Artykuły w czasopismach na temat „Localized embedded coding structures”
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Vergini, E., i D. A. Wisniacki. "Localized structures embedded in the eigenfunctions of chaotic Hamiltonian systems". Physical Review E 58, nr 5 (1.11.1998): R5225—R5228. http://dx.doi.org/10.1103/physreve.58.r5225.
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Goldberg, David Theo. "Coding Time". Critical Times 2, nr 3 (1.12.2019): 353–69. http://dx.doi.org/10.1215/26410478-7862517.
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Abstract This article analyzes the various ways algorithmic logic structures, streamlines, and delimits the conception of time and memory; orders the logics of social arrangement; and delimits the political. The author considers the ways in which algorithms extend racial discrimination, rendering it less visible, less discernible, and so more difficult to address. He briefly formulates a notion of crypto-value embedded within algorithmic self-conception and elaborates an algorithmic ontology. The latter is distinguished from the contemporary understanding of the post-human. The essay concludes with a reflection on a politics of street encounter as a counter to prevailing algorithmic constraints on the political. “Coding time” accordingly concerns the coding of time, the conception of time embedded in coding, the sociality and value that coding produces, and the implications for being and being human that the time of coding is manifesting.
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Collins, David J., Richard O’Rorke, Adrian Neild, Jongyoon Han i Ye Ai. "Acoustic fields and microfluidic patterning around embedded micro-structures subject to surface acoustic waves". Soft Matter 15, nr 43 (2019): 8691–705. http://dx.doi.org/10.1039/c9sm00946a.
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Interactions between substrate waves and microchannel walls generate spatially localized periodic acoustic forces for microscale patterning activities. We develop analytical models that can be readily applied to predict this periodicity.
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ABID, MALEK, BRUNO ANDREOTTI, STÉPHANE DOUADY i CAROLINE NORE. "Oscillating structures in a stretched–compressed vortex". Journal of Fluid Mechanics 450 (9.01.2002): 207–33. http://dx.doi.org/10.1017/s0022112001006449.
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The dynamics of a vortex subject to a localized stretching is numerically investigated. The structure of the flow is analysed in the case of an initially two-dimensional vortex surrounded by a periodic array of vortex rings localized far from its core. Amplified oscillations of both the axial vorticity and the stretching are found, in strong contrast with Burgers-like vortices. The resulting dynamics is the appearance, around the vortex, of successive vortical structures of smaller and smaller radius and alternate sign embedded in the previous vortical rings. The frequency scaling of the oscillations is recovered by linear analysis (Kelvin modes) but not the amplification nor the shape of the successive tori. An inviscid model based on structures is presented, which compares better with the numerical computations. These results suggest that the formalism of Kelvin waves is not sufficient to describe the full dynamics, which is instead related to the feedback of rotation on stretching and more conveniently described in terms of localized structures. We finally discuss the relative timescales of vortex stretching and of vortex reaction. The Burgers-like vortices, where there is no such reaction, turn out to correspond to a nearly pure strain field, slightly disturbed by rotation.
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Jenkins, R. Brian, Peter Joyce, Adam Kong i Charles Nelson. "Discerning Localized Thermal Heating from Mechanical Strain Using an Embedded Distributed Optical Fiber Sensor Network". Sensors 20, nr 9 (1.05.2020): 2583. http://dx.doi.org/10.3390/s20092583.
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Prior research has demonstrated that distributed optical fiber sensors (DOFS) based on Rayleigh scattering can be embedded in carbon fiber/epoxy composite structures to rapidly detect temperature changes approaching 1000 °C, such as would be experienced during a high energy laser strike. However, composite structures often experience mechanical strains that are also detected during DOFS interrogation. Hence, the combined temperature and strain response in the composite can interfere with rapid detection and measurement of a localized thermal impulse. In this research, initial testing has demonstrated the simultaneous response of the DOFS to both temperature and strain. An embedded DOFS network was designed and used to isolate and measure a localized thermal response of a carbon fiber/epoxy composite to a low energy laser strike under cyclic bending strain. The sensor interrogation scheme uses a simple signal processing technique to enhance the thermal response, while mitigating the strain response due to bending. While our ultimate goal is rapid detection of directed energy on the surface of the composite, the technique could be generalized to structural health monitoring of temperature sensitive components or smart structures.
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Gong, Kai, Jia-Jian Wu, Ying Liu, Qing Li, Run-Ran Liu i Ming Tang. "The Effective Healing Strategy against Localized Attacks on Interdependent Spatially Embedded Networks". Complexity 2019 (15.05.2019): 1–10. http://dx.doi.org/10.1155/2019/7912857.
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Many real-world infrastructure networks, such as power grids and communication networks, always depend on each other by their functional components that share geographic proximity. A lot of works were devoted to revealing the vulnerability of interdependent spatially embedded networks (ISENs) when facing node failures and showed that the ISENs are susceptible to geographically localized attacks caused by natural disasters or terrorist attacks. How to take emergency methods to prevent large scale of cascading failures on interdependent infrastructures is a longstanding problem. Here, we propose an effective strategy for the healing of local structures using the connection profile of a failed node, called the healing strategy by prioritizing minimum degrees (HPMD), in which a new link between two active low-degree neighbors of a failed node is established during the cascading process. Afterwards, comparisons are made between HPMD and three healing strategies based on three metrics: random choice, degree centrality, and local centrality, respectively. Simulations are performed on the ISENs composed of two diluted square lattices with the same size under localized attacks. Results show that HPMD can significantly improve the robustness of the system by enhancing the connectivity of low-degree nodes, which prevent the diffusion of failures from low-degree nodes to moderate-degree nodes. In particular, HPMD can outperform other three strategies in the size of the giant component of networks, critical attack radius, and the number of iterative cascade steps for a given quota of newly added links, which means HPMD is more effective, more timely, and less costly. The high performance of HPMD indicates low-degree nodes should be placed on the top priority for effective healing to resist the cascading of failures in the ISENs, which is totally different from the traditional methods that usually take high-degree nodes as critical nodes in a single network. Furthermore, HPMD considers the distance between a pair of nodes to control the variation in the network structures, which is more applicable to spatial networks than previous methods.
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Hobbs, Bruce E., i Alison Ord. "Localized and chaotic folding: the role of axial plane structures". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, nr 1965 (28.04.2012): 1966–2009. http://dx.doi.org/10.1098/rsta.2011.0426.
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Most natural fold systems are not sinusoidal in profile. A widely held view is that such irregularity derives solely from inherited initial geometrical perturbations. Although, undoubtedly, initial perturbations can contribute to irregularity, we explore a different (but complementary) view in which the irregular geometry results from some material or system softening process. This arises because the buckling response of a layer (or layers) embedded in a weaker matrix is controlled in a sensitive manner by the nature of the reaction forces exerted by the deforming matrix on the layer. In many theoretical treatments of the folding problem, this reaction force is assumed to be a linear function of some measure of the deformation or deformation rate. This paper is concerned with the influence of nonlinear reaction forces such as arise from nonlinear elasticity or viscosity. Localized folds arising from nonlinearity form in a fundamentally different way than the Biot wavelength selection process. As a particular example of nonlinear behaviour, we examine the influence of axial plane structures made up of layers of different mineralogy formed by chemical differentiation processes accompanying the deformation; they are referred to as metamorphic layering . The alternating mineralogical composition in the metamorphic layers means that the embedding matrix exerts a reaction force on the folded layers that varies not only with the deflection or the velocity of deflection of the layer, but also in a periodic manner along the length of the folded layers. The influence of this spatially periodic reaction force on the development of localized and chaotic folding is explored numerically.
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Lee, Sangkyun, i Jeonghyun Lee. "Compressed Learning of Deep Neural Networks for OpenCL-Capable Embedded Systems". Applied Sciences 9, nr 8 (23.04.2019): 1669. http://dx.doi.org/10.3390/app9081669.
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Deep neural networks (DNNs) have been quite successful in solving many complex learning problems. However, DNNs tend to have a large number of learning parameters, leading to a large memory and computation requirement. In this paper, we propose a model compression framework for efficient training and inference of deep neural networks on embedded systems. Our framework provides data structures and kernels for OpenCL-based parallel forward and backward computation in a compressed form. In particular, our method learns sparse representations of parameters using ℓ 1 -based sparse coding while training, storing them in compressed sparse matrices. Unlike the previous works, our method does not require a pre-trained model as an input and therefore can be more versatile for different application environments. Even though the use of ℓ 1 -based sparse coding for model compression is not new, we show that it can be far more effective than previously reported when we use proximal point algorithms and the technique of debiasing. Our experiments show that our method can produce minimal learning models suitable for small embedded devices.
