1,976 research outputs found
Three years of greenhouse gas column-averaged dry air mole fractions retrieved from satellite – Part 2: Methane
Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases. SCIAMACHY on ENVISAT is the first satellite instrument whose measurements are sensitive to concentration changes of the two gases at all altitude levels down to the Earth's surface where the source/sink signals are largest. We have processed three years (2003–2005) of SCIAMACHY near-infrared nadir measurements to simultaneously retrieve vertical columns of CO2 (from the 1.58 µm absorption band), CH4 (1.66 µm) and oxygen (O2 A-band at 0.76 µm) using the scientific retrieval algorithm WFM-DOAS. We show that the latest version of WFM-DOAS, version 1.0, which is used for this study, has been significantly improved with respect to its accuracy compared to the previous versions while essentially maintaining its high processing speed (~1 min per orbit, corresponding to ~6000 single measurements, and per gas on a standard PC). The greenhouse gas columns are converted to dry air column-averaged mole fractions, denoted XCO2 (in ppm) and XCH4 (in ppb), by dividing the greenhouse gas columns by simultaneously retrieved dry air columns. For XCO2 dry air columns are obtained from the retrieved O2 columns. For XCH4 dry air columns are obtained from the retrieved CO2 columns because of better cancellation of light path related errors compared to using O2 columns retrieved from the spectrally distant O2 A-band. Here we focus on a discussion of the XCH4 data set. The XCO2 data set is discussed in a separate paper (Part 1). For 2003 we present detailed comparisons with the TM5 model which has been optimally matched to highly accurate but sparse methane surface observations. After accounting for a systematic low bias of ~2% agreement with TM5 is typically within 1–2%. We investigated to what extent the SCIAMACHY XCH4 is influenced by the variability of atmospheric CO2 using global CO2 fields from NOAA's CO2 assimilation system CarbonTracker. We show that the CO2 corrected and uncorrected XCH4 spatio-temporal pattern are very similar but that agreement with TM5 is better for the CarbonTracker CO2 corrected XCH4. In line with previous studies (e.g., Frankenberg et al., 2005b) we find higher methane over the tropics compared to the model. We show that tropical methane is also higher when normalizing the CH4 columns with retrieved O2 columns instead of CO2. In consistency with recent results of Frankenberg et al. (2008b) it is shown that the magnitude of the retrieved tropical methane is sensitive to the choice of the spectroscopic line parameters of water vapour. Concerning inter-annual variability we find similar methane spatio-temporal pattern for 2003 and 2004. For 2005 the retrieved methane shows significantly higher variability compared to the two previous years, most likely due to somewhat larger noise of the spectral measurement
Neural reward-related reactions to monetary gains for self and charity
The aim of the present study was to examine the neural signatures of gaining money for self and charity. Young adults (N = 31,
21–24 years of age) underwent fMRI scanning while they performed a task in which they could earn money for themselves and
for a self-chosen charity by selecting one of two options with unknown outcomes. The results showed elevated activity in the
ventral striatum when gaining for the self only and for self and charity, but not when gaining for charity only. However, increased
ventral striatal activity when gaining for charity only was correlated with participants’ self-reported empathic concern and
enjoyment when winning for charity. Empathic concern was also related to donating a larger proportion of earnings to charity
after the MRI session. In short, these results reveal robust ventral striatal activity when gaining for oneself, but empathydependent individual differences in ventral striatal activity when gaining for charit
Neural reward related-reactions to monetar gains for self and charity are associated with donating behavior in adolescence
The aim of the current study was to examine neural signatures of gaining money for self and charity in adolescence.
Participants (N = 160, aged 11–21) underwent functional magnetic resonance imaging-scanning while performing a
zero-sum vicarious reward task in which they could either earn money for themselves at the expense of charity, for a
self-chosen charity at the expense of themselves, or for both parties. Afterwards, they could donate money to charity, which
we used as a behavioral index of giving. Gaining for self and for both parties resulted in activity in the ventral striatum
(specifically in the NAcc), but not gaining for charity. Interestingly, striatal activity when gaining for charity was positively
related to individual differences in donation behavior and perspective taking. Dorsal anterior cingulate cortex, insula and
precentral gyrus were active when gaining only for self, and temporal-parietal junction when gaining only for charity,
relative to gaining for both parties (i.e. under equity deviation). Taken together, these findings show that striatal activity
during vicarious gaining for charity depends on levels of perspective taking and predicts future acts of giving to charity.
