1,210 research outputs found

    Equipping for risk: Lessons learnt from the UK shale-gas experience on assessing environmental risks for the future geoenergy use of the deep subsurface

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    \ua9 2024 The Authors. Summary findings are presented from an investigation to improve understanding of the environmental risks associated with developing an unconventional-hydrocarbons industry in the UK. The EQUIPT4RISK project, funded by UK Research Councils, focused on investigations around Preston New Road (PNR), Fylde, Lancashire, and Kirby Misperton Site A (KMA), North Yorkshire, where operator licences to explore for shale gas by hydraulic fracturing (HF) were issued in 2016, although exploration only took place at PNR. EQUIPT4RISK considered atmospheric (greenhouse gases, air quality), water (groundwater quality) and solid-earth (seismicity) compartments to characterise and model local conditions and environmental responses to HF activities. Risk assessment was based on the source-pathway-receptor approach. Baseline monitoring of air around the two sites characterised the variability with meteorological conditions, and isotopic signatures were able to discriminate biogenic methane (cattle) from thermogenic (natural-gas) sources. Monitoring of a post-HF nitrogen-lift (well-cleaning) operation at PNR detected the release of atmospheric emissions of methane (4.2 \ub1 1.4 t CH4). Groundwater monitoring around KMA identified high baseline methane concentrations and detected ethane and propane at some locations. Dissolved methane was inferred from stable-isotopic evidence as overwhelmingly of biogenic origin. Groundwater-quality monitoring around PNR found no evidence of HF-induced impacts. Two approaches for modelling induced seismicity and associated seismic risk were developed using observations of seismicity and operational parameters from PNR in 2018 and 2019. Novel methodologies developed for monitoring include use of machine learning to identify fugitive atmospheric methane, Bayesian statistics to assess changes to groundwater quality, a seismicity forecasting model seeded by the HF-fluid injection rate and high-resolution monitoring of soil-gas methane. The project developed a risk-assessment framework, aligned with ISO 31000 risk-management principles, to assess the theoretical combined and cumulative environmental risks from operations over time. This demonstrated the spatial and temporal evolution of risk profiles: seismic and atmospheric impacts from the shale-gas operations are modelled to be localised and short-lived, while risk to groundwater quality is longer-term

    Age before beauty? Relationships between fertilization success and age-dependent ornaments in barn swallows

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    When males become more ornamented and reproduce more successfully as they grow older, phenotypic correlations between ornament exaggeration and reproductive success can be confounded with age effects in cross-sectional studies, and thus say relatively little about sexual selection on these traits. This is exemplified here in a correlative study of male fertilization success in a large colony of American barn swallows (Hirundo rustica erythrogaster). Previous studies of this species have indicated that two sexually dimorphic traits, tail length and ventral plumage coloration, are positively correlated with male fertilization success, and a mechanism of sexual selection by female choice has been invoked. However, these studies did not control for potential age-related variation in trait expression. Here, we show that male fertilization success was positively correlated with male tail length but not with plumage coloration. We also show that 1-year-old males had shorter tails and lower fertilization success than older males. This age effect accounted for much of the covariance between tail length and fertilization success. Still, there was a positive relationship between tail length and fertilization success among older males. But as this group consisted of males from different age classes, an age effect may be hidden in this relationship as well. Our data also revealed a longitudinal increase in both tail length and fertilization success for individual males. We argue that age-dependent ornament expression and reproductive performance in males complicate inferences about female preferences and sexual selection

    Selective conversion of 5-hydroxymethylfurfural to cyclopentanone derivatives over Cu-Al2O3 and Co-Al2O3 catalysts in water

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    The production of cyclopentanone derivatives from 5-hydroxymethylfurfural (HMF) using non-noble metal based catalysts is reported for the first time. Five different mixed oxides containing Ni, Cu, Co, Zn and Mg phases on an Al-rich amorphous support were prepared and characterised (XRD, ICP, SEM, TEM, H2-TPR, NH3/CO2-TPD and N2 sorption). The synthesised materials resulted in well-dispersed high metal loadings in a mesoporous network, exhibiting acid/base properties. The catalytic performance was tested in a batch stirred reactor under H2 pressure (20–50 bar) in the range T = 140–180 °C. The Cu–Al2O3 and the Co–Al2O3 catalysts showed a highly selective production of 3-hydroxymethylcyclopentanone (HCPN, 86%) and 3-hydroxymethylcyclopentanol (HCPL, 94%), respectively. A plausible reaction mechanism is proposed, clarifying the role of the reduced metal phases and the acid/basic sites on the main conversion pathways. Both Cu–Al2O3 and Co–Al2O3 catalysts showed a loss of activity after the first run, which can be reversed by a regeneration treatment. The results establish an efficient catalytic route for the production of the diol HCPL (reported for the first time) and the ketone HCPN from bio-derived HMF over 3d transition metals based catalysts in an environmental friendly medium such as water

