5,439 research outputs found

    Large-Eddy Simulation closures of passive scalar turbulence: a systematic approach

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    The issue of the parameterization of small scale (``subgrid'') turbulence is addressed in the context of passive scalar transport. We focus on the Kraichnan advection model which lends itself to the analytical investigation of the closure problem. We derive systematically the dynamical equations which rule the evolution of the coarse-grained scalar field. At the lowest-order approximation in l/rl/r, ll being the characteristic scale of the filter defining the coarse-grained scalar field and rr the inertial range separation, we recover the classical eddy-diffusivity parameterization of small scales. At the next-leading order a dynamical closure is obtained. The latter outperforms the classical model and is therefore a natural candidate for subgrid modelling of scalar transport in generic turbulent flows.Comment: 10 LaTex pages, 1 PS figure. Changes: comments added below previous (3.10); Previous (3.16) has been corrected; Minor changes in the conclusion

    Relação entre medidas de resultados centrados na pessoa e medidas clínicas convencionais em indivíduos com osteoartrose do joelho

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    OBJECTIVOS: Analisar a relação entre medidas clínicas convencionais da fisioterapia, testes funcionais e medidas genéricas e de condição específica do estado de saúde, bem como examinar o poder preditivo das medidas clínicas convencionais e dos testes funcionais nas medidas genéricas e de condição específica do estado de saúde, em indivíduos com osteoartrose (OA) do joelho. RELEVÂNCIA: Os resultados dos cuidados de fisioterapia prestados a indivíduos com OA do joelho são vulgarmente medidos através de medidas clínicas convencionais e testes funcionais, embora não se conheça claramente a adequação destas medidas para estimar a percepção global do indivíduo face ao seu estado de saúde. AMOSTRA: Participaram 37 pessoas (sexo: 25 mulheres, 12 homens; idade: 67,6±9,05 anos; estatura:161,3±6,8 cm; peso: 77,3±13.1 kg com OA do joelho. METODOLOGIA: as medidas clínicas avaliadas foram o teste muscular, a goniometria, a medição do ângulo Q. Foram administrados os testes funcionais de subir e descer escadas e o Timed Up & Go Test. O estado de saúde foi medido com os questionários MOS SF-36 e WOMAC. ANÁLISE ESTATÍSTICA: O coeficiente r de Pearson foi utilizado para analisar as relações entre as diferentes medidas de resultados. A análise de regressão (forward stepwise regression) foi utilizada para identificar as medidas clínicas convencionais da fisioterapia e os testes funcionais com poder preditivo sobre as medidas genéricas e de condição específica do estado de saúde. RESULTADOS/DISCUSSÃO: O Timed Up & Go Test combinado com o teste de subir escadas explicou 36% na percepção do WOMAC função, o teste de subir e descer escada combinado com a estatura explicaram 34,2% do MOS-SF-36 na dimensão desempenho físico. CONCLUSÃO: Das medidas de resultados abordadas, o Timed Up & Go Test o teste de descer escadas foram os que melhor estimaram a percepção da função do joelho. É recomendada a utilização destes testes na investigação dos resultados em fisioterapia em OA joelho

    The Real Colegio de Cirugía de Cádiz at the origins of Banco Santander: José María Botín y Cano (c. 1794-1865)

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    José María Botín y Cano (c. 1794–1865) estudió (1810-1816) en el Real Colegio de Medicina y Cirugía de Cádiz, ascendió a Cirujano Primero de la Armada y fue finalmente destinado a Santander en 1827. En 1828 casó con María Petra de Aguirre y Laurencín (c. 1802-¿?), madre de Antonio López-Dóriga y Aguirre (1822-1890), promotor del “Banco de Santander”. Los hijos varones del Matrimonio Botín Aguirre, Rafael (1834- 1903) y Emilio (1835-c. 1901), serán accionistas y altos cargos de él. Por tanto, José María fue: padrastro de un fundador; ascendiente de Directivos del “Banco de Santander”; y el origen de la “Saga Botín”, que sigue vinculada al hoy “Banco Santander”.Jose María Botín y Cano (c.1794-1865) studied (1810-1816) at the Royal College of Medicine and Surgery of Cadiz, he was promoted to First Surgeon of the Navy and was assigned to the city of Santander in 1827. In 1828 he married María Petra de Aguirre y Laurencín (c. 1802-¿?), mother of Antonio López-Dóriga y Aguirre (1822-1890), who was the promoter of the “Banco de Santander”. The sons of the Botín-Aguirre couple, Rafael (1834-1903) and Emilio (1835- c.1901), were shareholders and had senior positions in the bank. Therefore, José María Botín y Cano was: the stepfather of one of the founding members, ancestor of executives of the firm and the origin of the Botín family line, which is still linked to the called "Banco Santander" today

