Use of Otolith Strontium:Calcium Ratios for Hindcasting Larval Cod Gadus Morhua Distributions Relative to Water Masses on Georges Bank

The concentration ratios of strontium to calcium in laboratory-reared larval cod otoliths are shown to be related to the water temperature (T) at the time of otolith precipitation. This relationship is curvilinear, and is best described by a simple exponential equation of the form (Sr/Ca x 1000 = a exp(-T/b). We show that when Sr/Ca elemental analyses are related to the daily growth increments in the larval otoliths, relative temperature histories of individual field-caught larvae can be reconstructed from the egg stage to the time of capture. We present preliminary examples of how such reconstructed temperature histories of Atlantic cod Gadus morhua larvae, collected on Georges Bank during April and May 1993, may be interpreted in relation to the broad-scale larval distributions and the hydrography of the Bank

Visible light emission from reverse-biased silicon nanometer-scale diode-antifuses

Silicon nanometer-scale diodes have been fabricated to emit light in the visible range at low power consumption. Such structures are candidates for emitter elements in Si-based optical interconnect schemes. Spectral measurements of Electroluminescence (EL) on the reverse-biased nanometer-scale diodes brought into breakdown have been carried out over the photon energy range of 1.4-2.8 eV. Previously proposed mechanisms for avalanche emission from conventional silicon p-n junctions are discussed in order to understand the origin of the emission. Also the stability of the diodes has been tested. Results indicate that our nanometer-scale diodes are basically high quality devices. Furthermore due to the nanometer-scale dimensions, very high electrical fields and current densities are possible at low power consumption. This makes these diodes an excellent candidate to be utilized as a light source in Si-based sensors and actuator application

Observations of the Eastern Maine Coastal Current and Its Offshore Extensions in 1994

Cold surface temperatures, reflecting Scotian Shelf origins and local tidal mixing, serve as a tracer of the Eastern Maine Coastal Current and its offshore extensions, which appear episodically as cold plumes erupting from the eastern Maine shelf. A cold water plume emanating from the Eastern Maine Coastal Current in May 1994 was investigated using advanced very high resolution radiometer (AVHRR) imagery, shipboard surveys of physical and biochemical properties, and satellite-tracked drifters. Evidence is presented that suggests that some of the plume waters were entrained within the cyclonic circulation over Jordan Basin, while the major portion participated in an anticyclonic eddy at the distal end of the plume. Calculations of the nitrate transported offshore by the plume show that this feature can episodically export significant quantities of nutrients from the Eastern Maine Coastal Current to offshore regions that are generally nutrient depleted during spring-summer. A series of AVHRR images is used to document the seasonal along-shelf progression of the coastal plume separation point. We speculate on potential causes and consequences of plume separation from the coastal current and suggest that this feature may be an important factor influencing the patterns and overall biological productivity of the eastern Gulf of Maine

Observations of the Eastern Maine Coastal Current and Its Offshore Extensions in 1994

Cold surface temperatures, reflecting Scotian Shelf origins and local tidal mixing, serve as a tracer of the Eastern Maine Coastal Current and its offshore extensions, which appear episodically as cold plumes erupting from the eastern Maine shelf. A cold water plume emanating from the Eastern Maine Coastal Current in May 1994 was investigated using advanced very high resolution radiometer (AVHRR) imagery, shipboard surveys of physical and biochemical properties, and satellite-tracked drifters. Evidence is presented that suggests that some of the plume waters were entrained within the cyclonic circulation over Jordan Basin, while the major portion participated in an anticyclonic eddy at the distal end of the plume. Calculations of the nitrate transported offshore by the plume show that this feature can episodically export significant quantities of nutrients from the Eastern Maine Coastal Current to offshore regions that are generally nutrient depleted during spring-summer. A series of AVHRR images is used to document the seasonal along-shelf progression of the coastal plume separation point. We speculate on potential causes and consequences of plume separation from the coastal current and suggest that this feature may be an important factor influencing the patterns and overall biological productivity of the eastern Gulf of Maine

