387 research outputs found

    Intermediate depth and deep earthquakes: complexity of the Ibero-Magrhebian region

    Get PDF
    The Ibero-Magrhebian region is located at the plate boundary between Eurasia and Africa and it is a tectonically complex region. A sign of the complexity, is the occurrence of intermediate depth earthquakes (40<h<150 km), located in south Spain, between Granada- Malaga and at the west part of Alboran Sea, together with the occurrence of very deep earthquakes (h≈650 km) near Dúrcal (Granada). Intermediate depth shocks are mostly confined within a relatively narrow region (50 km width) located East of Gibraltar, extending NNE-SSW from the Malaga (Spain) area to a region offshore the Moroccan coast. We have studied focal mechanisms of these earthquakes from inversion of body wave. The stress pattern in the Ibero-Maghrebian region obtained from solutions of selected shallow, intermediate depth and deep shocks show the complexity of the region. The seismotectonic scheme show horizontal compression in NNW-SSE direction in the Gulf of Cádiz. In northern Africa, the stress pattern changes and it corresponds to strike-slip motion, with extends from west of the Gibraltar Strait until the western Algeria, where in the Oran region the horizontal compression N-S reapers, with a clear domain of the thrusting faults in Algeria. In the Alboran Sea there is horizontal extension in E-W direction for shallow events. The intermediate depth shock located at the western part of the Alboran Sea show a change on the stress pattern: to the west of 4.5oW, focal mechanisms show vertical tension axis, while to the east, they show vertical pressure axis. These stress orientations are not present in deep earthquakes, where the pressure axes dip 45o to the east. The intermediate and deep earthquakes may be related to some kind of subduction or delamination processes, more recent for the intermediate depth shocks and older for the very deep activity

    JAK2 aberrations in childhood B-cell precursor acute lymphoblastic leukemia

    Get PDF
    JAK2 abnormalities may serve as target for precision medicines in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In the current study we performed a screening for JAK2 mutations and translocations, analyzed the clinical outcome and studied the efficacy of two JAK inhibitors in primary BCP-ALL cells. Importantly, we identify a number of limitations of JAK inhibitor therapy. JAK2 mutations mainly occurred in the poor prognostic subtypes BCR-ABL1-like and non- BCR-ABL1-like B-other (negative for sentinel cytogenetic lesions). JAK2 translocations were restricted to BCR-ABL1-like cases. Momelotinib and ruxolitinib were cytotoxic in both JAK2 translocated and JAK2 mutated cells, although efficacy in JAK2 mutated cells highly depended on cytokine receptor activation by TSLP. However, our data also suggest that the effect of JAK inhibition may be compromised by mutations in alternative survival pathways and microenvironment-induced resistance. Furthermore, inhibitors induced accumulation of phosphorylated JAK2Y1007, which resulted in a profound re-activation of JAK2 signaling upon release of the inhibitors. This preclinical evidence implies that further optimization and evaluation of JAK inhibitor treatment is necessary prior to its clinical integration in pediatric BCP-ALL

    Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow

    Get PDF
    Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption.We usemultiparameter geophysical and geochemical data to show that the 110-squarekilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014-2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurface flow path explain the gradual, nearexponential decline of both collapse rate and the intensity of the 180-day-long eruption

    The prognostic role of intragenic copy number breakpoints and identification of novel fusion genes in paediatric high grade glioma

    Get PDF
    BACKGROUND: Paediatric high grade glioma (pHGG) is a distinct biological entity to histologically similar tumours arising in older adults, and has differing copy number profiles and driver genetic alterations. As functionally important intragenic copy number aberrations (iCNA) and fusion genes begin to be identified in adult HGG, the same has not yet been done in the childhood setting. We applied an iCNA algorithm to our previously published dataset of DNA copy number profiling in pHGG with a view to identify novel intragenic breakpoints. RESULTS: We report a series of 288 iCNA events in pHGG, with the presence of intragenic breakpoints itself a negative prognostic factor. We identified an increased number of iCNA in older children compared to infants, and increased iCNA in H3F3A K27M mutant tumours compared to G34R/V and wild-type. We observed numerous gene disruptions by iCNA due to both deletions and amplifications, targeting known HGG-associated genes such as RB1 and NF1, putative tumour suppressors such as FAF1 and KIDINS220, and novel candidates such as PTPRE and KCND2. We further identified two novel fusion genes in pHGG - CSGALNACT2:RET and the complex fusion DHX57:TMEM178:MAP4K3. The latter was sequence-validated and appears to be an activating event in pHGG. CONCLUSIONS: These data expand upon our understanding of the genomic events driving these tumours and represent novel targets for therapeutic intervention in these poor prognosis cancers of childhood.We are grateful for support from the Rosetrees Trust, the Brain Tumour Charity and Fundacao para a Ciencia e Tecnologia, Portugal (PhD Studentship SFRH/BD/33473/2008). DC, AM, LB and CJ acknowledge NHS funding to the Biomedical Research Centre

    Engineering REST-Specific Synthetic PUF Proteins to Control Neuronal Gene Expression: A Combined Experimental and Computational Study

    Get PDF
    Regulation of gene transcription is an essential mechanism for differentiation and adaptation of organisms. A key actor in this regulation process is the repressor element 1 (RE1)-silencing transcription factor (REST), a transcriptional repressor that controls more than 2000 putative target genes, most of which are neuron-specific. With the purpose of modulating REST expression, we exploited synthetic, ad hoc designed, RNA binding proteins (RBPs) able to specifically target and dock to REST mRNA. Among the various families of RBPs, we focused on the Pumilio and FBF (PUF) proteins, present in all eukaryotic organisms and controlling a variety of cellular functions. Here, a combined experimental and computational approach was used to design and test 8- and 16-repeat PUF proteins specific for REST mRNA. We explored the conformational properties and atomic features of the PUF-RNA recognition code by Molecular Dynamics simulations. Biochemical assays revealed that the 8- and 16-repeat PUF-based variants specifically bind the endogenous REST mRNA without affecting its translational regulation. The data also indicate a key role of stacking residues in determining the binding specificity. The newly characterized REST-specific PUF-based constructs act as excellent RNA-binding modules and represent a versatile and functional platform to specifically target REST mRNA and modulate its endogenous expression
    corecore