199 research outputs found

    Spatio-temporal earthquake clustering in the Western Corinth Gulf

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    Η ευρύτερη περιοχή του Κορινθιακού κόλπου λόγω της πολύπλοκης καιενδιαφέρουσας σεισμοτεκτονικής συμπεριφοράς που παρουσιάζει έχει αποτελέσει το αντικείμενο έρευνας πολλών μελετών (γεωλογικών, σεισμολογικών, γαιωδαιτικών κ.λ.π.). Τα τελευταία πέντε τουλάχιστον χρόνια έχει παρατηρηθεί μία έντονη σεισμική δραστηριότητα η οποία καλύπτει την περιοχή δυτικά του Αιγίου, το στενό Ρίου-Αντιρρίου μέχρι την πόλη της Πάτρας. Τα δεδομένα της παρούσας εργασίας καλύπτουντη χρονική περίοδο 2010-2011 κατά την οποία καταγράφηκε έντονη σεισμική δρστηριότητα με ισχυρούς σεισμούς (μέχρι Μ=5.5) και χωροχρονικές συγκεντρώσεις της σεισμικότητας. Οι καταγραφές των σεισμών από το Ενιαίο Ελληνικό Σεισμολογικό δίκτυο χρησιμοποιήθηκαν για τον ακριβή επαναπροσδιορισμό των εστιακώνπαραμέτρων των σεισμών με μέγεθος Μ≥1.5 χρησιμοποιώντας το πρόγραμμα HYPOINVERSE. Με βάση τα δεδομένα και τα αποτελέσματα από τον επαναπροσδιορισμό των εστιακών συντεταγμένων, η χωροχρονική κατανομή έδειξε ότι η σεισμικότητα συγκεντρώνεται σε κάποιες συστάδες σεισμών σε περιοχές που είναι πιθανό να συνδέονται και με ροή ρευστών λόγω της θέσης των σεισμών σε υποθαλάσσια περιοχή. Η παρούσα εργασία μελετά τη χωρική και χρονική κατανομήτης σεισμικότητας στο δυτικό τμήμα του Κορινθιακού κόλπου με σκοπό να ελεγχθεί τυχόν “μετανάστευση” της σεισμικότητας και σύνδεσή της με τις σεισμοτεκτονικά καθορισμένες περιοχές.Corinth Gulf has been studied, thoroughly using multidisciplinary approaches (geological, seismological, geodetic etc), which revealed its complicated tectonic behaviour. In the last five years or more, an intense continuous microseismic activity is observed in the westernmost part of the gulf covering the area from west of Aigio tothe area west of Rio Antirrio strait, near the city of Patras. Aiming to study in detail the properties of this microseismic manifestation, the recordings of the Hellenic Unified Seismological Network (HUSN) are used to accurately determine the focal coordinates of earthquakes with magnitudes M=1.5 or more. Relocation was performed using the HYPOINVERSE program, for all available data for the period 2010-2011 when earthquakes up to magnitude M=5.5 occurred. The space time plot of the epicentres shows that seismicity is not random in the area but formed distinctive clusters, indicating an E-W striking seismic zone whose patches are successively activated for certain periods. The present work deals with the investigation of spatio-temporal evolution of seismicity with the intention to examine the migration ofseismicity and multi-segment activation.

    DETERMINATION OF FAULT PLANE SOLUTIONS USING WAVEFORM AMPLITUDES AND RADIATION PATTERN

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    In the present work a modified version of the program FPFIT (Reasenberg and Oppenheimer, 1985) is developed, in order to improve the calculation of the fault plane solutions. The method is applied on selected earthquakes from short period waveform data in the Mygdonia basin (N. Greece) as recorded by the permanent network of the Seismological Station of Aristotle University of Thessaloniki during the period 1989-1999. The proposed modification of the FPFIT program was developed in order to minimize the derivation of multiple solutions, as well as the uncertainties in the location of Ρ and Τ axis of the determined fault plane solutions. Compared to the original version of FPFIT the modified approach takes also into account the radiation pattern of SV and SH waves. For each earthquake horizontal and vertical components of each station were used and the first arrivals of Ρ and S waves were picked. Using the maximum peak-to-peak amplitude of Ρ and S waves the ratio Pmax/(S/\/2max+SE2max)1/2 was estimated, where S/Vmax and SEmax are the maximum amplitudes of the two horizontal components (N-S, E-W) for the S waves and Pmax is the maximum amplitude of the vertical one for the P- waves. This ratio for the observed data, as well as the corresponding ratio Prad/iS/Aad+SlAad)1'2 of the synthetic data was used as a weight for the determination of the observed and theoretical P-wave polarities, respectively. The method was tested using synthetic data. A significant improvement of the results was found, compared to the original version of FPFIT. In particular, an improved approximation of the input focal mechanism is found, without multiple solutions and the best-estimated Ρ and Τ axes exhibit much smaller uncertainties. The addition of noise in the synthetic data didn't significantly change the results concerning the fault plane solutions. Finally, we have applied the modified program on a real data set of earthquakes that occurred in the Mygdonia basin

