Explaining variability in ciclosporin exposure in adult kidney transplant recipients

International audienc

Environmental health guideline for Municipal Public Health Services : Mercury in the indoor environment and health

Het RIVM heeft, in opdracht van het ministerie van VWS, met de GGD'en de richtlijn 'Kwik in het binnenmilieu en gezondheid' ontwikkeld. Hoewel de verkoop van de meeste kwikhoudende producten is verboden, blijven kwikincidenten mogelijk als oude, kwikhoudende, producten breken en daarbij vloeibare kwik vrijkomt. Hierdoor hebben GGD-medewerkers medische milieukunde behoefte aan informatie over de blootstellingsbepaling, de gezondheidskundige advieswaarden en de opruimprocedure na kwikincidenten. Kwikzilver, zoals vloeibaar kwik ook wel wordt genoemd, heeft meer negatieve effecten op de gezondheid dan de meeste mensen vermoeden en is daardoor een onderschat probleem. Langdurige blootstelling aan lage concentraties kwikdamp kan leiden tot ernstige gezondheidseffecten. Mensen kunnen gedurende langere tijd aan kwikdamp blootgesteld worden als kwik binnenshuis achterblijft na breuk van een kwikhoudend product. Een kleine hoeveelheid kwik kan gemakkelijk achterblijven in de vloerbedekking of in een kier, hoewel het lijkt alsof alles is verwijderd. Het doel van deze richtlijn is GGD-medewerkers achtergrondinformatie te geven en een handvat te bieden bij het beoordelen van kwikincidenten. De richtlijn geeft de benodigde informatie voor een zorgvuldige risicoanalyse en geeft adviezen over te nemen maatregelen. Een stappenplan is ontwikkeld als hulpmiddel bij de behandeling van een kwikincident. Tevens worden de mogelijkheden besproken om kwikincidenten in het binnenmilieu te voorkomen door bijvoorbeeld voorlichting te geven of door het inwisselen van thermometers aan te bieden. In de bijlagen staan voorbeeldteksten voor voorlichtingsdoeleinden.Although the sale of most mercury containing products is prohibited, mercury spills are still possible as old, mercury containing, products may break and release liquid mercury. Therefore, environmental health workers at the Municipal Public Health Services (GGD) need information concerning exposure assessment, health-based guideline values and clean-up procedures after mercury spills. For this purpose, the Ministry of Health, Welfare and Sport (VWS) commissioned the National Institute for Public Health and the Environment (RIVM) and the Municipal Public Health Services (GGD) to draw up a guideline on mercury in the indoor environment and health. Exposure to mercury leads to more adverse health effects than most people anticipate and is therefore an underestimated problem. Long-term exposure to low concentrations of mercury vapour can lead to serious health effects. People can be exposed to mercury vapour for a long time if traces of mercury remain indoors after breakage of a mercury containing product. Traces of mercury can easily be left unseen in floor carpeting or in a small crack after apparent cleaning. This guideline is aimed at providing Municipal Public Health Service workers with background information and it is an instrument for assessing mercury spills. The guideline provides the information required for a careful risk assessment and gives advice on measures to be taken. A step-by-step plan has been developed as guidance for the assessment of mercury spills. Possibilities to prevent mercury spills indoors are discussed, such as facilitating the exchange of mercury containing thermometers and providing information and education. The appendices contain example letters for education and information purposes.VW

Reference frames for reaching when decoupling eye and target position in depth and direction

Spatial representations in cortical areas involved in reaching movements were traditionally studied in a frontoparallel plane where the two-dimensional target location and the movement direction were the only variables to consider in neural computations. No studies so far have characterized the reference frames for reaching considering both depth and directional signals. Here we recorded from single neurons of the medial posterior parietal area V6A during a reaching task where fixation point and reaching targets were decoupled in direction and depth. We found a prevalent mixed encoding of target position, with eye-centered and spatiotopic representations differently balanced in the same neuron. Depth was stronger in defining the reference frame of eye-centered cells, while direction was stronger in defining that of spatiotopic cells. The predominant presence of various typologies of mixed encoding suggests that depth and direction signals are processed on the basis of flexible coordinate systems to ensure optimal motor response

Sensory transformations and the use of multiple reference frames for reach planning

The sensory signals that drive movement planning arrive in a variety of “reference frames”, so integrating or comparing them requires sensory transformations. We propose a model where the statistical properties of sensory signals and their transformations determine how these signals are used. This model captures the patterns of gaze-dependent errors found in our human psychophysics experiment when the sensory signals available for reach planning are varied. These results challenge two widely held ideas: error patterns directly reflect the reference frame of the underlying neural representation, and it is preferable to use a single common reference frame for movement planning. We show that gaze-dependent error patterns, often cited as evidence for retinotopic reach planning, can be explained by a transformation bias and are not exclusively linked to retinotopic representations. Further, the presence of multiple reference frames allows for optimal use of available sensory information and explains task-dependent reweighting of sensory signals