1,186 research outputs found

    Novel Compound Heterozygous Mutations Expand the Recognized Phenotypes of \u3cem\u3eFARS2\u3c/em\u3e-linked Disease

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    Mutations in mitochondrial aminoacyl-tRNA synthetases are an increasingly recognized cause of human diseases, often arising in individuals with compound heterozygous mutations and presenting with system-specific phenotypes, frequently neurologic. FARS2 encodes mitochondrial phenylalanyl transfer ribonucleic acid (RNA) synthetase (mtPheRS), perturbations of which have been reported in 6 cases of an infantile, lethal disease with refractory epilepsy and progressive myoclonus. Here the authors report the case of juvenile onset refractory epilepsy and progressive myoclonus with compound heterozygous FARS2 mutations. The authors describe the clinical course over 6 years of care at their institution and diagnostic studies including electroencephalogram (EEG), brain magnetic resonance imaging (MRI), serum and cerebrospinal fluid analyses, skeletal muscle biopsy histology, and autopsy gross and histologic findings, which include features shared with Alpers-Huttenlocher syndrome, Leigh syndrome, and a previously published case of FARS2 mutation associated infantile onset disease. The authors also present structure-guided analysis of the relevant mutations based on published mitochondrial phenylalanyl transfer RNA synthetase and related protein crystal structures as well as biochemical analysis of the corresponding recombinant mutant proteins

    HATS-5b: A Transiting hot-Saturn from the HATSouth Survey

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    We report the discovery of HATS-5b, a transiting hot-Saturn orbiting a G type star, by the HAT-South survey. HATS-5b has a mass of Mp=0.24 Mj, radius of Rp=0.91 Rj, and transits its host star with a period of P=4.7634d. The radius of HATS-5b is consistent with both theoretical and empirical models. The host star has a V band magnitude of 12.6, mass of 0.94 Msun, and radius of 0.87 Rsun. The relatively high scale height of HATS-5b, and the bright, photometrically quiet host star, make this planet a favourable target for future transmission spectroscopy follow-up observations. We reexamine the correlations in radius, equilibrium temperature, and metallicity of the close-in gas-giants, and find hot Jupiter-mass planets to exhibit the strongest dependence between radius and equilibrium temperature. We find no significant dependence in radius and metallicity for the close-in gas-giant population.Comment: 10 pages, submitted to A

    Seminal plasma as a source of prostate cancer peptide biomarker candidates for detection of indolent and advanced disease

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    Background:Extensive prostate specific antigen screening for prostate cancer generates a high number of unnecessary biopsies and over-treatment due to insufficient differentiation between indolent and aggressive tumours. We hypothesized that seminal plasma is a robust source of novel prostate cancer (PCa) biomarkers with the potential to improve primary diagnosis of and to distinguish advanced from indolent disease. <br>Methodology/Principal Findings: In an open-label case/control study 125 patients (70 PCa, 21 benign prostate hyperplasia, 25 chronic prostatitis, 9 healthy controls) were enrolled in 3 centres. Biomarker panels a) for PCa diagnosis (comparison of PCa patients versus benign controls) and b) for advanced disease (comparison of patients with post surgery Gleason score <7 versus Gleason score >>7) were sought. Independent cohorts were used for proteomic biomarker discovery and testing the performance of the identified biomarker profiles. Seminal plasma was profiled using capillary electrophoresis mass spectrometry. Pre-analytical stability and analytical precision of the proteome analysis were determined. Support vector machine learning was used for classification. Stepwise application of two biomarker signatures with 21 and 5 biomarkers provided 83% sensitivity and 67% specificity for PCa detection in a test set of samples. A panel of 11 biomarkers for advanced disease discriminated between patients with Gleason score 7 and organ-confined (<pT3a) or advanced (≥pT3a) disease with 80% sensitivity and 82% specificity in a preliminary validation setting. Seminal profiles showed excellent pre-analytical stability. Eight biomarkers were identified as fragments of N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase​,prostatic acid phosphatase, stabilin-2, GTPase IMAP family member 6, semenogelin-1 and -2. Restricted sample size was the major limitation of the study.</br> <br>Conclusions/Significance: Seminal plasma represents a robust source of potential peptide makers for primary PCa diagnosis. Our findings warrant further prospective validation to confirm the diagnostic potential of identified seminal biomarker candidates.</br&gt

    Flux front penetration in disordered superconductors

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    We investigate flux front penetration in a disordered type II superconductor by molecular dynamics (MD) simulations of interacting vortices and find scaling laws for the front position and the density profile. The scaling can be understood performing a coarse graining of the system and writing a disordered non-linear diffusion equation. Integrating numerically the equation, we observe a crossover from flat to fractal front penetration as the system parameters are varied. The value of the fractal dimension indicates that the invasion process is described by gradient percolation.Comment: 5 pages, 4 figures, to appear in Phys. Rev. Let

    HATS-1b: The First Transiting Planet Discovered by the HATSouth Survey

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    We report the discovery of HATS-1b, a transiting extrasolar planet orbiting the moderately bright V=12.05 G dwarf star GSC 6652-00186, and the first planet discovered by HATSouth, a global network of autonomous wide-field telescopes. HATS-1b has a period P~3.4465 d, mass Mp~1.86MJ, and radius Rp~1.30RJ. The host star has a mass of 0.99Msun, and radius of 1.04Rsun. The discovery light curve of HATS-1b has near continuous coverage over several multi-day periods, demonstrating the power of using a global network of telescopes to discover transiting planets.Comment: Submitted to AJ 10 pages, 5 figures, 6 table

    RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord

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    ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients

    The EFF-1A Cytoplasmic Domain Influences Hypodermal Cell Fusions in C. elegans But Is Not Dependent on 14-3-3 Proteins.