Staat van infectieziekten in Nederland, 2013

In dit rapport wordt gelinked naar een bijlage: appendix150205001.De uitbraak van mazelen in 2013 was de meest in het oog springende infectieziekte van dat jaar. Dit blijkt uit de Staat van Infectieziekten in Nederland 2013, die inzicht geeft in ontwikkelingen van infectieziekten bij de Nederlandse bevolking. Daarnaast worden de ontwikkelingen in het buitenland beschreven die voor Nederland relevant zijn. Met deze jaarlijkse uitgave informeert het RIVM beleidsmakers van het ministerie van Volksgezondheid, Welzijn en Sport (VWS). Elk jaar komt in de Staat van Infectieziekten een thema aan bod; dit jaar is dat de hoeveelheid jaren in goede gezondheid die verloren gaan (ziektelast) door infectieziekten. Sommige infectieziekten, zoals maag-darminfecties, komen erg vaak voor maar veroorzaken over het algemeen geen ernstige klachten. Andere daarentegen, bijvoorbeeld tetanus, komen slechts zelden voor maar veroorzaken relatief veel sterfgevallen. Een gezondheidsmaat die deze aspecten van ziekten combineert is de Disability Adjusted Life Year (DALY). Voor 32 infectieziekten is de ziektelast in Nederland tussen 2007 en 2011 geschat. De gemiddelde jaarlijkse ziektelast voor de totale Nederlandse bevolking was het hoogst voor ernstige pneumokokkenziekte (9444 DALY's per jaar) en griep (8670 DALY's per jaar), die respectievelijk 16 en 15 procent van de totale ziektelast van alle 32 infectieziekten vertegenwoordigen. Na polio en difterie (0 gevallen in de onderzochte periode), werd de laagste ziektelast geschat voor rodehond op 0,14 DALY's per jaar. De ziektelast voor deze ziekten is zo laag dankzij het Rijksvaccinatieprogramma. De ziektelast per individu varieerde van 0,2 DALY's per honderd infecties voor giardiasis (diarree die wordt veroorzaakt door een parasiet), tot 5081 en 3581 DALY's per honderd infecties voor respectievelijk hondsdolheid en een variant van de ziekte van Creutzfeldt-Jakob. Voor alle ziektelaststudies geldt dat de resultaten afhankelijk zijn van de modelparameters en aannames, en van de beschikbaarheid van accurate gegevens over de mate waarin de ziekten voorkomen. Toch kunnen deze schattingen informatief zijn voor beleidsmakers binnen de gezondheidszorg om prioriteiten te kunnen aanbrengen in preventieve en andere maatregelen.The measles outbreak in 2013 was the most striking infectious disease of that year. This is demonstrated in the State of Infectious Diseases in the Netherlands 2013, which provides insight into infectious disease trends in the Dutch population. Developments in other countries that are relevant for the Netherlands are also described. This annual RIVM publication informs policy-makers from the Ministry of Health, Welfare and Sport (VWS). Every year the State of Infectious Diseases in the Netherlands publishes reports on a particular theme. This year's topic concerns the estimation of disease burden: how many years of health life are lost due to infectious diseases? Some infectious diseases, such as gastrointestinal infections, occur frequently in the population, but do not generally give rise to serious complaints. In contrast, other diseases, for example tetanus, occur rarely but may lead to a high risk of death. A summary measure of population health that combines the morbidity and premature mortality attributable to a disease in a single quantity is the Disability Adjusted Life Year (DALY). For 32 infectious diseases, we estimated the disease burden in the Netherlands between 2007 and2011. The highest average annual burden for the total Netherlands population was estimated for invasive pneumococcal disease (9444 DALYs per year) and influenza (8670 DALYs per year), which represent 16 and 15 percent, respectively, of the total burden of all 32 diseases considered. After poliomyelitis and diphtheria (no cases in the period investigated), the lowest burden was estimated for rubella, at 0.14 DALYs per year. The extremely low burden for these diseases is due to the National Immunization Programme. The disease burden per individual varied from 0.2 DALYs per 100 infections for giardiasis (diarrhea that is caused by a parasite), to 5081 and 3581 DALYs per 100 infections for rabies and variant Creutzfeldt-Jakob disease, respectively. As with all burden of disease studies, results depend on disease model parameters and assumptions and on the availability of accurate data on the incidence of infection. Nevertheless, estimates of disease burden can be informative for public health policy-makers regarding the prioritization of preventive and other measures.Ministerie van VW

On the selective deposition of tin and tin oxide on various glasses using a high power diode laser

