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"Jantzen, Christian"
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The energy potential of soft rush (Juncus effusus L.) in different conversion routes
Background
Rushes are prominent wetland plants that are well adapted to conditions of waterlogging. Tall rushes like soft rush (
Juncus effusus
L.) tend to dominate the vegetation and offer a great biomass potential. Removing rush biomass is often necessary to enhance various ecosystem services of wetlands. There is an urgent need for sustainable use of the removed biomass apart from expensive composting ore useless landfill.
Methods
We investigated three alternative energy utilisation routes for soft rush biomass and evaluated their energetic potential: biomethanisation via wet fermentation technique (a), biomethanisation via solid-state fermentation technique (b) and combustion (c). Batch experiments (a), experimental fermenters (b), and thermo-calorimetric equipment (c) were used to measure energy output per unit rush biomass input.
Results
The wet fermentation technique had significantly higher biogas yields than solid-state fermentation (399 L
N
kg
−1
oDM compared to 258 L
N
kg
−1
oDM). These yields constitute 59 and 43%, respectively, of the biogas potential of maize silage as a reference. Solid-state fermentation technique needs longer retention time compared to wet co-digestion to earn comparable methane yields. Soft rush biomass shows high heating values (15.06 MJ kg FM
w15
−1
) compared to other herbaceous solid fuels.
Conclusions
Low costs for substrate production make energetic utilisation of
Juncus effusus
an interesting alternative, if short distances between fields and biomass conversion plant can be realised. All investigated conversion routes appear promising, provided that the substrate specifics are considered in the design of the conversion technique. Besides the size of the rush dominated area and the distribution of these areas in the landscape, the investment costs and the subsidies for the conversion plant play a pivotal role in the selection of the preferred conversion path.
Journal Article
Experience-Oriented Knowledge Organisation for the Transference of Scientific Knowledge from Universities to SMEs
Transferring scientific knowledge between universities and industry is known to be problematic, specifically for small and medium-sized enterprises (SMEs) that have limited resources and absorption capacity. A variety of channels is used for knowledge transfer. These include what is commonly referred to as generic pathways (e.g., scientific publications) and relational pathways (e.g., faculty consulting). The purpose of this research is to extend our knowledge about the design of knowledge organization for a generic pathway interface providing access to scientific knowledge in a research information management system. The analysis focuses on how to meet the characteristics of SMEs in the design and organisation of the subject terms and annotations in the navigation and searching system. The design is based on findings from a qualitative analysis of eight SMEs and on principles of experience design. Experience design was applied, because the classical KO design qualities seem not to be comprehensive goals for knowledge organisation for a generic pathway interface. The SMEs need guidance, encouragement, and inspiration. Experience designs are designs that have been created to provoke changes in a user’s state and behaviour by engaging this user emotionally and cognitively. The paper provides examples and discusses the outcome of the experience dimensions.
Journal Article
Designing Urban Experiences. The Case of Zuidas, Amsterdam
Zuidas is a new city centre, which is emerging in the outskirts of Amsterdam. The ambitious project of developing a new international city centre has been carefully planned as the Netherlands has a strong and meticulous tradition for urban planning. The planning has however not only encompassed traditional urban planning aspects such as infrastructure, environmental factors and aesthetics, but has also dealt with the design of urban experiences. Through an introduction of the framework of the structure of experiences, this article examines how urban experiences can be understood and analysed, and deals with how urban experiences can be designed through careful consideration of how experiences are constituted. Taking the psychological structure of experiences into account when designing urbanity is not only interesting, but also highly relevant as Zuidas is competing with other international venues such as La Défense, the Docklands and Potsdamer Platz.
