347 research outputs found

    Novel POLG variants associated with late-onset de novo status epilepticus and progressive ataxia

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    Mitochondrial disease is phenotypically and genetically heterogeneous with an estimated prevalence of 1 in 4,300.1 Mutations in the POLG gene, encoding the catalytic subunit of DNA polymerase gamma, are an important cause of mitochondrial disease. The spectrum of clinical manifestations in POLG-related mitochondrial disease is variable,2 with disease onset ranging from adulthood-onset dominant or recessive progressive external ophthalmoplegia (chronic progressive external ophthalmoplegia), ataxia-neuropathy spectrum, myoclonic epilepsy, myopathy, and sensory ataxia to childhood-onset Alpers syndrome, which is characterized by intractable seizures, psychomotor regression, and hepatic impairment. Epilepsy is a poor prognostic factor in POLG mutations,3 and the onset of epilepsy often clusters in childhood (<5 years) and teenage.4 However, late-onset epileptic encephalopathy is uncommon.4,5 Herein, we describe a patient who died of de novo, late-onset refractory status epilepticus with the identification of 2 novel variants in the POLG gene

    SLIP4EX- a program for routine slope stability analysis to include the effects of vegetation, reinforcement and hydrological changes

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    SLIP4EX is a straightforward computer program developed in connection with the EU funded ECOSLOPES project for routine stability analysis and the assessment of the contribution of vegetation to slope stability. The slope section is drawn up and dimensions and parameters are fed in to the Microsoft Excel based program for stability calculations and comparisons of Factors of Safety using different methods of analysis (Bishop, Janbu, Fellenius, Simple, Greenwood). The background and assumptions involved in the derivation of each of the methods is briefly described. The simplicity of the program enables the user to understand the nature of the analysis, explore the parameter assumptions made and compare the different methods of analysis. Soil reinforcement by geosynthetic layers or anchors, and vegetation effects of enhanced cohesion, changed water pressures, mass of vegetation, wind forces and root reinforcement forces are readily included in the analysis. The program is freely available on request from the author

    Earthshine observation of vegetation and implication for life detection on other planets - A review of 2001 - 2006 works

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    The detection of exolife is one of the goals of very ambitious future space missions that aim to take direct images of Earth-like planets. While associations of simple molecules present in the planet's atmosphere (O2O_2, O3O_3, CO2CO_2 etc.) have been identified as possible global biomarkers, we review here the detectability of a signature of life from the planet's surface, i.e. the green vegetation. The vegetation reflectance has indeed a specific spectrum, with a sharp edge around 700 nm, known as the "Vegetation Red Edge" (VRE). Moreover vegetation covers a large surface of emerged lands, from tropical evergreen forest to shrub tundra. Thus considering it as a potential global biomarker is relevant. Earthshine allows to observe the Earth as a distant planet, i.e. without spatial resolution. Since 2001, Earthshine observations have been used by several authors to test and quantify the detectability of the VRE in the Earth spectrum. The egetation spectral signature is detected as a small 'positive shift' of a few percents above the continuum, starting at 700 nm. This signature appears in most spectra, and its strength is correlated with the Earth's phase (visible land versus visible ocean). The observations show that detecting the VRE on Earth requires a photometric relative accuracy of 1% or better. Detecting something equivalent on an Earth-like planet will therefore remain challenging, moreover considering the possibility of mineral artifacts and the question of 'red edge' universality in the Universe.Comment: Invited talk in "Strategies for Life Detection" (ISSI Bern, 24-28 April 2006) to appear in a hardcopy volume of the ISSI Space Science Series, Eds, J. Bada et al., and also in an issue of Space Science Reviews. 13 pages, 8 figures, 1 tabl

