Characterisation of Novel Genetic Variants of Amyotrophic Lateral Sclerosis

Background: Amyotrophic lateral sclerosis (ALS) is an invariably fatal and relatively common neurodegenerative disorder without effective therapy. Identified genetic variants cluster in biological pathways including RNA processing, axonal transport, and protein homeostasis. Discovery of new genetic variants within new biological pathways highlights new disease biology, and can lead to novel therapeutic targets. This project will focus on the development of cell and animal models to characterise novel ALS-associated mutations associated with GLT8D1, CAV1 and CAV2. Aims and objectives: i) To evaluate the relative toxicity of ALS-associated GLT8D1 mutations in neuronal and non-neuronal cell lines via MTT and lactate dehydrogenase assays. ii) To investigate the effect of mutations on the enzyme activity of GLT8D1 using a UDP-Glo glycosyltransferase assay. iii) To test whether mutant GLT8D1 causes fragmentation of the Golgi network using immunocytochemistry. iv) To model GLT8D1 mutations in zebrafish larvae via RNA microinjection. v) To model CAV1/CAV2 enhancer mutations in neuronal and non-neuronal cells via CRISPR/Cas9 genome editing. vi) To measure ganglioside expression in human cells expressing GLT8D1, CAV1 and CAV2 mutations using live cell imaging. Results: I studied in detail two ALS-associated GLT8D1 mutations: R92C and G78W. The relative toxicity of the mutations in model systems mirrors the clinical severity. Mutated GLT8D1 exhibits in vitro cytotoxicity and induces motor deficits in zebrafish larvae consistent with ALS. Identified GLT8D1 mutations are proximal to the substrate-binding site; both R92C and G78W mutations impair GLT8D1 enzyme activity. An R92C mutation reduces membrane ganglioside expression, which is indicative of dysregulated neurotrophic signalling. Ganglioside biosynthesis occurs in the Golgi; GLT8D1 localises to the Golgi in neuronal and non-neuronal cells, and preliminary data suggests an R92C mutation causes Golgi fragmentation. The second stage of this project follows the identification of ALS-associated variation within an enhancer linked to expression of CAV1/CAV2. CAV1 and CAV2 encode major components of caveolae, which organise membrane lipid rafts (MLR) important for neurotrophic signalling. Gangliosides are a key component of MLR. Discovered enhancer mutations reduce CAV1/CAV2 expression and disrupt ganglioside expression within MLR in patient-derived cells; and CRISPR/Cas9 perturbation proximate to a patient-mutation is sufficient to reduce CAV1/CAV2 expression in neurons. Conclusions: These results place dysregulated ganglioside metabolism upstream in the pathogenesis of ALS. I propose that GLT8D1 and CAV1/CAV2 share a common pathway of pathogenesis in ALS via disruption of ganglioside recruitment to MLR and impaired neurotrophic signalling

Comorbidity of Arithmetic and Reading Disorder: Basic Number Processing and Calculation in Children With Learning Impairments

The aim of the present study was to investigate the cognitive profiles of primary school children (age 82-133 months) on a battery of basic number processing and calculation tasks. The sample consisted of four groups matched for age and IQ: arithmetic disorder only (AD;n = 20), reading disorder only (RD;n = 40), a comorbid group (n = 27), and an unimpaired control group (n = 40). Multiple 2 (RD vs. No RD) x 2 (AD vs. No AD) factorial ANCOVAs showed that children with RD had selective impairments in counting and number transcoding efficiency. In contrast, children with AD performed poorly in most tasks, including symbolic and nonsymbolic magnitude comparisons, subitizing, number line estimation, number sets, number transcoding accuracy, and calculation. These findings provide further support that AD is characterized by multiple, heterogeneous underlying deficits. In contrast, RD is associated with specific number processing impairments only if tasks require verbal processing. Taken together, the results fully support the assumption of comorbid additivity of AD and RD

Autoregulation of mazEF expression underlies growth heterogeneity in bacterial populations

