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Assessment of workflow feature selection on forest LAI prediction with sentinel-2A MSI, landsat 7 ETM+ and Landsat 8 OLI
No full textThe European Space Agency (ESA)'s Sentinel-2A (S2A) mission is providing time series that allow the characterisation of dynamic vegetation, especially when combined with the National Aeronautics and Space Administration (NASA)/United States Geological Survey (USGS) Landsat 7 (L7) and Landsat 8 (L8) missions. Hybrid retrieval workflows combining non-parametric Machine Learning Regression Algorithms (MLRAs) and vegetation Radiative Transfer Models (RTMs) were proposed as fast and accurate methods to infer biophysical parameters such as Leaf Area Index (LAI) from these data streams. However, the exact design of optimal retrieval workflows is rarely discussed. In this study, the impact of five retrieval workflow features on LAI prediction performance of MultiSpectral Instrument (MSI), Enhanced Thematic Mapper Plus (ETM+) and Operational Land Imager (OLI) observations was analysed over a Dutch beech forest site for a one-year period. The retrieval workflow features were the (1) addition of prior knowledge of leaf chemistry (two alternatives), (2) the choice of RTM (two alternatives), (3) the addition of Gaussian noise to RTM produced training data (four and five alternatives), (4) possibility of using Sun Zenith Angle (SZA) as an additional MLRA training feature (two alternatives), and (5) the choice of MLRA (six alternatives). The featureswere varied in a full grid resulting in 960 inversionmodels in order to find the overall impact on performance as well as possible interactions among the features. A combination of a Terrestrial Laser Scanning (TLS) time series with litter-trap derived LAI served as independent validation. The addition of absolute noise had the most significant impact on prediction performance. It improved the median prediction RootMean Square Error (RMSE) by 1.08m2m-2 when 5% noise was added compared to inversions with 0% absolute noise. The choice of the MLRA was second most important in terms of median prediction performance, which differed by 0.52m2m-2 between the best and worst model. The best inversion model achieved an RMSE of 0.91m2m-2 and explained 84.9% of the variance of the reference time series. The results underline the need to explicitly describe the used noise model in future studies. Similar studies should be conducted in other study areas, both forest and crop systems, in order to test the noise model as an integral part of hybrid retrieval workflows.</p
Technische bovengrenzen van P2O5 gehalte dikke fractie na scheiding drijfmest met decanteercentrifuge : Update 2020
No full textKleine vis in een kleine dwergvinvis. Toeval of trend? : Maag- en darminhoud van de jonge dwergvinvis die aanspoelde op Texel op 8 juli 2019
No full textLiever regenwormen dan panda’s in Gelderland : demonstratieproject voor het belang van regenwormen in de landbouw : rapportage regenwormenonderzoek
No full textInvang van mosselzaad in MZI’s : Resultaten 2019
No full textVoorliggend technisch rapport behandelt de resultaten van de oogst van mosselzaad in 2019 met de zogenaamde MosselZaadinvangsInstalaties (MZI’s) in de Oosterschelde, Voordelta en Waddenzee met als doel: • Inzicht te geven in de oogstresultaten in relatie tot de afspraken in het mosselconvenant. • Inzicht te geven in de geschiktheid van locaties voor MZI’s en de daarbij gebruikte invangsystemen. Dit rapport is opgesteld in opdracht van de PO Mosselcultuur. In 2019 is in de Nederlandse wateren in totaal 19,2 miljoen kg (192 duizend mosselton) mosselzaad geoogst van de MZI’s. Het merendeel hiervan, 16,5 miljoen kg, is ingevangen in de Waddenzee, waarvan 15,03 miljoen kg door transitiebedrijven en 1,43 miljoen kg door de voormalige experimenteerbedrijven. In de Oosterschelde is in 2019 2,0 miljoen kg en in de Voordelta 0,7 miljoen kg mosselzaad geoogst. Binnen het mosselconvenant is afgesproken de bodemzaadvisserij stapsgewijs af te bouwen. Deze afbouw gebeurt in een tempo waarin alternatieve bronnen voor mosselzaad als uitgangsmateriaal voor de kweek kunnen worden ontwikkeld en een rendabele kweek mogelijk blijft. MZI’s zijn daarvoor nu het belangrijkste alternatief. Inmiddels zijn twee stappen gezet. Per stap is afgesproken dat er per jaar een vangstverlies van 5,5 miljoen kg mosselzaad gecompenseerd moet worden. Met de tweede stap dient daarom 11 miljoen kg mosselzaad vanuit MZI’s in de Waddenzee