    Transcriptional response of ovine lung to infection with jaagsiekte sheep retrovirus

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    Jaagsiekte sheep retrovirus (JSRV) is the etiologic agent of ovine pulmonary adenocarcinoma (OPA), a neoplastic lung disease of sheep. OPA is an important economic and welfare issue for sheep farmers and a valuable naturally-occurring animal model for human lung adenocarcinoma. Here, we used RNA sequencing to study the transcriptional response of ovine lung tissue to infection by JSRV. We identified 1,971 ovine genes differentially-expressed in JSRV-infected lung compared to non-infected lung, including many genes with roles in carcinogenesis and immunomodulation. The differential expression of selected genes was confirmed using immunohistochemistry and RT-qPCR. A key finding was the activation of anterior-gradient-2, yes-associated protein-1 and amphiregulin in OPA tumor cells, indicating a role for this oncogenic pathway in OPA. In addition, there was differential expression of genes related to innate immunity including genes encoding cytokines, chemokines and complement system proteins. In contrast, there was little evidence for upregulation of genes involved in T-cell immunity. Many genes related to macrophage function were also differentially expressed, reflecting the increased abundance of these cells in OPA-affected lung tissue. Comparison of the genes differentially regulated in OPA with transcriptional changes occurring in human lung cancer revealed important similarities and differences between OPA and human lung adenocarcinoma. This study provides valuable new information on the pathogenesis of OPA and strengthens the use of this naturally occurring animal model for human lung adenocarcinoma

    Analysis of immune responses to attenuated alcelaphine herpesvirus 1 formulated with and without adjuvant

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    The experimental vaccine for bovine malignant catarrhal fever consists of viable attenuated alcelaphine herpesvirus 1 (AlHV-1) derived by extensive culture passage, combined with an oil-in-water adjuvant, delivered intramuscularly. This immunisation strategy was over 80% effective in previous experimental and field trials and protection appeared to be associated with induction of virus-neutralising antibodies. Whether the vaccine virus is required to be viable at the point of immunisation and whether adjuvant is required to induce the appropriate immune responses remains unclear. To address these issues two studies were performed, firstly to analyse immune responses in the presence and absence of adjuvant and secondly, to investigate immune responses to vaccines containing adjuvant plus viable or inactivated AlHV-1.The first study showed that viable attenuated AlHV-1 in the absence of adjuvant induced virus-specific antibodies but the titres of virus-neutralising antibodies were significantly lower than those induced by vaccine containing viable virus and adjuvant, suggesting adjuvant was required for optimal responses. In contrast, the second study found that the vaccine containing inactivated (>99.9%) AlHV-1 induced similar levels of virus-neutralising antibody to the equivalent formulation containing viable AlHV-1.Together these studies suggest that the MCF vaccine acts as an antigen depot for induction of immune responses, requiring adjuvant and a suitable antigen source, which need not be viable virus. These observations may help in directing the development of alternative MCF vaccine formulations for distribution in the absence of an extensive cold chain

    Updated Field Synopsis and Systematic Meta-Analyses of Genetic Association Studies in Cutaneous Melanoma: The MelGene Database