The MazF toxin sequence-specifically cleaves single-stranded RNA upon various stressful conditions, and it is activated as a part of the mazEF toxin–antitoxin module in Escherichia coli. Although autoregulation of mazEF expression through the MazE antitoxin-dependent transcriptional repression has been biochemically characterized, less is known about post-transcriptional autoregulation, as well as how both of these autoregulatory features affect growth of single cells during conditions that promote MazF production. Here, we demonstrate post-transcriptional autoregulation of mazF expression dynamics by MazF cleaving its own transcript. Single-cell analyses of bacterial populations during ectopic MazF production indicated that two-level autoregulation of mazEF expression influences cell-to-cell growth rate heterogeneity. The increase in growth rate heterogeneity is governed by the MazE antitoxin, and tuned by the MazF-dependent mazF mRNA cleavage. Also, both autoregulatory features grant rapid exit from the stress caused by mazF overexpression. Time-lapse microscopy revealed that MazF-mediated cleavage of mazF mRNA leads to increased temporal variability in length of individual cells during ectopic mazF overexpression, as explained by a stochastic model indicating that mazEF mRNA cleavage underlies temporal fluctuations in MazF levels during stress

Inducing superconductivity in Weyl semimetal microstructures by selective ion sputtering

Work by N.N. and J.G.A. is partly supported by the Office of Naval Research under the Electrical Sensors and Network Research Division, Award No. N00014-15-1-2674, and by the Gordon and Betty Moore Foundation’s EPiQS Initiative through Grant GBMF4374. M.D.B. and P.J.W.M. acknowledge funding through the Max Planck Society. M.D.B. acknowledges studentship funding from the EPSRC under grant no. EP/I007002/1. N.N. is supported by the NSF Graduate Research Fellowship Program under grant no. DGE 1106400. F.F. acknowledges support from a Lindemann Trust Fellowship of the English Speaking Union. R.I. is funded by the Air Force Office of Scientific Research Multidisciplinary University Research Initiative. T.M. is funded by Deutsche Forschungsgemeinschaft through GRK 1621 and SFB 1143. N.J.G. and E.D.B. were supported under the auspices of the U.S. Department of Energy, Office of Science. F.R. was supported by the Los Alamos National Laboratory Laboratory Directed Research and Development program. Data underpinning this publication can be accessed at http://dx.doi.org/10.17630/04280577-35c4-44e7-97d2-5c827ace7a4e.By introducing a superconducting gap in Weyl or Dirac semimetals, the superconducting state inherits the nontrivial topology of their electronic structure. As a result, Weyl superconductors are expected to host exotic phenomena, such as nonzero-momentum pairing due to their chiral node structure, or zero-energy Majorana modes at the surface. These are of fundamental interest to improve our understanding of correlated topological systems, and, moreover, practical applications in phase-coherent devices and quantum applications have been proposed. Proximity-induced superconductivity promises to allow these experiments on nonsuperconducting Weyl semimetals. We show a new route to reliably fabricate superconducting microstructures from the nonsuperconducting Weyl semimetal NbAs under ion irradiation. The significant difference in the surface binding energy of Nb and As leads to a natural enrichment of Nb at the surface during ion milling, forming a superconducting surface layer (Tc ~ 3.5 K). Being formed from the target crystal itself, the ideal contact between the superconductor and the bulk may enable an effective gapping of the Weyl nodes in the bulk because of the proximity effect. Simple ion irradiation may thus serve as a powerful tool for the fabrication of topological quantum devices from monoarsenides, even on an industrial scale.Publisher PDFPeer reviewe

Организационная культура в контексте социолого-управленческого подхода: новые аспекты феномена

