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A policy network approach has been developed to assess participatory policy processes in Ghana, Senegal, and Uganda. Theoretically, political influence measures correspond to two different influence mechanisms: vote-buying and informational lobbying. For each mechanism, separate measures were defined and empirically derived from corresponding policy networks. Exponential random graph models were used to assess the network-generating process, which allows for analysis of the robustness of the derived influence measures and the determinants of network structure. The results imply that participatory policy processes are dominated by donor and research organizations, while farm interests and civil society organizations have only a negligible influence. The design of stakeholder systems appears to be difficult since the observed network structures are mainly determined by relational factors that result from organizations’ social networking activities or other organizational attributes, such as reputation power, which cannot be easily controlled. Institutional factors such as membership in committees have only a minor impact.

The detection and identification of molecular gases are of high relevance in many applications within healthcare, production monitoring and safety as well as environmental monitoring. One of the major difficulties of trace gas analysis is due to the bulky and expensive systems, what excludes both mobile and handheld use. For this purpose we present our new system based on the Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS), which can provide the required properties for gas analysis. We have developed a compact detection unit where DFB laser, collimation optics and QTF are integrated in a 14-pin butterfly housing. Therefore an optimization of the DFB laser chips will be presented too. The results show, that the laser diodes not only provide excellent performance, but also allow a detection limit for the greenhouse gas methane and carbon dioxide in the ppm range.

The rapid detection of trace gases is of great relevance for various spectroscopy applications. In this regard, the technology of external cavity diode lasers (ECDLs) has firmly established itself due to its excellent properties. Outside of the laboratory environment, however, these still have some restrictions, especially with regard to high acquisition rates for sensitive spectroscopy applications and mode-hop-free tuning. In this article, we present our innovative GaSb-based ECDL concept, in which a resonantly driven microelectromechanical system actuator is used. With this, a defined frequency range can be tuned extremely fast and without mode hops. Results of the characterization and its use for the rapid detection of trace gases are presented.

An optimized D-DFB design is presented, which guarantees the best possible performance in the range from 1.9 µm to 4.5 µm. Results for the performance and its suitability for detecting trace gases are shown.

An MEMS based ECDL design with optimized curved gain chip for the MIR region is presented. Results of the characterization and its use for the rapid detection of trace gases are shown.

Optimized DFB lasers are presented. Results for the performance and its suitability for detecting trace gases are shown. We present our new QEPAS compact detection unit where everything is integrated into 14-pin butterfly housing.

GaSb based types of diode lasers may cover the spectral regime from below 1.8 μm up to 5 μm. For the wavelength regime of 1.8 μm to 2.5 μm InGaAsSb/GaSb MQW material is used. For 2.5 μm to 3.4 μm InAlGaAsSb/GaSb MQW material is used. For above 3μm, an ICL type of design is required. We realized a growth campaign of 10 GaSb based wavers for covering the wavelength regime from 1.9μm to 3μm. We report on the test, performance and applications results in molecular gas sensing of both, gain chips within an external cavity laser as well as on digital DFB lasers.

HITRAN promises better gas detection possibilities in the MIR wavelength regime than the NIR or the visible region because of the higher absorbencies. These promises are tested with different lasers on TDLAS and QEPAS applications.

The commercially available semiconductor lasers for the mid-infrared (MIR) region often do not reach the desired performance and represent a limitation for gas sensor technology. Here we present our digital distributed feedback filter (D-DFB) laser diodes based on GaSb gain material, which have been optimized in terms of facet reflectivity, chip length, and output power. These diodes now cover the wavelength range from 1900 nm up to 4500 nm and show excellent quality regarding their spectral characteristics. Results for the performance of the D-DFB laser design and its suitability for the detection of trace gases are shown in this publication.

Narrow linewidth tunable diode lasers are an important tool for spectroscopic instrumentation. Conventional external cavity diode lasers are designed as laboratory instrument and do not allow hand-held operation for portable instruments. A new miniaturized type of tunable external cavity tunable diode laser will be presented. The presentation will focus on requirements on the assembly technology of micro-optic components as well as on the physical properties of such devices. Examples for the realization of this new technology will be given in the NIR for Alkaline Spectroscopy as well as in the MIR at 1908nm.

The MIR wavelength regime promises better gas detection possibilities than the NIR or the visible region because of the higher absorbencies simulated by HITRAN. In the MIR region are many important absorption lines of significant gases, which are relevant in healthcare, production supervision, and safety and environmental monitoring. One of those gases is methane. CH4 shows significant variations in absorbance with a maximum at 3.3 μm, which results in low detection limits in the range of low ppm. Interband-cascade- and quantum-cascade-based lasers emit at higher wavelengths, where the absorbencies of methane are higher. The comparison is done by analyzing the performance of two spectroscopy applications: tunable diode laser absorption spectroscopy and quartz-enhanced photoacoustic spectroscopy.

SUMMARY The aim of this study was to assess changes in prevalence of overweight and obesity among children born in 1996 and 1990 in Vilnius city. The results were based on comparison of two longitudinal data sets (N = 624 and N = 389) collected from the personal health records of children born in 1996 and 1990 respectively. No statistically significant differences in final height and BMI were established between children born in 1990 and 1996; however, both boys and girls born in 1996 appeared to be higher and heavier at different ages compared to their peers born in 1990. After controlling for tempo, the differences in height between the two cohorts have become insignificant for girls, with exceptions at the age of 3 and 10 years; for boys, the differences between the cohorts have remained significant, however at a slightly lower level. More children born in 1996 tended to be overweight and obese. In six years, the prevalence of overweight in Vilnius children has more than doubled; the prevalence of obesity has increased up to five times in some age groups.

Aim: National European growth references differ. We aimed to convert (harmonize) currently used charts into a single unified interchangeable LMS format for each European nation. Methods: Nine currently used national European growth references from Belgium (2009), France (1979), Poland (2001), Sweden (2002), Switzerland (1989), the UK (1990), Italy (2006) and Germany (1979 and 1997) were harmonized and compared with the international WHO child growth standards and WHO growth reference data for 5–19 years. Results: European growth charts can be harmonized. The approach appears useful as height, and body mass index (BMI) is inappropriately represented by WHO references. European height references exhibit warping when plotted against the WHO reference. The French appears too short, the other Europeans too tall. Also, the BMI is not appropriately represented by the WHO references. Conclusions: Harmonizing references is a novel, convenient and cost-effective approach for converting historic and/or incomplete local or national growth reference charts into a unified interchangeable LMS format. Harmonizing facilitates producing growth references ‘on demand’, for limited regional purposes, for ethnically, socio-economically or politically defined minorities, but also for matching geographically different groups of children and adolescents for international growth and registry studies.

The wavelength, λ, range of 1.8 μm≤λ≤3.5 μm contains strong spectral absorption lines of many gases used in health, industry, safety, and medicine and whose sensitive and quantitative detection is desirable. However, the performance of InP diode lasers markedly deteriorates beyond λ∼2 μm. In this paper we present new results on developing tunable high power single mode laser diodes based on the GaSb material system with emission in the wavelength range of 1.8 μm≤λ≤2.2 μm.