Raw Materials are crucial in the development, production, and improvement of modern-day technology. Reliable access to critical, scarce, and valuable materials used in electronics is becoming a... Show moreRaw Materials are crucial in the development, production, and improvement of modern-day technology. Reliable access to critical, scarce, and valuable materials used in electronics is becoming a worldwide concern. Therefore, the quantification of material recovery from the urban mine is currently pursued worldwide. Commonly, data on (Waste) Electrical and Electronic Equipment is scattered, not harmo-nized, and uses different types of classifications and terminology. This provides a big challenge of a structured mapping of secondary raw materials in the urban mine. To address these issues, a state-of -the-art methodology has been developed and is presented by analyzing and tracking printed circuit boards in different key Electrical and Electronic Equipment over time. A total of 4051 composition data records where analyzed to extract the concentration of 19 elements in printed circuit boards between 1990 until 2020. The methodology harmonizes urban mine data, provides structured information that can be used to analyze and monitor the impact of product trends on their components and concentration of the elements in electronics. The resulting database and harmonization protocols are made freely available at the urban mine platform. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Ocean acidification is expected to impact the high latitude oceans first, as CO2 dissolves more easily in colder waters. At the current rate of anthropogenic CO2 emissions, the sub-Antarctic Zone... Show moreOcean acidification is expected to impact the high latitude oceans first, as CO2 dissolves more easily in colder waters. At the current rate of anthropogenic CO2 emissions, the sub-Antarctic Zone will start to experience undersaturated conditions with respect to aragonite within the next few decades, which will affect marine calcifying organisms. Shelled pteropods, a group of calcifying zooplankton, are considered to be especially sensitive to changes in carbonate chemistry because of their thin aragonite shells. Limacina retroversa is the most abundant pteropod in sub-Antarctic waters, and plays an important role in the carbonate pump. However, not much is known about its response to ocean acidification. In this study, we investigated differences in calcification between L. retroversa individuals exposed to ocean carbonate chemistry conditions of the past (pH 8.19; mid-1880s), present (pH 8.06), and near-future (pH 7.93; predicted for 2050) in the sub-Antarctic. After 3 days of exposure, calcification responses were quantified by calcein staining, shell weighing, and Micro-CT scanning. In pteropods exposed to past conditions, calcification occurred over the entire shell and the leading edge of the last whorl, whilst individuals incubated under present and near-future conditions mostly invested in extending their shells, rather than calcifying over their entire shell. Moreover, individuals exposed to past conditions formed larger shell volumes compared to present and future conditions, suggesting that calcification is already decreased in today's sub-Antarctic waters. Shells of individuals incubated under near-future conditions did not increase in shell weight during the incubation, and had a lower density compared to past and present conditions, suggesting that calcification will be further compromised in the future. This demonstrates the high sensitivity of L. retroversa to relatively small and short-term changes in carbonate chemistry. A reduction in calcification of L. retroversa in the rapidly acidifying waters of the sub-Antarctic will have a major impact on aragonite-CaCO3 export from oceanic surface waters to the deep sea. Show less
Shelled pteropods are widely regarded as bioindicators for ocean acidification, because their fragile aragonite shells are susceptible to increasing ocean acidity. While short-term incubations have... Show moreShelled pteropods are widely regarded as bioindicators for ocean acidification, because their fragile aragonite shells are susceptible to increasing ocean acidity. While short-term incubations have demonstrated that pteropod calcification is negatively impacted by ocean acidification, we know little about net calcification in response to varying ocean conditions in natural populations. Here, we examine in situ calcification of Limacina helicina pteropods collected from the California Current Ecosystem, a coastal upwelling system with strong spatial gradients in