Partitioning of melt energy and meltwater fluxes in the ablation zone of the west Greenland ice sheet

We present four years (August 2003–August 2007) of surface mass balance data from the ablation zone of the west Greenland ice sheet along the 67° N latitude circle. Sonic height rangers and automatic weather stations continuously measured accumulation/ablation and near-surface climate at distances of 6, 38 and 88 km from the ice sheet margin at elevations of 490, 1020 and 1520 m a.s.l. Using a melt model and reasonable assumptions about snow density and percolation characteristics, these data are used to quantify the partitioning of energy and mass fluxes during melt episodes. The lowest site receives very little winter accumulation, and ice melting is nearly continuous in June, July and August. Due to the lack of snow accumulation, little refreezing occurs and virtually all melt energy is invested in runoff. Higher up the ice sheet, the ice sheet surface freezes up during the night, making summer melting intermittent. At the intermediate site, refreezing in snow consumes about 10% of the melt energy, increasing to 40% at the highest site. The sum of these effects is that total melt and runoff increase exponentially towards the ice sheet margin, each time doubling between the stations. At the two lower sites, we estimate that radiation penetration causes 20–30% of the ice melt to occur below the surface

Emissions of transboundary air pollutants in the Netherlands 1990-2012 : Informative Inventory Report 2014

Emissies Nederland blijven in 2012 onder nationale plafonds De uitstoot van stikstofoxiden (NOx), ammoniak, zwaveldioxide en niet-methaan vluchtige organische stoffen (NMVOS) is in 2012 in Nederland licht gedaald. Daarmee bleef de uitstoot onder de maxima die de Europese Unie daaraan sinds 2010 stelt. Nederland voldoet daardoor, net als in 2011, aan de vier 'nationale emissieplafonds' (NEC) voor deze stoffen. Dit blijkt uit de Nederlandse emissiecijfers van grootschalige luchtverontreinigende stoffen. Het RIVM verzamelt en analyseert deze cijfers. Behalve bovengenoemde stoffen gaat het om de uitstoot van koolmonoxide, fijn stof (PM10), zware metalen en persistente organische stoffen (POP's). De uitstoot van al deze stoffen is tussen 1990 en 2012 gedaald. Dit komt vooral door schonere auto's en brandstoffen en door emissiebeperkende maatregelen van industriële sectoren. Meer kilometers door bromfietsen Door de jaren heen zijn de methoden om de emissies te berekenen verbeterd, wat nu resulteert in nauwkeurigere cijfers. De emissies van bromfietsen en motorfietsen zijn afhankelijk van het aantal gereden kilometers per jaar en daar is nu beter inzicht in. Het totale aantal gereden kilometers door bromfietsen blijkt in de afgelopen jaren bijna twee keer zo hoog is als werd gedacht. Daarmee is de uitstoot van schadelijke stoffen navenant hoger. Ten opzichte van andere typ voertuigen blijven bromfietsen echter een relatief kleine emissiebron en dragen ze beperkt bij aan de totale nationale emissies. In steden zijn ze wel een relevante bron. Het aantal gereden kilometers door motorfietsen, en daarmee de uitstoot, blijft in lijn met eerdere inzichten. Vrachtauto's zwaarder beladen De uitstoot van schadelijke stoffen door vrachtauto's is voor het eerst berekend op basis van recente inzichten in het gewicht van vrachtauto's. Trekker-opleggers blijken zwaarder beladen dan tot nu toe werd verondersteld. Ook rijden vrachtauto's vaker met een aanhanger dan tot nu toe werd aangenomen, waardoor ze zwaarder zijn. Een hoger gewicht betekent een hoger brandstofverbruik, en veelal ook een hogere uitstoot per gereden kilometer. De uitstoot van PM10 door vrachtauto's is hierdoor circa 5 procent hoger dan in de vorige IIR-rapportage. Hogere emissies ammoniak De uitstoot van ammoniak blijkt hoger dan eerder werd verondersteld vanwege enkele nieuwe inzichten; de cijfers zijn hierdoor vanaf 1997 bijgesteld. Zo worden luchtwassers, die voornamelijk op varkensstallen zitten, niet altijd gebruikt. Ook is vanaf 2002 in melkveestallen het leefoppervlak per dier toegenomen. Door het grotere contactoppervlak van mest met lucht wordt meer ammoniak uitgestoten. Door de aangepaste aannames is het nationale totaal met 6,6 kiloton verhoogd ten opzichte van 2011.Emissions the Netherlands in 2012 remain under national ceilings Emissions of nitrogen oxides (NOx), ammonia, sulphur dioxide and non-methane volatile organic compounds (NMVOC) in the Netherlands have slightly decreased in 2012. Consequently, the emissions stayed below the caps the European Union has set from 2010. Herewith, the Netherlands comply with all four so-called emission ceilings (NEC). This has become apparent from the emission data on air pollutants from the Netherlands. RIVM collects and reports these data. Besides above-mentioned substances, emissions of carbon monoxide, particulate matter (PM10), heavy metals and persistent organic pollutants (POPs) have been reported. The emissions of all substances have decreased in the 1990 - 2012 period. The downward trend may in particular be attributed to cleaner fuels, cleaner car engines and to emission reductions in the industrial sectors. More kilometres by mopeds Over the years emission calculation methods have been improved, resulting in higher data accuracy. In 2012, the emissions from mopeds and motorcycles have been calculated, based on improved knowledge of the mileages. The total number of kilometres driven by mopeds appears to have been nearly twice as high in recent years. As a result, the emissions of pollutants are proportionally higher. In relation to the total number of vehicles, the number of mopeds however remains relatively low and their contribution to the total national emissions is limited. In cities, they are a relevant source. The mileages by motorcycles, and consequently their emissions remain in line with previous insights. Heavy-duty vehicles carry heavier loads Emissions of pollutants by heavy-duty trucks have for the first time been calculated on the basis of recent insights in truck loads. Tractor-trailer combinations appear to carry heavier loads and the fraction of trailers behind rigid trucks is larger than previously assumed. A heavier load means a higher fuel use and for most substances a higher emission per kilometre driven. PM10 emissions by heavy-duty trucks are about 5 percent higher than in the previous IIR report. Higher agricultural ammonia emissions Agricultural ammonia emissions appear to be higher than previously assumed because of new insights. Air scrubbers on animal housing (predominantly pigs) were not always in use or even employed. Since 2002, the living space per animal has increased for dairy cattle housing. This resulted in a higher contact surface manure-air and thus more ammonia emitted. The new insights have raised the national total of ammonia emissions by about 6 percent compared to 2011

