56 research outputs found

    Global maps of soil temperature.

    Get PDF
    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km <sup>2</sup> resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km <sup>2</sup> pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

    Age at first birth in women is genetically associated with increased risk of schizophrenia

    Get PDF
    Prof. Paunio on PGC:n jäsenPrevious studies have shown an increased risk for mental health problems in children born to both younger and older parents compared to children of average-aged parents. We previously used a novel design to reveal a latent mechanism of genetic association between schizophrenia and age at first birth in women (AFB). Here, we use independent data from the UK Biobank (N = 38,892) to replicate the finding of an association between predicted genetic risk of schizophrenia and AFB in women, and to estimate the genetic correlation between schizophrenia and AFB in women stratified into younger and older groups. We find evidence for an association between predicted genetic risk of schizophrenia and AFB in women (P-value = 1.12E-05), and we show genetic heterogeneity between younger and older AFB groups (P-value = 3.45E-03). The genetic correlation between schizophrenia and AFB in the younger AFB group is -0.16 (SE = 0.04) while that between schizophrenia and AFB in the older AFB group is 0.14 (SE = 0.08). Our results suggest that early, and perhaps also late, age at first birth in women is associated with increased genetic risk for schizophrenia in the UK Biobank sample. These findings contribute new insights into factors contributing to the complex bio-social risk architecture underpinning the association between parental age and offspring mental health.Peer reviewe

    Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

    Get PDF
    Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

    The effect of four-wave mixing in fibers on optical frequency-division multiplexed systems

    No full text
    The optical nonlinearity in a single-mode fiber imposes a fundamental limitation on the capacity of optical frequency-division multiplexed (OFDM) systems. In particular, four-wave mixing (FWM) crosstalk may severely degrade the system performance when the fiber input powers are large and/or the channel spacing is too small. Theoretical and experimental results of the effects of FWM in OFDM systems are presented The theoretical results demonstrate the dependence of FWM on various systems parameters. Also included is an analysis of FWM in both unidirectional and bidirectional transmission systems. The receiver sensitivity degradation from FWM crosstalk was measured in a 16-channel coherent system. A sensitivity penalty of 0.4 dB resulted when a signal power of -3 dBm/channel was transmitted through 12 km of dispersion-shifted fiber

    Fibre four-wave mixing in multi-channel coherent systems

    No full text
    The crosstalk degradation due to four-wave mixing (FWM) in fiber is studied in a 155Mb/s, 16 channel coherent system with the signal powers amplified by an erbium-doped fiber amplifier. When a total power of +8.4dBm (0.46mW/channel) is launched into the fiber, the crosstalk degradation is 0.4dB. A theoretical study indicates the EWM dependence on fiber chromatic dispersion, the total number of channels, and the signal power levels and polarization states

    Fibre four-wave mixing induced by optical amplification in a 16 channel coherent system

    No full text
    In optical frequency division multiplexed systems, the nonlinear interaction between signal channels may set the ultimate limit on the allowable channel spacing, total number of channels, and maximum power per channel. The four-wave mixing (FWM) crosstalk in semiconductor amplifiers has been shown to cause a sensitivity degradation when the channel spacing is a few hundred megahertz. In contrast, when fiber amplifiers are used, nonlinear interactions have been considered negligible because of the long fluorescence time constant. However, we recently found that for a fiber amplifier with a saturation power in the 5-10-mW range, the transmission fiber following the amplifier can cause FWM crosstalk. Fiber FWM may also be observed without an amplifier if a wavelength selective coupler is used to combine the laser outputs with no splitting loss

    Glycosphingolipids as toxin receptors

    No full text
    A number of proteins produced by certain bacteria and plants are potently toxic to mammalian cells. This toxicity results from their ability to catalytically modify macromolecules that are required for essential cellular functions such as vesicular trafficking, cytoskeletal assembly, signalling or protein synthesis. To reach their targets, these proteins bind specific surface receptors before endocytosis and translocation across an internal membrane. The surface receptors exploited by different toxins include a range of proteins and lipids. Here we focus on specific glycosphingolipid receptors and two well-characterised subsets of toxins that exploit them for surface binding, intracellular trafficking, and signalling events. (C) 2004 Elsevier Ltd. All rights reserved
    corecore