7,045 research outputs found

    Implications for the U.S. of Anglo-French Defense Cooperation

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    The paper analyzes, from a predominantly UK perspective, the implications for the U.S. of the November 2, 2010, Anglo-French Defence Cooperation Treaty. The current pressures on British and French defence budgets were the primary driving force behind this cooperative effort. London and Paris have made steps toward improving joint efforts in a number of areas, with defence acquisition and industrial cooperation being prominent. In the UK, there appears to be strong political support at the highest levels, which has permeated to lower levels in the bureaucracy, while the UK defence industry appears to be cautiously optimistic about future business opportunities. The impact of enhanced Anglo-French cooperation on the U.S. would appear to be largely favourable for Washington. Rather than providing a basis for weakened UK attention to the U.S., as some fear, the efforts by London and Paris will potentially generate greater national military capability from scarce resources and could serve as a vehicle for broader European efforts to enhance their defence capabilities. While multinational European military development projects are viewed with scepticism in the UK, the Anglo-French arrangement could strengthen the prospects for bilateral projects in which other European states may elect to participate

    Cost effective combined axial fan and throttling valve control of ventilation rate

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    This paper is concerned with Proportional-Integral-Plus (PIP) control of ventilation rate in mechanically ventilated agricultural buildings. In particular, it develops a unique fan and throttling valve control system for a 22m3 test chamber, representing a section of a livestock building or glasshouse, at the Katholieke Universiteit Leuven. Here, the throttling valve is employed to restrict airflow at the outlet, so generating a higher static pressure difference over the control fan. In contrast with previous approaches, however, the throttling valve is directly employed as a second control actuator, utilising airflow from either the axial fan or natural ventilation. The new combined fan/valve configuration is compared with a commercially available PID-based controller and a previously developed scheduled PIP design, yielding a reduction in power consumption in both cases of up to 45%

    Attracting Preservice Teachers to Remote Locations

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    Teaching in rural/remote regions poses many challenges to teachers and is identified as a priority research area by the state government. Despite initiatives by the state government and university providers to solve the issue through various incentives designed to attract teachers, the problem remains significant. This research describes and analyses the impact of a regional university initiative to attract teachers to rural and remote locations in Queensland. The data was gathered through analysis of responses from preservice teachers completing education degrees at a regional university in Queensland. The data revealed that a pre-graduation teaching placement to a rural/remote region resulted in positive attitudinal changes towards applying for such a placement upon graduation. The results are significant and suggest that universities have a major role to play in work force planning for graduate teachers

    Formation Heights of Extreme Ultraviolet Lines in an Active Region Derived by Correlation of Doppler Velocity and Magnetic Field

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    We study the correlation heights, which indicate the formation height of Extreme Ultraviolet (EUV) lines in an active region using observations from the EUV Imaging Spectrometer (EIS) and Solar Optical Telescope (SOT) on board \emph{Hinode}. The nonlinear force-free field (NLFFF) optimization method is adopted to extrapolate the 3D magnetic fields to higher layers. Three subregions with different characteristics are selected in the active region for this study. The results show that the formation heights in different subregions vary with their different magnetic fields or velocity patterns. After solving the line blending problem between the He {\sc \romannumeral 2} 256.32 \AA and Si {\sc \romannumeral 10} 256.37 \AA lines by the double Gaussian curve fitting, we find that the transition region lies higher in a strong magnetic area. In a pre-flare heating area there possibly exist multithermal loops as implied by comparing the Doppler velocity and the magnetic field on the solar disk.Comment: 17 pages, 5 figures, 1 table, accepted for publication in Ap

    Extending Bauer's corollary to fractional derivatives

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    We comment on the method of Dreisigmeyer and Young [D. W. Dreisigmeyer and P. M. Young, J. Phys. A \textbf{36}, 8297, (2003)] to model nonconservative systems with fractional derivatives. It was previously hoped that using fractional derivatives in an action would allow us to derive a single retarded equation of motion using a variational principle. It is proven that, under certain reasonable assumptions, the method of Dreisigmeyer and Young fails.Comment: Accepted Journal of Physics A at www.iop.org/EJ/journal/JPhys

    Inferencia bayesiana para algunas leyes de Lanchester

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    Lanchester (1916) introdujo una serie de ecuaciones o leyes determinísticas para modelar los números de bajas en un combate sin refuerzos. Un inconveniente de estos modelos es que no son útiles ni para la inferencia ni para la predicción, ya que el resultado de una batalla viene determinado por los parámetros del sistema y los tamaños iniciales de cada ejército. Se han propuesto varias versiones estocásticas de las ecuaciones de Lanchester. En este artículo, se resumen algunos de estos modelos y se demuestra cómo utilizar la inferencia bayesiana para estimar los parámetros importantes dada la información a priori que proviene de batallas anteriores, simulaciones, etc. y dada una muestra de datos de un combate. Finalmente, se ilustran los métodos empleados con datos reales y simulados

    Antimicrobial treatment improves mycobacterial survival in nonpermissive growth conditions

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    Antimicrobials targeting cell wall biosynthesis are generally considered inactive against nonreplicating bacteria. Paradoxically, we found that under nonpermissive growth conditions, exposure of Mycobacterium bovis BCG bacilli to such antimicrobials enhanced their survival. We identified a transcriptional regulator, RaaS (for regulator of antimicrobial-assisted survival), encoded by bcg1279 (rv1219c) as being responsible for the observed phenomenon. Induction of this transcriptional regulator resulted in reduced expression of specific ATP-dependent efflux pumps and promoted long-term survival of mycobacteria, while its deletion accelerated bacterial death under nonpermissive growth conditions in vitro and during macrophage or mouse infection. These findings have implications for the design of antimicrobial drug combination therapies for persistent infectious diseases, such as tuberculosis
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