The ecosystem engineer Crassostrea gigas affects tidal flat morphology beyond the boundary of their reef structures
Walles, B. ; Salvador de Paiva, J. ; Prooijen, B. van; Ysebaert, T. ; Smaal, A.C. - \ 2015
Estuaries and coasts 38 (2015)3. - ISSN 1559-2723 - p. 941 - 950.
wadden sea - sediment dynamics - pacific oysters - native mussels - habitat - estuary - stabilization - enhancement - communities - adaptation
Ecosystem engineers that inhabit coastal and estuarine environments, such as reef building oysters, do not only stabilise the sediment within their reefs, but their influence might also extend far outside their reefs, affecting tidal flat morphology and protecting the surrounding soft-sediment environment against erosion. However, quantitative information is largely missing, and the spatially extended ecosystem engineering effects on the surrounding soft-sediment largely unstudied. To quantify this, we measured elevations around eleven natural Crassostrea gigas reefs occurring on tidal flats in the Oosterschelde estuary (the Netherlands). These tidal flats experience strong erosion as a consequence of human interventions in the system. Various reef sizes were chosen to test the proportional effects of reefs on tidal flat morphology. Measurements were used to create 3-dimensional surface maps to obtain properties of the reefs and the surrounding soft-sediment environment. The area of the oyster reefs ranged from 2 to 1,908 m2. Reef length varied between 1 and 61 m, reef width between 1 and 45 m, and reef height between 0.20 and 1.08 m. Reefs varied in shape, going from round shape structures to more elongated ones. We observed elevated areas (>5 cm elevation from the background intertidal slope) on the lee side of all reefs, caused by the interaction between the reef’s structure and locally prevailing wave conditions. The elevated area (i.e. the spatially extended ecosystem engineering effect) affected by the reef was of the same order of magnitude as the reef area. The elevated area was related to reef properties such as reef length, width, and height. Reef length, however, appeared to be the best predictor. These findings contribute to management solutions for coastal adaptation and protection. Our study clearly showed that oyster reefs not only protect the tidal flat under their footprint, but as well an area beyond the boundary of the reef
Nutrients trigger carbon storage
Vries, W. de - \ 2014
Nature Climate Change 4 (2014). - ISSN 1758-678X - p. 425 - 426.
nitrogen - co2 - productivity - respiration - enhancement - sink
Analysis of data from 92 forested sites across the globe indicates that nutrient availability is the dominant driver of carbon retention in forests.
Short-term effects of glucose and sucrose on cognitive performance and mood in elderly people
Zwaluw, N.L. van der; Rest, O. van de; Kessels, R.P.C. ; Groot, C.P.G.M. de - \ 2014
Journal of Clinical and Experimental Neuropsychology 36 (2014)5. - ISSN 1380-3395 - p. 517 - 527.
participants aged 24-81 - blood-glucose - normative data - older-adults - memory performance - diabetes-mellitus - subjective memory - enhancement - humans - carbohydrate
In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with self-reported memory complaints were included. Drinks consisted of 250 ml with dissolved glucose (50 g), sucrose (100 g), or a mixture of artificial sweeteners (placebo). Multiple neuropsychological tests were performed and were combined by means of z scores into four cognitive domains: episodic memory, working memory, attention and information (processing speed), and executive functioning. Mood was assessed with the short Profile of Mood Status (s-POMS) questionnaire. Blood glucose concentrations were measured at five time points to divide participants into those with a better or poorer blood glucose recovery. Performance on the domain of attention and information processing speed was significantly better after consuming the sucrose drink (domain score of 0.06, SD = 0.91) than after the placebo drink (–0.08, SD = 0.92, p = .04). Sucrose had no effect on the other three domains, and glucose had no effect on any of the domains compared to the placebo. When dividing participants into poorer or better glucose recoverers, the beneficial effect of sucrose on attention and information processing speed was only seen in participants with a poorer recovery. After sucrose consumption, depressive feelings and tension were slightly higher than after the placebo. To conclude, 100 g sucrose, but not 50 g glucose, optimized attention and information processing speed in the short term in this study in elderly people with subjective, mild memory complaints.
