105 research outputs found
Distributed microprocessors in a tactical universal modem
The distributed microprocessor system associated with a wideband signal conversion unit (WBSCU) is described. Multiple embedded 8086 and 2901 microprocessors, supported by dedicated hardware modules, perform the required real time operations for both transmit and receive functions. Commands from a host computer determine the configuration of the WBSCU via the IEEE 488 bus. Each of the four WBSCU channels is assigned to process a specified IF waveform; each channel configures its own resources and, in some cases, borrows resources from other channels. The processed waveform data is communicated from individual channels to redundant global memories. Data flow between the user community and global memories occurs via redundant 1553 buses through intelligent Bus Interface Units. Each WBSCU channel contains one 2901 bit slice machine and one 8086 microprocessor. The 2901 provides high speed processing capability for the most time critical operations. The 8086 is used for lower speed processing tasks where its high level language capability can be better exploited. Each 8086 has a global bus for wideband interprocessor communication, and a local bus for 8086/2901, master/slave communication. Software architecture consists of a control and communications structure governing mode dependent signal processing tasks
A Synthesis of Some α, γ, δ, &ksi;-Tettaketones Polyoxo Compounds. IV
A description is given of the preparation of the tetraketones Ia-f, which were characterized as quinoxaHne derivatives
A Synthesis of Some α, γ, δ, &ksi;-Tettaketones Polyoxo Compounds. IV
A description is given of the preparation of the tetraketones Ia-f, which were characterized as quinoxaHne derivatives
Implementation of ETX Metric within the AODV Protocol in the NS-3 Simulator
Modern life cannot be imagined without wireless ad hoc networks (WANETs). People use, in a daily manner, smart phones, laptops or tablet computers. With an increasing number of users of WANETs, the need for a fast throughput and small delay is increasing as well. One efficient way to provide users with such demands is to find an optimal route between source and destination node. Therefore, many routing protocols and metrics for WANETs are proposed in last decades. It is very important to test performances of the proposed protocols in various network scenarios. The computer simulation is a very efficient way to test routing protocols and to evaluate their significance and practical value. One of the most recent but very frequently used discrete-event network simulators is Network Simulator 3 (NS-3). In order to contribute to the NS-3 simulator development, an implementation of one of the most commonly used metric in WANET protocols the expected transmission count (ETX) is proposed in this paper. ETX metric is implemented within an ad-hoc on demand distance vector (AODV) protocol. The source code of this implementation is publicly available
Age-Related Skeletal Muscle Atrophy in Humans: An Immunohistochemical and Morphometric Study
The aim of this study was to determine age-related changes in three human muscles
with different function and location in the body. The cross sectional area and the percentage
of fibers type I, type IIA and type IIX were studied in vastus lateralis, deltoideus
and external intercostal muscle. Muscle samples were obtained from 30 male subjects,
aged 20–80 years. Fiber types were defined immunohistochemically, using monoclonal
antibodies specific for type I, type IIA and type IIX fibers. Cross sectional area of muscle
fibers was analyzed morphometrically by computerized image analysis. All muscle fiber
types (I, IIA, IIX) showed the reduction in the fiber size in all three examined muscles. In
all muscles the proportion of type I and type IIA was changed, but not in type IIX. With
increasing age results showed the increase in proportion of type I, while proportion of
type IIA fibers decreased, with vastus lateralis muscle being the most affected. These results
suggest that age-related muscle atrophy is not a general phenomenon, and does
not affect all muscles equally
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Flourishing workplaces: a multisensory approach to design and POE