Journal Article
Retracing the molecular basis and evolutionary history of the loss of benzaldehyde emission in the genus Capsella
• The transition from pollinator-mediated outbreeding to selfing has occurred many times in angiosperms. This is generally accompanied by a reduction in traits attracting pollinators, including reduced emission of floral scent. In Capsella, emission of benzaldehyde as a main component of floral scent has been lost in selfing C. rubella by mutation of cinnamate-CoA ligase CNL1. However, the biochemical basis and evolutionary history of this loss remain unknown, as does the reason for the absence of benzaldehyde emission in the independently derived selfer Capsella orientalis.
• We used plant transformation, in vitro enzyme assays, population genetics and quantitative genetics to address these questions.
• CNL1 has been inactivated twice independently by point mutations in C. rubella, causing a loss of enzymatic activity. Both inactive haplotypes are found within and outside of Greece, the centre of origin of C. rubella, indicating that they arose before its geographical spread. By contrast, the loss of benzaldehyde emission in C. orientalis is not due to an inactivating mutation in CNL1.
• CNL1 represents a hotspot for mutations that eliminate benzaldehyde emission, potentially reflecting the limited pleiotropy and large effect of its inactivation. Nevertheless, even closely related species have followed different evolutionary routes in reducing floral scent.
Journal Article
Epithelial Folding Through Local Degradation of an Elastic Basement Membrane Plate
Epithelia are polarized layers of cells that line the outer and inner surfaces of organs. At the basal side, the epithelial cell layer is supported by a basement membrane, which is a thin polymeric layer of self‐assembled extracellular matrix (ECM) that tightly adheres to the basal cell surface. Proper shaping of epithelial layers is an important prerequisite for the development of healthy organs during the morphogenesis of an organism. Experimental evidence suggests that local degradation of the basement membrane is one of the mechanisms that can drive epithelial folding. However, how folding emerges in the absence of tissue growth remains elusive. Here, we present a coarse‐grained plate theory model of the basement membrane that assumes force balance between i) cell‐transduced active forces and ii) deformation‐induced elastic forces. We verify key assumptions of this model through experiments in the Drosophila wing disc epithelium and demonstrate that the model can explain the emergence of outward epithelial folds upon local plate degradation. The model accounts for local degradation of the basement membrane as a mechanism for the generation of epithelial folds in the absence of epithelial growth. Epithelia are flat tissues with a solid‐like basement membrane attached to their basal surface. During embryonic development, epithelia need to undergo folding processes. While recent studies suggest that local degradation of the basement membrane drives epithelial folding, the mechanism remains elusive. Here, we present a plate theory model that explains how folding can emerge in the absence of tissue growth.
Journal Article
Benthic Reef Primary Production in Response to Large Amplitude Internal Waves at the Similan Islands (Andaman Sea, Thailand)
Coral reefs are facing rapidly changing environments, but implications for reef ecosystem functioning and important services, such as productivity, are difficult to predict. Comparative investigations on coral reefs that are naturally exposed to differing environmental settings can provide essential information in this context. One prevalent phenomenon regularly introducing alterations in water chemistry into coral reefs are internal waves. This study therefore investigates the effect of large amplitude internal waves (LAIW) on primary productivity in coral reefs at the Similan Islands (Andaman Sea, Thailand). The LAIW-exposed west sides of the islands are subjected to sudden drops in water temperature accompanied by enhanced inorganic nutrient concentrations compared to the sheltered east. At the central island, Ko Miang, east and west reefs are only few hundred meters apart, but feature pronounced differences. On the west lower live coral cover (-38 %) coincides with higher turf algae cover (+64 %) and growth (+54 %) compared to the east side. Turf algae and the reef sand-associated microphytobenthos displayed similar chlorophyll a contents on both island sides, but under LAIW exposure, turf algae exhibited higher net photosynthesis (+23 %), whereas the microphytobenthos displayed reduced net and gross photosynthesis (-19 % and -26 %, respectively) accompanied by lower respiration (-42 %). In contrast, the predominant coral Porites lutea showed higher chlorophyll a tissues contents (+42 %) on the LAIW-exposed west in response to lower light availability and higher inorganic nutrient concentrations, but net photosynthesis was comparable for both sides. Turf algae were the major primary producers on the west side, whereas microphytobenthos dominated on the east. The overall primary production rate (comprising all main benthic primary producers) was similar on both island sides, which indicates high primary production variability under different environmental conditions.