Effects of Pro-Tex on zebrafish (Danio rerio) larvae, adult common carp (Cyprinus carpio) and adult yellowtail kingfish (Seriola lalandi)
Boerrigter, J.G.J. ; Vis, J.W. van de; Bos, R. van den; Abbink, W. ; Spanings, T. ; Zethof, J. ; Louzao Martinez, L. ; Andel, W.F.M. van; Lopez-Luna, J. ; Flik, G. - \ 2014
Fish Physiology and Biochemistry 40 (2014)4. - ISSN 0920-1742 - p. 1201 - 1212.
artemia-franciscana larvae - heat-shock factor-1 - atlantic salmon - stress-response - expression - l. - heat-shock-protein-70 - hsp70 - fish - enhancement
Aquaculture practices bring several stressful events to fish. Stressors not only activate the hypothalamus–pituitary–interrenal-axis, but also evoke cellular stress responses. Up-regulation of heat shock proteins (HSPs) is among the best studied mechanisms of the cellular stress response. An extract of the prickly pear cactus (Opuntia ficus indica), Pro-Tex, a soluble variant of TEX-OE®, may induce expression of HSPs and reduce negative effects of cellular stress. Pro-Tex therefore is used to ameliorate conditions during stressful aquaculture-related practices. We tested Pro-Tex in zebrafish (Danio rerio), common carp (Cyprinus carpio L.) and yellowtail kingfish (Seriola lalandi) exposed to aquaculture-relevant stressors (thermal stress, net confinement, transport) and assessed its effects on stress physiology. Heat shock produced a mild increase in hsp70 mRNA expression in 5-day-old zebrafish larvae. Pro-Tex increased basal hsp70 mRNA expression, but decreased heat-shock-induced expression of hsp70 mRNA. In carp, Pro-Tex increased plasma cortisol and glucose levels, while it did not affect the mild stress response (increased plasma cortisol and glucose) to net confinement. In gills, and proximal and distal intestine, stress increased hsp70 mRNA expression; in the distal intestine, an additive enhancement of hsp70 mRNA expression by Pro-Tex was seen under stress. In yellowtail kingfish, Pro-Tex reduced the negative physiological effects of transport more efficiently than when fish were sedated with AQUI-S®. Overall, our data indicate that Pro-Tex has protective effects under high levels of stress only. As Pro-Tex has potential for use in aquaculture, its functioning and impact on health and welfare of fish should be further studied.
Balancing the organic load and light supply in symbiotic microalgal–bacterial biofilm reactors treating synthetic municipal wastewater
Boelee, N.C. ; Temmink, B.G. ; Janssen, M. ; Buisman, C.J.N. ; Wijffels, R.H. - \ 2014
Ecological Engineering 64 (2014). - ISSN 0925-8574 - p. 213 - 221.
afvalwaterbehandeling - biofilms - symbiose - algen - bacteriën - heterotrofe micro-organismen - fotosynthese - acetaten - stikstof - fosfor - nitrificatie - denitrificatie - biologische waterzuiveringsinstallaties - biobased economy - waste water treatment - biofilms - symbiosis - algae - bacteria - heterotrophic microorganisms - photosynthesis - acetates - nitrogen - phosphorus - nitrification - denitrification - biological water treatment plants - biobased economy - activated-sludge - nutrient removal - growth - phytoplankton - fluorescence - enhancement
Symbiotic microalgal–bacterial biofilms can be very attractive for municipal wastewater treatment. Microalgae remove nitrogen and phosphorus and simultaneously produce the oxygen that is required for the aerobic, heterotrophic degradation of organic pollutants. For the application of these biofilms in new wastewater treatment systems, the engineering aspects need to be investigated to obtain a balanced system where no additional oxygen is required. In this study symbiotic microalgal–bacterial biofilms were grown in flow cells with ammonium and phosphate, and with acetate as biodegradable organic pollutant at a hydraulic retention time of 4.5 h. The symbiotic biofilms removed acetate from 323 mg/L to 39 mg/L without an external oxygen or carbon dioxide supply at a removal rate of 43 g COD/m2/d. Ammonium and phosphate could not be completely removed, but removal rates of 3.2 g/m2/d and 0.41 g/m2/d were obtained, respectively. Further nitrogen removal may be obtained by nitrification and denitrification as the biofilm obtained a considerable heterotrophic denitrification capacity. The symbiotic relationship between microalgae and aerobic heterotrophs was proven by subsequently removing light and acetate. In both cases this resulted in the cessation of the symbiosis and in increasing effluent concentrations of both acetate and the nutrients ammonium and phosphate. Future research should investigate the dimensioning of an up-scaled symbiotic biofilm reactor, and the possibilities to obtain additional nitrogen and phosphorus removal under day–night cycles utilizing real wastewater.
