107 research outputs found

    Synonyms: The appendix of SQL/DS?

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    Citation: Eaton, R. (1992). Synonyms: The appendix of SQL/DS? DATABASE Programming & Design, 5(10) 25-27As I lay in my hospital room recovering from an emergency appendectomy, the surgeon described the operation. His confidence was comforting; that is, until he tried to explain the purpose of the tissue he had removed from me so hastily. He couldn't find the right words. And as he attempted to convince me that he really did know about appendixes, I concluded that he really didn't know their purpose. His interest in appendixes surfaced only when they became infected

    SQl/DS Tool Support and Third-Party Vendors: What's on the Horizon?

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    Citation: Eaton, R. (1992). SQl/DS Tool Support and Third-Party Vendors: What's on the Horizon? DATABASE Programming & Design, 5(10) 75-76In the beginning, there was SQL/DS. Developed by IBM as an expansion to Sequel (a derivative of its first relational DBMS effort, System R), it served VSE/SP installations, and later, VM/SP. Its reception was lukewarm. SQL/DS was slow out of the gate, perhaps due to the lack of complimentary products. Managing an SQL/DS database requires more set-up than the standard VSAM delete and define. Although the number of SQL/OS licenses has reached 7,500 to 8,000, few shops have given SQL/DS the nod as their "first team" data structure

    Repositories, data dictionaries, and encyclopedias for SQL/DS

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    Citation: Eaton, R. (1993). Repositories, data dictionaries, and encyclopedias for SQL/DS. DATABASE Programming & Design, 6(6) 21-22Justified Confusion and wonderment exists about the support of repositories, data dictionaries, and encyclopedias for the SQL/DS platform. In my role as an SQL/DS DBA, I was obliged to design and develop my own data dictionary. During the process, I developed an understanding of the various genre of development support databases. At their highest level of definition, reposi tories, encyclopedias, and data dictionaries are databases that support applications development. I may get some argument about this definition from business data modeling people, but hey, most of us are paid to deliver business systems. A business model is only valuable (to most of us, anyway) if it leads to a business solution. Thus, I refer to repositories, encyclopedias, and data dictionaries as applications-development support databases. For our purposes, let's agree that designing a business model is part of the applications-development process

    CASE Weight Test: A hands on approach to comparing and selecting CASE tools at Twentieth Century Services

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    Citation: Eaton, R. & Hayes, K. (1991). CASE Weight Test: A hands on approach to comparing and selecting CASE tools at Twentieth Century Services. CASE Trends: The Magazine for Computer-Aided Software Engineering, 3(8), 18-19R.G. Eaton and Karl W. Hayes are spearheading the implementation oflnformation Engineering (IE) at Twentieth Century Services, Inc. in Kansas City, MO. Twentieth Century had already decided on the need for automating an IE approach, so their task was straight forward: form a research group with the goal of comparing CASE vendOrs and recommending one toolset

    The efficacy of recombinant thrombopoietin in murine and nonhuman primate models for radiation-induced myelosuppression and stem cell transplantation

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    Radiation-induced pancytopenia proved to be a suitable model system in mice and rhesus monkeys for studying thrombopoietin (TPO) target cell range and efficacy. TPO was highly effective in rhesus monkeys exposed to the mid-lethal dose of 5 Gy (300 kV x-rays) TBI, a model in which it alleviated thrombocytopenia, promoted red cell reconstitution, accelerated reconstitution of immature CD34+ bone marrow cells, and potentiated the response to growth factors such as GM-CSF and G-CSF. In contrast to the results in the 5 Gy TBI model, TPO was ineffective following transplantation of limited numbers of autologous bone marrow or highly purified stem cells in monkeys conditioned with 8 Gy TBI. In the 5 Gy model, a single dose of TPO augmented by GM-CSF 24 h after TBI was effective in preventing thrombocytopenia. The strong erythropoietic stimulation may result in iron depletion, and TPO treatment should be accompanied by monitoring of iron status. This preclinical evaluation thus identified TPO as a potential major therapeutic agent for counteracting radiation-induced pancytopenia and demonstrated pronounced stimulatory effects on the reconstitution of immature CD34+ hemopoietic cells with multilineage potential. The latter observation explains the potentiation of the hematopoietic responses to G-CSF and GM-CSF when administered concomitantly. It also predicts the effective use of TPO to accelerate reconstitution of immature hematopoietic cells as well as possible synergistic effects in vivo with various other growth factors acting on immature stem cells and their direct lineage-committed progeny. The finding that a single dose of TPO might be sufficient for a clinically significant response emphasizes its potency and is of practical relevance. The heterogeneity of the TPO response encountered in the various models used for evaluation points to multiple mechanisms operating on the TPO response and heterogeneity of its target cells. Mechanistic mouse studies made apparent that the response of multilineage cells shortly after TBI to a single administration of TPO is quantitatively more important for optimal efficacy than the lineage-restricted response obtained at later intervals after TBI and emphasized the importance of a relatively high dose of TPO to overcome initial c-mpl-mediated clearance. Further elucidation of mechanisms determining efficacy might very well result in a further improvement, e.g., following transplantation of limited numbers of stem cells. Adverse effects of TPO administration to myelosuppressed or stem cell transplanted experimental animals were not observed