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Ohyama, Takako, Hazuki Takahashi, Harshita Sharma, Toshio Yamazaki, Stefano Gustincich, Yoshitaka Ishii i Piero Carninci. "An NMR-based approach reveals the core structure of the functional domain of SINEUP lncRNAs". Nucleic Acids Research 48, nr 16 (22.07.2020): 9346–60. http://dx.doi.org/10.1093/nar/gkaa598.
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Abstract Long non-coding RNAs (lncRNAs) are attracting widespread attention for their emerging regulatory, transcriptional, epigenetic, structural and various other functions. Comprehensive transcriptome analysis has revealed that retrotransposon elements (REs) are transcribed and enriched in lncRNA sequences. However, the functions of lncRNAs and the molecular roles of the embedded REs are largely unknown. The secondary and tertiary structures of lncRNAs and their embedded REs are likely to have essential functional roles, but experimental determination and reliable computational prediction of large RNA structures have been extremely challenging. We report here the nuclear magnetic resonance (NMR)-based secondary structure determination of the 167-nt inverted short interspersed nuclear element (SINE) B2, which is embedded in antisense Uchl1 lncRNA and upregulates the translation of sense Uchl1 mRNAs. By using NMR ‘fingerprints’ as a sensitive probe in the domain survey, we successfully divided the full-length inverted SINE B2 into minimal units made of two discrete structured domains and one dynamic domain without altering their original structures after careful boundary adjustments. This approach allowed us to identify a structured domain in nucleotides 31–119 of the inverted SINE B2. This approach will be applicable to determining the structures of other regulatory lncRNAs.
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Chiappini, Andrea, Guillaume Alombert-Goget, Cristina Armellini, Simone Berneschi, Brigitte Boulard, Massimo Brenci, Ilaria Cacciari i in. "Opal-Type Photonic Crystals: Fabrication and Application". Advances in Science and Technology 71 (październik 2010): 50–57. http://dx.doi.org/10.4028/www.scientific.net/ast.71.50.
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We report on fabrication and characterization of two different opal-like structures: (i) crystal exhibiting mechanochromism, i.e. change of colour when subjected to mechanical stress, composed of closely packed colloidal polystyrene particles (CPCP) embedded in a poly-dimethylsiloxane (PDMS) elastomeric matrix; (ii) metallo-dielectric systems (MDCS), based on the realization of inverse silica opal and following attachment of gold nanoparticles on the silica network of the inverse colloidal structure. Optical measurements, performed on the two structures, have demonstrated that: (i) when an horizontal strain is applied on the CPCP embedded in PDMS, a blue shift of the diffraction peak occurs as a function of the applied strain and (ii) MDCS have unique optical properties that combine the localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs) with the photonic band gap features of colloidal crystal structures. Finally, preliminary results on MDCS used as SERS substrate evidence a higher increase of the Raman signal in respect to that observed for others metallic structures.
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Pietruszczak, Stanisław, i Ehsan Haghighat. "Modeling of Fracture Propagation in Concrete Structures Using a Constitutive Relation with Embedded Discontinuity". Studia Geotechnica et Mechanica 36, nr 4 (28.02.2015): 27–33. http://dx.doi.org/10.2478/sgem-2014-0033.
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Abstract In this paper, the problem of modeling of mixed mode cracking in concrete structures is addressed within the context of a constitutive law with embedded discontinuity (CLED). This approach, which was originally developed for describing the propagation of localized deformation in a “smeared” sense, is enhanced here to model a discrete nature of crack propagation. The latter is achieved by coupling the CLED approach with the level-set method, which is commonly used within the framework of Extended Finite Element (XFEM). Numerical simulations of experimental tests conducted at Delft University, which involve four-point bending of a notched concrete beam under the action of two independent actuators, are presented. The results based on enhanced CLED approach are directly compared with XFEM simulations. The predictions from both these methodologies are quite consistent with the experimental data, thereby giving advantage to CLED scheme in view of its simplicity in the numerical implementation.
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Allen, Emily, i John Swensen. "Directional Stiffness Control Through Geometric Patterning and Localized Heating of Field’s Metal Lattice Embedded in Silicone". Actuators 7, nr 4 (27.11.2018): 80. http://dx.doi.org/10.3390/act7040080.
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This research explores a new realm of soft robotic materials where the stiffness magnitude, directionality, and spatial resolution may be precisely controlled. These materials mimic biological systems where localized muscle contractions and adjustment of tissue stiffness enables meticulous, intelligent movement. Here we propose the use of a low-melting-point (LMP) metal lattice structure as a rigid frame using localized heating to allow compliance about selectable axes along the lattice. The resulting shape of the lattice is modeled using product of exponentials kinematics to describe the serial chain of tunably compliant axes; this model is found to match the behavior of the physical test piece consisting of a Field’s metal (FM) lattice encased in silicone rubber. This concept could enable highly maneuverable robotic structures with significantly improved dexterity.
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Dou, Wen Li, Wen Xu, Shao Hui Xu, Guang Tao Fei i Yi Ming Xiao. "Near-Infrared Reflection Spectra of Copper Nanowire Array Structures". Advanced Materials Research 1118 (lipiec 2015): 125–28. http://dx.doi.org/10.4028/www.scientific.net/amr.1118.125.
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We present a detailed study on near-infrared (NIR) reflection spectra of Cu nanowire arrays (NWAs) which are embedded in porous anodic alumina oxide templates and with pore diameters from 35 nm to 80 nm. We find that the NIR reflection of these samples is out of the frequency regime for surface-plasmon resonance induced by intra-and inter-band excitations. However, the intensity of the NIR reflection of Cu NWAs depends strongly on sample parameters and temperature. The measurements are carried out at temperatures setting to be 4 K, 77 K, 200 K, and at room temperature. The optical response of the Cu NWAs in NIR bandwidth is attributed to localized surface-plasmon oscillations and the NIR reflectance increases with temperature up to room-temperature. The physical mechanisms behind these interesting findings are discussed.
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Hagge, Julia. "Easter eggs and semiotic cues: embedded meaning as early adolescents engage in programming-as-writing". English Teaching: Practice & Critique 20, nr 3 (17.08.2021): 368–84. http://dx.doi.org/10.1108/etpc-07-2020-0077.
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Purpose The purpose of this paper is to examine the ways in which early adolescent programmers embed meaning in their digital media created within an online programming community called Scratch. Design/methodology/approach The author completed an 18-month descriptive case study with 5 early adolescent participants. The research design included a multimodal analytic analysis of participant artifacts and inductive analysis of semi-structured interviews and transcription frames. Findings Participants embedded meaning to achieve four primary purposes, namely, to guide visitors through exhibits, to story, to engage in conversation and to game. To achieve each goal, the participants embedded unique semantic cues within specific Scratch structures. Research limitations/implications Questions for how researchers in literacy and learning can further explore meaning-making within programming-as-writing are suggested. Practical implications Connections to the supportive structures within Scratch are discussed in the context of programming-as-writing. Considerations regarding the use of Scratch to promote programming-as-writing are provided for educators. Originality/value The findings in this study provide an introductory step toward an enhanced understanding of the ways in which youth embed meaning into digital media as they engage in programming-as-writing. Although coding has been researched within the context of computer science, the use of coding in multimodal composition should be explored as it relates to literacy practices.
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Tuğay, Evrin, i Raşsit Turan. "Investigation of Photoluminescence Mechanisms from SiO2/Si:SiO2/SiO2 Structures in Weak Quantum Confined Regime by Deconvolution of Photoluminescence Spectra". Journal of Nanoscience and Nanotechnology 16, nr 4 (1.04.2016): 4052–64. http://dx.doi.org/10.1166/jnn.2016.10863.
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Si nanocrystals embedded in SiO2 matrix were prepared by co-sputtering method followed by a post annealing process in N2 ambient. By fixing sputtering parameters, the effects of annealing time and annealing temperature on the optical properties of Si nanocrystals are investigated. Origin and evolution of the photoluminescence (PL) in weak quantum confinement regime are discussed in the light of X-ray diffraction, Fourier transform infrared, and temperature dependent photoluminescence measurements. For all samples, the PL peaks tend to decompose to four Gaussian peaks in which attributed to the radiative defects in SiO2 matrix, nc-Si/SiO2 interface related localized defects, localized states in the amorphous Si band gap and quantum confinement of excitons in smaller nanocrystals. Considering the observation of luminescence and its decomposition tendency in nanocrystals with average sizes larger than exciton’s Bohr radius the necessity to distinguish between the role of smaller and larger nanocrystals in the PL mechanisms is discussed. Furthermore, possible origin of the interface related localized states in particular Si=O double bonds in the nc-Si/SiO2 interface and that of radiative defects in SiO2 matrix are discussed.
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Iqbal, Ali, Imran Touqir, Asim Ashfaque, Natasha Khan i Fahim Ashraf. "Comparison of Effects of Entropy Coding Schemes Cascaded with Set Partitioning in Hierarchical Trees". October 2018 37, nr 4 (1.10.2018): 507–20. http://dx.doi.org/10.22581/muet1982.1804.06.