Combinatory Effects of Texture and Aroma Modification on Taste Perception of Model Gels
Knoop, J.E. ; Sala, G. ; Smit, G. ; Stieger, M.A. - \ 2013
Chemosensory Perception 6 (2013)2. - ISSN 1936-5802 - p. 60 - 69.
sensory perception - flavor release - solution viscosity - sugar - fat - integration - odor - hydrocolloids - enhancement - preferences
In this study, the effects of texture modification and aroma-induced sweetness enhancement were systematically investigated in apple-flavored semi-solid Na-caseinate gels. Gels containing apple juice as a basic flavor were developed differing in stiffness, brittleness and serum release (texture modification), aroma, and sugar concentration (flavor modification). In a full factorial design (2 x 2 x 2), eight samples were evaluated by a sensory panel on ten attributes (five texture, five flavor). Sweetness was enhanced significantly by modification of texture, aroma, and sugar concentration. Texture modification was found to be by far the greatest contributor to overall sweetness. In comparison to texture modifications, aroma modification and changes of sugar concentration resulted only in small sweetness enhancement. When texture and aroma modifications are combined, a small additive effect of aroma modification on sweetness enhancement was found in addition to the sweetness enhancement caused by texture modification. This suggests that the relationship between texture (modification) and flavor (modification) and sweetness is additive in a nonlinear manner. It can be concluded that texture modification is a valid tool to enhance taste intensity. Hence, texture modification can compensate for a loss of sweet taste intensity induced by sugar reduction, while aroma-induced sweetness enhancement can contribute to further taste enhancement in order to develop healthier products.
Atmosphere-ocean ozone fluxes during the TexAQS 2006, STRATUS 2006, GOMECC 2007, GasEx 2008, and AMMA 2008 cruises
Helmig, D. ; Lang, E.K. ; Bariteau, L. ; Boylan, P. ; Fairall, C.W. ; Ganzeveld, L.N. ; Hare, J.E. ; Hueber, J. ; Pallandt, M. - \ 2012
Journal of Geophysical Research: Atmospheres 117 (2012). - ISSN 2169-897X - 15 p.
