2,976 research outputs found

    Improved AURA k-Nearest Neighbour approach

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    The k-Nearest Neighbour (kNN) approach is a widely-used technique for pattern classification. Ranked distance measurements to a known sample set determine the classification of unknown samples. Though effective, kNN, like most classification methods does not scale well with increased sample size. This is due to their being a relationship between the unknown query and every other sample in the data space. In order to make this operation scalable, we apply AURA to the kNN problem. AURA is a highly-scalable associative-memory based binary neural-network intended for high-speed approximate search and match operations on large unstructured datasets. Previous work has seen AURA methods applied to this problem as a scalable, but approximate kNN classifier. This paper continues this work by using AURA in conjunction with kernel-based input vectors, in order to create a fast scalable kNN classifier, whilst improving recall accuracy to levels similar to standard kNN implementations

    Decision Making Training in the Mission Operations Directorate

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    At JSC, we train our new flight controllers on a set of team skills that we call Space Flight Resource Management (SFRM). SFRM is akin to Crew Resource Management for the airlines and trains flight controllers to work as an effective team to reduce errors and improve safety. We have developed this training over the years with the assistance of Ames Research Center, Wyle Labs and University of Central Florida. One of the skills we teach is decision making/ problem solving (DM/PS). We teach DM/PS first in several classroom sessions, reinforce it in several part task training environments, and finally practice it in full-mission, full-team simulations. What I am proposing to talk about is this training flow: its content and how we teach it

    Biochemical Properties of a Decoy Oligodeoxynucleotide Inhibitor of STAT3 Transcription Factor.

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    Cyclic STAT3 decoy (CS3D) is a second-generation, double-stranded oligodeoxynucleotide (ODN) that mimics a genomic response element for signal transducer and activator of transcription 3 (STAT3), an oncogenic transcription factor. CS3D competitively inhibits STAT3 binding to target gene promoters, resulting in decreased expression of proteins that promote cellular proliferation and survival. Previous studies have demonstrated antitumor activity of CS3D in preclinical models of solid tumors. However, prior to entering human clinical trials, the efficiency of generating the CS3D molecule and its stability in biological fluids should be determined. CS3D is synthesized as a single-stranded ODN and must have its free ends ligated to generate the final cyclic form. In this study, we report a ligation efficiency of nearly 95 percent. The ligated CS3D demonstrated a half-life of 7.9 h in human serum, indicating adequate stability for intravenous delivery. These results provide requisite biochemical characterization of CS3D that will inform upcoming clinical trials

    The fat and the thin - a survey of nutritional status and disease patterns among urbanized Black South Africans

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    The nutritional status of and disease patterns in 449 healthy and 803 hospitalized urbanized Blacks in Durban were surveyed. While unemployed males were generally less fat than controls, obesity (i.e. weight 40% over that expected) was extremely common among female factory (33%) and female hospital 'domestic' (65%) employees. Undernutrition was significantly more common among patients and more marked in males, 82% having significantly reduced fat stores. Disease patterns were similar in malnourished male and female patients, with infective and respiratory diseases predominating. However, the pattern was different in overweight male and female patients, non-ischaemic cardiovascular diseases, particularly hypertension, predominating. The most common cause of death in males was respiratory disease, and in females cardiovascular disease. Overall, malnutrition was most common in the subgroup (N = 212) of patients who died. The results confirm the known associations between undernutrition and increased susceptibility to infection and mortality, and also between overnutrition and hypertensive cardiovascular disease. The observation that malnutrition and obesity can coexist within rapidly urbanized communities stresses the need for concurrent education on nutrition. The high incidence of 'hospital malnutri-tion' observed emphasizes the need for nutritional support in acutely ill patients

    Dynamic organization of DNA replication in mammalian cell nuclei: spatially and temporally defined replication of chromosome-specific alpha-satellite DNA sequences