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WT (Wavelet Transform) is considered as landmark for image compression because it represents a signal in terms of functions which are localized both in frequency and time domain. Wavelet sub-band coding exploits the self-similarity of pixels in images and arranges resulting coefficients in different sub-bands. A much simpler and fully embedded codec algorithm SPIHT (Set Partitioning in Hierarchical Trees) is widely used for the compression of wavelet transformed images. It encodes the transformed coefficients depending upon their significance comparative to the given threshold. Statistical analysis reveals that the output bit-stream of SPIHT comprises of long trail of zeroes that can be further compressed, therefore SPIHT is not advocated to be used as sole mean of compression. In this paper, wavelet transformed images have been initially compressed by using SPIHT technique and to attain more compression, the output bit streams of SPIHT are then fed to entropy encoders; Huffman and Arithmetic encoders, for further de-correlation. The comparison of two concatenations has been carried out by evaluating few factors like Bit Saving Capability, PSNR (Peak Signal to Noise Ratio), Compression Ratio and Elapsed Time. The experimental results of these cascading demonstrate that SPIHT combined with Arithmetic coding yields better compression ratio as compared to SPIHT cascaded with Huffman coding. Whereas, SPIHT once combined with Huffman coding is proved to be comparatively efficient.
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Lucocq, JM, JG Pryde, EG Berger i G. Warren. "A mitotic form of the Golgi apparatus in HeLa cells". Journal of Cell Biology 104, nr 4 (1.04.1987): 865–74. http://dx.doi.org/10.1083/jcb.104.4.865.
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Galactosyltransferase, a marker for trans-Golgi cisternae in interphase cells, was localized in mitotic HeLa cells embedded in Lowicryl K4M by immunoelectron microscopy. Specific labeling was found only over multivesicular structures that we term Golgi clusters. Unlike Golgi stacks in interphase cells, these clusters lacked elongated cisternae and ordered stacking of their components but did comprise two distinct regions, one containing electron-lucent vesicles and the other, smaller, vesiculo-tubular structures. Labeling for galactosyltransferase was found predominantly over the latter region. Both structures were embedded in a dense matrix that excluded ribosomes and the cluster was often bounded by cisternae of the rough endoplasmic reticulum, sometimes on all sides. Clusters were present at all stages of mitosis examined, which included prometaphase, metaphase, and telophase. They were also identified in conventionally processed mitotic cells and shown to contain another trans-Golgi marker, thiamine pyrophosphatase. Serial sectioning showed that clusters were discrete and globular and multiple copies appeared to be dispersed in the cytoplasm. Their possible role in the division of the Golgi apparatus is discussed.
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Gil-Guerrero, Sara, Nicolás Otero, Marta Queizán i Marcos Mandado Alonso. "Potential Application of h-BNC Structures in SERS and SEHRS Spectroscopies: A Theoretical Perspective". Sensors 19, nr 8 (21.04.2019): 1896. http://dx.doi.org/10.3390/s19081896.
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In this work, the electronic and optical properties of hybrid boron-nitrogen-carbon structures (h-BNCs) with embedded graphene nanodisks are investigated. Their molecular affinity is explored using pyridine as model system and comparing the results with the corresponding isolated graphene nanodisks. Time-dependent density functional theory (TDDFT) analysis of the electronic excited states was performed in the complexes in order to characterize possible surface and charge transfer resonances in the UV region. Static and dynamic (hyper)polarizabilities were calculated with coupled-perturbed Kohn-Sham theory (CPKS) and the linear and nonlinear optical responses of the complexes were analyzed in detail using laser excitation wavelengths available for (Hyper)Raman experiments and near-to-resonance excitation wavelengths. Enhancement factors around 103 and 108 were found for the polarizability and first order hyperpolarizability, respectively. The quantum chemical simulations performed in this work point out that nanographenes embedded within hybrid h-BNC structures may serve as good platforms for enhancing the (Hyper)Raman activity of organic molecules immobilized on their surfaces and for being employed as substrates in surface enhanced (Hyper)Raman scattering (SERS and SEHRS). Besides the better selectivity and improved signal-to-noise ratio of pristine graphene with respect to metallic surfaces, the confinement of the optical response in these hybrid h-BNC systems leads to strong localized surface resonances in the UV region. Matching these resonances with laser excitation wavelengths would solve the problem of the small enhancement factors reported in Raman experiments using pristine graphene. This may be achieved by tuning the size/shape of the embedded nanographene structure.
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Delgado González, Diana Catherine, Andrés Di Donato, Paolo Nicolas Catalano i Martín Gonzalo Bellino. "Silver Nanoparticle-Based Arrays into Mesoporous Thin Films Structures for Photoelectronic Circuits". Current Nanoscience 15, nr 3 (19.02.2019): 304–8. http://dx.doi.org/10.2174/1573413714666180716153501.
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Background: Silver nanosystems have attracted considerable attention for numerous applications in optoelectronics. The localized surface plasmon of silver nanoparticles embedded into mesoporous titania gives rise to an enhancement of local optical field in the vicinity of Ag nanoparticles which act as efficient light-trapping components, resulting in a visible wavelength-dependent photocurrent. Objective: In this paper, we synthetized patterned nanocomposites formed by titania mesoporous thin films loaded with alkanethiol functionalized Ag nanoparticles and we demonstrated that these stable and accessible nanostructures possess a photocurrent response. Method: Mesoporous thin films are created by combining sol-gel synthesis and template selfassembly. Based on a photolithography technique, silver nanoparticles were selectively photodeposited and then stabilized with octanethiols. Current vs. voltage curves with and without light were compared, where selective light wavelength measurements were achieved by using visible bandpass filters. The optofluidic behavior was evaluated by placing a drop of solutions on the mesoporous film. Results: We demonstrate photocurrent in these mesoporous thin film structures decorated with chemistabilized Ag nanoparticle-based conductive arrays, with significantly enhanced photocurrent peak at the plasmon resonant wavelength around 540 nm. Our findings offer a possibility to perform improved fluid detection with silver-mesoporous titania electronic devices. Conclusion: We showed that an optofluidic sensitive nanocomposite circuit consisting of alkanethiol- functionalized metal nanoparticles embedded in a mesoporous oxide thin film matrix can be produced.
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Das, Rabindra N., Timothy E. Antesberger, Francesco Marconi, Frank D. Egitto, Mark D. Poliks i Voya R. Markovich. "Laser Processing of 2-D and 3-D Structures for Tunable Embedded Capacitors". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, DPC (1.01.2011): 001949–76. http://dx.doi.org/10.4071/2011dpc-wp42.
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Material formulation, structuring, and modification are key to increasing the unit volume complexity and density of next generation electronic packaging products. Laser processing is finding an increasing number of applications in the fabrication of these advanced microelectronic devices. This is due, in part, to the ability to achieve highly localized treatment of materials with a spatial resolution of tens of microns. In addition, the process is data-driven, that is, patterns can be generated without the need for masking materials. In the present investigation, a variety of structures have been generated in polymer nanocomposites, nanoparticle films, and sol-gel thin films using a computer-controlled laser system. Specifically, micromachining technology has been used to produce both variable-thickness and discrete capacitors from a single sheet (layer) of capacitor material, such that both types of structures can be integrated into the same layer. In addition, the laser micromachining technology has been extended to design and develop new vertical multilayer embedded capacitors for high speed applications. High speed packages require thick dielectrics. Calculations show that multilayer vertical capacitors can be better than thick capacitors formed from a single layer. In general, multilayer embedded capacitors are fabricated by repeated lamination of resin-coated copper, or pre-preg with a capacitor core. This is a time consuming, lengthy process. As an alternative, we have deposited a single, thick capacitance layer, and subsequent laser micromachining has been used to form multiple parallel channels of a controlled depth. Metal deposition in the channels results in a multilayer embedded capacitor structure. Lasers micromaching can also provide various complex patterns such as 3-D spiral channels within a dielectric or magnetically active nanocomposite, subsequently filled with conducting materials to form inductors. This technique can be used to prepare inductors and capacitors in the same layer of nanocomposite material. Hence, the technique can be used to generate multi-functional structures for tunable device applications.
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Chun, Heoung Jae, Choong Hee Yi i Joon Hyung Byun. "Damage Identification by Embedded Piezoceramic Sensors in the Composite Plate". Key Engineering Materials 326-328 (grudzień 2006): 1697–700. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.1697.