ocean carbonate chemistry, dissolved oxygen and temperature. Depth-averaged pH ranged from 8.03 in warmer offshore waters to 7.77 in cold CO2-rich waters nearshore. Based on high-resolution micro-CT technology, we showed that shell thickness declined by similar to 37% along the upwelling gradient from offshore to nearshore water. Dissolution marks covered only similar to 2% of the shell surface area and were not associated with the observed variation in shell thickness. We thus infer that pteropods make thinner shells where upwelling brings more acidified and colder waters to the surface. Probably the thinner shells do not result from enhanced dissolution, but are due to a decline in calcification. Reduced calcification of pteropods is likely to have major ecological and biogeochemical implications for the cycling of calcium carbonate in the oceans. Show less
The central circadian pacemaker in mammals, the suprachiasmatic nucleus (SCN), is important for daily as well as seasonal rhythms. The SCN encodes seasonal changes in day length by adjusting phase... Show moreThe central circadian pacemaker in mammals, the suprachiasmatic nucleus (SCN), is important for daily as well as seasonal rhythms. The SCN encodes seasonal changes in day length by adjusting phase distribution among oscillating neurons thereby shaping the output signal used for adaptation of physiology and behavior. It is well-established that brief light exposure at the beginning and end of the day, also referred to as "skeleton" light pulses, are sufficient to evoke the seasonal behavioral phenotype. However, the effect of skeleton light exposure on SCN network reorganization remains unknown. Therefore, we exposed mice to brief morning and evening light pulses that mark the time of dawn and dusk in a short winter- or a long summer day. Single-cell PER2::LUC recordings, electrophysiological recordings of SCN activity, and measurements of GABA response polarity revealed that skeleton light-regimes affected the SCN network to the same degree as full photoperiod. These results indicate the powerful, yet potentially harmful effects of even relatively short light exposures during the evening or night for nocturnal animals. Show less
Brink, S. van den; Kleijn, R.; Tukker, A.; Huisman, J. 2019
We evaluated the use of a mock scanner training protocol as an alternative for sedation and for preparing young children for (functional) magnetic resonance imaging (MRI). Children with severe... Show moreWe evaluated the use of a mock scanner training protocol as an alternative for sedation and for preparing young children for (functional) magnetic resonance imaging (MRI). Children with severe mental retardation or developmental disorders were excluded. A group of 90 children (median age 6.5 years, range 3.65-14.5 years) participated in this study. Children were referred to the actual MRI investigation only when they passed the training. We assessed the pass rate of the mock scanner training sessions. In addition, the quality of both structural and functional MRI (fMRI) scans was rated on a semi-quantitative scale. The overall pass rate of the mock scanner training sessions was 85/90. Structural scans of diagnostic quality were obtained in 81/90 children, and fMRI scans with sufficient quality for further analysis were obtained in 30/43 of the children. Even in children under 7 years of age, who are generally sedated, the success rate of structural scans with diagnostic quality was 53/60. FMRI scans with sufficient quality were obtained in 23/36 of the children in this younger age group. The association between age and proportion of children with fMRI scans of sufficient quality was not statistically significant. We conclude that a mock MRI scanner training protocol can be useful to prepare children for a diagnostic MRI scan. It may reduce the need for sedation in young children undergoing MRI. Our protocol is also effective in preparing young children to participate in fMRI investigations. Show less
Voordat ik vertel over de vier maanden die ik in Zweden heb beleefd zal ik me eerst even voorstellen. Ik ben Jorien Huisman, 4 e _jaars studente Bestuurskunde met een minor psychologie. Misschien... Show moreVoordat ik vertel over de vier maanden die ik in Zweden heb beleefd zal ik me eerst even voorstellen. Ik ben Jorien Huisman, 4 e _jaars studente Bestuurskunde met een minor psychologie. Misschien kennen sommige van jullie me van de B.I.L.-reis naar Moskou vorig jaar. Ik zat toen in de commissie buitenland. Een grote hobby van mij is, behalve sporten, reizen; overal heen, ontdekken en het liefst met zoveel mogelijk uitdagingen. Show less
