6,303 research outputs found

    Knowledge and perceptions of national and provincial tuberculosis control programme managers in Pakistan about the WHO Stop TB strategy.

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    Objective To understand how national and provincial tuberculosis programme managers in Pakistan perceive and engage with the Stop TB strategy, its strengths, weaknesses and their experience in its implementation. National and provincial tuberculosis programme managers play an important role in effective implementation of the Stop TB strategy. Design A qualitative interview study was conducted with 10 national and provincial tuberculosis programme managers to understand how they perceive and engage with the Stop TB strategy, its strengths, weaknesses and their experience in its implementation. Managers were selected purposively; 10 managers were interviewed (six national staff and four from provincial level). Participants National and provincial tuberculosis programme managers in Pakistan. Managers were selected purposively; 10 managers were interviewed (six national staff and four from provincial level). Setting National and provincial tuberculosis programmes in Pakistan Main outcome measures 1. Knowledge and perceptions of national and provincial tuberculosis programme managers about the Stop TB strategy 2. Progress in implementing the strategy in Pakistan 3. Significant success factors 4. Significant implementation challenges 5. Lessons learnt to scale up successful implementation. Results The managers reported that most progress had been made in extending DOTS, health systems strengthening, public -private mixed interventions, MDR-TB care and TB/HIV care. The four factors that contributed significantly to progress were the availability of DOTS services, the public-private partnership approach, comprehensive guidance for TB control and government and donor commitment to TB control. Conclusion This study identified three main challenges as perceived by national and provincial tuberculosis programme managers in terms of implementing the Stop TB strategy: 1. Inadequate political commitment, 2. Issue pertaining to prioritisation of certain components in the TB strategy over others due to external influences and 3. Limitations in the overall health system. To improve the tuberculosis control programme in the country political commitment needs to be enhanced and public -private partnerships increased. This can be done through government prioritisation of TB control at both national and provincial levels; donor-funded components should not receive undue attention; and partnerships with the private health sector, health institutions not yet covered by DOTS services, non-governmental organisations and patient coalitions should be increased

    The Ultraviolet Imaging Telescope: Instrument and Data Characteristics

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    The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro observatory on the Space Shuttle Columbia in December 1990 and again on the Space Shuttle Endeavor in March 1995. Ultraviolet (1200-3300 Angstroms) images of a variety of astronomical objects, with a 40 arcmin field of view and a resolution of about 3 arcsec, were recorded on photographic film. The data recorded during the first flight are available to the astronomical community through the National Space Science Data Center (NSSDC); the data recorded during the second flight will soon be available as well. This paper discusses in detail the design, operation, data reduction, and calibration of UIT, providing the user of the data with information for understanding and using the data. It also provides guidelines for analyzing other astronomical imagery made with image intensifiers and photographic film.Comment: 44 pages, LaTeX, AAS preprint style and EPSF macros, accepted by PAS

    Snap evaporation of droplets on smooth topographies

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    Droplet evaporation on solid surfaces is important in many applications including printing, micro-patterning and cooling. While seemingly simple, the configuration of evaporating droplets on solids is difficult to predict and control. This is because evaporation typically proceeds as a “stick-slip” sequence—a combination of pinning and de-pinning events dominated by static friction or “pinning”, caused by microscopic surface roughness. Here we show how smooth, pinning-free, solid surfaces of non-planar topography promote a different process called snap evaporation. During snap evaporation a droplet follows a reproducible sequence of configurations, consisting of a quasi-static phase-change controlled by mass diffusion interrupted by out-of-equilibrium snaps. Snaps are triggered by bifurcations of the equilibrium droplet shape mediated by the underlying non-planar solid. Because the evolution of droplets during snap evaporation is controlled by a smooth topography, and not by surface roughness, our ideas can inspire programmable surfaces that manage liquids in heat- and mass-transfer applications

    Energy and phase relaxation of phosphorescent F centers in CaO

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    In this paper we study the temperature‐induced homogeneous broadening of the no‐phonon line in the emission spectrum of the F center in CaO. The linewidth can be fitted to n(n+1), where n is the thermally averaged occupation number of phonons with a frequency of 90 cm^(−1). The results are characteristic of elastic scattering of pseudolocalized phonons at the defect site. These phonons also appear to dynamically couple the Jahn–Teller components of the F center in the photoexcited^3 T_(1u) state and thus give rise to a temperature dependence of the lifetime of this phosphorescent state. Finally, from experiments using laser‐selective excitation it is concluded that the zero‐phonon emission peaking at 571.1 nm does not originate in the F center

    Libri novi

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43275/1/11046_2005_Article_BF02089133.pd

    Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics

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    Background Debates over the evolution of hominin bipedalism, a defining human characteristic, revolve around whether early bipeds walked more like humans, with energetically efficient extended hind limbs, or more like apes with flexed hind limbs. The 3.6 million year old hominin footprints at Laetoli, Tanzania represent the earliest direct evidence of hominin bipedalism. Determining the kinematics of Laetoli hominins will allow us to understand whether selection acted to decrease energy costs of bipedalism by 3.6 Ma. Methodology/Principal Findings Using an experimental design, we show that the Laetoli hominins walked with weight transfer most similar to the economical extended limb bipedalism of humans. Humans walked through a sand trackway using both extended limb bipedalism, and more flexed limb bipedalism. Footprint morphology from extended limb trials matches weight distribution patterns found in the Laetoli footprints. Conclusions These results provide us with the earliest direct evidence of kinematically human-like bipedalism currently known, and show that extended limb bipedalism evolved long before the appearance of the genus Homo. Since extended-limb bipedalism is more energetically economical than ape-like bipedalism, energy expenditure was likely an important selection pressure on hominin bipeds by 3.6 Ma

    Dual oscillator model of the respiratory neuronal network generating quantal slowing of respiratory rhythm

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    We developed a dual oscillator model to facilitate the understanding of dynamic interactions between the parafacial respiratory group (pFRG) and the preBötzinger complex (preBötC) neurons in the respiratory rhythm generation. Both neuronal groups were modeled as groups of 81 interconnected pacemaker neurons; the bursting cell model described by Butera and others [model 1 in Butera et al. (J Neurophysiol 81:382–397, 1999a)] were used to model the pacemaker neurons. We assumed (1) both pFRG and preBötC networks are rhythm generators, (2) preBötC receives excitatory inputs from pFRG, and pFRG receives inhibitory inputs from preBötC, and (3) persistent Na+ current conductance and synaptic current conductances are randomly distributed within each population. Our model could reproduce 1:1 coupling of bursting rhythms between pFRG and preBötC with the characteristic biphasic firing pattern of pFRG neurons, i.e., firings during pre-inspiratory and post-inspiratory phases. Compatible with experimental results, the model predicted the changes in firing pattern of pFRG neurons from biphasic expiratory to monophasic inspiratory, synchronous with preBötC neurons. Quantal slowing, a phenomena of prolonged respiratory period that jumps non-deterministically to integer multiples of the control period, was observed when the excitability of preBötC network decreased while strengths of synaptic connections between the two groups remained unchanged, suggesting that, in contrast to the earlier suggestions (Mellen et al., Neuron 37:821–826, 2003; Wittmeier et al., Proc Natl Acad Sci USA 105(46):18000–18005, 2008), quantal slowing could occur without suppressed or stochastic excitatory synaptic transmission. With a reduced excitability of preBötC network, the breakdown of synchronous bursting of preBötC neurons was predicted by simulation. We suggest that quantal slowing could result from a breakdown of synchronized bursting within the preBötC
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