122 research outputs found

    Non-Destructive Testing of Magnetically Impelled Arc Butt Welding of Mild Steel Tubes

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    This paper presents the results of Non-Destructive Testing on Magnetically Impelled Arc Butt (MIAB) welded mild steel tubes of 27mm OD and 1.5mm thickness. As part of this work, the tests covered were radiography, liquid penetrant, and magnetic particle testing. The testing results indicate that porosity, penetration levels and the defects found are within acceptable limits as per standard. For this experimental work, the selection of parameters was based on trial and error adopted in preliminary trials. The irregularities found in the non-destructive testing samples have enabled the fine-tuning of process parameters. The optimum values of hydraulic pressure, weld time and weld current are assessed to be 30-35bar, 5.5s and 150 A, respectively 270 A for this dimension of tubes. This work focuses on the experimental observations of MIAB welding and Non-destructive testing results for MS tubes of the selected dimension, which have not been reported in the existing literature. The achieved input forms the database for the parametric study of this process. The optimum parametric ranges obtained from the results can be extrapolated to be used for joining tubes of different dimensions and can also form the inputs for reaching parameter and response dependency equations

    Different Dystrophin-like Complexes Are Expressed in Neurons and Glia

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    Duchenne muscular dystrophy is a fatal muscle disease that is often associated with cognitive impairment. Accordingly, dystrophin is found at the muscle sarcolemma and at postsynaptic sites in neurons. In muscle, dystrophin forms part of a membrane-spanning complex, the dystrophin-associated protein complex (DPC). Whereas the composition of the DPC in muscle is well documented, the existence of a similar complex in brain remains largely unknown. To determine the composition of DPC-like complexes in brain, we have examined the molecular associations and distribution of the dystrobrevins, a widely expressed family of dystrophin-associated proteins, some of which are components of the muscle DPC. β-Dystrobrevin is found in neurons and is highly enriched in postsynaptic densities (PSDs). Furthermore, β-dystrobrevin forms a specific complex with dystrophin and syntrophin. By contrast, α-dystrobrevin-1 is found in perivascular astrocytes and Bergmann glia, and is not PSD-enriched. α-Dystrobrevin-1 is associated with Dp71, utrophin, and syntrophin. In the brains of mice that lack dystrophin and Dp71, the dystrobrevin–syntrophin complexes are still formed, whereas in dystrophin-deficient muscle, the assembly of the DPC is disrupted. Thus, despite the similarity in primary sequence, α- and β-dystrobrevin are differentially distributed in the brain where they form separate DPC-like complexes

    Absence of α-Syntrophin Leads to Structurally Aberrant Neuromuscular Synapses Deficient in Utrophin

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    The syntrophins are a family of structurally related proteins that contain multiple protein interaction motifs. Syntrophins associate directly with dystrophin, the product of the Duchenne muscular dystrophy locus, and its homologues. We have generated α-syntrophin null mice by targeted gene disruption to test the function of this association. The α-Syn−/− mice show no evidence of myopathy, despite reduced levels of α-dystrobrevin–2. Neuronal nitric oxide synthase, a component of the dystrophin protein complex, is absent from the sarcolemma of the α-Syn−/− mice, even where other syntrophin isoforms are present. α-Syn−/− neuromuscular junctions have undetectable levels of postsynaptic utrophin and reduced levels of acetylcholine receptor and acetylcholinesterase. The mutant junctions have shallow nerve gutters, abnormal distributions of acetylcholine receptors, and postjunctional folds that are generally less organized and have fewer openings to the synaptic cleft than controls. Thus, α-syntrophin has an important role in synapse formation and in the organization of utrophin, acetylcholine receptor, and acetylcholinesterase at the neuromuscular synapse

    Yes-Associated Protein 65 Localizes P62c-Yes to the Apical Compartment of Airway Epithelia by Association with Ebp50

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    We recently showed that the COOH terminus of the cystic fibrosis transmembrane conductance regulator associates with the submembranous scaffolding protein EBP50 (ERM-binding phosphoprotein 50 kD; also called Na+/H+ exchanger regulatory factor). Since EBP50 associates with ezrin, this interaction links the cystic fibrosis transmembrane conductance regulator (CFTR) to the cortical actin cytoskeleton. EBP50 has two PDZ domains, and CFTR binds with high affinity to the first PDZ domain. Here, we report that Yes-associated protein 65 (YAP65) binds with high affinity to the second EBP50 PDZ domain. YAP65 is concentrated at the apical membrane in airway epithelia and interacts with EBP50 in cells. The COOH terminus of YAP65 is necessary and sufficient to mediate association with EBP50. The EBP50–YAP65 interaction is involved in the compartmentalization of YAP65 at the apical membrane since mutant YAP65 proteins lacking the EBP50 interaction motif are mislocalized when expressed in airway epithelial cells. In addition, we show that the nonreceptor tyrosine kinase c-Yes is contained within EBP50 protein complexes by association with YAP65. Subapical EBP50 protein complexes, containing the nonreceptor tyrosine kinase c-Yes, may regulate apical signal transduction pathways leading to changes in ion transport, cytoskeletal organization, or gene expression in epithelial cells

    Użycie FPGA i Java do szybkiego prototypowania dekodera H.264/AVC działającego w czasie rzeczywistym

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    This paper reports on an attempt to implement a real-time hardware H.264 video decoder. The initial results of the project are presented: a customized RISC core and some digital modules, both of which have been implemented in Xilinx FPGA. The former has to serve as a host processor that supervises the latter, which speed up the essential decoding subtasks. The system is designed and tested using a software decoder and diagnostic tools, which are implemented in Java using the object-oriented paradigm. Our experiences allow us to recommend the combination of FPGA and Java technologies as a good basis for rapid prototyping of advanced DSP algorithms.W pracy przedstawiono raport z próby implementacji działającego w czasie rzeczywistym sprzętowego dekodera wideo standardu H.264. Zaprezentowano wstępne wyniki projektu: jądro RISC i wybrane moduły cyfrowe zaimplementowane z użyciem Xilinx FPGA. Jądro ma służyć jako nadrzędny procesor sterujący pozostałymi obwodami dekodera, które przyśpieszają podstawowe etapy dekodowania. System jest projektowany i testowany w oparciu o dekoder programowy i narzędzia diagnostyczne, które są implementowane obiektowo w Javie. Uzyskane rezultaty pozwalają autorom rekomendować połączenie FPGA i Java jako dobrą podstawę do szybkiego prototypowania zaawansowanych algorytmów DSP
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