31,598 research outputs found

    Recirculation effects produced by a pair of heated jets impinging on a ground plane

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    Exhaust recirculation effects produced by two heated jets impinging on ground plan

    On control laws for discrete linear repetitive processes with dynamic boundary conditions

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    Repetitive processes are characterized by a series of sweeps, termed passes, through a set of dynamics defined over a finite duration known as the pass length. On each pass an output, termed the pass profile, is produced which acts as a forcing function on, and hence contributes to, the dynamics of the next pass profile. This can lead to oscillations in the sequence of pass profiles produced which increase in amplitude in the pass-to-pass direction and cannot be controlled by application of standard control laws. Here we give new results on the design of physically based control laws for so-called discrete linear repetitive processes which arise in applications areas such as iterative learning control

    Elucidating the role of DEPTOR in Alzheimer's disease

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    This article has been made available through the Brunel Open Access Publishing Fund.The mammalian or mechanistic target of rapamycin (mTOR) is a Ser/Thr protein kinase that, in response to nutrient stimulation, regulates cellular growth, proliferation, survival, protein synthesis and gene transcription. It has also been implicated in Alzheimer's disease (AD) with neuronal cells and hippocampal slices of AD transgenic mice experiencing dysregulated mTOR and synaptic plasticity in response to treatment with the toxic amyloid β (Aβ1-42) peptide, which has been implicated in AD. DEP domain-containing mTOR-interacting protein (DEPTOR) is a protein which can bind to mTOR and cause its inhibition, and functions as a regulatory protein of mTOR to control its activity. The inhibition of mTOR has been shown to have a neuroprotective effect; in an animal model, it was shown to protect against Aβ-induced neurotoxicity. In the present study, to investigate to role of DEPTOR in a model of AD, we neuronally differentiated the SH-SY5Y cell line and examined the effects of treatment with an Aβ42 peptide, thus mimicking plaque formation. This resulted in a significant increase in mTOR and a significant decrease in DEPTOR expression compared to the unstimulated controls. Moreover, to the best of our knowledge, we demonstrate for the first time a reduction in the protein level of DEPTOR in the precentral gyrus, postcentral gyrus and occipital lobe of a brain with AD compared to a normal control, as well as a significant reduction in DEPTOR expression in samples from late-onset AD (LOAD) compared to early-onset familial AD (EOFAD). The reduction in DEPTOR expression in cases of AD compared to healthy controls can lead to an augmentation of mTOR signalling, leading to Aβ accumulation, which in turn leads to a further reduction in DEPTOR expression. This results in the accumulation of amyloid plaque, shifting the balance from neuroprotection to neurodegeneration

    A technique for correcting ERTS data for solar and atmospheric effects

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    The author has identified the following significant results. Based on processing ERTS CCTs and ground truth measurements collected on Michigan test site for January through June 1973 the following results are reported: (1) atmospheric transmittance varies from: 70 to 85% in band 4, 77 to 90% in band 5, 80 to 94% in band 6, and 84 to 97% in band 7 for one air mass; (2) a simple technique was established to determine atmospheric scattering seen by ERTS-1 from ground-based measurements of sky radiance. For March this scattering was found to be equivalent to that produced by a target having a reflectance of 11% in band 4, 5% in band 5, 3% in band 6, and 1% in band 7; (3) computer ability to classify targets under various atmospheric conditions was determined. Classification accuracy on some targets (i.e. bare soil, tended grass, etc.) hold up even under the most severe atmospheres encountered, while performance on other targets (trees, urban, rangeland, etc.) degrades rapidly when atmospheric conditions change by the smallest amount

    Sellers Competing for Buyers in Online Markets: Reserve Prices, Shill Bids, and Auction Fees

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    We consider competition between sellers offering similar items in concurrent online auctions through a mediating auction institution, where each seller must set its individual auction parameters (such as the reserve price) in such a way as to attract buyers. We show that in the case of two sellers with asymmetric production costs, there exists a pure Nash equilibrium in which both sellers set reserve prices above their production costs. In addition, we show that, rather than setting a reserve price, a seller can further improve its utility by shill bidding (i.e., bidding as a buyer in its own auction). This shill bidding is undesirable as it introduces inefficiencies within the market. However, through the use of an evolutionary simulation, we extend the analytical results beyond the two seller case, and we then show that these inefficiencies can be effectively reduced when the mediating auction institution uses auction fees based on the difference between the auction closing and reserve prices

