Continuous wave waveguide laser at room temperature in Nd3+-doped Zn:LiNbO3

Copyright (2001) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 79.25 (2001):4088-4090 and may be found at http://apl.aip.org

A Net Energy Analysis of the Global Agriculture, Aquaculture, Fishing and Forestry System

The global agriculture, aquaculture, fishing and forestry (AAFF) energy system is subject to three unsustainable trends: (1) the approaching biophysical limits of AAFF; (2) the role of AAFF as a driver of environmental degradation; and (3) the long-term declining energy efficiency of AAFF due to growing dependence on fossil fuels. In response, we conduct a net energy analysis for the period 1971–2017 and review existing studies to investigate the global AAFF energy system and its vulnerability to the three unsustainable trends from an energetic perspective. We estimate the global AAFF system represents 27.9% of societies energy supply in 2017, with food energy representing 20.8% of societies total energy supply. We find that the net energy-return-on-investment (net EROI) of global AAFF increased from 2.87:1 in 1971 to 4.05:1 in 2017. We suggest that rising net EROI values are being fuelled in part by ‘depleting natures accumulated energy stocks’. We also find that the net energy balance of AAFF increased by 130% in this period, with at the same time a decrease in both the proportion of rural residents and also the proportion of the total population working in AAFF—which decreased from 19.8 to 10.3%. However, this comes at the cost of growing fossil fuel dependency which increased from 43.6 to 62.2%. Given the increasing probability of near-term fossil fuel scarcity, the growing impacts of climate change and environmental degradation, and the approaching biophysical limits of global AAFF, ‘Odum’s hoax’ is likely soon to be revealed

Les essais randomisés contrôlés, révolution des politiques de développement ? Une évaluation de la Banque mondiale de l'empowerment au bangladesh

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Are boys and girls still digitally differentiated? The case of catalonian teenagers

This article presents a study of ICT use and attitudes related to the computer use of girls and boys from Catalonia in order to detect which gender differences may explain the low presence of women in the ICT field and to design a pro-posal of actions in schools to help reduce these differences

Correlation between compositional and refractive index profiles in LiNbO3 : Zn diffused optical waveguides

Waveguides fabrication in Z- and X-cut LiNbO3 crystals by vapor zinc diffusion has been studied by secondary ion mass spectrometry and optical measurements. Compositional analysis of diffused substrates shows the formation of a Zn rich superficial layer, followed by a deeper region with decreasing Zn concentration. A subsequent thermal annealing process has been performed to let zinc ions further diffuse into the substrates. The composition profiles have been correlated with the refractive index profiles, reconstructed by optical reflectivity measurements. The results and the nature of the detected layers are discussed and correlated with previous x-ray studies obtained in the same samples

Compositional characterisation of Zn-diffused lithium niobate waveguides

Rutherford backscattering (RBS) and secondary- ion mass spectrometry techniques have been used to investigate the two-step process involved during waveguide fabrication in LiNbO3 using Zn-vapour diffusion. Compositional analysis (O, Nb, Li and Zn) in the two steps has been characterised. RBS analysis reveals that the first step, involving a heating of the substrate under a metallic Zn atmosphere, gives rise to a partial exchange between the Nb and Li ions from the crystals and the Zn from the vapour source. The second treatment at higher tem- perature in an open atmosphere diffuses the Zn deeper into the substrate, thus forming an optical waveguide, while the Nb and Li ions recover their bulk values

T cells with dysfunctional mitochondria induce multimorbidity and premature senescence.

This study was supported by the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI16/188, PI19/855, as well as PI16/02110 to B.I.), the European Regional Development Fund (ERDF), and the European Commission through H2020-EU.1.1 and European Research Council grant ERC-2016-StG 715322-EndoMitTalk. This work was partially supported by Comunidad de Madrid (S2017/BMD-3867 RENIM-CM). M.M. is supported by the Miguel Servet Program (CP 19/014). G.S.-H. is supported by FPI-UAM, J.O (FJCI-2017-33855) and E.G-R (IJC2018-036850) by Juan de la Cierva, and E.C. by Atracción de Talento Investigador 2017-T2/BMD-5766 (Comunidad de Madrid and UAM). B.I. was supported by ERC research grant ERC-2018-CoG 819775-MATRIX.The effect of immunometabolism on age-associated diseases remains uncertain. In this work, we show that T cells with dysfunctional mitochondria owing to mitochondrial transcription factor A (TFAM) deficiency act as accelerators of senescence. In mice, these cells instigate multiple aging-related features, including metabolic, cognitive, physical, and cardiovascular alterations, which together result in premature death. T cell metabolic failure induces the accumulation of circulating cytokines, which resembles the chronic inflammation that is characteristic of aging ("inflammaging"). This cytokine storm itself acts as a systemic inducer of senescence. Blocking tumor necrosis factor-α signaling or preventing senescence with nicotinamide adenine dinucleotide precursors partially rescues premature aging in mice with Tfam-deficient T cells. Thus, T cells can regulate organismal fitness and life span, which highlights the importance of tight immunometabolic control in both aging and the onset of age-associated diseases.S