334 research outputs found

    Recognition without identification, erroneous familiarity, and déjà vu

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    Déjà vu is characterized by the recognition of a situation concurrent with the awareness that this recognition is inappropriate. Although forms of déjà vu resolve in favor of the inappropriate recognition and therefore have behavioral consequences, typical déjà vu experiences resolve in favor of the awareness that the sensation of recognition is inappropriate. The resultant lack of behavioral modification associated with typical déjà vu means that clinicians and experimenters rely heavily on self-report when observing the experience. In this review, we focus on recent déjà vu research. We consider issues facing neuropsychological, neuroscientific, and cognitive experimental frameworks attempting to explore and experimentally generate the experience. In doing this, we suggest the need for more experimentation and amore cautious interpretation of research findings, particularly as many techniques being used to explore déjà vu are in the early stages of development.PostprintPeer reviewe

    Individual Eigenvalue Distributions for the Wilson Dirac Operator

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    We derive the distributions of individual eigenvalues for the Hermitian Wilson Dirac Operator D5 as well as for real eigenvalues of the Wilson Dirac Operator DW. The framework we provide is valid in the epsilon regime of chiral perturbation theory for any number of flavours Nf and for non-zero low energy constants W6, W7, W8. It is given as a perturbative expansion in terms of the k-point spectral density correlation functions and integrals thereof, which in some cases reduces to a Fredholm Pfaffian. For the real eigenvalues of DW at fixed chirality nu this expansion truncates after at most nu terms for small lattice spacing "a". Explicit examples for the distribution of the first and second eigenvalue are given in the microscopic domain as a truncated expansion of the Fredholm Pfaffian for quenched D5, where all k-point densities are explicitly known from random matrix theory. For the real eigenvalues of quenched DW at small "a" we illustrate our method by the finite expansion of the corresponding Fredholm determinant of size nu.Comment: 20 pages, 5 figures; v2: typos corrected, refs added and discussion of W6 and W7 extende

    Trace-gas metabolic versatility of the facultative methanotroph Methylocella silvestris

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    The climate-active gas methane is generated both by biological processes and by thermogenic decomposition of fossil organic material, which forms methane and short-chain alkanes, principally ethane, propane and butane1, 2. In addition to natural sources, environments are exposed to anthropogenic inputs of all these gases from oil and gas extraction and distribution. The gases provide carbon and/or energy for a diverse range of microorganisms that can metabolize them in both anoxic3 and oxic zones. Aerobic methanotrophs, which can assimilate methane, have been considered to be entirely distinct from utilizers of short-chain alkanes, and studies of environments exposed to mixtures of methane and multi-carbon alkanes have assumed that disparate groups of microorganisms are responsible for the metabolism of these gases. Here we describe the mechanism by which a single bacterial strain, Methylocella silvestris, can use methane or propane as a carbon and energy source, documenting a methanotroph that can utilize a short-chain alkane as an alternative to methane. Furthermore, during growth on a mixture of these gases, efficient consumption of both gases occurred at the same time. Two soluble di-iron centre monooxygenase (SDIMO) gene clusters were identified and were found to be differentially expressed during bacterial growth on these gases, although both were required for efficient propane utilization. This report of a methanotroph expressing an additional SDIMO that seems to be uniquely involved in short-chain alkane metabolism suggests that such metabolic flexibility may be important in many environments where methane and short-chain alkanes co-occur

    On duality symmetry in perturbative quantum theory

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    Non-compact symmetries of extended 4d supergravities involve duality rotations of vectors and thus are not manifest off-shell invariances in standard "second-order" formulation. To study how such symmetries are realised in the quantum theory we consider examples in 2 dimensions where vector-vector duality is replaced by scalar-scalar one. Using a "doubled" formulation, where fields and their momenta are treated on an equal footing and the duality becomes a manifest symmetry of the action (at the expense of Lorentz symmetry), we argue that the corresponding on-shell quantum effective action or S-matrix are duality symmetric as well as Lorentz invariant. The simplest case of discrete Z_2 duality corresponds to a symmetry of the S-matrix under flipping the sign of the negative-chirality scalars in 2 dimensions or phase rotations of chiral (definite-helicity) parts of vectors in 4 dimensions. We also briefly discuss some 4d models and comment on implications of our analysis for extended supergravities.Comment: 21 pages, Latex v2: comments and references added v3: references and minor comments adde