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    Five distinct patterns of DNA replication have been identified during S-phase in asynchronous and synchronous cultures of mammalian cells by conventional fluorescence microscopy, confocal laser scanning microscopy, and immunoelectron microscopy. During early S-phase, replicating DNA (as identified by 5-bromodeoxyuridine incorporation) appears to be distributed at sites throughout the nucleoplasm, excluding the nucleolus. In CHO cells, this pattern of replication peaks at 30 min into S-phase and is consistent with the localization of euchromatin. As S-phase continues, replication of euchromatin decreases and the peripheral regions of heterochromatin begin to replicate. This pattern of replication peaks at 2 h into S-phase. At 5 h, perinucleolar chromatin as well as peripheral areas of heterochromatin peak in replication. 7 h into S-phase interconnecting patches of electron-dense chromatin replicate. At the end of S-phase (9 h), replication occurs at a few large regions of electron-dense chromatin. Similar or identical patterns have been identified in a variety of mammalian cell types. The replication of specific chromosomal regions within the context of the BrdU-labeling patterns has been examined on an hourly basis in synchronized HeLa cells. Double labeling of DNA replication sites and chromosome-specific alpha-satellite DNA sequences indicates that the alpha-satellite DNA replicates during mid S-phase (characterized by the third pattern of replication) in a variety of human cell types. Our data demonstrates that specific DNA sequences replicate at spatially and temporally defined points during the cell cycle and supports a spatially dynamic model of DNA replication

    Fatal right ventricular infarction caused by Bioglue coronary embolism

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    Spitz and wingless, emanating from distinct borders, cooperate to establish cell fate across the engrailed domain in the drosophila epidermis

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    A key step in development is the establishment of cell type diversity across a cellular field. Segmental patterning within the Drosophila embryonic epidermis is one paradigm for this process. At each parasegment boundary, cells expressing the Wnt family member Wingless confront cells expressing the homeoprotein Engrailed. The Engrailed-expressing cells normally differentiate as one of two alternative cell types. In investigating the generation of this cell type diversity among the 2-cell-wide Engrailed stripe, we previously showed that Wingless, expressed just anterior to the Engrailed cells, is essential for the specification of anterior Engrailed cell fate. In a screen for additional mutations affecting Engrailed cell fate, we identified anterior open/yan, a gene encoding an inhibitory ETS-domain transcription factor that is negatively regulated by the Rasl-MAP kinase signaling cascade. We find that Anterior Open must be inactivated for posterior Engrailed cells to adopt their correct fate. This is achieved by the EGF receptor (DER), which is required autonomously in the Engrailed cells to trigger the Ras1-MAP kinase pathway. Localized activation of DER is accomplished by restricted processing of the activating ligand, Spitz. Processing is confined to the cell row posterior to the Engrailed domain by the restricted expression of Rhomboid. These cells also express the inhibitory ligand Argos, which attenuates the activation of DER in cell rows more distant from the ligand source. Thus, distinct signals flank each border of the Engrailed domain, as Wingless is produced anteriorly and Spitz posteriorly. Since we also show that En cells have the capacity to respond to either Wingless or Spitz, these cells must choose their fate depending on the relative level of activation of the two pathways.Louise O’Keefe, Scott T. Dougan, Limor Gabay, Erez Raz, Ben-Zion Shilo and Stephen DiNard

    Initial Estimates On Shipping’s Cost Impacts and Emissions for a Range of Policy Options - A Prototype Model

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    Shipping was estimated, in 2007, to be responsible for 3.3% of anthropogenic CO2 emissions. Scenarios for future growth in transport demand suggest that this share could substantially increase in the next 40 years, and without regulation the growth in emissions associated with that demand growth would be uncontrolled. Modelling can be used to understand the potential trajectories of emissions from the shipping industry and its potential development and impacts under foreseeable economic scenarios. Modelling can also be used to estimate the response (in terms of changes to those emissions trajectories and impacts on the industry) due to hypothetical regulation and policies. This paper proposes methods for conceptualizing the different components of the shipping industry for these purposes

    Impact of comet Shoemaker-Levy 9 on Jupiter

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    Three-dimensional numerical simulations of the impact of Comet Shoemaker-Levy 9 on Jupiter and the resulting vapor plume expansion were conducted using the Smoothed Particle Hydrodynamics (SPH) method. An icy body with a diameter of 2 km can penetrate to an altitude of -350 km (0 km = 1 bar) and most of the incident kinetic energy is transferred to the atmosphere between -100 km to -250 km. This energy is converted to potential energy of the resulting gas plume. The unconfined plume expands vertically and has a peak radiative power approximately equal to the total radiation from Jupiter's disc. The plume rises a few tens of atmospheric scale heights in ∼10² seconds. The rising plume reaches the altitude of ∼3000 km, but no atmospheric gas is accelerated to the escape velocity (∼60 km/s)
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