beschikbaar te zijn. Met daaraan toegevoegd de nog te formaliseren derde sluitingsstap in de transitie dient 14,0 Miljoen kg MZI-zaad in de Waddenzee beschikbaar te zijn. Met de productie van 15,0 miljoen kg mosselzaad door transitiebedrijven in 2019 is hierin voorzien. De hoeveelheid ingehangen MZI-substraat was ongeveer gelijk met 2018, maar de oogst was in kwantitatieve zin 7,5% lager dan in 2018. De gegevens laten zien dat in 2019 in de Waddenzee minder mosselbiomassa per meter touw-substraat geoogst is dan in 2018 (respectievelijk 2,9 kg/m vs. 3,8 kg/m), terwijl de oogst per vierkante meter net-substraat in 2019 juist beter was dan in 2018 (respectievelijk 42,8 kg/m2 vs. 31,6 kg/m2). Onderliggende gegevens laten zien dat vooral het relatief slechte resultaat op locatie Zuidmeep debet is aan het verschil tussen 2019 en 2018
Use of Physiologically Based Kinetic Modeling to Predict Rat Gut Microbial Metabolism of the Isoflavone Daidzein to S-Equol and Its Consequences for ERα Activation
No full textScope: To predict gut microbial metabolism of xenobiotics and the resulting plasma concentrations of metabolites formed, an in vitro–in silico-based testing strategy is developed using the isoflavone daidzein and its gut microbial metabolite S-equol as model compounds. Methods and results: Anaerobic rat fecal incubations are optimized and performed to derive the apparent maximum velocities (Vmax) and Michaelis–Menten constants (Km) for gut microbial conversion of daidzein to dihydrodaidzein, S-equol, and O-desmethylangolensin, which are input as parameters for a physiologically based kinetic (PBK) model. The inclusion of gut microbiota in the PBK model allows prediction of S-equol concentrations and slightly reduced predicted maximal daidzein concentrations from 2.19 to 2.16 µm. The resulting predicted concentrations of daidzein and S-equol are comparable to in vivo concentrations reported. Conclusion: The optimized in vitro approach to quantify kinetics for gut microbial conversions, and the newly developed PBK model for rats that includes gut microbial metabolism, provide a unique tool to predict the in vivo consequences of daidzein microbial metabolism for systemic exposure of the host to daidzein and its metabolite S-equol. The predictions reveal a dominant role for daidzein in ERα-mediated estrogenicity despite the higher estrogenic potency of its microbial metabolite S-equol.</p
A qualitative exploration of the experiences of community health animation on malaria control in rural Malawi
No full textBackground: While great strides have been achieved in fighting malaria through the Roll Back Malaria (RBM) strategy, the recent world malaria report shows an increase in malaria-related deaths compared to previous years. Malaria control tools are efficacious and effective in preventing the disease; however, the human behaviour aspect of the intervention strategies is weak due to heavy reliance on positive human health behaviour. The challenge lies in adoption of control interventions by the target population which, to an extent, may include access to prevention and treatment tools. We present a qualitative assessment of the use of the Health Animator (HA) model for Information, Education and Communication (IEC) to improve adoption and use of malaria control by promoting positive health behaviours. Results: We conducted 3 Focus Group Discussions (FGDs) and 23 individual in-depth interviews (IDIs) with HAs. Each FGD consisted of 8 participants. Data was analysed using QSR International NVivo 10 software. There are four main themes emerging regarding HA experiences. The perceptions include; collaborative work experience, personal motivation and growth, community participation with health animation and challenges with implementation. Results suggest that HAs were pleased with the training as they gained new information regarding malaria, which affected their use of malaria control interventions within their families. Knowledge was well assimilated from the trainings and influenced personal growth in becoming a community leader. Support from the leadership within the village and the health system was important in legitimising the main messages. The community responded positively to the workshops valued the information imparted. The voluntary nature of the work in a poverty-stricken community affected sustainability. Conclusions: There is need to empower communities with strategies within their reach. Functioning traditional social support structures are a crucial element in sustainability. Voluntarism is also key for sustainability, especially for rural and remote communities with limited sources of income.</p