    On graviton non-Gaussianities during inflation

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    We consider the most general three point function for gravitational waves produced during a period of exactly de Sitter expansion. The de Sitter isometries constrain the possible shapes to only three: two preserving parity and one violating parity. These isometries imply that these correlation functions should be conformal invariant. One of the shapes is produced by the ordinary gravity action. The other shape is produced by a higher derivative correction and could be as large as the gravity contribution. The parity violating shape does not contribute to the bispectrum [1106.3228, 1108.0175], even though it is present in the wavefunction. We also introduce a spinor helicity formalism to describe de Sitter gravitational waves with circular polarization. These results also apply to correlation functions in Anti-de Sitter space. They also describe the general form of stress tensor correlation functions, in momentum space, in a three dimensional conformal field theory. Here all three shapes can arise, including the parity violating one.Comment: 51 pages, v2: Corrected statement about parity violation in the gravitational wave bispectrum. Some other changes and references adde

    Autosomal recessive cardiomyopathy and sudden cardiac death associated with variants in MYL3.

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    PURPOSE: Variants in genes encoding sarcomeric proteins are the most common cause of inherited cardiomyopathies. However, the underlying genetic cause remains unknown in many cases. We used exome sequencing to reveal the genetic etiology in patients with recessive familial cardiomyopathy. METHODS: Exome sequencing was carried out in three consanguineous families. Functional assessment of the variants was performed. RESULTS: Affected individuals presented with hypertrophic or dilated cardiomyopathy of variable severity from infantile- to early adulthood-onset and sudden cardiac death. We identified a homozygous missense substitution (c.170C>A, p.[Ala57Asp]), a homozygous translation stop codon variant (c.106G>T, p.[Glu36Ter]), and a presumable homozygous essential splice acceptor variant (c.482-1G>A, predicted to result in skipping of exon 5). Morpholino knockdown of the MYL3 orthologue in zebrafish, cmlc1, resulted in compromised cardiac function, which could not be rescued by reintroduction of MYL3 carrying either the nonsense c.106G>T or the missense c.170C>A variants. Minigene assay of the c.482-1G>A variant indicated a splicing defect likely resulting in disruption of the EF-hand Ca2+ binding domains. CONCLUSIONS: Our data demonstrate that homozygous MYL3 loss-of-function variants can cause of recessive cardiomyopathy and occurrence of sudden cardiac death, most likely due to impaired or loss of myosin essential light chain function

    DNA Methylation Analysis of Bone Marrow Cells at Diagnosis of Acute Lymphoblastic Leukemia and at Remission

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    To detect genes with CpG sites that display methylation patterns that are characteristic of acute lymphoblastic leukemia (ALL) cells, we compared the methylation patterns of cells taken at diagnosis from 20 patients with pediatric ALL to the methylation patterns in mononuclear cells from bone marrow of the same patients during remission and in non-leukemic control cells from bone marrow or blood. Using a custom-designed assay, we measured the methylation levels of 1,320 CpG sites in regulatory regions of 413 genes that were analyzed because they display allele-specific gene expression (ASE) in ALL cells. The rationale for our selection of CpG sites was that ASE could be the result of allele-specific methylation in the promoter regions of the genes. We found that the ALL cells had methylation profiles that allowed distinction between ALL cells and control cells. Using stringent criteria for calling differential methylation, we identified 28 CpG sites in 24 genes with recurrent differences in their methylation levels between ALL cells and control cells. Twenty of the differentially methylated genes were hypermethylated in the ALL cells, and as many as nine of them (AMICA1, CPNE7, CR1, DBC1, EYA4, LGALS8, RYR3, UQCRFS1, WDR35) have functions in cell signaling and/or apoptosis. The methylation levels of a subset of the genes were consistent with an inverse relationship with the mRNA expression levels in a large number of ALL cells from published data sets, supporting a potential biological effect of the methylation signatures and their application for diagnostic purposes