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    We updated a field synopsis of genetic associations of cutaneous melanoma (CM) by systematically retrieving and combining data from all studies in the field published as of August 31, 2013. Data were available from 197 studies, which included 83,343 CM cases and 187,809 controls and reported on 1,126 polymorphisms in 289 different genes. Random-effects meta-analyses of 81 eligible polymorphisms evaluated in >4 data sets confirmed 20 single-nucleotide polymorphisms across 10 loci (TYR, AFG3L1P, CDK10, MYH7B, SLC45A2, MTAP, ATM, CLPTM1L, FTO, and CASP8) that have previously been published with genome-wide significant evidence for association (P<5 × 10−8) with CM risk, with certain variants possibly functioning as proxies of already tagged genes. Four other loci (MITF, CCND1, MX2, and PLA2G6) were also significantly associated with 5 × 10−8<P<1 × 10−3. In supplementary meta-analyses derived from genome-wide association studies, one additional locus located 11 kb upstream of ARNT (chromosome 1q21) showed genome-wide statistical significance with CM. Our approach serves as a useful model in analyzing and integrating the reported germline alterations involved in CM

    The European DISABKIDS project: development of seven condition-specific modules to measure health related quality of life in children and adolescents

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    BACKGROUND: The European DISABKIDS project aims to enhance the Health Related Quality of Life (HRQoL) of children and adolescents with chronic medical conditions and their families. We describe the development of the seven cross-nationally tested condition-specific modules of the European DISABKIDS HRQoL instrument in a population of children and adolescents. The condition-specific modules are intended for use in conjunction with the DISABKIDS chronic generic module. METHODS: Focus groups were used to construct the pilot version of the DISABKIDS condition-specific HRQoL modules for asthma, juvenile idiopathic arthritis, atopic dermatitis, cerebral palsy, cystic fibrosis, diabetes and epilepsy. Analyses were conducted on pilot test data in order to construct field test versions of the modules. A series of factor analyses were run, first, to determine potential structures for each condition-specific module, and, secondly, to select a reduced number of items from the pilot test to be included in the field test. Post-field test analyses were conducted to retest the domain structure for the final DISABKIDS condition-specific modules. RESULTS: The DISABKIDS condition-specific modules were tested in a pilot study of 360 respondents, and subsequently in a field test of 1152 respondents in 7 European countries. The final condition-specific modules consist of an 'Impact' domain and an additional domain (e.g. worry, stigma, treatment) with between 10 to 12 items in total. The Cronbach's alpha of the final domains was found to vary from 0.71 to 0.90. CONCLUSION: The condition-specific modules of the DISABKIDS instrument were developed through a step-by-step process including cognitive interview, clinical expertise, factor analysis, correlations and internal consistency. A cross-national pilot and field test were necessary to collect these data. In general, the internal consistency of the domains was satisfactory to high. In future, the DISABKIDS instrument may serve as a useful tool with which to assess HRQoL in children and adolescents with a chronic condition. The condition-specific modules can be used in conjunction with the DISABKIDS chronic generic module

    UK Greenhouse Gas Inventory 1990 to 2021: annual report for submission under the Framework Convention on Climate Change

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    This is the United Kingdom’s National Inventory Report (NIR) submitted in 2023 to the United Nations Framework Convention on Climate Change (UNFCCC). It contains national greenhouse gas emission estimates for the period 1990-2021, and descriptions of the methods used to produce the estimates. The greenhouse gas inventory (GHGI) is based on the same datasets used by the UK in the National Atmospheric Emissions Inventory (NAEI) for reporting atmospheric emissions under other international agreements. The GHGI is therefore consistent with these other air emissions inventories where they overlap. The greenhouse gas inventory is compiled on behalf of the UK Department for Energy Security and Net Zero (DESNZ) for the Science and Innovation for Climate and Energy (SICE) Directorate, by Ricardo Energy & Environment. We acknowledge the positive support and advice from DESNZ throughout the work, and we are grateful for the help of all those who have contributed to this NIR. A list of the contributors can be found in Chapter 18. The GHGI is compiled according to the Intergovernmental Panel on Climate Change (IPCC) 2006 Guidelines (IPCC, 2006). Each year the inventory is updated to include the latest data available. Improvements to the methodology are backdated as necessary to ensure a consistent time series. Methodological changes are made to take account of new data sources, or new guidance from IPCC, and new research, sponsored by DESNZ or otherwise

    Influence of electrolyte co-additives on the performance of dye-sensitized solar cells

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    The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs). The most effective additives are 4-tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides. In a comparative work, we investigated in detail the action of TBP and NMBI additives in ionic liquid-based redox electrolytes with varying iodine concentrations, in order to extract the optimum additive/I2 ratio for each system. Different optimum additive/I2 ratios were determined for TBP and NMBI, despite the fact that both generally work in a similar way. Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive. Under the best operation conditions, power conversion efficiencies as high as 8% were obtained
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