    Detection and localization of double compression in MP3 audio tracks

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    In this work, by exploiting the traces left by double compression in the statistics of quantized modified discrete cosine transform coefficients, a single measure has been derived that allows to decide whether an MP3 file is singly or doubly compressed and, in the last case, to devise also the bit-rate of the first compression. Moreover, the proposed method as well as two state-of-the-art methods have been applied to analyze short temporal windows of the track, allowing the localization of possible tampered portions in the MP3 file under analysis. Experiments confirm the good performance of the proposed scheme and demonstrate that current detection methods are useful for tampering localization, thus offering a new tool for the forensic analysis of MP3 audio tracks

    SuperCLASS - III. Weak lensing from radio and optical observations in Data Release 1

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    We describe the first results on weak gravitational lensing from the SuperCLASS survey: the first survey specifically designed to measure the weak lensing effect in radio-wavelength data, both alone and in cross-correlation with optical data. We analyse 1.53deg2 of optical data from the Subaru telescope and 0.26deg2 of radio data from the e-MERLIN and VLA telescopes (the DR1 data set). Using standard methodologies on the optical data only we make a significant (10σ) detection of the weak lensing signal (a shear power spectrum) due to the massive supercluster of galaxies in the targeted region. For the radio data we develop a new method to measure the shapes of galaxies from the interferometric data, and we construct a simulation pipeline to validate this method. We then apply this analysis to our radio observations, treating the e-MERLIN and VLA data independently. We achieve source densities of 0.5 arcmin−2 in the VLA data and 0.06 arcmin−2 in the e-MERLIN data, numbers which prove too small to allow a detection of a weak lensing signal in either the radio data alone or in cross-correlation with the optical data. Finally, we show preliminary results from a visibility-plane combination of the data from e-MERLIN and VLA which will be used for the forthcoming full SuperCLASS data release. This approach to data combination is expected to enhance both the number density of weak lensing sources available, and the fidelity with which their shapes can be measured

    Using self-organizing maps to investigate environmental factors regulating colony size and breeding success of the White Stork (Ciconia ciconia)

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    We studied variations in the size of breeding colonies and in breeding performance of White Storks Ciconia ciconia in 2006–2008 in north-east Algeria. Each colony site was characterized using 12 environmental variables describing the physical environment, land-cover categories, and human activities, and by three demographic parameters: the number of breeding pairs, the number of pairs with chicks, and the number of fledged chicks per pair. Generalized linear mixed models and the self-organizing map algorithm (SOM, neural network) were used to investigate effects of biotic, abiotic, and anthropogenic factors on demographic parameters and on their relationships. Numbers of breeding pairs and of pairs with chicks were affected by the same environmental factors, mainly anthropogenic, which differed from those affecting the number of fledged chicks per pair. Numbers of fledged chicks per pair was not affected by colony size or by the number of nests with chicks. The categorization of the environmental variables into natural and anthropogenic, in connection with demographic parameters, was relevant to detect factors explaining variation in colony size and breeding parameters. The SOM proved a relevant tool to help determine actual dynamics in White Stork colonies, and thus to support effective conservation decisions at a regional scale

    The role of charged residues in the transmembrane helices of monocarboxylate transporter 1 and its ancillary protein basigin in determining plasma membrane expression and catalytic activity

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    Monocarboxylate transporters MCT1-MCT4 require basigin (CD147) or embigin (gp70), ancillary proteins with a glutamate residue in their single transmembrane (TM) domain, for plasma membrane (PM) expression and activity. Here we use site-directed mutagenesis and expression in COS cells or Xenopus oocytes to investigate whether this glutamate (Glu218 in basigin) may charge-pair with a positively charged TM-residue of MCT1. Such residues were predicted using a new molecular model of MCT1 based upon the published structure of the E. coli glycerol-3-phosphate transporter. No evidence was obtained for Arg306 (TM 8) of MCT1 and Glu218 of basigin forming a charge-pair; indeed E218Q-basigin could replace WT-basigin, although E218R-basigin was inactive. No PM expression of R306E-MCT1 or D302R-MCT1 was observed but D302R/R306D-MCT1 reached the PM, as did R306K-MCT1. However, both were catalytically inactive suggesting that Arg306 and Asp302 form a charge-pair in either orientation, but their precise geometry is essential for catalytic activity. Mutation of Arg86 to Glu or Gln within TM3 of MCT1 had no effect on plasma membrane expression or activity of MCT1. However, unlike WT-MCT1, these mutants enabled expression of E218R-basigin at the plasma membrane of COS cells. We propose that TM3 of MCT1 lies alongside the TM of basigin with Arg86 adjacent to Glu218 of basigin. Only when both these residues are positively charged (E218R-basigin with WT-MCT1) is this interaction prevented; all other residue pairings at these positions may be accommodated by charge-pairing or stabilization of unionized residues through hydrogen bonding or local distortion of the helical structure