The deposition of SnO2 using a 120 W high power diode laser (HPDL) on both fused silica and soda-lime-silica glass has been successfully demonstrated. Deposition on both glass substrates was carried out with laser power densities of 650-1600 W cm-2 and at rates of 420-1550 mm min-1. The thickness of the deposited layers was typically around 250 m. The maximum theoretical coverage rate that it may be possible to achieve using the HPDL was calculated as being 3.72 m2 h-1. Owing to the wettability characteristics of Sn, it proved impossible to deposit the metal on either glass substrate. Evidence of solidified microstructures was observed, with the microstructures differing considerably across the same deposited track. These differences were attributed to variations in the solidification rate, R, and the thermal gradient, G. Adhesion of the SnO2 with the soda-lime-silica glass was found to be due to mechanical bonding. The adhesion of the SnO2 with the fused silica was seen to the result of a chemical bond arising from an interface region between the SnO2 and the fused silica glass substrate. This interface region was found to be comprised of mainly Si and rich with Sn3O4

Palaeoecological study of a Weichselian wetland site in the Netherlands suggests a link with Dansgaard-Oeschger climate oscillation

Botanical microfossils, macroremains and oribatid mites of a Weichselian interstadial deposit in the central Netherlands point to a temporary, sub-arctic wetland in a treeless landscape. Radiocarbon dates and OSL dates show an age between ca. 54.6 and 46.6 ka cal BP. The vegetation succession, starting as a peat-forming wetland that developed into a lake, might well be linked with a Dansgaard-Oeschger climatic cycle. We suggest that during the rapid warming at the start of a D-O cycle, relatively low areas in the landscape became wetlands where peat was formed. During the more gradual temperature decline that followed, evaporation diminished; the wetlands became inundated and lake sediments were formed. During subsequent sub-arctic conditions the interstadial deposits were covered with wind-blown sand. Apart from changes in effective precipitation also the climate-related presence and absence of permafrost conditions may have played a role in the formation of the observed sedimentological sequence from sand to peat, through lacustrine sediment, with coversand on top. The Wageningen sequence may correspond with D-O event 12, 13 or 14. Some hitherto not recorded microfossils were described and illustrated

The time to extinction for an SIS-household-epidemic model

We analyse a stochastic SIS epidemic amongst a finite population partitioned into households. Since the population is finite, the epidemic will eventually go extinct, i.e., have no more infectives in the population. We study the effects of population size and within household transmission upon the time to extinction. This is done through two approximations. The first approximation is suitable for all levels of within household transmission and is based upon an Ornstein-Uhlenbeck process approximation for the diseases fluctuations about an endemic level relying on a large population. The second approximation is suitable for high levels of within household transmission and approximates the number of infectious households by a simple homogeneously mixing SIS model with the households replaced by individuals. The analysis, supported by a simulation study, shows that the mean time to extinction is minimized by moderate levels of within household transmission

Monitoring the spread of meticillin-resistant Staphylococcus aureus in The Netherlands from a reference laboratory perspective

SummaryBackgroundIn The Netherlands, efforts to control meticillin-resistant Staphylococcus aureus (MRSA) in hospitals have been largely successful due to stringent screening of patients on admission and isolation of those that fall into defined risk categories. However, Dutch hospitals are not free of MRSA, and a considerable number of cases are found that do not belong to any of the risk categories. Some of these may be due to undetected nosocomial transmission, whereas others may be introduced from unknown reservoirs.AimIdentifying multi-institutional clusters of MRSA isolates to estimate the contribution of potential unobserved reservoirs in The Netherlands.MethodsWe applied a clustering algorithm that combines time, place, and genetics to routine data available for all MRSA isolates submitted to the Dutch Staphylococcal Reference Laboratory between 2008 and 2011 in order to map the geo-temporal distribution of MRSA clonal lineages in The Netherlands.FindingsOf the 2966 isolates lacking obvious risk factors, 579 were part of geo-temporal clusters, whereas 2387 were classified as MRSA of unknown origin (MUOs). We also observed marked differences in the proportion of isolates that belonged to geo-temporal clusters between specific multi-locus variable number of tandem repeat analysis (MLVA) clonal complexes, indicating lineage-specific transmissibility. The majority of clustered isolates (74%) were present in multi-institutional clusters.ConclusionThe frequency of MRSA of unknown origin among patients lacking obvious risk factors is an indication of a largely undefined extra-institutional but genetically highly diverse reservoir. Efforts to understand the emergence and spread of high-risk clones require the pooling of routine epidemiological information and typing data into central databases