    Mitochondrial DNA deletions and depletion within paraspinal muscles

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    AIMS: Although mitochondrial abnormalities have been reported within paraspinal muscles in patients with axial weakness and neuromuscular disease as well as with ageing, the basis of respiratory deficiency in paraspinal muscles is not known. This study aimed to determine the extent and basis of respiratory deficiency in paraspinal muscles from cases undergoing surgery for degenerative spinal disease and post mortem cases without a history of spinal disease, where age-related histopathological changes were previously reported. METHODS: Cervical and lumbar paraspinal muscles were obtained peri-operatively from 13 patients and from six post mortem control cases (age range 18–82 years) without a neurological disease. Sequential COX/SDH (mitochondrial respiratory chain complex IV/complex II) histochemistry was performed to identify respiratory-deficient muscle fibres (lacking complex IV with intact complex II activity). Real-time polymerase chain reaction, long-range polymerase chain reaction and sequencing were used to identify and characterize mitochondrial DNA (mtDNA) deletions and determine mtDNA copy number status. Mitochondrial respiratory chain complex subunits were detected by immunohistochemistry. RESULTS: The density of respiratory-deficient fibres increased with age. On average, 3.96% of fibres in paraspinal muscles were respiratory-deficient (range 0–10.26). Respiratory deficiency in 36.8% of paraspinal muscle fibres was due to clonally expanded mtDNA deletions. MtDNA depletion accounted for further 13.5% of respiratory deficiency. The profile of immunohistochemically detected subunits of complexes was similar in respiratory-deficient fibres with and without mtDNA deletions or mtDNA depletion. CONCLUSIONS: Paraspinal muscles appeared to be particularly susceptible to age-related mitochondrial respiratory chain defects. Clonally expanded mtDNA deletions and focal mtDNA depletion may contribute towards the development of age-related postural abnormalities

    Interventions for promoting physical activity in people with neuromuscular disease

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    BACKGROUND: The World Health Organization (WHO) recommends that people of all ages take regular and adequate physical activity. If unable to meet the recommendations due to health conditions, international guidance advises being as physically active as possible. Evidence from community interventions of physical activity indicate that people living with medical conditions are sometimes excluded from participation in studies. In this review, we considered the effects of activity-promoting interventions on physical activity and well-being in studies, as well as any adverse events experienced by participants living with inherited or acquired neuromuscular diseases (NMDs).  OBJECTIVES: To assess the effects of interventions designed to promote physical activity in people with NMD compared with no intervention or alternative interventions. SEARCH METHODS: On 30 April 2020, we searched Cochrane Neuromuscular Specialised Register, CENTRAL, Embase, MEDLINE, and ClinicalTrials.Gov. WHO ICTRP was not accessible at the time. SELECTION CRITERIA: We considered randomised or quasi-randomised trials, including cross-over trials, of interventions designed to promote physical activity in people with NMD compared to no intervention or alternative interventions. We specifically included studies that reported physical activity as an outcome measure. Our main focus was studies in which promoting physical activity was a stated aim but we also included studies in which physical activity was assessed as a secondary or exploratory outcome. DATA COLLECTION AND ANALYSIS: We used standard Cochrane procedures. MAIN RESULTS: The review included 13 studies (795 randomised participants from 12 studies; number of participants unclear in one study) of different interventions to promote physical activity. Most studies randomised a minority of invited participants. No study involved children or adolescents and nine studies reported minimal entry criteria for walking. Participants had one of nine inherited or acquired NMDs. Types of intervention included structured physical activity support, exercise support (as a specific form of physical activity), and behaviour change support that included physical activity or exercise. Only one included study clearly reported that the aim of intervention was to increase physical activity. Other studies reported or planned to analyse the effects of intervention on physical activity as a secondary or exploratory outcome measure. Six studies did not report results for physical activity outcomes, or the data were not usable. We judged 10 of the 13 included studies at high or unclear risk of bias from incomplete physical activity outcome reporting. We did not perform a meta-analysis for any comparison because of differences in interventions and in usual care. We also found considerable variation in how studies reported physical activity as an outcome measure. The studies that reported physical activity measurement did not always clearly report intention-to-treat (ITT) analysis or whether final assessments occurred during or after intervention. Based on prespecified measures, we included three comparisons in our summary of findings. A physical activity programme (weight-bearing) compared to no physical activity programme One study involved adults with diabetic peripheral neuropathy (DPN) and reported weekly duration of walking during and at the end of a one-year intervention using a StepWatch ankle accelerometer. Based on the point estimate and low-certainty evidence, intervention may have led to an important increase in physical activity per week; however, the 95% confidence interval (CI) included the possibility of no difference or an effect in either direction at three months (mean difference (MD) 34 minutes per week, 95% CI -92.19 to 160.19; 69 participants), six months (MD 68 minutes per week, 95% CI -55.35 to 191.35; 74 participants), and 12 months (MD 49 minutes per week, 95% CI -75.73 to 173.73; 70 participants). Study-reported effect estimates for foot lesions and full-thickness ulcers also included the possibility of no difference, a higher, or lower risk with intervention. A sensor-based, interactive exercise programme compared to no sensor-based, interactive exercise programme One study involved adults with DPN and reported duration of walking over 48 hours at the end of four weeks' intervention using a t-shirt embedded PAMSys sensor. It was not possible to draw conclusions about the effectiveness of the intervention from the very low-certainty evidence (MD -0.64 hours per 48 hours, 95% CI -2.42 to 1.13; 25 participants). We were also unable to draw conclusions about impact on the Physical Component Score (PCS) for quality of life (MD 0.24 points, 95% CI -5.98 to 6.46; 35 participants; very low-certainty evidence), although intervention may have made little or no difference to the Mental Component Score (MCS) for quality of life (MD 5.10 points, 95% CI -0.58 to 10.78; 35 participants; low-certainty evidence). A functional exercise programme compared to a stretching exercise programme One study involved adults with spinal and bulbar muscular atrophy and reported a daily physical activity count at the end of 12 weeks' intervention using an Actical accelerometer. It was not possible to draw conclusions about the effectiveness of either intervention (requiring compliance) due to low-certainty evidence and unconfirmed measurement units (MD -8701, 95% CI -38,293.30 to 20,891.30; 43 participants). Functional exercise may have made little or no difference to quality of life compared to stretching (PCS: MD -1.10 points, 95% CI -5.22 to 3.02; MCS: MD -1.10 points, 95% CI -6.79 to 4.59; 49 participants; low-certainty evidence). Although studies reported adverse events incompletely, we found no evidence of supported activity increasing the risk of serious adverse events. AUTHORS' CONCLUSIONS: We found a lack of evidence relating to children, adolescents, and non-ambulant people of any age. Many people living with NMD did not meet randomised controlled trial eligibility criteria. There was variation in the components of supported activity intervention and usual care, such as physical therapy provision. We identified variation among studies in how physical activity was monitored, analysed, and reported. We remain uncertain of the effectiveness of promotional intervention for physical activity and its impact on quality of life and adverse events. More information is needed on the ITT population, as well as more complete reporting of outcomes. While there may be no single objective measure of physical activity, the study of qualitative and dichotomous change in self-reported overall physical activity might offer a pragmatic approach to capturing important change at an individual and population level