marine boundary-layer - dry deposition - surface - atlantic - iodine - water - coastal - parameterization - enhancement - chemistry
A ship-based eddy covariance ozone flux system was deployed to investigate the magnitude and variability of ozone surface fluxes over the open ocean. The flux experiments were conducted on five cruises on board the NOAA research vessel Ronald Brown during 2006-2008. The cruises covered the Gulf of Mexico, the southern as well as northern Atlantic, the Southern Ocean, and the persistent stratus cloud region off Chile in the eastern Pacific Ocean. These experiments resulted in the first ship-borne open-ocean ozone flux measurement records. The median of 10 min oceanic ozone deposition velocity (v(d)) results from a combined similar to 1700 h of observations ranged from 0.009 to 0.034 cm s(-1). For the Gulf of Mexico cruise (Texas Air Quality Study (TexAQS)) the median v(d) (interquartile range) was 0.034 (0.009-0.065) cm s(-1) (total number of 10 min measurement intervals, N-f = 1953). For the STRATUS cruise off the Chilean coast, the median v(d) was 0.009 (0.004-0.037) cm s(-1) (N-f = 1336). For the cruise from the Gulf of Mexico and up the eastern U. S. coast (Gulf of Mexico and East Coast Carbon cruise (GOMECC)) a combined value of 0.018 (0.006-0.045) cm s(-1) (N-f = 1784) was obtained (from 0.019 (-0.014-0.043) cm s(-1), N-f = 663 in the Gulf of Mexico, and 0.018 (-0.004-0.045) cm s(-1), N-f = 1121 in the North Atlantic region). The Southern Ocean Gas Exchange Experiment (GasEx) and African Monsoon Multidisciplinary Analysis (AMMA), the Southern Ocean and northeastern Atlantic cruises, respectively, resulted in median ozone v(d) of 0.009 (-0.005-0.026) cm s(-1) (N-f = 2745) and 0.020 (-0.003-0.044) cms(-1) (N-f = 1147). These directly measured ozone deposition values are at the lower end of previously reported data in the literature (0.01-0.12 cm s(-1)) for ocean water. Data illustrate a positive correlation (increase) of the oceanic ozone uptake rate with wind speed, albeit the behavior of the relationship appears to differ during these cruises. The encountered wide range of meteorological and ocean biogeochemical conditions is used to investigate fundamental drivers of oceanic O-3 deposition and for the evaluation of a recently developed global oceanic O-3 deposition modeling system.
Targeted PLGA nano- but not microparticles specifically deliver antigen to human dendritic cells via DC-SIGN in vitro
Cruz, L.J. ; Tacken, P.J. ; Fokkink, R.G. ; Joosten, B. ; Cohen Stuart, M.A. ; Albericio, F. ; Torensma, R. ; Figdor, C.G. - \ 2010
Journal of Controlled Release 144 (2010)2. - ISSN 0168-3659 - p. 118 - 126.
nanoparticle vaccines - multilectin receptor - immune-responses - drug-release - vivo - induction - antibody - immunotherapy - enhancement - activation
Vaccine efficacy is strongly enhanced by antibody-mediated targeting of vaccine components to dendritic cells (DCs), which are professional antigen presenting cells. However, the options to link antigens or immune modulators to a single antibody are limited. Here, we engineered versatile nano- and micrometer-sized slow-release vaccine delivery vehicles that specifically target human DCs to overcome this limitation. The nano- (NPs) and microparticles (MPs), with diameters of approximately 200nm and 2microm, consist of a PLGA core coated with a polyethylene glycol-lipid layer carrying the humanized targeting antibody hD1, which does not interact with complement or Fc receptors and recognizes the human C-type lectin receptor DC-SIGN on DCs. We studied how these particles interact with human DCs and blood cells, as well as the kinetics of PLGA-encapsulated antigen degradation within DCs. Encapsulation of antigen resulted in almost 38% degradation for both NPs and MPs 6days after particle ingestion by DCs, compared to 94% when nonencapsulated, soluble antigen was used. In contrast to the MPs, which were taken up rather nonspecifically, the NPs effectively targeted human DCs. Consequently, targeted delivery only improved antigen presentation of NPs and induced antigen-dependent T cell responses at 10-100 fold lower concentrations than nontargeted NPs
|Reviewing progress towards finding an acceptable natural flavour alternative to salt
Busch, J.L.H.C. ; Batenburg, M. ; Velden, R. van der; Smit, G. - \ 2009
Agro Food Industry Hi-Tech 20 (2009)5. - ISSN 1722-6996 - p. 66 - 68.
taste - perception - aroma - 3-hydroxy-4,5-dimethyl-2(5h)-furanone - enhancement - impact
The level of sodium in food products needs to be lowered in order to help reduce incidences of hypertension and cardiovascular diseases of the world population. Important functionalities of salt (NaCl) – salty taste and flavour enhancement – are to be delivered by replacer systems. One approach is enhancement of saltiness by aroma. We show that saltiness and the overall flavour profile are increased upon addition of extra beef flavouring in a salt-reduced beef bouillon. Furthermore, the saltiness enhancement potency of the single compound sotolone (savoury note) is demonstrated. Practical perspectives of the application of aroma for sodium reduction and routes of natural production of sotolone are discussed.
