Is routine karyotyping required in prenatal samples with a molecular or metabolic referral?

As a routine, karyotyping of invasive prenatal samples is performed as an adjunct to referrals for DNA mutation detection and metabolic testing. We performed a retrospective study on 500 samples to assess the diagnostic value of this procedure. These samples included 454 (90.8%) chorionic villus (CV) and 46 (9.2%) amniocenteses specimens. For CV samples karyotyping was based on analyses of both short-term culture (STC) and long-term culture (LTC) cells. Overall, 19 (3.8%) abnormal karyotypes were denoted: four with a common aneuploidy (trisomy 21, 18 and 13), two with a sex chromosomal aneuploidy (Klinefelter syndrome), one with a sex chromosome mosaicism and twelve with various autosome mosaicisms. In four cases a second invasive test was performed because of an abnormal finding in the STC. Taken together, we conclude that STC and LTC karyotyping has resulted in a diagnostic yield of 19 (3.8%) abnormal cases, including 12 cases (2.4%) with an uncertain significance. From a diagnostic point of view, it is desirable to limit uncertain test results as secondary test findings. Therefore, we recommend a more targeted assay, such as e.g. QF-PCR, as a replacement of the STC and to provide parents the autonomy to choose between karyotyping and QF-PCR

Assessment of groundwater status in accordance with the Water Framework Directive

Dit rapport bevat een erratum d.d. 9 januari 2008 op de laatste paginaDe Europese Kaderrichtlijn Water (KRW) moet ervoor zorgen dat de kwaliteit van het oppervlakte- en grondwater in Europa in 2015 op orde komt. Het grondwater moet daarbij niet alleen aan zijn eigen doelstellingen voldoen, voldoende water van goede kwaliteit, maar ook aan de doelstellingen van de ecosystemen die door kwellend grondwater worden beinvloed. Het grondwater mag geen negatieve invloed hebben op de bijbehorende oppervlaktewateren en grondwaterafhankelijke terrestrische ecosystemen. In dit rapport wordt een beoordelingsmethode voorgesteld om vast te stellen wanneer de toestand van het grondwater niet voldoet aan de doelstellingen van de bijbehorende aquatische en terrestrische ecosystemen. Deze beoordeling gaat enerzijds uit van de doelstellingen voor de bijbehorende oppervlaktewateren en de grondwaterafhankelijke terrestrische ecosystemen en anderzijds van de beschikbare meetgegevens over de toestand van het oppervlaktewater, het terrestrisch systeem en het grondwater. Waarschijnlijk zal de grondwatertoestand door verdroging en de uitspoeling van bijvoorbeeld nutrienten, bestrijdingsmiddelen en zware metalen in een aantal gebieden niet voldoen aan de doelstellingen voor het oppervlaktewater en de terrestrische ecosystemen. Het al in gang gezette mestbeleid, verdrogingbeleid en de KRW zelf zullen een deel van de problemen oplossen. Daarnaast geeft het rapport voor een groot aantal landschaptypen met een grote natuurbehoudswaarde een overzicht van de ecohydrologische relaties en potentiele bedreigingen door aantasting van het grondwaterlichaam.The European Water Framework Directive (WFD) requires that all inland and coastal waters must reach a good chemical and ecological status by 2015. According to Annex V of the WFD, groundwater should not only meet its own environmental objectives, ensuring "sufficient water of good quality", but also the objectives for the ecosystems affected by groundwater seepage. Groundwater may not have a negative influence on associated surface waters and groundwater-dependent terrestrial ecosystems. This report presents an assessment system to determine when the status of the groundwater fails to meet the WFD objectives for the surface waters and terrestrial ecosystems which are directly associated with the groundwater body. In the assessment, the monitoring data available on the status of the groundwater and the associated surface water and terrestrial ecosystems are compared to the objectives which have been achieved for these systems. The environmental objectives for surface water and terrestrial ecosystems in a number of regions will most likely not be met due to groundwater drawdown and the drainage of, for example, nutrients, pesticides and heavy metals. Current polices on manure and fertilizer application, water drawdown and sanitation, including those of WFD, will improve the present groundwater situation. This report also presents an overview of the eco-hydrological relations of a large number of ecologically valuable Dutch landscapes as well as the potential threats to these landscapes when the groundwater system is adversely affected. This information is essential for the management of nature reserves in the Netherlands.VROM-DG

Mobilizing cognition for speeded action: try-harder instructions promote motivated readiness in the constant-foreperiod paradigm

We examined the effect of motivational readiness on cognitive performance. An important but still not sufficiently elaborated question is whether individuals can voluntarily increase cognitive efficiency for an impending target event, given sufficient preparation time. Within the framework of the constant-foreperiod design (comparing reaction time performance in blocks of short and long foreperiod intervals, FPs), we examined the effect of an instruction to try harder (instructional cue: standard vs. effort) in a choice-reaction task on performance speed and variability. Proceeding from previous theoretical considerations, we expected the instruction to speed-up processing irrespective of FP length, while error rate should be increased in the short-FP but decreased in the long-FP condition. Overall, the results confirmed this prediction. Importantly, the distributional (ex-Gaussian and delta plot) analysis revealed that the instruction to try harder decreased distributional skewness (i.e., longer percentiles were more affected), indicating that mobilization ensured temporal performance stability (persistence)