    A hybrid organic–inorganic polariton LED

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    Polaritons are quasi-particles composed of a superposition of excitons and photons that can be created within a strongly coupled optical microcavity. Here, we describe a structure in which a strongly coupled microcavity containing an organic semiconductor is coupled to a second microcavity containing a series of weakly coupled inorganic quantum wells. We show that optical hybridisation occurs between the optical modes of the two cavities, creating a delocalised polaritonic state. By electrically injecting electron–hole pairs into the inorganic quantum-well system, we are able to transfer energy between the cavities and populate organic-exciton polaritons. Our approach represents a new strategy to create highly efficient devices for emerging ‘polaritonic’ technologies

    Consensus-based statements for the management of mitochondrial stroke-like episodes

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    Background: Focal-onset seizures and encephalopathy are prominent features of a stroke-like episode, which is a severe neurological manifestation associated with subtypes of mitochondrial disease. Despite more than 30 years of research, the acute treatment of stroke-like episodes remains controversial.Methods: We used the modified Delphi process to harness the clinical expertise of a group of mitochondrial disease specialists from five European countries to produce consensus guidance for the acute management of stroke-like episodes and commonly associated complications.Results: Consensus on a new definition of mitochondrial stroke-like episodes was achieved and enabled the group to develop diagnostic criteria based on clinical features, neuroimaging and/or electroencephalogram findings. Guidelines for the management of strokelike episodes were agreed with aggressive seizure management strongly recommended at the outset of stroke-like episodes.Conclusions: Our consensus statement defines stroke-like episodes in terms of an epileptic encephalopathy and we have used this to revise both diagnostic criteria and guidelines for management. A prospective, multi-centre, randomised controlled trial is required for evaluating the efficacy of any compound on modifying the trajectory of stroke-like episodes.</p

