358 research outputs found
Effect analysis of transient scenarios for successful water management strategies
Recent scenario studies on water management focus on one or two projection years and the effects on the water system and functions. The future is however more complex and dynamic. Therefore, we analyse transient scenarios in order to evaluate the performance of water management strategies. Current available simulation tools are not suitable for this purpose. Therefore, we have developed and used a tool to simulate 50-100 year long time series and that is good and fast enough to simulate the effects of these scenarios and strategies on the water system and the interaction with the human system. We present the first step by means of a case study
Exploring high-end climate change scenarios for flood protection of the Netherlands
This international scientific assessment has been carried out at the request of the Dutch Delta Committee. The "Deltacommissie" requested that the assessment explore the high-end climate change scenarios for flood protection of the Netherlands. It is a state-of–the art scientific assessment of the upper bound values and longer term projections (for sea level rise up to 2200) of climate induced sea level rise, changing storm surge conditions and peak discharge of river Rhine. It comprises a review of recent studies, model projections and expert opinions of more than 20 leading climate scientists from different countries around the North Sea, Australia and the US
An outbreak of severe respiratory tract infection caused by human metapneumovirus in a residential care facility for elderly in Utrecht, the Netherlands, January to March 2010
Recognition of infections with human metapneumovirus (HMPV) among institutionalised elderly is rising. When HMPV was found to be the causative agent of an outbreak of pneumonia in a residential care facility for elderly in the Netherlands, an elaborate outbreak investigation was set up, including active surveillance for new cases. From clinical cases, defined by fever (> 38°C) and symptoms of respiratory tract infections, respiratory samples for analyses of viral pathogens by real-time Reverse Transcriptase Polymerase Chain Reaction (rRT-PCR) and blood samples for determination of HMPV-specific IgM and IgG antibody titres were taken. Five staff members and 18 residents fulfilled the clinical case definition. Of those, five residents tested positive for HMPV by rRT-PCR. The combination of rRT-PCR and serology identified nine confirmed cases, six probable cases, six possible cases and ruled out two persons as cases. Among residents, the outbreak of HMPV had an attack rate, ranging from 5% for laboratory-confirmed cases, to 13% for clinical cases. This outbreak investigation shows that HMPV is a potential serious pathogen for institutionalised elderly
Light, alertness, and alerting effects of white light:A literature overview
Light is known to elicit non-image-forming responses, such as effects on alertness. This has been reported especially during light exposure at night. Nighttime results might not be translatable to the day. This article aims to provide an overview of (1) neural mechanisms regulating alertness, (2) ways of measuring and quantifying alertness, and (3) the current literature specifically regarding effects of different intensities of white light on various measures and correlates of alertness during the daytime. In general, the present literature provides inconclusive results on alerting effects of the intensity of white light during daytime, particularly for objective measures and correlates of alertness. However, the various research paradigms employed in earlier studies differed substantially, and most studies tested only a limited set of lighting conditions. Therefore, the alerting potential of exposure to more intense white light should be investigated in a systematic, dose-dependent manner with multiple correlates of alertness and within one experimental paradigm over the course of day
Daytime melatonin and light independently affect human alertness and body temperature
Light significantly improves alertness during the night (Cajochen, Sleep Med Rev, 11, 2007 and 453; Ruger et al., AJP Regul Integr Comp Physiol, 290, 2005 and R1413), but results are less conclusive at daytime (Lok et al., J Biol Rhythms, 33, 2018 and 589). Melatonin and core body temperature levels at those times of day may contribute to differences in alerting effects of light. In this experiment, the combined effect of daytime exogenous melatonin administration and light intensity on alertness, body temperature, and skin temperature was studied. The goal was to assess whether (a) alerting effects of light are melatonin dependent, (b) soporific effects of melatonin are mediated via the thermoregulatory system, and (c) light can improve alertness after melatonin-induced sleepiness during daytime. 10 subjects (5 females, 5 males) received melatonin (5 mg) in dim (10 lux) and, on a separate occasion, in bright polychromatic white light (2000 lux). In addition, they received placebo both under dim and bright light conditions. Subjects participated in all four conditions in a balanced order, yielding a balanced within-subject design, lasting from noon to 04:00 pm. Alertness and performance were assessed half hourly, while body temperature and skin temperature were measured continuously. Saliva samples to detect melatonin concentrations were collected half hourly. Melatonin administration increased melatonin concentrations in all subjects. Subjective sleepiness and distal skin temperature increased after melatonin ingestion. Bright light exposure after melatonin administration did not change subjective alertness scores, but body temperature and proximal skin temperature increased, while distal skin temperature decreased. Light exposure did not significantly affect these parameters in the placebo condition. These results indicate that (a) exogenous melatonin administration during daytime increases subjective sleepiness, confirming a role for melatonin in sleepiness regulation, (b) bright light exposure after melatonin ingestion significantly affected thermoregulatory parameters without altering subjective sleepiness, therefore temperature changes seem nonessential for melatonin-induced sleepiness, (c) subjective sleepiness was increased by melatonin ingestion, but bright light administration was not able to improve melatonin-induced sleepiness feelings nor performance. Other (physiological) factors may therefore contribute to differences in alerting effects of light during daytime and nighttime
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