    Study of porous wall low density wind tunnel diffusers

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    Porous wall wind tunnel diffusers used with low density hypersonic nozzl

    Overlapping Coalition Formation for Efficient Data Fusion in Multi-Sensor Networks

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    This paper develops new algorithms for coalition formation within multi-sensor networks tasked with performing wide-area surveillance. Specifically, we cast this application as an instance of coalition formation, with overlapping coalitions. We show that within this application area sub-additive coalition valuations are typical, and we thus use this structural property of the problem to we derive two novel algorithms (an approximate greedy one that operates in polynomial time and has a calculated bound to the optimum, and an optimal branch-and-bound one) to find the optimal coalition structure in this instance. We empirically evaluate the performance of these algorithms within a generic model of a multi-sensor network performing wide area surveillance. These results show that the polynomial algorithm typically generated solutions much closer the optimal than the theoretical bound, and prove the effectiveness of our pruning procedure

    Market-Based Task Allocation Mechanisms for Limited Capacity Suppliers

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    This paper reports on the design and comparison of two economically-inspired mechanisms for task allocation in environments where sellers have finite production capacities and a cost structure composed of a fixed overhead cost and a constant marginal cost. Such mechanisms are required when a system consists of multiple self-interested stakeholders that each possess private information that is relevant to solving a system-wide problem. Against this background, we first develop a computationally tractable centralised mechanism that finds the set of producers that have the lowest total cost in providing a certain demand (i.e. it is efficient). We achieve this by extending the standard Vickrey-Clarke-Groves mechanism to allow for multi-attribute bids and by introducing a novel penalty scheme such that producers are incentivised to truthfully report their capacities and their costs. Furthermore our extended mechanism is able to handle sellers' uncertainty about their production capacity and ensures that individual agents find it profitable to participate in the mechanism. However, since this first mechanism is centralised, we also develop a complementary decentralised mechanism based around the continuous double auction. Again because of the characteristics of our domain, we need to extend the standard form of this protocol by introducing a novel clearing rule based around an order book. With this modified protocol, we empirically demonstrate (with simple trading strategies) that the mechanism achieves high efficiency. In particular, despite this simplicity, the traders can still derive a profit from the market which makes our mechanism attractive since these results are a likely lower bound on their expected returns

    Standardized Consent Forms for Surgical Procedures: An Intervention to Improve the Resident-led Informed Consent Process

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    Objectives and Goals: To provide high quality, consistent consent forms for common surgical procedures and improve resident workflow by creating and implementing standardized printed consents for common surgical procedures. These consents will be used by residents consenting patients in the ED or inpatient setting. Consents shall include standardized procedure descriptions, risks and benefits of the procedure, and alternative treatment option descriptions, risks and benefitshttps://jdc.jefferson.edu/patientsafetyposters/1057/thumbnail.jp

    An evaluation of the spatial resolution of soil moisture information

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    Rainfall-amount patterns in the central regions of the U.S. were assessed. The spatial scales of surface features and their corresponding microwave responses in the mid western U.S. were investigated. The usefulness for U.S. government agencies of soil moisture information at scales of 10 km and 1 km. was ascertained. From an investigation of 494 storms, it was found that the rainfall resulting from the passage of most types of storms produces patterns which can be resolved on a 10 km scale. The land features causing the greatest problem in the sensing of soil moisture over large agricultural areas with a radiometer are bodies of water. Over the mid-western portions of the U.S., water occupies less than 2% of the total area, the consequently, the water bodies will not have a significant impact on the mapping of soil moisture. Over most of the areas, measurements at a 10-km resolution would adequately define the distribution of soil moisture. Crop yield models and hydrological models would give improved results if soil moisture information at scales of 10 km was available
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