720 research outputs found

    An Agent Based Approach of Collective Foraging

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    In this paper the behaviour of a bee colony is modeled as a society of communicating agents acting in parallel and synchroniz-ing their behaviour. Two computational models for defining the agents behaviour are introduced and compared and tools developed for these models are briefly illustrated.Ministerio de Ciencia y Tecnología TIC2002-04220-C03-0

    Heterogeneously integrated III-V/Si multi-wavelength laser based on a ring resonator array multiplexer

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    A 4-channel multi-wavelength laser integrated on a silicon waveguide circuit is realized. Waveguide-coupled output powers of 2mW and a side mode suppression ratio of more than 45dB for all channels is realized

    III-V/silicon first order distributed feedback lasers integrated on SOI waveguide circuits

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    Heterogeneously integrated III-V-on-silicon first order distributed feedback lasers utilizing an ultra-thin DVS-BCB die-to-wafer bonding process are reported. A novel design exploiting high confinement in the active waveguide is demonstrated. 5 mW output power coupled to a silicon waveguide, 40 dB side mode suppression ratio and continuous wave operation up to 60°C is obtained

    Control of tuberculosis in large cities in developed countries: an organizational problem

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    Tuberculosis (TB) is still a serious public health issue, even in large cities in developed countries. Control of this old disease is based on complicated programs that require completion of long treatments and contact tracing. In an accompanying research article published in BMC Public Health, Bothamley and colleagues found that areas with a ratio lower than one nurse per forty notifications had increased rates with respect to TB notifications, smear-positive cases, loss to follow-up and treatment abandonment across the UK. Furthermore, in these areas there was less opportunity for directly observed therapy, assistance with complex needs, educational outreach and new-entrant screening. In this commentary, we discuss the importance of improving organizational aspects and evaluating TB control programs. According to Bothamley and colleagues, a ratio of one nurse per forty notifications is an effective method of reducing the high TB incidences observed in London and in other cities in developed countries, or to maintain the decline in incidence in cities with lower incidences. It is crucial to evaluate TB programs every year to detect gaps early
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