    Reactive direction control for a mobile robot: A locust-like control of escape direction emerges when a bilateral pair of model locust visual neurons are integrated

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    Locusts possess a bilateral pair of uniquely identifiable visual neurons that respond vigorously to the image of an approaching object. These neurons are called the lobula giant movement detectors (LGMDs). The locust LGMDs have been extensively studied and this has lead to the development of an LGMD model for use as an artificial collision detector in robotic applications. To date, robots have been equipped with only a single, central artificial LGMD sensor, and this triggers a non-directional stop or rotation when a potentially colliding object is detected. Clearly, for a robot to behave autonomously, it must react differently to stimuli approaching from different directions. In this study, we implement a bilateral pair of LGMD models in Khepera robots equipped with normal and panoramic cameras. We integrate the responses of these LGMD models using methodologies inspired by research on escape direction control in cockroaches. Using ‘randomised winner-take-all’ or ‘steering wheel’ algorithms for LGMD model integration, the khepera robots could escape an approaching threat in real time and with a similar distribution of escape directions as real locusts. We also found that by optimising these algorithms, we could use them to integrate the left and right DCMD responses of real jumping locusts offline and reproduce the actual escape directions that the locusts took in a particular trial. Our results significantly advance the development of an artificial collision detection and evasion system based on the locust LGMD by allowing it reactive control over robot behaviour. The success of this approach may also indicate some important areas to be pursued in future biological research

    Tg2576 Cortical Neurons That Express Human Ab Are Susceptible to Extracellular Aβ-Induced, K+ Efflux Dependent Neurodegeneration

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    Background: One of the key pathological features of AD is the formation of insoluble amyloid plaques. The major constituent of these extracellular plaques is the beta-amyloid peptide (Aβ), although Aβ is also found to accumulate intraneuronally in AD. Due to the slowly progressive nature of the disease, it is likely that neurons are exposed to sublethal concentrations of both intracellular and extracellular Aβ for extended periods of time. Results: In this study, we report that daily exposure to a sublethal concentration of Aβ1-40 (1 μM) for six days induces substantial apoptosis of cortical neurons cultured from Tg2576 mice (which express substantial but sublethal levels of intracellular Aβ). Notably, untreated Tg2576 neurons of similar age did not display any signs of apoptosis, indicating that the level of intracellular Aβ present in these neurons was not the cause of toxicity. Furthermore, wildtype neurons did not become apoptotic under the same chronic Aβ1-40 treatment. We found that this apoptosis was linked to Tg2576 neurons being unable to maintain K⁺ homeostasis following Aβ treatment. Furthermore, blocking K⁺ efflux protected Tg2576 neurons from Aβ-induced neurotoxicity. Interestingly, chronic exposure to 1 μM Aβ1-40 caused the generation of axonal swellings in Tg2576 neurons that contained dense concentrations of hyperphosphorylated tau. These were not observed in wildtype neurons under the same treatment conditions. Conclusions: Our data suggest that when neurons are chronically exposed to sublethal levels of both intra- and extra-cellular Aβ, this causes a K⁺-dependent neurodegeneration that has pathological characteristics similar to AD.9 page(s

    The Native Copper- and Zinc- Binding Protein Metallothionein Blocks Copper-Mediated Aβ Aggregation and Toxicity in Rat Cortical Neurons

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    Background: A major pathological hallmark of AD is the deposition of insoluble extracellular b-amyloid (Ab) plaques. There are compelling data suggesting that Ab aggregation is catalysed by reaction with the metals zinc and copper. Methodology/Principal Findings: We now report that the major human-expressed metallothionein (MT) subtype, MT-2A, is capable of preventing the in vitro copper-mediated aggregation of Ab1–40 and Ab1–42. This action of MT-2A appears to involve a metal-swap between Zn 7MT-2A and Cu(II)-Ab, since neither Cu 10MT-2A or carboxymethylated MT-2A blocked Cu(II)-Ab aggregation. Furthermore, Zn7MT-2A blocked Cu(II)-Ab induced changes in ionic homeostasis and subsequent neurotoxicity of cultured cortical neurons. Conclusions/Significance: These results indicate that MTs of the type represented by MT-2A are capable of protecting against Ab aggregation and toxicity. Given the recent interest in metal-chelation therapies for AD that remove metal from Ab leaving a metal-free Ab that can readily bind metals again, we believe that MT-2A might represent a different therapeuti

    A review of the fossil record of turtles of the clade Pan-Carettochelys

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    Turtles of the total clade Pan-Carettochelys have a relatively poor fossil record that extends from the Early Cretaceous. The clade is only found in Asia during the Cretaceous, but spreads to Europe and North America during the Eocene. Neogene finds are restricted to Europe, Africa and Australia, whereas the only surviving species, Carettochelys insculpta, lives in New Guinea and the Northern Territories of Australia. The ecology of fossil pan-carettochelyids appears similar to that of the extant C. insculpta, although more primitive representatives were likely less adapted to brackish water. Current phylogenies only recognize three internested clades: Pan- Carettochelys, Carettochelyidae and Carettochelyinae. A taxonomic review of the group concludes that of 25 named taxa, 13 are nomina valida, 7 are nomina invalida, 3 are nomina dubia, and 2 are nomina nuda
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