On the use of mass-conserving wind fields in chemistry-transport models

A new method has been developed that provides mass-conserving wind fields for global chemistry-transport models. In previous global Eulerian modeling studies a mass-imbalance was found between the model mass transport and the surface pressure tendencies. Several methods have been suggested to correct for this imbalance, but so far no satisfactory solution has been found. Our new method solves these problems by using the wind fields in a spherical harmonical form (divergence and vorticity) by mimicing the physics of the weather forecast model as closely as possible. A 3-D chemistry-transport model was used to show that the calculated ozone fields with the new processing method agree remarkably better with ozone observations in the upper troposphere and lower stratosphere. In addition, the calculated age of air in the lower stratosphere show better agreement with observations, although the air remains still too young in the extra-tropical stratosphere

Multidimensional en-face OCT imaging of the retina.

Fast T-scanning (transverse scanning, en-face) was used to build B-scan or C-scan optical coherence tomography (OCT) images of the retina. Several unique signature patterns of en-face (coronal) are reviewed in conjunction with associated confocal images of the fundus and B-scan OCT images. Benefits in combining T-scan OCT with confocal imaging to generate pairs of OCT and confocal images similar to those generated by scanning laser ophthalmoscopy (SLO) are discussed in comparison with the spectral OCT systems. The multichannel potential of the OCT/SLO system is demonstrated with the addition of a third hardware channel which acquires and generates indocyanine green (ICG) fluorescence images. The OCT, confocal SLO and ICG fluorescence images are simultaneously presented in a two or a three screen format. A fourth channel which displays a live mix of frames of the ICG sequence superimposed on the corresponding coronal OCT slices for immediate multidimensional comparison, is also included. OSA ISP software is employed to illustrate the synergy between the simultaneously provided perspectives. This synergy promotes interpretation of information by enhancing diagnostic comparisons and facilitates internal correction of movement artifacts within C-scan and B-scan OCT images using information provided by the SLO channel

Budgetary Costs of Tax Facilities for Pension Savings: An Empirical Analysis

A wide variety of tax regimes for (occupational) private pension saving are in place around the world. Generally, pension saving is taxed at a relatively low rate, although the revenue loss due to tax facilities for pension savings and/or pension tax expenditures may differ across countries. A strong fiscal stimulus to build up pension capital will support funding. However, these tax facilities may become an expensive business for governments. This paper investigates the ex ante budgetary effects of a cash-flow tax regime for pension savings by full present-value calculations. The fiscal subsidy on pension savings in several (European) countries is often associated with the application of the cash-flow treatment of pensions under the personal income tax: pension contributions are tax exempt, capital income of pension funds is tax-exempt, and pension benefits are taxed, but usually the elderly aged 65 years and over are taxed at a relatively low rate. This form can be described as EET, with E denoting an exemption or relief from tax and T denoting a point at which tax is payable. Indeed, tax treatment of pension saving can have other forms as well. We consider a specified form of a comprehensive income tax system (TTE) as an appropriate benchmark. Using the TTE-benchmark, the ex ante budgetary cost of the current tax treatment of pension saving in countries can be quantified. We employ an empirical analysis for the Netherlands, because this country belongs, with its three pension pillars and its sound funding, to the leading group of countries in Europe with a solid pension system. Our calculations, using Income Panel Data from Statistics Netherlands for the years 1990-2003, show that current taxation on a cash-flow basis means on balance a major loss to the Treasury (compared to the benchmark). For the year 2003 we estimate a fiscal subsidy associated with the current Dutch tax rule of 1.2 to 1.5 percent of GDP, depending on the assumed rate of return on pension capital

Updated African biomass burning emission inventories in the framework of the AMMA-IDAF program, with an evaluation of combustion aerosols

African biomass burning emission inventories for gaseous and particulate species have been constructed at a resolution of 1 km by 1km with daily coverage for the 2000–2007 period. These inventories are higher than the GFED2 inventories, which are currently widely in use. Evaluation specifically focusing on combustion aerosol has been carried out with the ORISAM-TM4 global chemistry transport model which includes a detailed aerosol module. This paper compares modeled results with measurements of surface BC concentrations and scattering coefficients from the AMMA Enhanced Observations period, aerosol optical depths and single scattering albedo from AERONET sunphotometers, LIDAR vertical distributions of extinction coefficients as well as satellite data. Aerosol seasonal and interannual evolutions over the 2004–2007 period observed at regional scale and more specifically at the Djougou (Benin) and Banizoumbou (Niger) AMMA/IDAF sites are well reproduced by our global model, indicating that our biomass burning emission inventory appears reasonable

Civil Aircraft for the regular investigation of the atmosphere based on an instrumented container: The new CARIBIC system

