Understanding the causes of the ~90 ppmv atmospheric CO swings between glacial and interglacial climates is an important open challenge in paleoclimate research. Although the regularity of the glacial-interglacial cycles hints at a single driving mechanism, Earth System models require many independent physical and biological processes to explain the full observed CO signal. Here we show that biologically sequestered carbon in the ocean can explain an atmospheric CO change of 75 ± 40 ppmv, based on a mass balance calculation using published carbon isotopic measurements.
View Article and Find Full Text PDFSmall-scale turbulent mixing drives the upwelling of deep water masses in the abyssal ocean as part of the global overturning circulation. However, the processes leading to mixing and the pathways through which this upwelling occurs remain insufficiently understood. Recent observational and theoretical work has suggested that deep-water upwelling may occur along the ocean's sloping seafloor; however, evidence has, so far, been indirect.
View Article and Find Full Text PDFTesting, contact tracing, and isolation (TTI) is an epidemic management and control approach that is difficult to implement at scale because it relies on manual tracing of contacts. Exposure notification apps have been developed to digitally scale up TTI by harnessing contact data obtained from mobile devices; however, exposure notification apps provide users only with limited binary information when they have been directly exposed to a known infection source. Here we demonstrate a scalable improvement to TTI and exposure notification apps that uses data assimilation (DA) on a contact network.
View Article and Find Full Text PDFInteractors of protein products of known genes for frontotemporal dementia (FTD) are likely to be involved in the molecular pathways towards disease. We therefore applied protein interaction network (PIN) analysis to prioritize candidate genes for rare variant association analysis. We created an FTD-PIN starting from known FTD genes downloading their physical interactors and performed functional enrichment analyses.
View Article and Find Full Text PDFCharacterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis.
View Article and Find Full Text PDFThe G4C2-repeat expansion in C9orf72 is the most common cause of frontotemporal dementia and of amyotrophic lateral sclerosis. The variability of age at onset and phenotypic presentations is a hallmark of C9orf72 disease. In this study, we aimed to identify modifying factors of disease onset in C9orf72 carriers using a family-based approach, in pairs of C9orf72 carrier relatives with concordant or discordant age at onset.
View Article and Find Full Text PDFThe human genome expresses thousands of natural antisense transcripts (NAT) that can regulate epigenetic state, transcription, RNA stability or translation of their overlapping genes. Here we describe MAPT-AS1, a brain-enriched NAT that is conserved in primates and contains an embedded mammalian-wide interspersed repeat (MIR), which represses tau translation by competing for ribosomal RNA pairing with the MAPT mRNA internal ribosome entry site. MAPT encodes tau, a neuronal intrinsically disordered protein (IDP) that stabilizes axonal microtubules.
View Article and Find Full Text PDFImportance: Substantial genome-wide association study (GWAS) work in Parkinson disease (PD) has led to the discovery of an increasing number of loci shown reliably to be associated with increased risk of disease. Improved understanding of the underlying genes and mechanisms at these loci will be key to understanding the pathogenesis of PD.
Objective: To investigate what genes and genomic processes underlie the risk of sporadic PD.
Frontotemporal dementia (FTD) is regarded as the second most common form of young-onset dementia after Alzheimer's disease (AD).FTD is a complex neurodegenerative condition characterised by heterogeneous clinical, pathological and genetic features. No efficient measures for early diagnosis and therapy are available.
View Article and Find Full Text PDFBackground: The genetic basis of variation in the progression of primary tauopathies has not been determined. We aimed to identify genetic determinants of survival in progressive supranuclear palsy (PSP).
Methods: In stage one of this two stage genome-wide association study (GWAS), we included individuals with PSP, diagnosed according to pathological and clinical criteria, from two separate cohorts: the 2011 PSP GWAS cohort, from brain banks based at the Mayo Clinic (Jacksonville, FL, USA) and in Munich (Germany), and the University College London PSP cohort, from brain banks and the PROSPECT study, a UK-wide longitudinal study of patients with atypical parkinsonian syndromes.