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The embedded structural health monitoring system is envisioned to be an important factor of future structural systems. One of the many attractions of in situ health monitoring system is its capability to inspect the structural systems in less intrusive way over many other visual inspections which require disassembly of built up structures when some indications have appeared that damages have occurred in the structural systems The vacuum assisted resin transfer molding (VARTM) process is used to fabricate woven-glass/phenol composite specimens which have the PZT sensor array embedded in them. The embedded piezoceramic (PZT) sensors are used as both transmitters and receivers. A damage identification approach is developed for a woven-glass/phenol composite laminates with known localized defects. Propagation of the Lamb waves in laminates and their interactions with the defects are examined. Lamb waves are generated by the high power ultrasonic analyzer. A real time active diagnosis system is therefore established. The results obtained show that satisfactory detection accuracy could be achieved by proposed method.
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Dunne, R. C., i S. K. Sitaraman. "Warpage and Interfacial Stress Distribution in a Single-Level Integrated Module (SLIM)". Journal of Electronic Packaging 119, nr 3 (1.09.1997): 197–203. http://dx.doi.org/10.1115/1.2792234.
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The thermomechanical behavior of a new multilayered substrate with embedded passive components is the focus of this study. Such structures are typically susceptible to localized interfacial stresses near the free edge, which might initiate delamination and subsequent failure of the electronic component. The effect of some key parameters—base layer material, interlayer dielectric material, base layer thickness, and temperature range—on substrate warpage and interfacial shear and peel stress distribution is presented. Material and design recommendations for improved thermomechanical response are suggested based on this initial parametric study.
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Ferla, Matteo P., Alistair T. Pagnamenta, David Damerell, Jenny C. Taylor i Brian D. Marsden. "MichelaNglo: sculpting protein views on web pages without coding". Bioinformatics 36, nr 10 (15.02.2020): 3268–70. http://dx.doi.org/10.1093/bioinformatics/btaa104.
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Abstract Motivation The sharing of macromolecular structural information online by scientists is predominantly performed via 2D static images, since the embedding of interactive 3D structures in webpages is non-trivial. Whilst the technologies to do so exist, they are often only implementable with significant web coding experience. Results Michelaɴɢʟo is an accessible and open-source web-based application that supports the generation, customization and sharing of interactive 3D macromolecular visualizations for digital media without requiring programming skills. A PyMOL file, PDB file, PDB identifier code or protein/gene name can be provided to form the basis of visualizations using the NGL JavaScript library. Hyperlinks that control the view can be added to text within the page. Protein-coding variants can be highlighted to support interpretation of their potential functional consequences. The resulting visualizations and text can be customized and shared, as well as embedded within existing websites by following instructions and using a self-contained download. Michelaɴɢʟo allows researchers to move away from static images and instead engage, describe and explain their protein to a wider audience in a more interactive fashion. Availability and implementation Michelaɴɢʟo is hosted at michelanglo.sgc.ox.ac.uk. The Python code is freely available at https://github.com/thesgc/MichelaNGLo, along with documentations about its implementation.
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Beaume, Cédric, Alain Bergeon, Hsien-Ching Kao i Edgar Knobloch. "Convectons in a rotating fluid layer". Journal of Fluid Mechanics 717 (1.02.2013): 417–48. http://dx.doi.org/10.1017/jfm.2012.585.
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AbstractTwo-dimensional convection in a plane layer bounded by stress-free perfectly conducting horizontal boundaries and rotating uniformly about the vertical is considered. Time-independent spatially localized structures, called convectons, of even and odd parity are computed. The convectons are embedded within a self-generated shear layer with a compensating shear flow outside the structure. These states are organized within a bifurcation structure called slanted snaking and may be present even when periodic convection sets in supercritically. These interesting properties are traced to the presence of a conserved quantity and hence to the use of stress-free boundary conditions.
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Bettica, A., i A. B. Johnson. "Ultrastructural immunogold labeling of glial filaments in osmicated and unosmicated epoxy-embedded tissue." Journal of Histochemistry & Cytochemistry 38, nr 1 (styczeń 1990): 103–9. http://dx.doi.org/10.1177/38.1.2152935.
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On-grid (post-embedding) immunolabeling methods with epoxy resins have been difficult to apply to thin structures such as intermediate filaments, which may remain inaccessible within the plastic. In this study, glial fibrillary acidic protein (GFAP), the major protein of astrocyte intermediate filaments, was localized with a post-embedding immunogold method, using both unosmicated and osmicated material embedded in epoxy resin. The tissue studied was from a diagnostic brain biopsy on a child with Alexander's disease. This disorder is characterized by proliferation of astrocyte intermediate filaments and formation of Rosenthal fibers. With unosmicated tissue, as in a previous study, extensive labeling of the glial filaments was achieved only when ultra-thin sections were pre-treated with dilute sodium ethoxide, an agent that dissolves plastic. Fifteen-nm gold could be used. With osmicated tissue, localization to glial filaments required pre-treatment with sodium ethoxide and with the oxidizing agent sodium metaperiodate, followed by the use of small (5 nm) colloidal gold. That 5-nm gold was required for labeling filaments in osmicated material suggested that osmication increases problems of penetrability and antigen accessibility within ultra-thin sections. The large Rosenthal fibers were labeled by 15-nm gold in both unosmicated and osmicated material. The methods employed may be useful for electron immunolocalizations to other thin structures in material embedded in epoxy resin.
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Gusev, V. D., L. A. Miroshnichenko, T. N. Titkova, Yu P. Dzhioev, I. V. Kozlova i A. I. Paramonov. "Structured RNA Markers for Genotyping of Tick-Borne Encephalitis Virus". Mathematical Biology and Bioinformatics 13, nr 1 (16.03.2018): 13–37. http://dx.doi.org/10.17537/2018.13.13.
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Tick-borne encephalitis is one of the most dangerous natural focal infections. The causative agent of the disease is tick-borne encephalitis virus (TBEV ) transmitted by ticks . There are three main subtypes of TBEV with different clinical manifestations of the disease, but existence of other subtypes is also possible. Effectiveness of the disease treatment can largely depend on the correct identification of TBEV genotype. Comprehensive information about the genotype is contained in the full coding sequence of TBEV genome. А limited number of genotyping markers can be extracted from it in the form of relatively short structured RNA fragments. In this paper, a rather general approach to the isolation of structured RNA markers for the genotyping of TBEV is formulated. Three types of structures are considered: periodicity, fractal-like constructs and compactly localized combinations of different types of repetitions. The choice of these structures for the purposes of genotyping and their possible role in the formation of the pathogenic potential of the virus is substantiated. The approach was tested on the full coding sequences of TBEV (161 strains). Examples of the most characteristic markers of each of the three types are given.
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Kambe, K., A. Yamamoto, T. Yoshimori, K. Hirayoshi, R. Ogawa i Y. Tashiro. "Preferential localization of heat shock protein 47 in dilated endoplasmic reticulum of chicken chondrocytes." Journal of Histochemistry & Cytochemistry 42, nr 7 (lipiec 1994): 833–41. http://dx.doi.org/10.1177/42.7.8014466.
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We investigated the distribution of heat shock protein 47 (hsp47) in cultured chicken embryonic chondrocytes and epiphyseal chondrocytes of tibial bones from 1-day-old to 6-week-old chickens. Northern blot and immunoblot analyses revealed that hsp47 exists in epiphyseal cartilage and cultured chondrocytes. Confocal laser immunofluorescence microscopy showed that hsp47 was localized mainly in the many granular structures found in the cytoplasm that contain Type II collagen. Epiphyseal cartilage and cultured chondrocytes were embedded in LR White resin and hsp47 was detected by protein A-immunogold electron microscopy. Gold particles were localized exclusively in the cisternal space of the endoplasmic reticulum (ER), and the labeling density of the cisternal space of the dilated ER was always higher than that of the non-dilated ER. In all the differentiating zones of epiphyseal cartilage, the labeling density was highest in the hypertrophic cells. These findings suggest that hsp47 plays an important role(s) in the synthesis, processing, and assembly of Type II collagen.
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Runov, A., I. Voronkov, Y. Asano, W. Baumjohann, M. Fujimoto, R. Nakamura, T. Takada i in. "Structure of the near-Earth plasma sheet during tailward flows". Annales Geophysicae 26, nr 3 (26.03.2008): 709–24. http://dx.doi.org/10.5194/angeo-26-709-2008.
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Abstract. A detailed analysis of successive tailward flow bursts in the near-Earth magnetotail (X~−19 RE) plasma sheet is performed on the basis of in-situ multi-point observations by the Cluster spacecraft on 15 September 2001. The tailward flows were detected during a northward IMF interval, 2.5 h after a substorm expansion. Each flow burst (Vx<300 km/s) was associated with local auroral activation. Enhancements of the parallel and anti-parallel ~1 keV electron flux were detected during the flows. The spacecraft configuration enables to monitor the neutral sheet (Bx≈0) and the level of Bx≈10–15 nT simultaneously, giving a possibility to distinguish between closed plasmoid-like structures and open NFTE-like surges. The data analysis shows NFTE-like structures and localized current filaments embedded into the tailward plasma flow. 3-D shapes of the structures were reconstructed using the four-point magnetic filed measurements and the particle data.