These findings provide insight in the individual differences in the subjective value of prosocial outcome
The longevity risk of the Dutch Actuarial Association’s projection model
Accurate assessment of the risk that arises from further increases in life expectancy is crucial for the financial sector, in particular for pension funds and life insurance companies. The Dutch Actuarial Association presented a revised projection model in 2010, while in the same year two fundamentally different approaches were published by other institutions. This situation invites study of the consequences that the choice of projection model has on estimates of future life expectancy, which is the purpose of this paper. We firstly compare the three approaches against theoretical findings in the international literature. Secondly, we compare their outcomes in terms of period and cohort survival. In addition, we estimate the impact of each model on the present value of future pension payments. Our results indicate that, even in the short term, remarkable differences in life expectancy occur that also translate into different pension values. The literature review suggests that there is currently no blueprint for mortality projections; that calls for the application of various approaches to discount the uncertainty of the individual models. Instead of relying on extrapolation methods only, the pension sector should also take expert-driven forecasts into account as well as approaches that model causal influences on mortality. The model of the Actuarial Association could be improved by taking cohort influences into account as well as the estimate of uncertainty bounds around the outcome measure. Also, the consistency of the projection in terms of the age and gender dimensions but also other countries should be enhanced
Integrating care for people with depression: developments in the Netherlands
Introduction: In this article we describe the history and present state of integrated care for people with depression in the Netherlands. The central question is: what are the developments in integrated care for people with depression in the Netherlands?Methods: We describe these developments from the role of an observer, and make use of several sources: important Dutch policy documents and research documents, our own national survey carried out in 2007, a number of reports and project descriptions and searches in PubMed and Google. Also key people were contacted to supply additional information.Results: In the Netherlands two separate phases can be distinguished within integrated care for people with depression. From the beginning of the 1990s, specialized secondary Mental Health Care (MHC) began to develop care programmes, including programmes for people with depression. The implementation of these care programmes has taken years. Mass usage of care programmes only went ahead once the large-scale mergers between ambulatory and clinical MHC organizations around 2000 had taken effect. An analysis of these programmes shows, that they did not lead to integration with primary care. This changed in the second phase from around 2000. Then attention was directed more towards strengthening the GP within the treatment of depression, collaboration between primary and specialized care and the development of collective integrated care packages.Discussion: We relate these developments to projects in other countries and discuss the scientific basis by using evidence of international literature reviews and metastudies. Some general recommendations are given about functional costing, the physical presence of MHC specialists in the primary care sector and the use of a common national standard for both primary care and specialized MHC
Forecasting differences in life expectancy by education
Forecasts of life expectancy (LE) have fuelled debates about the sustainability and dependability of pension and healthcare systems. O
Effect of residual catalyst on the vibrational modes of single-walled carbon nanotubes
Raman scattering measurements of single-walled carbon nanotubes prepared by laser ablation with Ni/Co catalyst show that samples that have not been purified have a graphitic mode frequency that is 8 cm -1 lower than that of samples from which most of the catalyst has been removed. The shift is attributed to charge transfer from the catalyst particles to the nanotubes. The charge transfer from the residual catalyst also affects the temperature dependence of the radial breathing mode
One-third of the new paediatric patients with sickle cell disease in The Netherlands are immigrants and do not benefit from neonatal screening
Modelling of multi-lateral well geometries for geothermal applications
Well inflow modelling in different numerical simulation
approaches are compared for a multi-lateral well. Specifically radial wells
will be investigated, which can be created using Radial Jet Drilling (RJD).
In this technique, powerful hydraulic jets are used to create small diameter
laterals (25–50 mm) of limited length (up to 100 m) from a well. The
laterals, also called radials, leave the backbone at a 90° angle. In
this study we compare three numerical simulators and a semi-analytical tool
for calculating inflow of a radial well. The numerical simulators are FE
approaches (CSMP and GOLEM) and an FV approach with explicit well model
(Eclipse®). A series of increasingly complex
well configurations is simulated, including one with inflow from a fault.
Although all simulators generally are reasonably close in terms of the total
well flow (deviations < 4 % for the homogeneous cases), the
distribution of the flow over the different parts of the well can vary
significantly. Also, the FE approaches are more sensitive to grid size when
the flow is dominated by radial flow to the well since they do not include a
dedicated well model. In the FE approaches, lower dimensional elements (1-D
for the well and 2-D for the faults) were superimposed into a 3-D space. In
case the flow is dominated by fracture flow, the results from the FV approach
in Eclipse deviates from the FE methods.</p
Persistent precordial "hyperacute" T-waves signify proximal left anterior descending artery occlusion
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