A Dutch MYH7 founder mutation, p.(Asn1918Lys), is associated with early onset cardiomyopathy and congenital heart defects

Background Mutations in the myosin heavy chain 7 (MYH7) gene commonly cause cardiomyopathy but are less frequently associated with congenital heart defects. Methods In th

SNP association study in PMS2-associated Lynch syndrome

Lynch syndrome (LS) patients are at high risk of developing colorectal cancer (CRC). Phenotypic variability might in part be explained by common susceptibility loci identified in Genome Wide Association Studies (GWAS). Previous studies focused mostly on MLH1, MSH2 and MSH6 carriers, with conflicting results. We aimed to determine the role of GWAS SNPs in PMS2 mutation carriers. A cohort study was performed in 507 PMS2 carriers (124 CRC cases), genotyped for 24 GWAS SNPs, including SNPs at 11q23.1 and 8q23.3. Hazard ratios (HRs) were calculated using a weighted Cox regression analysis to correct for ascertainment bias. Discrimination was assessed with a concordance statistic in a bootstrap cross-validation procedure. Individual SNPs only had non-significant associations with CRC occurrence with HRs lower than 2, although male carriers of allele A at rs1321311 (6p21.31) may have increased risk of CRC (HR = 2.1, 95% CI 1.2–3.0). A polygenic risk score (PRS) based on 24 HRs had an HR of 2.6 (95% CI 1.5–4.6) for the highest compared to the lowest quartile, but had no discriminative ability (c statistic 0.52). Previously suggested SNPs do not modify CRC risk in PMS2 carriers. Future large studies are needed for improved risk stratification among Lynch syndrome patients

De geprotocolleerde Interapy-behandeling van depressie via het internet; resultaten van een gerandomiseerde trial