    NGTS-11 b (TOI-1847 b): A Transiting Warm Saturn Recovered from a TESS Single-transit Event

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    We report the discovery of NGTS-11 b (=TOI-1847 b), a transiting Saturn in a 35.46-day orbit around a mid K-type star (Teff=5050 K). We initially identified the system from a single-transit event in a TESS full-frame image light-curve. Following seventy-nine nights of photometric monitoring with an NGTS telescope, we observed a second full transit of NGTS-11 b approximately one year after the TESS single-transit event. The NGTS transit confirmed the parameters of the transit signal and restricted the orbital period to a set of 13 discrete periods. We combined our transit detections with precise radial velocity measurements to determine the true orbital period and measure the mass of the planet. We find NGTS-11 b has a radius of 0.817+0.028-0.032 RJR_J, a mass of 0.344+0.092-0.073 MJM_J, and an equilibrium temperature of just 435+34-32 K, making it one of the coolest known transiting gas giants. NGTS-11 b is the first exoplanet to be discovered after being initially identified as a TESS single-transit event, and its discovery highlights the power of intense photometric monitoring in recovering longer-period transiting exoplanets from single-transit events

    Polymerase II Promoter Strength Determines Efficacy of microRNA Adapted shRNAs

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    Since the discovery of RNAi and microRNAs more than 10 years ago, much research has focused on the development of systems that usurp microRNA pathways to downregulate gene expression in mammalian cells. One of these systems makes use of endogenous microRNA pri-cursors that are expressed from polymerase II promoters where the mature microRNA sequence is replaced by gene specific duplexes that guide RNAi (shRNA-miRs). Although shRNA-miRs are effective in directing target mRNA knockdown and hence reducing protein expression in many cell types, variability of RNAi efficacy in cell lines has been an issue. Here we show that the choice of the polymerase II promoter used to drive shRNA expression is of critical importance to allow effective mRNA target knockdown. We tested the abundance of shRNA-miRs expressed from five different polymerase II promoters in 6 human cell lines and measured their ability to drive target knockdown. We observed a clear positive correlation between promoter strength, siRNA expression levels, and protein target knockdown. Differences in RNAi from the shRNA-miRs expressed from the various promoters were particularly pronounced in immune cells. Our findings have direct implications for the design of shRNA-directed RNAi experiments and the preferred RNAi system to use for each cell type

    Surgical management of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb

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    Dural arteriovenous fistulas located in the vicinity of the jugular foramen are complex vascular malformations and belong to the most challenging skull base lesions to treat. The authors comprehensively analyze multiple features in a series of dural arteriovenous fistulas with transosseous arterial feeders involving the jugular bulb. Four patients who underwent surgery via the transcondylar approach to treat dural arteriovenous fistulas around the jugular foramen were retrospectively reviewed. Previously, endovascular treatment was attempted in all patients. The success of the surgical treatment was examined with postoperative angiography. Complete obliteration of the dural arteriovenous fistulas (DAVFs) was achieved in three patients, and significant flow reduction in one individual. All patients had a good postoperative outcome, and only one experienced mild hypoglossal nerve palsy. Despite extensive bone drilling, an occipitocervical fusion was necessary in only one patient with bilateral lesions. The use of an individually tailored transcondylar approach to treat dural arteriovenous fistulas at the region of the jugular foramen is most effective. This approach allows for complete obliteration of the connecting arterial feeders, and removal of bony structures containing pathological vessels
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