983 resultados para Steering Clear


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Previous research suggests that low n-3 long-chain polyunsaturated fatty acid (n-3PUFA) status is associated with higher levels of depression in clinical populations. This analysis aimed to investigate the relationship between depressed mood and n-3PUFA status in a non-clinical population. The analysis was conducted on data collected as part of a large randomized controlled trial investigating the impact of n-3PUFA supplementation on depressed mood in a community-based population. On entry into the trial, data on depressed mood were collected using the Depression, Anxiety and Stress Scales (DASS) and the Beck Depression Inventory (BDI). Plasma concentrations of various n-3PUFAs and n-6 long-chain polyunsaturated fatty acids (n-6PUFAs) were obtained from fasting venous blood samples, and various demographics were also measured. Using regression, there was no evidence of an association between either measure of depressed mood and any of the measures of n-3PUFA status or of n-6PUFA: n-3PUFA ratios. Clear associations were also not found when demographic factors were included in the analyses. These findings suggest that n-3PUFAs may not have a role in the aetiology of minor depression. This is also consistent with the results of other studies that have not demonstrated an association between depressed mood and n-3PUFA status in non-clinical populations and epidemiological studies that have not demonstrated an association between depressed mood and n-3PUFA intake in these populations. (C) 2008 Elsevier Ltd. All rights reserved.

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The design is described of a double layer frequency selective surface which can produce a differential phase shift of 180 ° as the wave propagates through it at normal incidence. The hand of an applied circularly polarized signal is reversed due to the 180° phase shift, and it is demonstrated that the exit circularly polarized output signal can be phase advanced or phase retarded by 180 ° upon rotation of the elements comprising the structure. This feature allows the surface to act as a spatial phase shifter. In this paper the beam steering capabilities of a 10 × 10 array of such elements are demonstrated. Here the individual elements comprising the array are rotated relative to each other in order to generate a progressive phase shift. At normal incidence the 3 dB Axial Ratio Bandwidth for LHCP to RHCP conversion is 5.3% and the insertion loss was found to be -2.3 dB, with minimum axial ratio of 0.05 dB. This array is shown to be able to steer a beam from -40 ° to +40 ° while holding axial ratio at the pointing angle to below 4 dB. The measured radiation patterns match the theoretical calculation and full-wave simulation results. © 2010 IEEE.

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The use of radars in detecting low flying, small targets is being explored for several decades now. However radar with counter-stealth abilities namely the passive, multistatic, low frequency radars are in the focus recently. Passive radar that uses Digital Video Broadcast Terrestrial (DVB-T) signals as illuminator of opportunity is a major contender in this area. A DVB-T based passive radar requires the development of an antenna array that performs satisfactorily over the entire DVB-T band. At Fraunhofer FHR, there is currently a need for an array antenna to be designed for operation over the 450-900 MHz range with wideband beamforming and null steering capabilities. This would add to the ability of the passive radar in detecting covert targets and would improve the performance of the system. The array should require no mechanical adjustments to inter-element spacing to correspond to the DVB-T carrier frequency used for any particular measurement. Such an array would have an increased flexibility of operation in different environment or locations.

The design of such an array antenna and the applied techniques for wideband beamforming and null steering are presented in the thesis. The interaction between the inter-element spacing, the grating lobes and the mutual couplings had to be carefully studied and an optimal solution was to be reached at that meets all the specifications of the antenna array for wideband applications. Directional beams, nulls along interference directions, low sidelobe levels, polarization aspects and operation along a wide bandwidth of 450-900 MHz were some of the key considerations.

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The scenario of electron capture and loss has been recently proposed for the formation of negative ion and neutral atom beams with up to MeV kinetic energy [S. Ter-Avetisyan, Appl. Phys. Lett. 99, 051501 (2011)]. Validation of these processes and of their generic nature is here provided in experiments where the ion source and the interaction medium have been spatially separated. Fast positive ions accelerated from a laser plasma source are sent through a cold spray where their charge is changed. Such formed neutral atom or negative ion has nearly the same momentum as the original positive ion. Experiments are released for protons, carbon, and oxygen ions and corresponding beams of negative ions and neutral atoms have been obtained. The electron capture and loss phenomenon is confirmed to be the origin of the negative ion and neutral atom beams. The equilibrium ratios of different charge components and cross sections have been measured. Our method is general and allows the creation of beams of neutral atoms and negative ions for different species which inherit the characteristics of the positive ion source.

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Commentary on: Ramasamy Venkatasalu M, Whiting D, Cairnduff K. Life after the Liverpool Care Pathway (LCP): a qualitative study of critical care practitioners delivering end-of-life care. J Adv Nurs 2015;71:2108–18.