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Phull, Hardeep S., Hui Q. Pan, Robert S. Butler, Donna E. Hansel i Margot S. Damaser. "Vulnerability of continence structures to injury by simulated childbirth". American Journal of Physiology-Renal Physiology 301, nr 3 (wrzesień 2011): F641—F649. http://dx.doi.org/10.1152/ajprenal.00120.2011.
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The goal of this study was to examine acute morphological changes, edema, muscle damage, inflammation, and hypoxia in urethral and vaginal tissues with increasing duration of vaginal distension (VD) in a rat model. Twenty-nine virgin Sprague-Dawley rats underwent VD under anesthesia with the use of a modified Foley catheter inserted into the vagina and filled with saline for 0, 1, 4, or 6 h. Control animals were anesthetized for 4 h without catheter placement. Urogenital organs were harvested after intracardiac perfusion of fixative. Tissues were embedded, sectioned, and stained with Masson's trichrome or hematoxylin and eosin stains. Regions of hypoxia were measured by hypoxyprobe-1 immunohistochemistry. Within 1 h of VD, the urethra became vertically elongated and displaced anteriorly. Edema was most prominent in the external urethral sphincter (EUS) and urethral/vaginal septum within 4 h of VD, while muscle disruption and fragmentation of the EUS occurred after 6 h. Inflammatory damage was characterized by the presence of polymorphonuclear leukocytes in vessels and tissues after 4 h of VD, with the greatest degree of infiltration occurring in the EUS. Hypoxia localized mostly to the vaginal lamina propria, urethral smooth muscle, and EUS within 4 h of VD. Increasing duration of VD caused progressively greater tissue edema, muscle damage, and morphological changes in the urethra and vagina. The EUS underwent the greatest insult, demonstrating its vulnerability to childbirth injury.
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Mayor, Thibault, Ulrike Hacker, York-Dieter Stierhof i Erich A. Nigg. "The mechanism regulating the dissociation of the centrosomal protein C-Nap1 from mitotic spindle poles". Journal of Cell Science 115, nr 16 (15.08.2002): 3275–84. http://dx.doi.org/10.1242/jcs.115.16.3275.
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The centrosomal protein C-Nap1 is thought to play an important role in centrosome cohesion during interphase of the cell cycle. At the onset of mitosis, when centrosomes separate for bipolar spindle formation, C-Nap1 dissociates from centrosomes. Here we report the results of experiments aimed at determining whether the dissociation of C-Nap1 from mitotic centrosomes is triggered by proteolysis or phosphorylation. Specifically, we analyzed both the cell cycle regulation of endogenous C-Nap1 and the fate of exogenously expressed full-length C-Nap1. Western blot analyses suggested a reduction in the endogenous C-Nap1 level during M phase, but studies using proteasome inhibitors and destruction assays performed in Xenopus extracts argue against ubiquitin-dependent degradation of C-Nap1. Instead, our data indicate that the mitotic C-Nap1 signal is reduced as a consequence of M-phase-specific phosphorylation. Overexpression of full-length C-Nap1 in human U2OS cells caused the formation of large structures that embedded the centrosome and impaired its microtubule nucleation activity. Remarkably, however, these centrosome-associated structures did not interfere with cell division. Instead, centrosomes were found to separate from these structures at the onset of mitosis, indicating that a localized and cell-cycle-regulated activity can dissociate C-Nap1 from centrosomes. A prime candidate for this activity is the centrosomal protein kinase Nek2, as the formation of large C-Nap1 structures was substantially reduced upon co-expression of active Nek2. We conclude that the dissociation of C-Nap1 from mitotic centrosomes is regulated by localized phosphorylation rather than generalized proteolysis.
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Puvion-Dutilleul, F., J. P. Bachellerie, N. Visa i E. Puvion. "Rearrangements of intranuclear structures involved in RNA processing in response to adenovirus infection". Journal of Cell Science 107, nr 6 (1.06.1994): 1457–68. http://dx.doi.org/10.1242/jcs.107.6.1457.
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We have studied in HeLa cells at the electron microscope level the response to adenovirus infection of the RNA processing machinery. Components of the spliceosomes were localized by in situ hybridization with biotinylated U1 and U2 DNA probes and by immunolabeling with Y12 anti-Sm monoclonal antibody, whereas poly(A)+ RNAs were localized by specific binding of biotinylated poly(dT) probe. At early stages of nuclear transformation, the distribution of small nuclear RNPs was similar to that previously described in non-infected nuclei (Visa, N., Puvion-Dutilleul, F., Bachellerie, J.P. and Puvion, E., Eur. J. Cell Biol. 60, 308–321, 1993; Visa, N., Puvion-Dutilleul, F., Harper, F., Bachellerie, J. P. and Puvion, E., Exp. Cell Res. 208, 19–34, 1993). As the infection progresses, the large virus-induced inclusion body consists of a central storage site of functionally inactive viral genomes surrounded by a peripheral shell formed by clusters of interchromatin granules, compact rings and a fibrillogranular network in which are embedded the viral single-stranded DNA accumulation sites. Spliceosome components and poly(A)+ RNAs were then exclusively detected over the clusters of interchromatin granules and the fibrillogranular network whereas the viral single-stranded DNA accumulation sites and compact rings remained unlabeled, thus appearing to not be directly involved in splicing. Our data, therefore, suggest that the fibrillogranular network, in addition to being the site of viral transcription, is also a major site of viral RNA splicing. Like the clusters of interchromatin granules, which had been already involved in spliceosome assembly, they could also have a role in the sorting of viral spliced polyadenylated mRNAs before export to the cytoplasm. The compact rings, which contain non-polyadenylated viral RNA, might accumulate the non-used portions of the viral transcripts resulting from differential poly(A)+ site selection.
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Viale, G., P. Dell'Orto, P. Braidotti i G. Coggi. "Ultrastructural localization of intracellular immunoglobulins in Epon-embedded human lymph nodes. An immunoelectron microscopic investigation using the immunogold staining (IGS) and the avidin-biotin-peroxidase complex (ABC) methods." Journal of Histochemistry & Cytochemistry 33, nr 5 (maj 1985): 400–406. http://dx.doi.org/10.1177/33.5.2580880.
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The ultrastructural localization of intracellular immunoglobulins on ultrathin sections of glutaraldehyde-fixed, postosmicated, and Epon-embedded human lymph nodes has been achieved using such highly sensitive immunocytochemical techniques as immunogold staining and avidin-biotin-peroxidase complex. These immunoelectron microscopic techniques allow the identification of intracellular immunoglobulins without affecting the ultrastructural morphology of the tissue, since they do not require any pretreatment of the sections with proteolytic enzymes or deresinating agents. Therefore, immunoglobulins can be precisely localized in the cell organelles; structures whose morphology is well preserved. The availability of a reliable postembedding staining procedure for the ultrastructural localization of immunoglobulins is of definite value for investigations on human lymphoid tissue, both normal and pathological.
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Farano, Mirko, Stefania Cherubini, Jean-Christophe Robinet i Pietro De Palma. "Optimal bursts in turbulent channel flow". Journal of Fluid Mechanics 817 (15.03.2017): 35–60. http://dx.doi.org/10.1017/jfm.2017.107.
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Bursts are recurrent, transient, highly energetic events characterized by localized variations of velocity and vorticity in turbulent wall-bounded flows. In this work, a nonlinear energy optimization strategy is employed to investigate whether the origin of such bursting events in a turbulent channel flow can be related to the presence of high-amplitude coherent structures. The results show that bursting events correspond to optimal energy flow structures embedded in the fully turbulent flow. In particular, optimal structures inducing energy peaks at short time are initially composed of highly oscillating vortices and streaks near the wall. At moderate friction Reynolds numbers, through the bursts, energy is exchanged between the streaks and packets of hairpin vortices of different sizes reaching the outer scale. Such an optimal flow configuration reproduces well the spatial spectra as well as the probability density function typical of turbulent flows, recovering the mechanism of direct-inverse energy cascade. These results represent an important step towards understanding the dynamics of turbulence at moderate Reynolds numbers and pave the way to new nonlinear techniques to manipulate and control the self-sustained turbulence dynamics.
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KHAMLICH, S., B. D. NGOM, C. K. KOTSEDI, K. BOUZIANE, E. MANIKANDAN i M. MAAZA. "MORPHOLOGICAL AND CRYSTALLOGRAPHIC PROPERTIES OF RARE EARTH OXIDES COATINGS DEPOSITED BY DOUBLE DUAL BEAM-PLD". Surface Review and Letters 21, nr 01 (luty 2014): 1450001. http://dx.doi.org/10.1142/s0218625x14500012.