    The Phoenix Deep Survey: The 1.4 GHz microJansky catalogue

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    The initial Phoenix Deep Survey (PDS) observations with the Australia Telescope Compact Array have been supplemented by additional 1.4 GHz observations over the past few years. Here we present details of the construction of a new mosaic image covering an area of 4.56 square degrees, an investigation of the reliability of the source measurements, and the 1.4 GHz source counts for the compiled radio catalogue. The mosaic achieves a 1-sigma rms noise of 12 microJy at its most sensitive, and a homogeneous radio-selected catalogue of over 2000 sources reaching flux densities as faint as 60 microJy has been compiled. The source parameter measurements are found to be consistent with the expected uncertainties from the image noise levels and the Gaussian source fitting procedure. A radio-selected sample avoids the complications of obscuration associated with optically-selected samples, and by utilising complementary PDS observations including multicolour optical, near-infrared and spectroscopic data, this radio catalogue will be used in a detailed investigation of the evolution in star-formation spanning the redshift range 0 < z < 1. The homogeneity of the catalogue ensures a consistent picture of galaxy evolution can be developed over the full cosmologically significant redshift range of interest. The 1.4 GHz mosaic image and the source catalogue are available on the web at http://www.atnf.csiro.au/~ahopkins/phoenix/ or from the authors by request.Comment: 16 pages, 11 figures, 4 tables. Accepted for publication by A

    Neutrophil swarms require LTB4 and integrins at sites of cell death in vivo

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    Neutrophil recruitment from blood to extravascular sites of sterile or infectious tissue damage is a hallmark of early innate immune responses, and the molecular events leading to cell exit from the bloodstream have been well defined1,2. Once outside the vessel, individual neutrophils often show extremely coordinated chemotaxis and cluster formation reminiscent of the swarming behaviour of insects3,4,5,6,7,8,9,10,11. The molecular players that direct this response at the single-cell and population levels within the complexity of an inflamed tissue are unknown. Using two-photon intravital microscopy in mouse models of sterile injury and infection, we show a critical role for intercellular signal relay among neutrophils mediated by the lipid leukotriene B4, which acutely amplifies local cell death signals to enhance the radius of highly directed interstitial neutrophil recruitment. Integrin receptors are dispensable for long-distance migration12, but have a previously unappreciated role in maintaining dense cellular clusters when congregating neutrophils rearrange the collagenous fibre network of the dermis to form a collagen-free zone at the wound centre. In this newly formed environment, integrins, in concert with neutrophil-derived leukotriene B4 and other chemoattractants, promote local neutrophil interaction while forming a tight wound seal. This wound seal has borders that cease to grow in kinetic concert with late recruitment of monocytes and macrophages at the edge of the displaced collagen fibres. Together, these data provide an initial molecular map of the factors that contribute to neutrophil swarming in the extravascular space of a damaged tissue. They reveal how local events are propagated over large-range distances, and how auto-signalling produces coordinated, self-organized neutrophil-swarming behaviour that isolates the wound or infectious site from surrounding viable tissue

    Microjansky sources at 1.4 GHz

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    We present a deep 1.4 GHz survey made with the Australia Telescope Compact Array (ATCA), having a background RMS of 9 microJy near the image phase centre, up to 25 microJy at the edge of a 50' field of view. Over 770 radio sources brighter than 45 microJy have been catalogued in the field. The differential source counts in the deep field provide tentative support for the growing evidence that the microjansky radio population exhibits significantly higher clustering than found at higher flux density cutoffs. The optical identification rate on CCD images is approximately 50% to R=22.5, and the optical counterparts of the faintest radio sources appear to be mainly single galaxies close to this optical magnitude limit.Comment: 6 pages, 4 figures, accepted by ApJ Letters 4 May 199