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Objective: An interprofessional steering committee was created at Université de Montréal’s Faculty of Medicine to examine how social media are integrated in medical and health professional education in universities across the globe, and to propose a strategic plan for integrating social media in the Faculty’s various curricula. This presentation will summarize the steering committee’s work and describe the librarian’s contribution. Methods: The Committee’s project leader first conducted a literature search on best practices of social media in medical and health professional curricula. A reference website was then created (mse.med.umontreal.ca) to provide easy access to a large number of the articles and resources reviewed. A steering committee was constituted and 11 meetings were held over a 9-month period. The Committee comprised 18 members and included assistant deans, academic program directors, professors, communication advisors, undergraduate and graduate students and a librarian. An online survey on social media use by students and professors of the Faculty was conducted, ten pilot projects were put forward and a three-year strategic plan was proposed. Results: A total of 1508 students and 565 professors participated in the survey. Results showed that both groups had a strong interest in learning how social media could be integrated in academic and professional activities. Participants reported concern with risks associated with social media use and expressed the need for a Faculty policy and guidelines. The librarian’s contribution to the steering committee included: writing posts on the website’s internal blog, assisting in the design of the survey questionnaires and writing the final report’s survey results chapter. She also proposed two pilot projects: creating a social media learning portal and an altmetrics workshop. Conclusions: Based on the literature review and the survey results, the Committee affirmed the importance of integrating social media in the various study programs of the Faculty of Medicine. Despite the restricted timeline, this interprofessional steering committee was able to carry out its mandate because of the leadership and expertise of each of its members. As the librarian had the most experience with the use of social media in a professional context, her knowledge was instrumental in assisting the project leader in a group mainly composed of social media non-users.

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This 'study' deals with a preliminary study of automatic beam steering properly in conducting polyaniline . Polyaniline in its undoped and doped .state was prepared from aniline by the chemical oxidative polymerization method. Dielectric properties of the samples were studied at S-band microwave frequencies using cavity perturbation technique. It is found that undoped po/vanihne is having greater dielectric loss and conductivity contpared with the doped samples. The beam steering property is studied using a perspex rod antenna and HP 85/OC vector network analyzer. The shift in the radiated beam is studied for different do voltages. The results show that polyaniline is a good nutterial far beam steering applications.

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A novel fixed frequency beam scanning microstrip leaky wave antenna is reported. The beam scanning at fixed frequency is achieved by reactive loading. Simulation and measured results shows frequency scanability of 80° as well as fixed frequency beam steering of 68° over the −10 dB impedance band of 4.56–5.06 GHz.

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Using a crossed-beam apparatus with a double hemispherical electron spectrometer, we have studied the spectrum of electrons released in thermal energy ionizing collisions of metastable He^*(2^3S) atoms with ground state Yb(4f^14 6s^2 ^1S_0) atoms, thereby providing the first Penning electron spectrum of an atomic target with-4f-electrons. In contrast to the HeI (58.4nm) and NeI (73.6/74.4nm) photoelectron spectra of Yb, which show mainly 4f- and 6s-electron emission in about a 5:1 ratio, the He^*(2^3S) Penning electron spectrum is dominated by 6s-ionization, acoompnnied by some correlation- induced 6p-emission (8% Yb+( 4f^14 6p^2P) formation) and very little 4f-ionization (<_~ 2.5%). This astounding result is attributed to the electron exchange mechanism for He^*(2^3S) ionization and reflects the poor overlap of the target 4f-electron wavefunction with the 1s-hole of He^*(2^3S), as discussed on thc basis of Dirac-Fock wave functions for the Yb orbitals and through calculations of the partial ionization cross sections involving semiempirical complex potentiale. The presented case may be regarded as the elearest atomic example for the surface sensitivity of He^*(2^3S) Penning ionization observed so far.

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La desnutrición infantil y la pobreza se encuentran asociadas y estas a su vez con el progreso de los países. Conocer las determinantes sociales y económicas de la niñez que padece de bajo peso es necesario para crear escenarios propicios para el adecuado desarrollo de la primera infancia y de esta manera contribuir con la superación de la pobreza en el marco de sistemas sanitarios equitativos. Se realiza una descripción de las características socio-económicas y un análisis de posibles asociaciones entre estas y el bajo peso infantil de una muestra de infantes de uno de los sectores de mayor vulnerabilidad y pobreza de Bogotá (Colombia). La tasa del bajo peso infantil en la muestra del estudio en más alta a la presentada en Bogotá y Colombia (8.5%, 2.9% y 3.4% respectivamente). Al realizar el análisis de las posibles asociaciones entre el bajo peso y las variables de estudio, se evidencia que las relaciones son débiles entre la primera y las segundas, siendo la condición de desplazamiento la que mayor asociación positiva presenta con la deficiencia nutricional seguido del rango de edad entre los 25 y 36 meses. La situación que presenta mayor independencia con respecto al bajo peso infantil es contar con vivienda propia seguida del sexo. La desnutrición infantil se presenta en niveles importantes en sectores de mayor vulnerabilidad con implicaciones para el adecuado desarrollo de los infantes y para las intenciones de reducción de los índices de pobreza en el país. El fortalecimiento de las políticas públicas que favorezca el desarrollo infantil, la superación de la pobreza y las inequidades en los sistemas de salud deben contemplar acciones integrales dirigidas a los más vulnerables, con la participación de la sociedad civil y los sectores públicos y privados, el compromiso político y económico de los gobiernos y reglas claras que contribuyan a la solución estructural de la pobreza y que promueva el adecuado desarrollo infantil.