An airfreight container with automated instruments for measurement of atmospheric gases and trace compounds was operated on a monthly basis onboard a Boeing 767-300 ER of LTU International Airways during long-distance flights from 1997 to 2002 (CARIBIC, Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container, http://www.caribic-atmospheric.com). Subsequently a more advanced system has been developed, using a larger capacity container with additional equipment and an improved inlet system. CARIBIC phase #2 was implemented on a new long-range aircraft type Airbus A340-600 of the Lufthansa German Airlines (Star Alliance) in December 2004, creating a powerful flying observatory. The instrument package comprises detectors for the measurement of O3, total and gaseous H2O, NO and NOy, CO, CO2, O2, Hg, and number concentrations of sub-micrometer particles (>4 nm, >12 nm, and >18 nm diameter). Furthermore, an optical particle counter (OPC) and a proton transfer mass spectrometer (PTR-MS) are incorporated. Aerosol samples are collected for analysis of elemental composition and particle morphology after flight. Air samples are taken in glass containers for laboratory analyses of hydrocarbons, halocarbons and greenhouse gases (including isotopic composition of CO2) in several laboratories. Absorption tubes collect oxygenated volatile organic compounds. Three differential optical absorption spectrometers (DOAS) with their telescopes mounted in the inlet system measure atmospheric trace gases such as BrO, HONO, and NO2. A video camera mounted in the inlet provides information about clouds along the flight track. The flying observatory, its equipment and examples of measurement results are reported

Sources of increase in lowermost stratospheric sulphurous and carbonaceous aerosol background concentrations during 1999–2008 derived from CARIBIC flights

This study focuses on sulphurous and carbonaceous aerosol, the major constituents of particulate matter in the lowermost stratosphere (LMS), based on in situ measurements from 1999 to 2008. Aerosol particles in the size range of 0.08–2 µm were collected monthly during intercontinental flights with the CARIBIC passenger aircraft, presenting the first long-term study on carbonaceous aerosol in the LMS. Elemental concentrations were derived via subsequent laboratory-based ion beam analysis. The stoichiometry indicates that the sulphurous fraction is sulphate, while an O/C ratio of 0.2 indicates that the carbonaceous aerosol is organic. The concentration of the carbonaceous component corresponded on average to approximately 25% of that of the sulphurous, and could not be explained by forest fires or biomass burning, since the average mass ratio of Fe to K was 16 times higher than typical ratios in effluents from biomass burning. The data reveal increasing concentrations of particulate sulphur and carbon with a doubling of particulate sulphur from 1999 to 2008 in the northern hemisphere LMS. Periods of elevated concentrations of particulate sulphur in the LMS are linked to downward transport of aerosol from higher altitudes, using ozone as a tracer for stratospheric air. Tropical volcanic eruptions penetrating the tropical tropopause are identified as the likely cause of the particulate sulphur and carbon increase in the LMS, where entrainment of lower tropospheric air into volcanic jets and plumes could be the cause of the carbon increase

Geschilbeslechtingsdelta 2003

This is a report of a survey among Dutch citizens into their experience with problems which might have a legal solution (justiciable problems). The survey provides information about: 1. The incidence of justiciable problems within the population; 2. The strategies people choose to solve these problems; 3. The outcome of the different strategies used for resolving justiciable problems; 4. The public perception of the legal system.Uit het onderzoek blijkt dat (potentieel) juridische problemen alom aanwezig zijn in het dagelijks leven. Mensen lossen veel van die problemen zelf op. Lang niet altijd wordt een beroep gedaan op rechtshulp en slechts een relatief klein gedeelte van de problemen wordt voorgelegd aan een gerechtelijke instantie. Ook het aandeel van alternatieve geschilbeslechtingsmethoden (bindend advies, mediation) is beperkt. Het onderzoek bevat geen aanwijzingen dat het aanbod van rechtshulp in zijn algemeenheid tekortschiet of dat de kwaliteit daarvan ontoereikend is. Er is een zeer breed scala aan adviserende en hulpverlenende instanties waarvan burgers gebruik maken en burgers zijn overwegend tevreden over de geboden diensten. INHOUD: 1. Opzet van het onderzoek 2. Geschillen en opIossingsstrategieën 3. Het landschap van juridische problemen 4. Oplossingstrategieën I - de aanloop 5. Oplossingstrategieën II - de afloop 6. Doelen, kosten, resultaten 7. Waardering van juridische voorzieningen 8. Conclusie en discussi

Developing a mHealth intervention to promote uptake of HIV testing among African communities in the UK: a qualitative study

Background: HIV-related mHealth interventions have demonstrable efficacy in supporting treatment adherence, although the evidence base for promoting HIV testing is inconclusive. Progress is constrained by a limited understanding of processes used to develop interventions and weak theoretical underpinnings. This paper describes a research project that informed the development of a theory-based mHealth intervention to promote HIV testing amongst city-dwelling African communities in the UK. Methods: A community-based participatory social marketing design was adopted. Six focus groups (48 participants in total) were undertaken and analysed using a thematic framework approach, guided by constructs from the Health Belief Model. Key themes were incorporated into a set of text messages, which were pre-tested and refined. Results: The focus groups identified a relatively low perception of HIV risk, especially amongst men, and a range of social and structural barriers to HIV testing. In terms of self-efficacy around HIV testing, respondents highlighted a need for communities and professionals to work together to build a context of trust through co-location in, and co-involvement of, local communities which would in turn enhance confidence in, and support for, HIV testing activities of health professionals. Findings suggested that messages should: avoid an exclusive focus on HIV, be tailored and personalised, come from a trusted source, allay fears and focus on support and health benefits. Conclusions: HIV remains a stigmatized and de-prioritized issue within African migrant communities in the UK, posing barriers to HIV testing initiatives. A community-based participatory social marketing design can be successfully used to develop a culturally appropriate text messaging HIV intervention. Key challenges involved turning community research recommendations into brief text messages of only 160 characters. The intervention needs to be evaluated in a randomized control trial. Future research should explore the application of the processes and methodologies described in this paper within other communities