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Various rare earth oxide nanostructures were synthesized for the first time by dual-double pulsed gas feeding/pulsed laser deposition. The optically transparent and insulating nanostructures do not exhibit the standard columnar configuration of rare earth oxide thin films but rather dense structures and a significant chemical stoichiometry. More precisely, they exhibit single crystallographic low temperature phases with preferential textures, generally similar to that of the bulk used powder targets. For the cubic fluorine type CeO 2 and Ho 2 O 3 films, an epitaxial growth is observed with a special feature noticed in the case of the Eu 2 O 3 nanostructure. For this latter, localized and very large oriented crystallites embedded in disordered packed pyramidal crystallites are observed.
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Fink, Ruth B., Myrna F. Schwartz, Elizabeth Rochon, Jessica L. Myers, Gail Simon Socolof i Ruth Bluestone. "Syntax Stimulation Revisited". American Journal of Speech-Language Pathology 4, nr 4 (listopad 1995): 99–104. http://dx.doi.org/10.1044/1058-0360.0404.99.
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A multiple-probes variant of the multiple-baseline across-behaviors design was used to study the extent of generalization associated with syntax stimulation (SS) training. To assess whether acquisition of specific structures generalized across tasks, we used a specially designed sentence elicitation probe, Picture Description with Structure Modeling (PDSM; Fink et al., 1994). To assess whether training enhanced morphosyntactic production in connected speech, we used the coding scheme developed by Saffran, Berndt, and Schwartz (1989). Four subjects with chronic nonfluent aphasia were trained to produce active, passive, and embedded sentences using materials and procedures from the Helm Elicited Language Program for Syntax Stimulation (Helm-Estabrooks, 1981). These sentence structures were trained in successive phases with generalization probes administered before and after each phase. Three subjects with aphasia served as controls. Strong within-task generalization was observed and, in contrast to previous studies, generalization to the novel sentence elicitation task (PDSM). SS training did not yield measurable gains in narrative production.
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Deviatiiarov, Ruslan, Rustam Ayupov, Alexander Laikov, Elena Shagimardanova, Takahiro Kikawada i Oleg Gusev. "Diversity and Regulation of S-Adenosylmethionine Dependent Methyltransferases in the Anhydrobiotic Midge". Insects 11, nr 9 (16.09.2020): 634. http://dx.doi.org/10.3390/insects11090634.
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Multiple co-localized paralogs of genes in Polypedilum vanderplanki’s genome have strong transcriptional response to dehydration and considered to be a part of adaptation machinery at the larvae stage. One group of such genes represented by L-isoaspartate O-methyltransferases (PIMT). In order to highlight specific role of PIMT paralogization in desiccation tolerance of the larvae we annotated and compared S-adenosylmethionine (SAM) dependent methyltransferases of four insect species. From another side we applied co-expression analysis in desiccation/rehydration time course and showed that PIMT coding genes could be separated into five clusters by expression profile. We found that among Polypedilum vanderplanki’s PIMTs only PIMT1 and PIMT2 have enzymatic activity in normal physiological conditions. From in silico analysis of the protein structures we found two highly variable regions outside of the active center, but also amino acid substitutions which may affect SAM stabilization. Overall, in this study we demonstrated features of Polypedilum vanderplanki’s PIMT coding paralogs related to different roles in desiccation tolerance of the larvae. Our results also suggest a role of different SAM-methyltransferases in the adaptation, including GSMT, JHAMT, and candidates from other classes, which could be considered in future studies.
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Yang, Mo, Sakereh Carter, Shaifaly Parmar, Desta D. Bume, David R. Calabrese, Xiao Liang, Kamyar Yazdani i in. "Targeting a noncanonical, hairpin-containing G-quadruplex structure from the MYCN gene". Nucleic Acids Research 49, nr 14 (21.07.2021): 7856–69. http://dx.doi.org/10.1093/nar/gkab594.
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Abstract The MYCN gene encodes the transcription factor N-Myc, a driver of neuroblastoma (NB). Targeting G-quadruplexes (G4s) with small molecules is attractive strategy to control the expression of undruggable proteins such as N-Myc. However, selective binders to G4s are challenging to identify due to the structural similarity of many G4s. Here, we report the discovery of a small molecule ligand (4) that targets the noncanonical, hairpin containing G4 structure found in the MYCN gene using small molecule microarrays (SMMs). Unlike many G4 binders, the compound was found to bind to a pocket at the base of the hairpin region of the MYCN G4. This compound stabilizes the G4 and has affinity of 3.5 ± 1.6 μM. Moreover, an improved analog, MY-8, suppressed levels of both MYCN and MYCNOS (a lncRNA embedded within the MYCN gene) in NBEB neuroblastoma cells. This work indicates that the approach of targeting complex, hybrid G4 structures that exist throughout the human genome may be an applicable strategy to achieve selectivity for targeting disease-relevant genes including protein coding (MYCN) as well as non-coding (MYCNOS) gene products.
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Kirkham, Glen R., James Ware, Thomas Upton, Stephanie Allen, Kevin M. Shakesheff i Lee DK Buttery. "Localized Induction of Gene Expression in Embryonic Stem Cell Aggregates Using Holographic Optical Tweezers to Create Biochemical Gradients". Regenerative Engineering and Translational Medicine 6, nr 3 (26.08.2019): 251–61. http://dx.doi.org/10.1007/s40883-019-00114-5.
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Abstract Three-dimensional (3D) cell models that mimic the structure and function of native tissues are enabling more detailed study of physiological and pathological mechanisms in vitro. We have previously demonstrated the ability to build and manipulate 3D multicellular microscopic structures using holographic optical tweezers (HOTs). Here, we show the construction of a precisely patterned 3D microenvironment and biochemical gradient model consisting of mouse embryoid bodies (mEBs) and polymer microparticles loaded with retinoic acid (RA), embedded in a hydrogel. We demonstrate discrete, zonal expression of the RA-inducible protein Stra8 within mEBs in response to release of RA from polymer microparticles, corresponding directly to the defined 3D positioning of the microparticles using HOTs. These results demonstrate the ability of this technology to create chemical microgradients at definable length scales and to elicit, with fidelity and precision, specific biological responses. This technique can be used in the study of in vitro microenvironments to enable new insights on 3D cell models, their cellular assembly, and the delivery of drug or biochemical molecules for engineering and interrogation of functional and morphogenic responses.
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Ludwig, Kai, Boris Schade, Christoph Böttcher, Thomas Korte, Nina Ohlwein, Bolormaa Baljinnyam, Michael Veit i Andreas Herrmann. "Electron Cryomicroscopy Reveals Different F1+F2 Protein States in Intact Parainfluenza Virions". Journal of Virology 82, nr 7 (23.01.2008): 3775–81. http://dx.doi.org/10.1128/jvi.02154-07.
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ABSTRACT Electron cryomicrographs of intact parainfluenza virus 5 (PIV5) virions revealed two different surface structures, namely, a continuous layer and distinct individual spikes. The structure of these spikes reconstructed from intact virions was compared with known F ectodomain structures and was found to be different from the prefusion PIV5 F0 structure but, surprisingly, very similar to the human PIV3 F postfusion structure. Hence, we conclude that the individual F1+F2 spikes in intact PIV5 virions also correspond to the postfusion state. Since the observed fusion activity of PIV5 virions has to be associated with prefusion F1+F2 proteins, they have necessarily to be localized in the continuous surface structure. The data therefore strongly suggest that the prefusion state of the F1+F2 protein requires stabilization, most probably by the association with hemagglutinin-neuraminidase. The conversion of F1+F2 proteins from the prefusion toward the postfusion state while embedded in the virus membrane is topologically difficult to comprehend on the basis of established models and demands reconsideration of our current understanding.
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Zaki, Ahmad, Megat Azmi Megat Johari, Wan Muhd Aminuddin Wan Hussin i Yessi Jusman. "Experimental Assessment of Rebar Corrosion in Concrete Slab Using Ground Penetrating Radar (GPR)". International Journal of Corrosion 2018 (21.11.2018): 1–10. http://dx.doi.org/10.1155/2018/5389829.
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Corrosion of steel reinforcement is a major cause of structural damage that requires repair or replacement. Early detection of steel corrosion can limit the extent of necessary repairs or replacements and costs associated with the rehabilitation works. The ground penetrating radar (GPR) method has been found to be a useful method for evaluating reinforcement corrosion in existing concrete structures. In this paper, GPR was utilized to assess corrosion of steel reinforcement in a concrete slab. A technique for accelerating reinforcement bar corrosion using direct current (DC) power supply with 5% sodium chloride (NaCl) solution was used to induce corrosion to embedded reinforcement bars (rebars) in this concrete slab. A 2 GHz GPR was used to assess the corrosion of the rebars. The analysis of the results of the GPR data obtained shows that corrosion of the rebars could be effectively localized and assessed.