We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts.
View Article and Find Full Text PDFFrontotemporal dementia (FTD) is a clinical, genetic, and pathologic heterogeneous group of neurodegenerative diseases. In this study, we investigated the role of APOƐ4, rs5848 in GRN, and rs1042522 in TP53 gene as disease risk factors and/or phenotype modifiers in 440 FTD patients, including 175 C9orf72 expansion carriers. We found that the C9orf72 expansion carriers showing an earlier age at onset (p < 0.
View Article and Find Full Text PDFJ Neuropathol Exp Neurol
August 2020
Sialic acid-binding immunoglobulin-type lectins, which are predominantly expressed in immune cells, represent a family of immunomodulatory receptors with inhibitory and activating signals, in both healthy and disease states. Genetic factors are important in all forms of dementia, especially in early onset dementia. CD33 was recently recognized as a genetic risk factor for Alzheimer disease (AD).
View Article and Find Full Text PDFBackground: The past decade has seen the rise of omics data for the understanding of biological systems in health and disease. This wealth of information includes protein-protein interaction (PPI) data derived from both low- and high-throughput assays, which are curated into multiple databases that capture the extent of available information from the peer-reviewed literature. Although these curation efforts are extremely useful, reliably downloading and integrating PPI data from the variety of available repositories is challenging and time consuming.
View Article and Find Full Text PDFBiodegradable polymeric nanoparticles (NPs) are attracting increasing attention as carriers for drug delivery. However, one of the main factors limiting their transition to the market is their premature degradation and release of the payload during the storage. Therefore, for increasing the formulation shelf-life, the removal of water is of paramount importance.
View Article and Find Full Text PDFThe mean state of the atmosphere and ocean is set through a balance between external forcing (radiation, winds, heat and freshwater fluxes) and the emergent turbulence, which transfers energy to dissipative structures. The forcing gives rise to jets in the atmosphere and currents in the ocean, which spontaneously develop turbulent eddies through the baroclinic instability. A critical step in the development of a theory of climate is to properly include the eddy-induced turbulent transport of properties like heat, moisture, and carbon.
View Article and Find Full Text PDFWe analyzed the frequency of intermediate alleles (IAs) in the ATXN1, ATXN2, and HTT genes in several neurodegenerative diseases. The study included 1126 patients with Alzheimer's disease (AD), 440 patients with frontotemporal dementia (FTD), and 610 patients with Parkinson's disease. In all cohorts, we genotyped ATXN1 and ATXN2 CAG repeats.
View Article and Find Full Text PDFThe semantic variant of primary progressive aphasia (svPPA) is a clinical syndrome characterized by neurodegeneration and progressive loss of semantic knowledge. Unlike many other forms of frontotemporal lobar degeneration (FTLD), svPPA has a highly consistent underlying pathology composed of TDP-43 (a regulator of RNA and DNA transcription metabolism). Previous genetic studies of svPPA are limited by small sample sizes and a paucity of common risk variants.
View Article and Find Full Text PDFInt J Environ Res Public Health
July 2019
To remove the mineral oil impregnating the insulating paper present in old, disconnected, underground electrical cables, which represents a threat to the environment, two approaches are investigated at laboratory (1 m) and pilot (10 m) scales. The first one involves in situ polymerization to clog the inner channel of the cables and to enable the washing of the outer paper region impregnated by the oil by axial flow of a displacing fluid (water). The second approach leaves the inner channel open and employs repeated cycles of pressurization and rest to displace the oil contained in the paper by radially pushing the water from the inner channel into the outer layers.
View Article and Find Full Text PDFFrontotemporal lobar degeneration (FTLD) is the second most common form of dementia after Alzheimer's disease. The study and the dissection of FTLD is complex due to its clinical, pathological, and genetic heterogeneity. In this review, we survey the state-of-the-art genetics of familial FTLD and recapitulate our current understanding of the genetic architecture of sporadic FTLD by summarizing results of genome-wide association studies performed in FTLD to date.
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