Altered expression of β-galactosidase-1-like protein 3 (Glb1l3) in the retinal pigment epithelium (RPE)-specific 65-kDa protein knock-out mouse model of Leber’s congenital amaurosis

Purpose: In this study, we investigated the expression of the gene encoding beta-galactosidase (Glb)-1-like protein 3 (Glb1l3), a member of the glycosyl hydrolase 35 family, during retinal degeneration in the retinal pigment epithelium (RPE)-specific 65-kDa protein knockout (Rpe65(-/-)) mouse model of Leber congenital amaurosis (LCA). Additionally, we assessed the expression of the other members of this protein family, including beta-galactosidase-1 (Glb1), beta-galactosidase-1-like (Glb1l), and beta-galactosidase-1-like protein 2 (Glb1l2).Methods: The structural features of Glb1l3 were assessed using bioinformatic tools. mRNA expression of Glb-related genes was investigated by oligonucleotide microarray, real-time PCR, and reverse transcription (RT) -PCR. The localized expression of Glb1l3 was assessed by combined in situ hybridization and immunohistochemistry.Results: Glb1l3 was the only Glb-related member strongly downregulated in Rpe65(-/-) retinas before the onset and during progression of the disease. Glb1l3 mRNA was only expressed in the retinal layers and the RPE/choroid. The other Glb-related genes were ubiquitously expressed in different ocular tissues, including the cornea and lens. In the healthy retina, expression of Glb1l3 was strongly induced during postnatal retinal development; age-related increased expression persisted during adulthood and aging.Conclusions: These data highlight early-onset downregulation of Glb1l3 in Rpe65-related disease. They further indicate that impaired expression of Glb1l3 is mostly due to the absence of the chromophore 11-cis retinal, suggesting that Rpe65 deficiency may have many metabolic consequences in the underlying neuroretina

Attosecond emission from chromium plasma

International audienceWe present the first measurement of the attosecond emission generated from underdense plasma produced on a solid target. We generate high-order harmonics of a femtosecond Ti:sapphire laser focused in a weakly ionized underdense chromium plasma. Using the " Reconstruction of Attosecond Beating by Interference of Two-photon Transitions " (RABITT) technique, we show that the 11 th to the 19 th harmonic orders form in the time domain an attosecond pulse train with each pulse having 300 as duration, which is only 1.05 times the theoretical Fourier transform limit. Measurements reveal a very low positive group delay dispersion of 4200 as 2. Beside its fundamental interest, high-order harmonic generation in plasma plumes could thus provide an intense source of attosecond pulses for applications

Collision induced cluster fragmentation: From fragment size distributions to the caloric curve

IPMInternational audienceWe report on a cluster fragmentation study involving collisions of high-energy (60 keV/amu) H3+(H2)m hydrogen cluster ions (m=9, 11) with atomic helium or fullerenes. The experimental characterisation of the cluster fragmentation not only by the average fragment size distribution but also by a statistical analysis of the fragmentation events has become possible owing to a recently developed multi-coincidence technique in which all the fragments of all collisions occurring in the experiment are mass analysed on an event-by-event basis. By selecting specific decay reactions we can start after the energizing collision with a microcanonical cluster ion ensemble of fixed excitation energy. From the respective fragment distributions for these selected decay reactions we derive corresponding temperatures of the decaying cluster ions. The relation between this temperature and the excitation energy (caloric curve) exhibits the typical prerequisites of a first order phase transition in a finite system, in the present case signalling the transition from a bound cluster type situation to the free gas phase

New fitting scheme to obtain effective potential from Car-Parrinello molecular dynamics simulations: Application to silica

A fitting scheme is proposed to obtain effective potentials from Car-Parrinello molecular dynamics (CPMD) simulations. It is used to parameterize a new pair potential for silica. MD simulations with this new potential are done to determine structural and dynamic properties and to compare these properties to those obtained from CPMD and a MD simulation using the so-called BKS potential. The new potential reproduces accurately the liquid structure generated by the CPMD trajectories, the experimental activation energies for the self-diffusion constants and the experimental density of amorphous silica. Also lattice parameters and elastic constants of alpha-quartz are well-reproduced, showing the transferability of the new potential.Comment: 6 pages, 5 figure

Attosecond dynamics through a Fano resonance: Monitoring the birth of a photoelectron