Рассматриваются особенности нового социолого-управленческого подхода, обосновывается, что он является комплексным, сочетающим системный, деятельностный и феноменологический подходы. Возможность сочетания в одном подходе трех других базируется на полипарадигмальности социологии. Методы. Основу исследования составляют фундаментальные идеи социологии, сравнительный анализ, междисциплинарный подход. Результаты. Организационная культура анализируется с позиции социолого-управленческого подхода. Он позволяет рассматривать организационную культуру как объективно-субъективное образование в единстве трех составляющих. На основе первой составляющей, базирующейся на системном подходе, культура организации рассматривается как сложная система. На основании второй составляющей, базирующейся на деятельностления», как способ деятельности организации. Третья составляющая, базирующаяся на феноменологическом подходе, позволяет говорить о культуре организации как о культурном поле конструирования социальной реальности. Будучи системной, культура организации имеет ряд особенных свойств. Подход к организационной культуре как «субъекту управления» позволяет выявить такие ее особенности, как способность регулировать действия индивидов, упорядочивание организационных социальных процессов, придание смысла существования, объединение индивидов в общие социокультурные пространства, участие в преобразованиях и вещей, и человека. В пределах культуры организации осуществляется постоянное конструирование социальной реальности. В результате организации предстают как системы, в которых коллективные действия сознательно координируются. Социолого-управленческий подход получил эмпирическую проверку в процессе исследования организационной культуры организаций малого бизнеса.The author considers the features of the new sociologic-management approach and justifies that it is integrated, combining system, activity and phenomenological approaches. The possibility of combining three other approaches in one is based on polyparadigmality of sociology. Methods. Fundamental sociological ideas, comparative analysis, interdisciplinary approach are foundation of the research. The results. The sociological and managerial approach is applied to such a phenomenon of social reality as an organizational culture. The sociological and managerial approach focuses on the fact that organizational culture as an objectively-subjective entity is a complex system (a systematic approach), first of all, included in higher-level systems. It has a complex system structure. Secondly, it is a «subject of management» and it characterizes the way the organization works (activity approach). Thirdly, it is a cultural area for construction of social reality (a phenomenological approach). As a complex system, the organization culture has a complex internal structure and is characterized by a number of essential properties. Organizational culture as a «subject of management » regulates the actions of people, social processes in the organization, gives meaning orientation through ensuring the continuity of social experience, socialization, integration of people into unified sociocultural continuums, the common cultural area, participates in the transformation of human beings. As a result, organizations appear as systems in which collective actions are consciously coordinated. The sociological and managerial approach has been empirically tested in investigation of the organizational culture of small business organizations

International time transfer between precise timing facilities secured with a quantum key distribution network

Global Navigation Satellite Systems (GNSSs), such as GPS and Galileo, provide precise time and space coordinates globally and constitute part of the critical infrastructure of modern society. To reliably operate GNSS, a highly accurate and stable system time is required, such as the one provided by several independent clocks hosted in Precise Timing Facilities (PTFs) around the world. Periodically, the relative clock offset between PTFs is measured to have a fallback system to synchronize the GNSS satellite clocks. The security and integrity of the communication between PTFs is of paramount importance: if compromised, it could lead to disruptions to the GNSS service. Therefore, it is a compelling use-case for protection via Quantum Key Distribution (QKD), since this technology provides information-theoretic security. We have performed a field trial demonstration of such use-case by sharing encrypted time synchronization information between two PTFs, one located in Oberpfaffenhofen (Germany) and one in Matera (Italy) - more than 900km apart as the crow flies. To bridge this large distance, a satellite-QKD system is required, plus a "last-mile" terrestrial link to connect the optical ground station (OGS) to the actual location of the PTF. In our demonstration we have deployed two full QKD systems to protect the last-mile connection at both the locations and have shown via simulation that upcoming QKD satellites will be able to distribute keys between Oberpfaffenhofen and Matera exploiting already existing OGSs

Pathogen- and Host-Directed Antileishmanial Effects Mediated by Polyhexanide (PHMB)

BACKGROUND:Cutaneous leishmaniasis (CL) is a neglected tropical disease caused by protozoan parasites of the genus Leishmania. CL causes enormous suffering in many countries worldwide. There is no licensed vaccine against CL, and the chemotherapy options show limited efficacy and high toxicity. Localization of the parasites inside host cells is a barrier to most standard chemo- and immune-based interventions. Hence, novel drugs, which are safe, effective and readily accessible to third-world countries and/or drug delivery technologies for effective CL treatments are desperately needed. METHODOLOGY/PRINCIPAL FINDINGS:Here we evaluated the antileishmanial properties and delivery potential of polyhexamethylene biguanide (PHMB; polyhexanide), a widely used antimicrobial and wound antiseptic, in the Leishmania model. PHMB showed an inherent antileishmanial activity at submicromolar concentrations. Our data revealed that PHMB kills Leishmania major (L. major) via a dual mechanism involving disruption of membrane integrity and selective chromosome condensation and damage. PHMB's DNA binding and host cell entry properties were further exploited to improve the delivery and immunomodulatory activities of unmethylated cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODN). PHMB spontaneously bound CpG ODN, forming stable nanopolyplexes that enhanced uptake of CpG ODN, potentiated antimicrobial killing and reduced host cell toxicity of PHMB. CONCLUSIONS:Given its low cost and long history of safe topical use, PHMB holds promise as a drug for CL therapy and delivery vehicle for nucleic acid immunomodulators