Psychologische behandelingen via internet bieden een nieuwe mogelijkheid voor de geestelijke gezondheidszorg. In samenwerking met de Stichting Mentrum ggz Amsterdam heeft Interapy een behandeling voor depressie via internet opgezet. De behandeling bestaat uit cognitief-gedragstherapeutische interventies, zoals psycho-educatie, schrijfopdrachten, registratie, activatie, het uitdagen van negatieve automatische gedachten en terugvalpreventie. Dit artikel beschrijft de procedure, de behandeling en de resultaten van een vergelijkende studie onder cliënten die matig tot ernstig depressief waren. De cliënten die direct actief werden behandeld (N = 32) verbeterden significant meer dan de cliënten in de psycho-educatieconditie (N = 14). Deze tweede groep kreeg de actieve behandeling ongeveer twaalf weken later. De effecten waren groot. In de actief behandelde groep liet 75 procent van de cliënten klinisch relevante verbetering zien, in de psycho-educatieconditie was dat percentage 36. Uit de follow-up na zes weken bleek dat de verbeteringen standhielden

Seasonal speedup of a Greenland marine-terminating outlet glacier forced by surface melt–induced changes in subglacial hydrology

Peer reviewedPublisher PD

An introduction to InP-based generic integration technology

Photonic integrated circuits (PICs) are considered as the way to make photonic systems or subsystems cheap and ubiquitous. PICs still are several orders of magnitude more expensive than their microelectronic counterparts, which has restricted their application to a few niche markets.Recently, a novel approach in photonic integration is emerging which will reduce the R&D and prototyping costs and the throughput time of PICs by more than an order of magnitude. It will bring the application of PICs that integrate complex and advanced photonic functionality on a single chip within reach for a large number of small and larger companies and initiate a breakthrough in the application of Photonic ICs. The paper explains the concept of generic photonic integration technology using the technology developed by the COBRA research institute of TU Eindhoven as an example, and it describes the current status and prospects of generic InP-based integration technology.Funding is acknowledged by the EU-projects ePIXnet, EuroPIC and PARADIGM and the Dutch projects NRC Photonics, MEMPHIS, IOP Photonic Devices and STW GTIP. Many others have contributed and the authors would like to thank other PARADIGM and EuroPIC partners for their help in discussions, particularly Michael Robertson (CIP).This is the final published version distributed under a Creative Commons Attribution License. It can also be viewed on the publisher's website at: http://iopscience.iop.org/0268-1242/29/8/08300

Mineral phosphorus drives glacier algal blooms on the Greenland Ice Sheet

Melting of the Greenland Ice Sheet is a leading cause of land-ice mass loss and cryosphere-attributed sea level rise. Blooms of pigmented glacier ice algae lower ice albedo and accelerate surface melting in the ice sheet’s southwest sector. Although glacier ice algae cause up to 13% of the surface melting in this region, the controls on bloom development remain poorly understood. Here we show a direct link between mineral phosphorus in surface ice and glacier ice algae biomass through the quantification of solid and fluid phase phosphorus reservoirs in surface habitats across the southwest ablation zone of the ice sheet. We demonstrate that nutrients from mineral dust likely drive glacier ice algal growth, and thereby identify mineral dust as a secondary control on ice sheet melting.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Verification of model simulated mass balance, flow fields and tabular calving events of the Antarctic ice sheet against remotely sensed observations

The Antarctic ice sheet (AIS) has the greatestpotential for global sea level rise. This study simulates AISice creeping, sliding, tabular calving, and estimates the totalmass balances, using a recently developed, advanced icedynamics model, known as SEGMENT-Ice. SEGMENTIceis written in a spherical Earth coordinate system.Because the AIS contains the South Pole, a projectiontransfer is performed to displace the pole outside of thesimulation domain. The AIS also has complex ice-watergranularmaterial-bedrock configurations, requiringsophisticated lateral and basal boundary conditions.Because of the prevalence of ice shelves, a ‘girder yield’type calving scheme is activated. The simulations of presentsurface ice flow velocities compare favorably with InSARmeasurements, for various ice-water-bedrock configurations.The estimated ice mass loss rate during 2003–2009agrees with GRACE measurements and provides morespatial details not represented by the latter. The modelestimated calving frequencies of the peripheral ice shelvesfrom 1996 (roughly when the 5-km digital elevation andthickness data for the shelves were collected) to 2009compare well with archived scatterometer images. SEGMENT-Ice’s unique, non-local systematic calving schemeis found to be relevant for tabular calving. However, theexact timing of calving and of iceberg sizes cannot besimulated accurately at present. A projection of the futuremass change of the AIS is made, with SEGMENT-Iceforced by atmospheric conditions from three differentcoupled general circulation models. The entire AIS is estimatedto be losing mass steadily at a rate of*120 km3/a atpresent and this rate possibly may double by year 2100