3,683 research outputs found

    Rotatable non-circular forebody flow controller

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    The invention is a rotatable, non-circular forebody flow controller. The apparatus comprises a small geometric device located at a nose of a forebody of an aircraft and a non-circular cross-sectional area that extends toward the apex of the aircraft. The device is symmetrical about a reference plane and preferably attaches to an axle which in turn attaches to a rotating motor. The motor rotates the device about an axis of rotation. Preferably, a control unit connected to an aircraft flight control computer signals to the rotating motor the proper rotational positioning of the geometric device

    The Morita equivalence between parametrized spectra and module spectra

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    We give a Quillen equivalence between May and Sigurdsson's model category of parametrized spectra over BG, and Mandell, May, Schwede, and Shipley's model category of modules over the orthogonal ring spectrum \Sigma^\infty_+ G, for each topological group G. More generally, for a topological category C we introduce an "aggregate" model structure on the category of diagrams of spectra indexed by C, and prove that it is Quillen equivalent to spectra over BC. This lifts several earlier results, and leads to a complete characterization of the dualizable parametrized spectra, answering a question of May and Sigurdsson.Comment: 24 pages, to appear in Contemporary Mathematic

    When are Women More Generous than Men?

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    Previous research on gender differences in behavior has led to seemingly contradictory findings about generosity. From data generated by 290 subject pairs, we find that women are more sensitive than men to the costs of generous actions when deciding whether or not to be generous. The factors that affect the level of generosity observed in our experiments are reciprocal motivation, the level of money payoffs, and the level of social distance in the experimental protocol. The relatively greater sensitivity of women to the costs of generous behavior can explain most of the apparent inconsistencies in previously-reported findings.

    Assigning Intentions when Actions are Unobservable: the Impact of Trembling in the Trust Game

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    This paper reports laboratory experiments investigating behavior when players may make inferences about the intentions behind others' prior actions based on higher- or lower-accuracy information about those actions. We investigate a trust game with first mover trembling, a game in which nature determines whether the first mover's decision is implemented or reversed. The results indicate that second movers give first movers the benefit of the doubt. However, first movers do not anticipate this response. Ultimately, it appears that subjects are thinking on at least three levels when making decisions: they are concerned with their own material well being, the trustworthiness of their counterpart, and how their own actions will be perceived.

    Development and field assessment of a quantitative PCR for the detection and enumeration of the noxious bloom-former Anabaena planktonica

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    Anabaena planktonica is a harmful, bloom-forming freshwater cyanobacterium, which has arrived recently in New Zealand. In the short time since its incursion (<10 yr), A. planktonica has spread rapidly throughout lakes in the North Island. To date, the identification and enumeration of A. planktonica has been undertaken using light microscopy. There is an urgent demand for a highly sensitive and specific quantitative detection method that can be combined with a high sample processing capability in order to increase sampling frequency. In this study, we sequenced 36 cyanobacterial 16S rRNA genes (partial), complete intergenic transcribed spacers (ITS), and 23S rRNA genes (partial) of fresh-water cyanobacteria found in New Zealand. The sequences were used to develop an A. Planktonica specific TaqMan QPCR assay targeting the long ITS1-L and the 5´ terminus of the 23S rRNA gene. The QPCR method was linear (R2 = 0.999) over seven orders of magnitude with a lower end sensitivity of approximately five A. planktonica cells in the presence of exogenous DNA. The quantitative PCR (QPCR) method was used to assess the spatial distribution and seasonal population dynamics of A. planktonica from the Lower Karori Reservoir (Wellington, New Zealand) over a five-month period. The QPCR results were compared directly to microscopic cell counts and found to correlate significantly (95% confidence level) under both bloom and non-bloom conditions. The current QPCR assay will be an invaluable tool for routine monitoring programs and in research investigating environmental factors that regulate the population dynamics and the blooming of A. planktonica

    Surgical salvage in patients with advanced testicular cancer: indications, risks and outcomes

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    The purpose of this review is to present a comprehensive and updated review of the literature and summary of the indications, risks and outcomes related to salvage, desperation and late relapse surgery for advanced testicular cancer. After completing a thorough review of the current literature, this review has attempted to provide an overview of the indications for salvage, desperation and late relapse retroperitoneal lymph node dissection (RPLND) followed by a summary of the histopathologic and clinical outcomes regarding each. Recent literature, combined with a significant contribution from historical studies suggest that while testicular cancer is a relatively uncommon malignancy overall, it represents the most common solid organ malignancy for young men. Although a significant number of men are cured with a combination of first-line treatments, the remaining men are a diverse and often challenging cohort who require the benefit of expertise to improve their outcomes. The role of surgical strategies in the salvage, desperation and late relapse settings is unquestionable, although the most important question remains who will benefit. This often requires a multi-disciplinary approach at centers specializing in this disease process in order to recognize who should get surgery, what surgery to do and how to minimize the potential morbidity associated with the operation

    Engineering prediction of turbulent skin friction and heat transfer in high-speed flow

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    A large collection of experimental turbulent-skin-friction and heat-transfer data for flat plates and cones was used to determine the most accurate of six of the most popular engineering-prediction methods; the data represent a Mach number range from 4 to 13 and ratio of wall to total temperature ranging from 0.1 to 0.7. The Spalding and Chi method incorporating virtual-origin concepts was found to be the best prediction method for Mach numbers less than 10; the limited experimental data for Mach numbers greater than 10 were not well predicted by any of the engineering methods except the Coles method

    Origin and reduction of wakefields in photonic crystal accelerator cavities

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    Photonic crystal (PhC) defect cavities that support an accelerating mode tend to trap unwanted higher-order modes (HOMs) corresponding to zero-group-velocity PhC lattice modes at the top of the bandgap. The effect is explained quite generally from photonic band and perturbation theoretical arguments. Transverse wakefields resulting from this effect are observed in a hybrid dielectric PhC accelerating cavity based on a triangular lattice of sapphire rods. These wakefields are, on average, an order of magnitude higher than those in the waveguide-damped Compact Linear Collider (CLIC) copper cavities. The avoidance of translational symmetry (and, thus, the bandgap concept) can dramatically improve HOM damping in PhC-based structures.Comment: 11 pages, 18 figures, 2 table
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