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Periods of accelerated seismicity have been observed during the preparation process of many large earthquakes. This accelerating seismicity can be detected by the Accelerated Moment Release (AMR) method and its recent Revised version (R-AMR) when the two techniques are applied to earthquake catalogues. The main aim of this study is to investigate the seismicity preceding large mainshocks and possibly increase our comprehension of the underlying physics. In particular, we applied both the AMR and R-AMR to the seismicity preceding 14 large worldwide shallow earthquakes, i.e. with focal depth less than 40 km, with magnitude M > 6 for Mediterranean area, and M ≥ 6.4 in the rest of the world, occurred from 2014 to 2018. Twelve case studies were analysed in the framework of SwArm For Earthquake study project funded by ESA, comprising the period 2014–2016; two additional cases were also considered to confirm the goodness of the methodology outside the period of the project catalogues. In total, R-AMR shows better performances than AMR, in 11 cases out of 14. In particular, in four out of 14 cases (i.e. 28.6%), the R-AMR method shows that acceleration exists due to an evident clustering in time–space on the faults, thus guiding the convergence of the fit; in seven cases (i.e. 50%) the R-AMR discloses acceleration, although no clustering around the fault is present; the remaining three cases (i.e. 21.4%) show no emerging acceleration from background. Finally, when R-AMR is compared with simulations, we verify that in most of the cases the acceleration is real and not casual. [ABSTRACT FROM AUTHOR]

Electrochemical sandwich immunoassay strategies involving the use of carboxyl-functionalized magnetic microbeads (cMBs) and magnetic nanoparticles (cMNPs) have been evaluated and compared. The proteolytically cleaved soluble tyrosine kinase receptor sAXL was used as the target analyte. Antibodies against AXL were covalently immobilized on cMBs or cMNPs. Immunobinding of AXL was detected by means of a secondary biotinylated antibody and a streptavidin-horseradish peroxidase conjugate. The electrochemical transduction was accomplished by capturing the cMBs or cMNPs bearing the immunoconjugates onto screen-printed carbon electrodes (SPCEs) by using a small magnet. The amperometric response was measured at −0.20 V (vs the silver pseudo-reference electrode of the SPCE) upon the addition of HO in the presence of hydroquinone as the redox mediator. The calibration plots for AXL extended up to 7.5 ng mL when cMBs were used for the preparation of the immunosensor and up to 40 ng mL in the case of using cMNPs. The respective slope values were 158 (cMBs) and 43 nA mL ng (cMNPs), while the achieved LODs were 74 (cMBs) and 75 pg mL (cMNPs). Although the immunosensors prepared with cMBs provided a shorter range of linearity, they exhibited a 3.7-times larger sensitivity than those constructed with cMNPs. The successful application of the new strategies was demonstrated for the determination of the endogenous content of sAXL in real human serum samples (a cut-off value of 71 ng mL have been established for patients with risk of heart failure). The immunosensors constructed using cMBs or cMNPs can be advanta geously compared, in terms of sensitivity and fabrication time, with the only immunosensor for AXL previously reported. In addition, these new immunosensors took approximately half time than ELISA to perform the assay. [ABSTRACT FROM AUTHOR]

The study of the temporal evolution of the dipole moment variations is a forefront research topic in Earth sciences. It constrains geodynamo simulations and is used to correct cosmogenic isotope production, which is evidence of past solar activity, and it is used to study possible correlations between the geomagnetic field and the climate. In this work, we have analysed the main error sources in the geomagnetic dipole moment computation from palaeomagnetic data: the influence of the non-dipole terms in the average approach, the inhomogeneous distribution of the current palaeomagnetic database, and the averaging procedure used to obtain the evolution of the dipole moment. To evaluate and quantify these effects, we have used synthetic data from a global model based on instrumental and satellite data, the International Geomagnetic Reference Field: 11th generation. Results indicate that the non-dipole terms contribute on a global scale of <6 % in the averaged dipole moment, whereas the regional non-dipole contribution can show deviations of up to 35 % in some regions such as Oceania, and different temporal trends with respect to the global dipole moment evolution in other ones, such as Europe and Asia. A regional weighting scheme seems the best option to mitigate these effects in the dipole moment average approach. But when directional and intensity palaeomagnetic information is available on a global scale, and in spite of the inhomogeneity of the database, global modelling presents more reliable values of the geomagnetic dipole moment. [ABSTRACT FROM AUTHOR]

Drosophila melanogaster contains a single copy of the gene encoding translation eukaryotic initiation factor eIF-4E, which maps in the 67A2B1 region of chromosome 3L. A genomic clone containing the entire eIF-4E gene was isolated and sequenced. Comparison of this sequence with a cDNA previously obtained in our laboratory and 5′-RACE analysis revealed the existence of three mRNAs that are generated by alternative splicing of a primary transcript. All of them have different 5′untranslated leader regions. Two of the mRNAs encode the same eIF-4E polypeptide, whose sequence has been deduced from the cDNA clone. The third mRNA species contains a new open reading frame, possibly encoding another isoform of eIF-4E, which is very similar in size to the other but has a different N-terminal sequence. Several sequences which may be involved in the regulation of transcription initiation of the eIF-4E gene, except for a consensus TATA box, were found upstream of the putative transcription initiation sites. Expression of the eIF-4E gene is spatially and temporally controlled during embryonic development. It is ubiquitously expressed during embryogenesis but transcripts preferentially accumulate in certain tissues, particularly in the pole cells, at different developmental stages. [ABSTRACT FROM AUTHOR]

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper. [ABSTRACT FROM AUTHOR]

The production of cosmogenic isotopes offers a unique way to reconstruct solar activity during the Holocene. It is influenced by both the solar and Earth magnetic fields and thus their combined effect needs to be disentangled to infer past solar irradiance. Nowadays, it is assumed that the long-term variations of cosmogenic production are modulated by the geomagnetic field and that the solar field dominates over shorter wavelengths. In this process, the effects of the non-dipolar terms of the geomagnetic field are considered negligible. Here we analyse these assumptions and demonstrate that, for a constant solar modulation potential, the geomagnetic field exerts a strong modulation of multi-centennial to millennial wavelengths (periods of 800 and 2200 yr). Moreover, we demonstrate that the non-dipole terms derived from the harmonic degree 3 and above produce maximum differences of 7% in the global average radiocarbon production rate. The results are supported by the identification, for the first time, of a robust coherence between the production rates independently estimated from geomagnetic reconstructions and that inferred from natural archives. This implies the need to review past solar forcing reconstructions, with important implications both for the assessment of solar-climate relationships as well as for the present and future generation of paleoclimate models. [ABSTRACT FROM AUTHOR]