890 research outputs found

    Image data processing system requirements study. Volume 2: Appendixes

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    Supporting information for the ERS loading study contains computer simulation loading output including printout description, and similar output representing data that include night station contacts

    Image data processing system requirements study. Volume 1: Analysis

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    Digital image processing, image recorders, high-density digital data recorders, and data system element processing for use in an Earth Resources Survey image data processing system are studied. Loading to various ERS systems is also estimated by simulation

    EOS image data processing system definition study

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    The Image Processing System (IPS) requirements and configuration are defined for NASA-sponsored advanced technology Earth Observatory System (EOS). The scope included investigation and definition of IPS operational, functional, and product requirements considering overall system constraints and interfaces (sensor, etc.) The scope also included investigation of the technical feasibility and definition of a point design reflecting system requirements. The design phase required a survey of present and projected technology related to general and special-purpose processors, high-density digital tape recorders, and image recorders

    Volterra-Prabhakar derivative of distributed order and some applications

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    The paper studies the exact solution of two kinds of generalized Fokker-Planck equations in which the integral kernels are given either by the distributed order function k1(t)=∫01t−μ/Γ(1−μ)dμk_{1}(t) = \int_{0}^{1} t^{-\mu}/\Gamma(1- \mu) d\mu or the distributed order Prabhakar function k2(α,γ;λ;t)=∫01eα,1−μ−γ(λ;t)dμk_{2}(\alpha, \gamma; \lambda; t) = \int_{0}^{1} e^{-\gamma}_{\alpha, 1 - \mu}(\lambda; t) d\mu, where the Prabhakar function is denoted as eα,1−μ−γ(λ;t)e^{-\gamma}_{\alpha, 1 - \mu}(\lambda; t). Both of these integral kernels can be called the fading memory functions and are the Stieltjes functions. It is also shown that their Stieltjes character is enough to ensure the non-negativity of the mean square values and higher even moments. The odd moments vanish. Thus, the solution of generalized Fokker-Planck equations can be called the probability density functions. We introduce also the Volterra-Prabhakar function and its generalization which are involved in the definition of k2(α,γ;λ;t)k_{2}(\alpha, \gamma; \lambda; t) and generated by it the probability density function p2(x,t)p_2(x, t)

    Quest for hyperheavy toroidal nuclei

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    We investigate the possibility of observing toroidal breakup configurations in Au+Au collisions using the CHIMERA multidetector system. BUU simulations indicate that the threshold energy for toroidal configuration formation is around 23 MeV/nucleon. The simulations of the Decay process using the static model code ETNA indicate the sensitivity of some observables to different studied break-up geometries

    Epigenetic silencing of nucleolar rRNA genes in Alzheimer\u27s disease

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    BACKGROUND: Ribosomal deficits are documented in mild cognitive impairment (MCI), which often represents an early stage Alzheimer\u27s disease (AD), as well as in advanced AD. The nucleolar rRNA genes (rDNA), transcription of which is critical for ribosomal biogenesis, are regulated by epigenetic silencing including promoter CpG methylation. METHODOLOGY/PRINCIPAL FINDINGS: To assess whether CpG methylation of the rDNA promoter was dysregulated across the AD spectrum, we analyzed brain samples from 10 MCI-, 23 AD-, and, 24 age-matched control individuals using bisulfite mapping. The rDNA promoter became hypermethylated in cerebro-cortical samples from MCI and AD groups. In parietal cortex, the rDNA promoter was hypermethylated more in MCI than in advanced AD. The cytosine methylation of total genomic DNA was similar in AD, MCI, and control samples. Consistent with a notion that hypermethylation-mediated silencing of the nucleolar chromatin stabilizes rDNA loci, preventing their senescence-associated loss, genomic rDNA content was elevated in cerebrocortical samples from MCI and AD groups. CONCLUSIONS/SIGNIFICANCE: In conclusion, rDNA hypermethylation could be a new epigenetic marker of AD. Moreover, silencing of nucleolar chromatin may occur during early stages of AD pathology and play a role in AD-related ribosomal deficits and, ultimately, dementia
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