968 research outputs found
Managed groundwater development for water-supply security in Sub-Saharan Africa: Investment priorities
In numerous countries of Sub-Saharan Africa the strategic agenda of the water-sector is undergoing substantial change because of demographic pressure, climate change and economic transformation. Two new policy questions are arising from the need to make better use of available groundwater storage to improve water-supply security:• What is the scope for promoting much increased groundwater use for irrigated agriculture, and how might the investment risks be reduced and sustainable outcomes ensured?• How can the demand to expand urban groundwater use, for both further supplementing municipal water-supply systems and for direct in situ water supply, be best channelled to maximise the benefits whilst minimising the risks?This ‘new agenda’ poses very different challenges from the long-standing requirement to provide rural water supplies of adequate coverage, reliability and quality (which, while still not yet fully addressed, is outside the scope of this paper). Balanced answers to these new questions are needed to provide a sound basis for appropriate investment policies on managed groundwater development and adequate institutional provisions for their implementation. They are discussed here from the standpoint of the GW-MATE experience in some World Bank-supported projects in eastern Africa during 2001-2010, together with a review of some developments in western Africa and insights from parts of Asia and Latin America
Two-dimensional spatiotemporal monitoring of temperature in photothermal therapy using hybrid photoacoustic-ultrasound transmission tomography
Recently, we presented an add-on to a photoacoustic (PA) computed tomography imager that permits the simultaneous imaging of ultrasound (US) transmission parameters such as the speed of sound (SOS), without additional measurements or instruments. This method uses strong absorbers positioned outside the object in the path of light for producing laser-induced US to interrogate the object in a conventional PA imager. Here, we investigate the feasibility of using this approach, first with PA to pin-point the location of photothermal therapeutic agents and then with serial SOS tomograms to image and monitor the resulting local temperature changes when the agents are excited with continuous wave (CW) light. As the object we used an agar-based tissue-mimicking cylinder carrying beads embedded with different concentrations of gold nanospheres. PA and SOS tomograms were simultaneously acquired as the gold nanospheres were photothermally heated using a 532-nm CW laser. In a first approximation, using the relation between SOS of water and temperature, the SOS tomograms were converted into temperature maps. The experimental results were verified using simulations: Monte Carlo modeling of light propagation through a turbid medium and using the obtained absorbed energy densities in heat diffusion modeling for spatial temperature distributio
Wat weten Nederlanders van salmonella en welke maatregelen nemen ze tijdens een uitbraak?
Voedselgerelateerde Salmonella-infecties zijn een wereldwijd probleem. Gedurende een grootschalige uitbraak is het van belang dat het publiek de maatregelen neemt die door de GGD’en en de overheid worden geadviseerd. Om de naleving van deze maatregelen te vergoten, is het essentieel om inzicht te hebben in hoe en waar het publiek informatie vergaart en welke factoren bepalen of zij wel of niet de geadviseerde maatregelen neemt. Uit dit onderzoek blijkt dat GGD’en en overheid tijdens een uitbraak hun boodschap het beste via massamedia kunnen verspreiden. Wikipedia lijkt een veelbelovend kanaal om het publiek kennis bij te brengen over Salmonella
Dissociable corticostriatal circuits underlie goal-directed vs. cue-elicited habitual food seeking after satiation: Evidence from a multimodal MRI study
Eye–hand coordination during manual object transport with the affected and less affected hand in adolescents with hemiparetic cerebral palsy
In the present study we investigated eye–hand coordination in adolescents with hemiparetic cerebral palsy (CP) and neurologically healthy controls. Using an object prehension and transport task, we addressed two hypotheses, motivated by the question whether early brain damage and the ensuing limitations of motor activity lead to general and/or effector-specific effects in visuomotor control of manual actions. We hypothesized that individuals with hemiparetic CP would more closely visually monitor actions with their affected hand, compared to both their less affected hand and to control participants without a sensorimotor impairment. A second, more speculative hypothesis was that, in relation to previously established deficits in prospective action control in individuals with hemiparetic CP, gaze patterns might be less anticipatory in general, also during actions performed with the less affected hand. Analysis of the gaze and hand movement data revealed the increased visual monitoring of participants with CP when using their affected hand at the beginning as well as during object transport. In contrast, no general deficit in anticipatory gaze control in the participants with hemiparetic CP could be observed. Collectively, these findings are the first to directly show that individuals with hemiparetic CP adapt eye–hand coordination to the specific constraints of the moving limb, presumably to compensate for sensorimotor deficits
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