a single-mode fiber (SMF) and we have measured the delay between groups of optical modes for different SMF lengths. With the appropriate SMF length, we have obtained a quasi-null delay. In this configuration, subpicosecond pulses with 18 W peak power have been demonstrated for 10-GHz MLL. These performances demonstrate the potential of InAs/InP MLL for frequency comb generation up to tetahertz domain and high peak power optical pulse generation

High power directly modulated DFB lasers for large dynamic range optical transmission

International audienceIn this letter we present high power and low RIN (Relative Intensity Noise) directly modulated distributed feedback lasers at 1.55 µm for analog transmissions (for radars and electronic warfare)

Laser semiconducteur à verrouillage de modes pour la génération de peignes de fréquence THz

Les peignes de fréquence optique sont aujourd'hui utilisés pour la métrologie ou la génération d'impulsions ultra-courtes. Des solutions à base de lasers fibrés à verrouillage de modes [1], de microrésonateurs [2] ou de génération de bandes latérales grâce à des modulateurs de Mach-Zehnder [3] ont été démontré pour la génération de ces peignes optiques. Dans cet article, nous présentons le développement d'un laser semiconducteur à verrouillage de modes (10 GHz) pour la génération de peignes de fréquence. Le design novateur du laser, à base de bâtonnets quantiques et d'une semelle permet à la fois une forte puissance et une faible largeur de raie RF

High-Power Tunable Dilute Mode DFB Laser With Low RIN and Narrow Linewidth

International audienceWe have developed a 1-mm-long high-power DFB laser using an asymmetrical cladding based on the dilute waveguide technique. We have obtained about 180 mW output power at 25 °C and >30 mW at 15 °C-85 °C chip temperature with >55-dB sidemode suppression ratio. This temperature range allows a 9.7-nm wavelength tunability. For high output power, the relative intensity noise is lower than −160 dB/Hz in the 0.08-40-GHz frequency range and the optical linewidth is better than 300 kHz