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    BACKGROUND: Regulatory and biophysical mechanisms of cell-cell fusion are largely unknown despite the fundamental requirement for fused cells in eukaryotic development. Only two cellular fusogens that are not of clear recent viral origin have been identified to date, both in nematodes. One of these, EFF-1, is necessary for most cell fusions in Caenorhabditis elegans. Unregulated EFF-1 expression causes lethality due to ectopic fusion between cells not developmentally programmed to fuse, highlighting the necessity of tight fusogen regulation for proper development. Identifying factors that regulate EFF-1 and its paralog AFF-1 could lead to discovery of molecular mechanisms that control cell fusion upstream of the action of a membrane fusogen. Bioinformatic analysis of the EFF-1A isoform\u27s predicted cytoplasmic domain (endodomain) previously revealed two motifs that have high probabilities of interacting with 14-3-3 proteins when phosphorylated. Mutation of predicted phosphorylation sites within these motifs caused measurable loss of eff-1 gene function in cell fusion in vivo. Moreover, a human 14-3-3 isoform bound to EFF-1::GFP in vitro. We hypothesized that the two 14-3-3 proteins in C. elegans, PAR-5 and FTT-2, may regulate either localization or fusion-inducing activity of EFF-1. METHODOLOGY/PRINCIPAL FINDINGS: Timing of fusion events was slightly but significantly delayed in animals unable to produce full-length EFF-1A. Yet, mutagenesis and live imaging showed that phosphoserines in putative 14-3-3 binding sites are not essential for EFF-1::GFP accumulation at the membrane contact between fusion partner cells. Moreover, although the EFF-1A endodomain was required for normal rates of eff-1-dependent epidermal cell fusions, reduced levels of FTT-2 and PAR-5 did not visibly affect the function of wild-type EFF-1 in the hypodermis. CONCLUSIONS/SIGNIFICANCE: Deletion of the EFF-1A endodomain noticeably affects the timing of hypodermal cell fusions in vivo. However, prohibiting phosphorylation of candidate 14-3-3-binding sites does not impact localization of the fusogen. Hypodermal membrane fusion activity persists when 14-3-3 expression levels are reduced

    Finite-volume matrix Hamiltonian model for a Delta - NPi system

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    A matrix Hamiltonian model is developed to address the finite-volume effects appearing in studies of baryon resonances in lattice QCD. The Hamiltonian model includes interaction terms in a transparent way and can be readily generalized to address multichannel problems. The eigenvalue equation of the model is exactly solvable and can be matched onto chiral effective field theory. The model is investigated in the case of Δ→Nπ scattering. A robust method for determining the resonance parameters from lattice QCD is developed. It involves constraining the free parameters of the model based on the lattice spectrum in question. The method is tested in the context of a set of pseudodata, and a picture of the model dependence is obtained by examining a variety of regularization schemes in the model. A comparison is made with the LĂŒscher method, and it is found that the matrix Hamiltonian method is equally robust. Both methods are tested in a more realistic scenario, where a background interaction corresponding to direct Nπ↔Nπ scattering is incorporated into the pseudodata. The resulting extraction of the resonance parameters associated with the Δ baryon resonance provides evidence that an effective field theory style of approach yields a successful realization of finite-volume effects in the context of baryon resonances.J. M. M. Hall, A. C.-P. Hsu, D. B. Leinweber, A.W. Thomas, and R. D. Youn

    Talk to the Virtual Hands: Self-Animated Avatars Improve Communication in Head-Mounted Display Virtual Environments

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    Background When we talk to one another face-to-face, body gestures accompany our speech. Motion tracking technology enables us to include body gestures in avatar-mediated communication, by mapping one's movements onto one's own 3D avatar in real time, so the avatar is self-animated. We conducted two experiments to investigate (a) whether head-mounted display virtual reality is useful for researching the influence of body gestures in communication; and (b) whether body gestures are used to help in communicating the meaning of a word. Participants worked in pairs and played a communication game, where one person had to describe the meanings of words to the other. Principal Findings In experiment 1, participants used significantly more hand gestures and successfully described significantly more words when nonverbal communication was available to both participants (i.e. both describing and guessing avatars were self-animated, compared with both avatars in a static neutral pose). Participants ‘passed’ (gave up describing) significantly more words when they were talking to a static avatar (no nonverbal feedback available). In experiment 2, participants' performance was significantly worse when they were talking to an avatar with a prerecorded listening animation, compared with an avatar animated by their partners' real movements. In both experiments participants used significantly more hand gestures when they played the game in the real world. Conclusions Taken together, the studies show how (a) virtual reality can be used to systematically study the influence of body gestures; (b) it is important that nonverbal communication is bidirectional (real nonverbal feedback in addition to nonverbal communication from the describing participant); and (c) there are differences in the amount of body gestures that participants use with and without the head-mounted display, and we discuss possible explanations for this and ideas for future investigation
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