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Prichard, Mark N., Sanju Jairath, Mark E. T. Penfold, Stephen St. Jeor, Marlene C. Bohlman i Gregory S. Pari. "Identification of Persistent RNA-DNA Hybrid Structures within the Origin of Replication of Human Cytomegalovirus". Journal of Virology 72, nr 9 (1.09.1998): 6997–7004. http://dx.doi.org/10.1128/jvi.72.9.6997-7004.1998.
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ABSTRACT Human cytomegalovirus (HCMV) lytic-phase DNA replication initiates at the cis-acting origin of replication, oriLyt. oriLyt is a structurally complex region containing repeat elements and transcription factor binding sites. We identified two site-specific alkali-labile regions within oriLyt which flank an alkali-resistant DNA segment. These alkali-sensitive regions were the result of the degradation of two RNA species embedded within oriLyt and covalently linked to viral DNA. The virus-associated RNA, vRNA, was identified by DNase I treatment of HCMV DNA obtained from sucrose gradient purified virus. This heterogeneous population of vRNA was end labeled and used as a hybridization probe to map the exact location of vRNAs within oriLyt. vRNA-1 is localized between restriction endonuclease sitesXhoI at nucleotide (nt) 93799 and SacI at nt 94631 and is approximately 500 bases long. The second vRNA, vRNA-2, lies within a region which exhibits a heterogeneous restriction pattern located between the SphI (nt 92636) and BamHI (nt 93513) and is approximately 300 bases long. This region was previously shown to be required for oriLyt replication (D. G. Anders, M. A. Kacica, G. S. Pari, and S. M. Punturieri, J. Virol. 66:3373–3384, 1992). RNase H analysis determined that vRNA-2 forms a persistent RNA-DNA hybrid structure in the context of the viral genome and in an oriLyt-containing plasmid used in the transient-replication assay.
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Kanemaru, Takaaki, Teruyoshi Kondo, Kei-ichiro Nakamura, Hiroyuki Morimoto, Kentaro Nishi i Shin-ichiro Isobe. "A simple preparation method for CLEM using pre-embedding immunohistochemistry with a novel fluorescent probe and stable embedding resin". Microscopy 70, nr 4 (22.01.2021): 368–74. http://dx.doi.org/10.1093/jmicro/dfab005.
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Abstract Correlative light and electron microscopy (CLEM) is an excellent approach for examining the cellular localization of biomolecules. Here, we developed a simple method for CLEM by combining pre-embedding immunohistochemistry with a novel fluorescent probe, namely Fluolid NS Orange, and an embedding resin called ʻDurcupan™ʼ. Specimens were embedded in Durcupan™ or LR White after immunolabeling and post-fixation using glutaraldehyde and osmium tetroxide. Next, ultrathin sections were prepared on a finder grid with navigation markers. The section of the specimen embedded in Durcupan™ was found to be more stable against electron beam irradiation than specimens embedded in LR White. A fluorescence light microscopy image and a transmission electron microscopy (TEM) image, at wide-field, and low magnification, were independently obtained with the same ultrathin section. Using the three corners between finder grid bars as landmarks, fluorescence light microscopy images were superimposed with wide-field, low-magnification TEM images to identify the region of interest, which was subsequently enlarged to ascertain cellular structures localized beneath fluorescent signals. However, the enlarged TEM images appeared blurred, and fluorescence signals had a hazy appearance. To resolve this, the enlarged TEM images were replaced by high-resolution TEM images focused directly on the region of interest, thereby facilitating the collection of high-resolution CLEM images. The simple sample processing method for CLEM using osmium-resistant Fluolid NS Orange and electron beam damage-resistant Durcupan™ allowed the determination of the precise localization of fluorescence signals at subcellular levels.
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Ding, Yi-Min, Jun-Jie Shi, Min Zhang, Meng Wu, Hui Wang, Yu-Lang Cen, Shu-Hang Pan i Wen-Hui Guo. "Tuning the electronic and optical properties of hexagonal boron-nitride nanosheet by inserting graphene quantum dots". Modern Physics Letters B 32, nr 06 (28.02.2018): 1850084. http://dx.doi.org/10.1142/s0217984918500847.
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It is difficult to integrate two-dimensional (2D) graphene and hexagonal boron-nitride (h-BN) in optoelectronic nanodevices, due to the semi-metal and insulator characteristic of graphene and h-BN, respectively. Using the state-of-the-art first-principles calculations based on many-body perturbation theory, we investigate the electronic and optical properties of h-BN nanosheet embedded with graphene dots. We find that C atom impurities doped in h-BN nanosheet tend to phase-separate into graphene quantum dots (QD), and BNC hybrid structure, i.e. a graphene dot within a h-BN background, can be formed. The band gaps of BNC hybrid structures have an inverse relationship with the size of graphene dot. The calculated optical band gaps for BNC structures vary from 4.71 eV to 3.77 eV, which are much smaller than that of h-BN nanosheet. Furthermore, the valence band maximum is located in C atoms bonded to B atoms and conduction band minimum is located in C atoms bonded to N atoms, which means the electron and hole wave functions are closely distributed around the graphene dot. The bound excitons, localized around the graphene dot, determine the optical spectra of the BNC hybrid structures, in which the exciton binding energies decrease with increase in the size of graphene dots. Our results provide an important theoretical basis for the design and development of BNC-based optoelectronic nanodevices.
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Dieck, Susannetom, Lydia Sanmartí-Vila, Kristina Langnaese, Karin Richter, Stefan Kindler, Antje Soyke, Heike Wex i in. "Bassoon, a Novel Zinc-finger CAG/Glutamine-repeat Protein Selectively Localized at the Active Zone of Presynaptic Nerve Terminals". Journal of Cell Biology 142, nr 2 (27.07.1998): 499–509. http://dx.doi.org/10.1083/jcb.142.2.499.
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The molecular architecture of the cytomatrix of presynaptic nerve terminals is poorly understood. Here we show that Bassoon, a novel protein of >400,000 Mr, is a new component of the presynaptic cytoskeleton. The murine bassoon gene maps to chromosome 9F. A comparison with the corresponding rat cDNA identified 10 exons within its protein-coding region. The Bassoon protein is predicted to contain two double-zinc fingers, several coiled-coil domains, and a stretch of polyglutamines (24 and 11 residues in rat and mouse, respectively). In some human proteins, e.g., Huntingtin, abnormal amplification of such poly-glutamine regions causes late-onset neurodegeneration. Bassoon is highly enriched in synaptic protein preparations. In cultured hippocampal neurons, Bassoon colocalizes with the synaptic vesicle protein synaptophysin and Piccolo, a presynaptic cytomatrix component. At the ultrastructural level, Bassoon is detected in axon terminals of hippocampal neurons where it is highly concentrated in the vicinity of the active zone. Immunogold labeling of synaptosomes revealed that Bassoon is associated with material interspersed between clear synaptic vesicles, and biochemical studies suggest a tight association with cytoskeletal structures. These data indicate that Bassoon is a strong candidate to be involved in cytomatrix organization at the site of neurotransmitter release.
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Afiouni, Fida, i Charlotte M. Karam. "Structure, agency, and notions of career success". Career Development International 19, nr 5 (2.09.2014): 548–71. http://dx.doi.org/10.1108/cdi-01-2013-0007.
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Purpose – The purpose of this paper is to explore notions of career success from a process-oriented perspective. The authors argue that success can be usefully conceptualized as a subjectively malleable and localized construct that is continually (re)interpreted and (re)shaped through the interaction between individual agency and macro-level structures. Design/methodology/approach – The paper employs a qualitative methodology drawing on 32 in-depth semi-structured interviews with female academics from eight countries in the Arab Middle East. Findings – Findings of this study provide an empirical validation of the suggested Career Success Framework and moves toward an integrative model of objective and subjective career success criteria. More specifically, the findings showed that women's definitions of success are: first, localized in that they capture considerations relating to predominant institutions in the region (i.e. family and gender ideology); second, subjectively malleable in that they capture women's agency embedded in specific macro-level structures; and finally, process oriented in that they reflect a dynamic interaction between the structure agency as well as the subsequent actions, strategies, and behaviors women adopt to alleviate tension and reach their personal notions of career success. Practical implications – The authors suggest that there may be value in customizing human resource management policies in the region around the salience of family and community service. Moreover, organizations can play a pivotal role in supporting women to work through the experienced tensions. Examples of such support are mentoring programs, championing female role models, and designing corporate social responsibility initiatives geared toward shifting mandated gender structures in the region. Finally, the authors argue that organizations could benefit by supporting women's atypical patterns of career engagement to allow for interactions with wider circles of stakeholders such as the community. This requires organizations to rethink their career success criteria to allow for the integration of non-traditional elements of career. Social implications – Adopting a more process-oriented view of career success avoids reification by drawing attention to local macro-level structures as well as individual agency. It also suggests that existing norms for how “success” is understood are only one element in a wider process of what it means to be “successful”, thereby opening space for more diverse and localized conceptualizations. Originality/value – This paper provides a more process-oriented consideration of career success, highlighting the importance of understanding how perceived tensions shape an individual's behaviors, actions, and career strategies. The value of this contribution is that it allows us to better understand the complex interaction of structure and agency in shaping an individual's notions of career success.