Journal Article
Follow-up home visits with registered dietitians have a positive effect on the functional and nutritional status of geriatric medical patients after discharge: a randomized controlled trial
Objective:
To assess the additional benefits of individualized nutritional counselling by a registered dietitian in geriatric patients’ home after discharge from hospital, in relation to risk of re-admissions, functional status, nutritional status, use of social services and mortality.
Design:
Twelve-week single-blind randomized controlled study.
Setting and subjects:
Geriatric medical patients (65+ years) at nutritional risk.
Interventions:
Participants were randomly allocated to receive a visit in their homes, either three individualized nutritional counselling by a registered dietitian complemented with three follow-up visits by general practitioners or three follow-up visits by general practitioners alone.
Main measures:
Primary outcome was risk of re-admissions. Secondary outcomes were functional status (hand grip strength, chair stand, mobility, disability and tiredness in daily activities, rehabilitation capacity), nutritional status (weight, BMI, energy and protein intake), need of social services (home care, home nursing, meals-on-wheels) and mortality.
Results:
One hundred and fifty-two patients were included; 132 (87%) completed the first and 124 (82%) the second data collection after 12 weeks. Ten per cent of the participants had three contacts with their general practitioner, while compliance with the dietetic intervention was almost 100%. Odds ratio for re-admission and mortality after 26 weeks was 1.62 (95% confidence interval (CI) 0.85 to 3.10) and 0.60 (95% CI 0.17 to 2.13). The intervention had a positive effect on functional status (i.e. mobility, P = 0.029), and nutritional status (i.e. weight, P = 0.035; energy intake, P < 0.001; protein intake, P = 0.001) and the use of meals-on wheels was reduced (P = 0.084).
Conclusion:
Follow-up home visits with registered dietitians have a positive effect on the functional and nutritional status of geriatric medical patients after discharge.
Journal Article
Benthic Primary Production Budget of a Caribbean Reef Lagoon (Puerto Morelos, Mexico)
High photosynthetic benthic primary production (P) represents a key ecosystem service provided by tropical coral reef systems. However, benthic P budgets of specific ecosystem compartments such as macrophyte-dominated reef lagoons are still scarce. To address this, we quantified individual and lagoon-wide net (Pn) and gross (Pg) primary production by all dominant functional groups of benthic primary producers in a typical macrophyte-dominated Caribbean reef lagoon near Puerto Morelos (Mexico) via measurement of O₂ fluxes in incubation experiments. The photosynthetically active 3D lagoon surface area was quantified using conversion factors to allow extrapolation to lagoon-wide P budgets. Findings revealed that lagoon 2D benthic cover was primarily composed of sand-associated microphytobenthos (40%), seagrasses (29%) and macroalgae (27%), while seagrasses dominated the lagoon 3D surface area (84%). Individual Pg was highest for macroalgae and scleractinian corals (87 and 86 mmol O₂ m(-2) specimen area d(-1), respectively), however seagrasses contributed highest (59%) to the lagoon-wide Pg. Macroalgae exhibited highest individual Pn rates, but seagrasses generated the largest fraction (51%) of lagoon-wide Pn. Individual R was highest for scleractinian corals and macroalgae, whereas seagrasses again provided the major lagoon-wide share (68%). These findings characterise the investigated lagoon as a net autotrophic coral reef ecosystem compartment revealing similar P compared to other macrophyte-dominated coastal environments such as seagrass meadows and macroalgae beds. Further, high lagoon-wide P (Pg: 488 and Pn: 181 mmol O₂ m(-2) lagoon area d(-1)) and overall Pg:R (1.6) indicate substantial benthic excess production within the Puerto Morelos reef lagoon and suggest the export of newly synthesised organic matter to surrounding ecosystems.
Journal Article