How can we design workplaces which occupants thrive in, which are functional but are also expressive? Drawing on research about the senses and office related studies this paper demonstrates how buildings can be designed to allow for positive multi-sensory experiences. In order to design a creative and productive workplace, it is essential to consider how the environment is making us feel, behave and act within it. As the workplace continues to evolve, the case is made for a sensory palette framework to drive a systems approach to building environmental design enabling the integration of the multi-modal sensory relationship of people’s reactions within various environmental settings. Technological advances, in the form of wearables that monitor our physiological and stress responses offer the opportunity to capture empirical data, further enabling the investigation to see how a diverse range of environmental settings affect our physical, mental and social wellbeing. The paper goes on to develop the established conceptual theories of ‘Flourish’ proposing a move beyond comfort when designing the interiors and the mechanics of facility controls towards a sensory impacts framework that considers a whole life costing approach using the Flourish Model sets the basis for a design and post-occupancy evaluation toolkit
BACE1-cleavage of Sez6 and Sez6L is elevated in Niemann-Pick type C disease mouse brains
It is intriguing that a rare, inherited lysosomal storage disorder Niemann-Pick type C (NPC) shares similarities with Alzheimer’s disease (AD). We have previously reported an enhanced processing of β-amyloid precursor protein (APP) by β-secretase (BACE1), a key enzyme in the pathogenesis of AD, in NPC1-null cells. In this work, we characterized regional and temporal expression and processing of the recently identified BACE1 substrates seizure protein 6 (Sez6) and seizure 6-like protein (Sez6L), and APP, in NPC1-/- (NPC1) and NPC1+/+ (wt) mouse brains. We analysed 4-weeks old brains to detect the earliest changes associated with NPC, and 10-weeks of age to identify changes at terminal disease stage. Sez6 and Sez6L were selected due to their predominant cleavage by BACE1, and their potential role in synaptic function that may contribute to presentation of seizures and/or motor impairments in NPC patients. While an enhanced BACE1-cleavage of all three substrates was detected in NPC1 vs. wt-mouse brains at 4- weeks of age, at 10-weeks increased proteolysis by BACE1 was observed for Sez6L in the cortex, hippocampus and cerebellum of NPC1-mice. Interestingly, both APP and Sez6L were found to be expressed in Purkinje neurons and their immunostaining was lost upon Purkinje cell neurodegeneration in 10-weeks old NPC1 mice. Furthermore, in NPC1- vs. wt-mouse primary cortical neurons, both Sez6 and Sez6L showed increased punctuate staining within the endolysosomal pathway as well as increased Sez6L and BACE1-positive puncta. This indicates that a trafficking defect within the endolysosomal pathway may play a key role in enhanced BACE1-proteolysis in NPC disease. Overall, our findings suggest that enhanced proteolysis by BACE1 could be a part of NPC disease pathogenesis. Understanding the basic biology of BACE1 and the functional impact of cleavage of its substrates is important to better evaluate the therapeutic potential of BACE1 against AD and, possibly, NPC disease
Application of Consensus Scoring and Principal Component Analysis for Virtual Screening against β-Secretase (BACE-1)
BACKGROUND: In order to identify novel chemical classes of β-secretase (BACE-1) inhibitors, an alternative scoring protocol, Principal Component Analysis (PCA), was proposed to summarize most of the information from the original scoring functions and re-rank the results from the virtual screening against BACE-1. METHOD: Given a training set (50 BACE-1 inhibitors and 9950 inactive diverse compounds), three rank-based virtual screening methods, individual scoring, conventional consensus scoring and PCA, were judged by the hit number in the top 1% of the ranked list. The docking poses were generated by Surflex, five scoring functions (Surflex_Score, D_Score, G_Score, ChemScore, and PMF_Score) were used for pose extraction. For each pose group, twelve scoring functions (Surflex_Score, D_Score, G_Score, ChemScore, PMF_Score, LigScore1, LigScore2, PLP1, PLP2, jain, Ludi_1, and Ludi_2) were used for the pose rank. For a test set, 113,228 chemical compounds (Sigma-Aldrich® corporate chemical directory) were docked by Surflex, then ranked by the same three ranking methods motioned above to select the potential active compounds for experimental test. RESULTS: For the training set, the PCA approach yielded consistently superior rankings compared to conventional consensus scoring and single scoring. For the test set, the top 20 compounds according to conventional consensus scoring were experimentally tested, no inhibitor was found. Then, we relied on PCA scoring protocol to test another different top 20 compounds and two low micromolar inhibitors (S450588 and 276065) were emerged through the BACE-1 fluorescence resonance energy transfer (FRET) assay. CONCLUSION: The PCA method extends the conventional consensus scoring in a quantitative statistical manner and would appear to have considerable potential for chemical screening applications
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