Production of phycocyanin by Leptolyngbya sp. in desert environments
No full textLeptolyngbya sp. QUCCCM 56 was investigated as a possible alternative to A. platensis, for the production of phycocyanin-rich biomass under desert conditions. Under elevated temperatures and light intensities, of up to 40 °C and 1800 μmol·m−2·s−1, the strain's biomass productivity was up to 45% higher as compared to reported productivities for A. platensis, with comparable phycocyanin content. Increasing temperatures were found to improve the biomass productivity and phycocyanin content, which, at 40 °C, were 1.09 ± 0.03 gX·L−1·d−1 and 72.12 ± 3.52 mgPC·gX −1, respectively. The optimum biomass productivity was found at a light intensity of 300 μmol·m−2·s−1, with higher light intensities causing a decrease of 15%. Furthermore, of the various phycocyanin extraction methods tested, bead-beating in phosphate buffer had the highest combined phycocyanin yield (169.9 ± 3.6 mgPC·gX) and purity (7.37 ± 0.16) for Leptolyngbya sp. For A. platensis, this extraction method also resulted in the highest extract purities (3.78 ± 0.04). The extract purities obtained for Leptolyngbya sp. are considerably higher than other reported phycocyanin purities, and further investigation is recommended to study the scale-up of both Leptolyngbya sp. and bead-beating for commercial scale high-grade phycocyanin production under desert conditions.</p
Highly resolved spatiotemporal simulations for exploring mixed fishery dynamics
No full textTo understand how data resolution impacts inference on mixed fisheries interactions we developed a highly resolved spatiotemporal discrete-event simulation model MixFishSim incorporating: i) delay-difference population dynamics, ii) population movement using Gaussian Random Fields to simulate patchy, heterogeneously distributed and moving fish populations, and iii) fishery dynamics for multiple fleet characteristics based on population targeting under an explore-exploit strategy. We applied MixFishSim to infer community structure when using data generated from: commercial catch, a fixed-site sampling survey design and the true (simulated) underlying populations. In doing so we thereby establish the potential limitations of fishery-dependent data in providing a robust characterisation of spatiotemporal distributions. Different spatial patterns were evident and the effectiveness of a simulated spatial closure was reduced when data were aggregated across larger spatial areas. The simulated area closure showed that aggregation across time periods has less of a negative impact on the closure success than aggregation over space. While not as effective as when based on the true population, closures based on high catch rates observed in commercial data were still able to reduce fishing on a protected species. Our framework allows users to explore the assumptions in modelling observational data and evaluate the underlying dynamics of such approaches at fine spatial and temporal resolutions. From our application we conclude that commercial data, while containing bias, provides a useful tool for managing catches in mixed fisheries if applied at the correct spatiotemporal scale.</p
Reframing human excreta management as part of food and farming systems
No full textRecognition of human excreta as a resource, rather than as waste, has led to the emergence of a range of new and innovative nutrient recovery solutions. Nevertheless, the management of human excreta remains largely rooted in current sanitation and wastewater management approaches, which often makes nutrient recovery an add-on to existing infrastructures. In this paper, we argue that framing human excreta management as a resource recovery challenge within waste management obscures important trade-offs. We explore the factors that would be brought to the fore by reframing human excreta management as part of food and farming systems. We find that such a reframing would accentuate (at least) six aspects of critical importance that are currently largely overlooked. Recognizing that the proposed framing may also have its limitations, we argue that it has the potential to better guide human excreta management towards long-term global food, soil, and nutrient security while reducing the risk of compromising other priorities related to human and environmental health.</p