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Ganesan, Shridar, Daniel P. Silver, Ronny Drapkin, Roger Greenberg, Jean Feunteun i David M. Livingston. "Association of BRCA1 with the inactive X chromosome and XIST RNA". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 359, nr 1441 (29.01.2004): 123–28. http://dx.doi.org/10.1098/rstb.2003.1371.
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Breast cancer, early onset 1 (BRCA1) encodes a nuclear protein that participates in breast and ovarian cancer suppression. The molecular basis for the gender and tissue specificity of the BRCA1 cancer syndrome is unknown. Recently, we observed that a fraction of BRCA1 in female cells is localized on the inactive X chromosome (Xi). Chromatin immunoprecipitation (ChIP) experiments have demonstrated that BRCA1 physically associates with Xi–specific transcript (XIST) RNA, a non–coding RNA known to coat Xi and to participate in the initiation of its inactivation during early embryogenesis. Cells lacking wild–type BRCA1 show abnormalities in Xi, including lack of proper XIST RNA localization. Reintroduction of wild–type, but not mutant, BRCA1 can correct this defect in XIST localization in these cells. Depletion of BRCA1 in female diploid cells led to a defect in proper XIST localization on Xi and in the development of normal Xi heterchromatic superstructure. Moreover, depletion of BRCA1 led to an increased likelihood of re–expression of a green fluorescent protein (GFP) reporter gene embedded on Xi. Taken together, these findings are consistent with a model in which BRCA1 function contributes to the maintenance of proper Xi heterochromatin superstructure. Although the data imply a novel gender–specific consequence of BRCA1 loss, the relevance of the BRCA1/Xi function to the tumour suppressor activity of BRCA1 remains unclear and needs to be tested.
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Weinman, S., C. Ores-Carton, F. Escaig, J. Feinberg i S. Puszkin. "Calmodulin immunoelectron microscopy: redistribution during ram spermatogenesis and epididymal maturation. II." Journal of Histochemistry & Cytochemistry 34, nr 9 (wrzesień 1986): 1181–93. http://dx.doi.org/10.1177/34.9.3734420.
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Affinity-purified monospecific antibodies and indirect immunogold and immunoferritin labeling on ultra-thin sections of low-temperature Lowicryl K4M-embedded samples were used to study the redistribution of calmodulin in ram spermatids and epididymal spermatozoa at the electron microscopic level. Calmodulin appeared as an integral component of well-defined structures or organelles of these cells. In young spermatids, calmodulin was localized in the nucleus, cytoplasm, and developing acrosome. During spermatogenesis and epididymal maturation, calmodulin left the acrosome to reach the perinuclear substance and finally became concentrated in the post-acrosomal area of the head, although some calmodulin remained associated with the tip of the acrosome. Such a redistribution is consistent with the preferential location of Ca2+ in the post-acrosomal cytoplasm of ejaculated spermatozoa. Calmodulin was also observed in the flagellum associated with the plasma membrane and with the motility apparatus, between coarse fibers and axonemal microtubules. These changes in calmodulin distribution may account for the Ca2+-dependent regulation of spermatogenesis and sperm maturation. Calmodulin therefore appears to be a pleiotropic regulator of male gamete development and functions.
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Jeffery, William R. "Identification of proteins and mRNAs in isolated yellow crescents of ascidian eggs". Development 89, nr 1 (1.10.1985): 275–87. http://dx.doi.org/10.1242/dev.89.1.275.
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The yellow crescent or myoplasm is a localized cytoplasmic region in eggs of the ascidian Styela that is partitioned to the larval tail muscle and mesenchyme cells during embryonic development. To determine whether the myoplasm contains a specific subset of maternal macromolecules, its abundant proteins and mRNAs were identified and compared to those present in the remainder of the egg. This was accomplished by exploiting a newly developed method for the mass fractionation of yellow crescents which is based on the presence of a unique cytoskeletal domain in the yellow crescent region. The fractionation yields a yellow crescent fraction (YCF) representing the myoplasm and a supernatant fraction representing the nonmyoplasmic regions. The YCF comprises structures which contain the characteristic myoplasmic organelles and about 10% of the protein, 8% of the RNA, and 1–3% of the poly (A) of whole eggs. Two-dimensional gel electrophoresis indicated that the YCF contains 15 polypeptides that are undetectable in the supernatant fraction and 43 polypeptides that are significantly depleted in the latter fraction. The proteins restricted to the YCF are both of cytoskeletal and noncytoskeletal origin. In vitro translation of RNA in a message-dependent lysate and analysis of [35S]methionine-labelled polypeptide products by two-dimensional gel electrophoresis did not reveal qualitative differences between the YCF and the supernatant fraction. Furthermore, the mRNAs coding for two polypeptides that were localized in the myoplasm were not restricted to the YCF. The results suggest that qualitative differences in proteins but not in prevalent mRNAs exist between the yellow crescent and the other cytoplasmic regions of Styela eggs.
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Liu, Su, Candan Gurses, Zhiyi Sha, Michael M. Quach, Altay Sencer, Nerses Bebek, Daniel J. Curry i in. "Stereotyped high-frequency oscillations discriminate seizure onset zones and critical functional cortex in focal epilepsy". Brain 141, nr 3 (30.01.2018): 713–30. http://dx.doi.org/10.1093/brain/awx374.
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Abstract High-frequency oscillations in local field potentials recorded with intracranial EEG are putative biomarkers of seizure onset zones in epileptic brain. However, localized 80–500 Hz oscillations can also be recorded from normal and non-epileptic cerebral structures. When defined only by rate or frequency, physiological high-frequency oscillations are indistinguishable from pathological ones, which limit their application in epilepsy presurgical planning. We hypothesized that pathological high-frequency oscillations occur in a repetitive fashion with a similar waveform morphology that specifically indicates seizure onset zones. We investigated the waveform patterns of automatically detected high-frequency oscillations in 13 epilepsy patients and five control subjects, with an average of 73 subdural and intracerebral electrodes recorded per patient. The repetitive oscillatory waveforms were identified by using a pipeline of unsupervised machine learning techniques and were then correlated with independently clinician-defined seizure onset zones. Consistently in all patients, the stereotypical high-frequency oscillations with the highest degree of waveform similarity were localized within the seizure onset zones only, whereas the channels generating high-frequency oscillations embedded in random waveforms were found in the functional regions independent from the epileptogenic locations. The repetitive waveform pattern was more evident in fast ripples compared to ripples, suggesting a potential association between waveform repetition and the underlying pathological network. Our findings provided a new tool for the interpretation of pathological high-frequency oscillations that can be efficiently applied to distinguish seizure onset zones from functionally important sites, which is a critical step towards the translation of these signature events into valid clinical biomarkers. 5721572971001 awx374media1 5721572971001
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Zhang, Zhao, Jiahuan Ren, Haijun Zhang, Zheng Zhang, Guangcan Liu i Shuicheng Yan. "DLRF-Net: A Progressive Deep Latent Low-Rank Fusion Network for Hierarchical Subspace Discovery". ACM Transactions on Multimedia Computing, Communications, and Applications 17, nr 1s (31.03.2021): 1–24. http://dx.doi.org/10.1145/3402030.
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Low-rank coding-based representation learning is powerful for discovering and recovering the subspace structures in data, which has obtained an impressive performance; however, it still cannot obtain deep hidden information due to the essence of single-layer structures. In this article, we investigate the deep low-rank representation of images in a progressive way by presenting a novel strategy that can extend existing single-layer latent low-rank models into multiple layers. Technically, we propose a new progressive Deep Latent Low-Rank Fusion Network (DLRF-Net) to uncover deep features and the clustering structures embedded in latent subspaces. The basic idea of DLRF-Net is to progressively refine the principal and salient features in each layer from previous layers by fusing the clustering and projective subspaces, respectively, which can potentially learn more accurate features and subspaces. To obtain deep hidden information, DLRF-Net inputs shallow features from the last layer into subsequent layers. Then, it aims at recovering the hierarchical information and deeper features by respectively congregating the subspaces in each layer of the network. As such, one can also ensure the representation learning of deeper layers to remove the noise and discover the underlying clean subspaces, which will be verified by simulations. It is noteworthy that the framework of our DLRF-Net is general and is applicable to most existing latent low-rank representation models, i.e., existing latent low-rank models can be easily extended to the multilayer scenario using DLRF-Net. Extensive results on real databases show that our framework can deliver enhanced performance over other related techniques.