    The frequent BRCA1 mutation 1135insA has multiple origins: a haplotype study in different populations

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    BACKGROUND: Analysis of the chromosomal background upon which a mutation occurs can be used to reconstruct the origins of specific disease-causing mutations. The relatively common BRCA1 mutation, 1135insA, has been previously identified as a Norwegian founder mutation. We performed haplotype analysis of individuals from breast and ovarian cancer families from four different ethnic backgrounds who had been identified as carriers of the BRCA1: 1135insA mutation. METHODS: Four microsatellite markers (D17S855, D17S1322, D17S1323 and D17S1325) located within or near the BRCA1 gene were genotyped in mutation carriers from 6 families of French Canadian, Italian and Dutch descent. Haplotypes were inferred from the genotype data and compared between these families and with the previously reported Norwegian founder haplotype. RESULTS: The 1135insA mutation was found to occur on three distinct haplotype backgrounds. The families from Norway shared a distinct haplotype while the families of French Canadian, Italian, and Dutch descent were found to occur on one of two additional, distinct backgrounds. CONCLUSION: Our results indicate that while the Norwegian haplotype including 1135insA represents an ancient Norwegian mutation, the same mutation has occurred independently in the other populations examined. In centres where targeted mutation testing is performed, exclusively or prior to gene sequencing, our findings suggest that this recurring mutation should be included in targeted mutation panels, irrespective of the ethnic origin of the persons tested

    SuperCLASS - I. The super cluster assisted shear survey: Project overview and data release 1

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    The SuperCLuster Assisted Shear Survey (SuperCLASS) is a legacy programme using the e-MERLIN interferometric array. The aim is to observe the sky at L-band (1.4 GHz) to a r.m.s. of 7μJybeam−1 over an area of ∼1deg2 centred on the Abell 981 supercluster. The main scientific objectives of the project are: (i) to detect the effects of weak lensing in the radio in preparation for similar measurements with the Square Kilometre Array (SKA); (ii) an extinction free census of star formation and AGN activity out to z ∼ 1. In this paper we give an overview of the project including the science goals and multiwavelength coverage before presenting the first data release. We have analysed around 400 h of e-MERLIN data allowing us to create a Data Release 1 (DR1) mosaic of ∼0.26deg2 to the full depth. These observations have been supplemented with complementary radio observations from the Karl G. Jansky Very Large Array (VLA) and optical/near infrared observations taken with the Subaru, Canada-France-Hawaii, and Spitzer Telescopes. The main data product is a catalogue of 887 sources detected by the VLA, of which 395 are detected by e-MERLIN and 197 of these are resolved. We have investigated the size, flux, and spectral index properties of these sources finding them compatible with previous studies. Preliminary photometric redshifts, and an assessment of galaxy shapes measured in the radio data, combined with a radio-optical cross-correlation technique probing cosmic shear in a supercluster environment, are presented in companion papers

    Cellular preservation of musculoskeletal specializations in the Cretaceous bird Confuciusornis

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    The hindlimb of theropod dinosaurs changed appreciably in the lineage leading to extant birds, becoming more ‘crouched’ in association with changes to body shape and gait dynamics. This postural evolution included anatomical changes of the foot and ankle, altering the moment arms and control of the muscles that manipulated the tarsometatarsus and digits, but the timing of these changes is unknown. Here, we report cellular-level preservation of tendon- and cartilage-like tissues from the lower hindlimb of Early Cretaceous Confuciusornis. The digital flexor tendons passed through cartilages, cartilaginous cristae and ridges on the plantar side of the distal tibiotarsus and proximal tarsometatarsus, as in extant birds. In particular, fibrocartilaginous and cartilaginous structures on the plantar surface of the ankle joint of Confuciusornis may indicate a more crouched hindlimb posture. Recognition of these specialized soft tissues in Confuciusornis is enabled by our combination of imaging and chemical analyses applied to an exceptionally preserved fossil
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