    Stress corrosion cracking in Al-Zn-Mg-Cu aluminum alloys in saline environments

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    Copyright 2013 ASM International. This paper was published in Metallurgical and Materials Transactions A, 44A(3), 1230 - 1253, and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.Stress corrosion cracking of Al-Zn-Mg-Cu (AA7xxx) aluminum alloys exposed to saline environments at temperatures ranging from 293 K to 353 K (20 °C to 80 °C) has been reviewed with particular attention to the influences of alloy composition and temper, and bulk and local environmental conditions. Stress corrosion crack (SCC) growth rates at room temperature for peak- and over-aged tempers in saline environments are minimized for Al-Zn-Mg-Cu alloys containing less than ~8 wt pct Zn when Zn/Mg ratios are ranging from 2 to 3, excess magnesium levels are less than 1 wt pct, and copper content is either less than ~0.2 wt pct or ranging from 1.3 to 2 wt pct. A minimum chloride ion concentration of ~0.01 M is required for crack growth rates to exceed those in distilled water, which insures that the local solution pH in crack-tip regions can be maintained at less than 4. Crack growth rates in saline solution without other additions gradually increase with bulk chloride ion concentrations up to around 0.6 M NaCl, whereas in solutions with sufficiently low dichromate (or chromate), inhibitor additions are insensitive to the bulk chloride concentration and are typically at least double those observed without the additions. DCB specimens, fatigue pre-cracked in air before immersion in a saline environment, show an initial period with no detectible crack growth, followed by crack growth at the distilled water rate, and then transition to a higher crack growth rate typical of region 2 crack growth in the saline environment. Time spent in each stage depends on the type of pre-crack (“pop-in” vs fatigue), applied stress intensity factor, alloy chemistry, bulk environment, and, if applied, the external polarization. Apparent activation energies (E a) for SCC growth in Al-Zn-Mg-Cu alloys exposed to 0.6 M NaCl over the temperatures ranging from 293 K to 353 K (20 °C to 80 °C) for under-, peak-, and over-aged low-copper-containing alloys (~0.8 wt pct), they are typically ranging from 20 to 40 kJ/mol for under- and peak-aged alloys, and based on limited data, around 85 kJ/mol for over-aged tempers. This means that crack propagation in saline environments is most likely to occur by a hydrogen-related process for low-copper-containing Al-Zn-Mg-Cu alloys in under-, peak- and over-aged tempers, and for high-copper alloys in under- and peak-aged tempers. For over-aged high-copper-containing alloys, cracking is most probably under anodic dissolution control. Future stress corrosion studies should focus on understanding the factors that control crack initiation, and insuring that the next generation of higher performance Al-Zn-Mg-Cu alloys has similar longer crack initiation times and crack propagation rates to those of the incumbent alloys in an over-aged condition where crack rates are less than 1 mm/month at a high stress intensity factor

    Distinctive features of orbital adipose tissue (OAT) in Graves’ Orbitopathy

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    Depot specific expansion of orbital-adipose-tissue (OAT) in Graves’ Orbitopathy (GO) is associated with lipid metabolism signaling defects. We hypothesize that the unique adipocyte biology of OAT facilitates its expansion in GO. A comprehensive comparison of OAT and white-adipose-tissue (WAT) was performed by light/electron-microscopy, lipidomic and transcriptional analysis using ex vivo WAT, healthy OAT (OAT-H) and OAT from GO (OAT-GO). OAT-H/OAT-GO have a single lipid-vacuole and low mitochondrial number. Lower lipolytic activity and smaller adipocytes of OAT-H/OAT-GO, accompanied by similar essential linoleic fatty acid (FA) and (low) FA synthesis to WAT, revealed a hyperplastic OAT expansion through external FA-uptake via abundant SLC27A6 (FA-transporter) expression. Mitochondrial dysfunction of OAT in GO was apparent, as evidenced by the increased mRNA expression of uncoupling protein 1 (UCP1) and mitofusin-2 (MFN2) in OAT-GO compared to OAT-H. Transcriptional profiles of OAT-H revealed high expression of Iroquois homeobox-family (IRX-3&5), and low expression in HOX-family/TBX5 (essential for WAT/BAT (brown-adipose-tissue)/BRITE (BRown-in-whITE) development). We demonstrated unique features of OAT not presented in either WAT or BAT/BRITE. This study reveals that the pathologically enhanced FA-uptake driven hyperplastic expansion of OAT in GO is associated with a depot specific mechanism (the SLC27A6 FA-transporter) and mitochondrial dysfunction. We uncovered that OAT functions as a distinctive fat depot, providing novel insights into adipocyte biology and the pathological development of OAT expansion in GO

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
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