    Microlens Parallaxes with SIRTF

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    The Space Infrared Telescope Facility (SIRTF) will drift away from the Earth at about 0.1 AU/yr. Microlensing events will therefore have different characteristics as seen from the satellite and the Earth. From the difference, it is possible in principle to measure v-tilde, the transverse velocity of the lens projected onto the observer plane. Since v-tilde has very different values for different populations (disk, halo, Large Magellanic Cloud), such measurements could help identify the location, and hence the nature, of the lenses. I show that the method previously developed by Gould for measuring such satellite parallaxes fails completely in the case of SIRTF: it is overwhelmed by degeneracies which arise from fact that the Earth and satellite observations are in different band passes. I develop a new method which allows for observations in different band passes and yet removes all degeneracies. The method combines a purely ground-based measurement of the "parallax asymmetry" with a measurement of the delay between the time the event peaks at the Earth and satellite. In effect, the parallax asymmetry determines the component of v-tilde in the Earth-Sun direction, while the delay time measures the component of v-tilde in the direction of the Earth's orbit.Comment: 21 pages plus 3 figure

    Optimal Microlensing Observations

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    One of the major limitations of microlensing observations toward the Large Magellanic Cloud (LMC) is the low rate of event detection. What can be done to improve this rate? Is it better to invest telescope time in more frequent observations of the inner high surface-brightness fields, or in covering new, less populated outer fields? How would a factor 2 improvement in CCD sensitivity affect the detection efficiency? Would a series of major (factor 2--4) upgrades in telescope aperture, seeing, sky brightness, camera size, and detector efficiency increase the event rate by a huge factor, or only marginally? I develop a simplified framework to address these questions. With observational resources fixed at the level of the MACHO and EROS experiments, the biggest improvement (factor ~2) would come by reducing the time spent on the inner ~25 deg^2 and applying it to the outer ~100 deg^2. By combining this change with the characteristics of a good medium-size telescope (2.5 m mirror, 1" point spread function, thinned CCD chips, 1 deg^2 camera, and dark sky), it should be possible to increase the detection of LMC events to more than 100 per year (assuming current estimates of the optical depth apply to the entire LMC).Comment: Submitted to ApJ, 13 pages plus 3 figure

    Smart home power management system for electric vehicle battery charger and electrical appliance control

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    This paper presents a power management system (PMS) designed for smart homes aiming to deal with the new challenges imposed by the proliferation of plug-in electric vehicles (EVs) and their coexistence with other residential electrical appliances. The PMS is based on a hybrid wireless network architecture composed by a local hub/gateway and several Bluetooth Low Energy (BLE) and Wi-Fi sensor/actuator devices. These wireless devices are used to transfer information inside the smart home using the MQTT (Message Queuing Telemetry Transport) protocol. Based on the proposed solution, the current consumption of the EV battery charger and other residential electrical appliances are dynamically monitored and controlled by using a configurable algorithm, ensuring that the total current consumption does not cause the tripping of the home circuit breaker. An Android client application allows the user to monitor and configure the system operation in real-time, a developed Wi Fi smart plug permits to measure the RMS values of current of the connected electrical appliance and change its state of operation remotely, and an EV battery charger may be controlled in terms of operating power according to set-points received from the Android client application. Experimental tests are used to evaluate the quality of service provided by the developed smart home platform in terms of communication delay and reliability. An experimental validation for different conditions of operation of the proposed smart home PMS concerning the power operation of the EV battery charger with the proposed control algorithm is also presented.info:eu-repo/semantics/acceptedVersio

    Detection and isolation of exotic Newcastle disease virus from field-collected flies.

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    Flies were collected by sweep net from the vicinity of two small groups of "backyard" poultry (10-20 chickens per group) that had been identified as infected with exotic Newcastle disease virus (family Paramyxoviridae, genus avulavirus, ENDV) in Los Angeles County, CA, during the 2002-2003 END outbreak. Collected flies were subdivided into pools and homogenized in brain-heart infusion broth with antibiotics. The separated supernatant was tested for the presence of ENDV by inoculation into embryonated chicken eggs. Exotic Newcastle disease virus was isolated from pools of Phaenicia cuprina (Wiedemann), Fannia canicularis (L.), and Musca domestica L., and it was identified by hemagglutination inhibition with Newcastle disease virus antiserum. Viral concentration in positive pools was low (&lt;1 egg infectious dose50 per fly). Isolated virus demonstrated identical monoclonal antibody binding profiles as well as 99% sequence homology in the 635-bp fusion gene sequence compared with ENDV recovered from infected commercial egg layer poultry during the 2002 outbreak
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