This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science on 354, 11 november 2016, DOI: 10.1126/science.aah5188The dynamics of quantum systems are encoded in the amplitude and phase of wave packets. However, the rapidity of electron dynamics on the attosecond scale has precluded the complete characterization of electron wave packets in the time domain. Using spectrally resolved electron interferometry, we were able to measure the amplitude and phase of a photoelectron wave packet created through a Fano autoionizing resonance in helium. In our setup, replicas obtained by two-photon transitions interfere with reference wave packets that are formed through smooth continua, allowing the full temporal reconstruction, purely from experimental data, of the resonant wave packet released in the continuum. In turn, this resolves the buildup of the autoionizing resonance on an attosecond time scale. Our results, in excellent agreement with ab initio time-dependent calculations, raise prospects for detailed investigations of ultrafast photoemission dynamics governed by electron correlation, as well as coherent control over structured electron wave packetsWe thank S. Weber for crucial contributions to the PLFA attosecond beamline, D. Cubaynes, M. Meyer, F. Penent, J. Palaudoux, for setup and test of the electron spectrometer, and O. Smirnova, for fruitful discussions. Supported by ITN-MEDEA 641789, ANR-15-CE30-0001-01-CIMBAAD, ANR11-EQPX0005-ATTOLAB, the European Research Council Advanced Grant XCHEM no. 290853, the European COST Action XLIC CM1204, and the MINECO Project no. FIS2013-42002-R. We acknowledge allocation of computer time from CCC-UAM and Mare Nostrum BS

Exercise electrocardiogram in middle-aged and older leisure time sportsmen: 100 exercise tests would be enough to identify one silent myocardial ischemia at risk for cardiac event

BACKGROUND: The importance of exercise electrocardiogram (ECG) has been controversial in the prevention of cardiac events among sportsmen. The aim of this study was to determine the frequency of silent myocardial ischemia (SMI) from an exercise ECG and its relationship with induced coronary angiographic assessment and potentially preventable cardiac events. METHODS: This prospective cohort study included leisure time asymptomatic sportsmen over 35years old, referred from 2011 to 2014 in the Sports Medicine Unit of the University Hospital of Saint-Etienne. RESULTS: Of the cohort of 1500 sportsmen (1205 men; mean age 50.7±9.4years; physical activity level 32.8±26.8MET-h/week), 951 (63%) had at least one cardiovascular disease (CVD) risk factor. Family history, medical examination and standard resting 12-lead were collected. A total of 163 exercise ECGs (10.9%) were defined as positive, most of them due to SMI (n=129, 8.6%). SMI was an indication for coronary angiography in 23 cases, leading to 17 documented SMIs (1.1%), including 11 significant stenoses requiring revascularization. In multivariate logistic regression analysis, a high risk of CVD (OR=2.65 [CI 95%: 1.33-5.27], p=0.005) and an age >50years (OR=2.71 [CI 95%: 1.65-4.44], p<0.0001) were independently associated with confirmed SMI. CONCLUSIONS: The association of positive exercise ECG with significant coronary stenosis was stronger among sportsmen with CVD risk factors and older than 50years. Screening by exercise ECG can lower the risk of cardiac events in middle-aged and older sportsmen. One hundred tests would be enough to detect one silent myocardial ischemia at risk for cardiac event

Deployment characterization of a floatable tidal energy converter on a tidal channel, Ria Formosa, Portugal

This paper presents the results of a pilot experiment with an existing tidal energy converter (TEC), Evopod 1 kW floatable prototype, in a real test case scenario (Faro Channel, Ria Formosa, Portugal). A baseline marine geophysical, hydrodynamic and ecological study based on the experience collected on the test site is presented. The collected data was used to validate a hydro-morphodynamic model, allowing the selection of the installation area based on both operational and environmental constraints. Operational results related to the description of power generation capacity, energy capture area and proportion of energy flux are presented and discussed, including the failures occurring during the experimental setup. The data is now available to the scientific community and to TEC industry developers, enhancing the operational knowledge of TEC technology concerning efficiency, environmental effects, and interactions (i.e. device/environment). The results can be used by developers on the licensing process, on overcoming the commercial deployment barriers, on offering extra assurance and confidence to investors, who traditionally have seen environmental concerns as a barrier, and on providing the foundations whereupon similar deployment areas can be considered around the world for marine tidal energy extraction.Acknowledgements The paper is a contribution to the SCORE project, funded by the Portuguese Foundation for Science and Technology (FCT e PTDC/ AAG-TEC/1710/2014). Andre Pacheco was supported by the Portu- guese Foundation for Science and Technology under the Portuguese Researchers' Programme 2014 entitled “Exploring new concepts for extracting energy from tides” (IF/00286/2014/CP1234). Eduardo GGorbena has received funding for the OpTiCA project from the ~ Marie Skłodowska-Curie Actions of the European Union's H2020- MSCA-IF-EF-RI-2016/under REA grant agreement n [748747]. The authors would like to thank to the Portuguese Maritime Authorities and Sofareia SA for their help on the deployment.info:eu-repo/semantics/publishedVersio