In situ chemical reduction (ISCR) technologies: Significance of low eh reactions
Dolfing, J. ; Eekert, M.H.A. van; Seech, A. ; Vogan, J. ; Mueller, J. - \ 2007
Soil and Sediment Contamination 17 (2007)1. - ISSN 1532-0383 - p. 63 - 74.
long-term performance - zero-valent zinc - carbon-tetrachloride - aliphatic-compounds - iron - dechlorination - groundwater - hydrogen - culture - enhancement
Zero valent iron (ZVI; Fe(0)) has been successfully employed for the transformation and subsequent detoxification of a wide range of environmental contaminants, including chlorinated organics, heavy metals, nitroaromatics and, to some degree, perchlorate. The combined use of ZVI plus controlled release carbon has been shown to generate environmental conditions defined herein as in situ chemical reduction (ISCR) that facilitate the microbiological, chemical and/or physical destruction of various contaminants. In this context, the salient features of ISCR are: (i) its low redox potential; and (ii) its propensity to produce H-2. In this paper we discuss the thermodynamics of these characteristics (with special emphasis on ZVI reactions) and provide representative case studies documenting the safe and effective use of ISCR technology to rapidly remove halogenated organics from impacted subsurface environments.
Coupling microscale vegetation-soil water and macroscale vegetation-precipitation feedbacks in semiarid ecosystems
Dekker, S.C. ; Rietkerk, M. ; Bierkens, M.F.P. - \ 2007
Global Change Biology 13 (2007)3. - ISSN 1354-1013 - p. 671 - 678.
grazing systems - subgrid variability - atmosphere - climate - interception - enhancement - moisture - balance - regions - models
At macroscale, land¿atmosphere exchange of energy and water in semiarid zones such as the Sahel constitutes a strong positive feedback between vegetation density and precipitation. At microscale, however, additional positive feedbacks between hydrology and vegetation such as increase of infiltration due to increase of vegetation, have been reported and have a large impact on vegetation distribution and spatial pattern formation. If both macroscale and microscale positive feedbacks are present in the same region, it is reasonable to assume that these feedback mechanisms are connected. In this study, we develop and analyse a soil-vegetation-atmosphere model coupling large-scale evapotranspiration¿precipitation feedback with a model of microscale vegetation¿hydrology feedback to study the integration of these nonlinearities at disparate scales. From our results, two important conclusions can be drawn: (1) it is important to account for spatially explicit vegetation dynamics at the microscale in climate models (the strength of the precipitation feedback increased up to 35% by accounting for these microscale dynamics); (2) studies on resilience of ecosystems to climate change should always be cast within a framework of possible large-scale atmospheric feedback mechanism (substantial changes in vegetation resilience resulted from incorporating macroscale precipitation feedback). Analysis of full-coupled modelling shows that both type of feedbacks markedly influence each other and that they should both be accounted for in climate change models.
Two Lactobacillus strains, isolated from breast milk, differently modulate the immune response
Diaz-Ropero, M.P. ; Martin, R. ; Sierra, S. ; Lara-Villoslada, F. ; Rodriguez, J.M. ; Xaus, J. ; Olivares, M. - \ 2007
Journal of Applied Microbiology 102 (2007)2. - ISSN 1364-5072 - p. 337 - 343.
lactic-acid bacteria - dendritic cells - colonization - enhancement - expression - maturation - probiotics - rhamnosus - diarrhea - flora
Aims: The ability of two different Lactobacillus strains (Lactobacillus salivarius CECT5713 and Lactobacillus fermentum CECT5716), isolated from human breast milk, to modulate the immune response was examined. Methods and Results: In rodent bone-marrow-derived macrophages (BMDM), the presence of Lact. fermentum CECT5716 induced pro-inflammatory cytokines, in contrast to the activation of IL-10 induced by Lact. salivarius CECT5713. Although both strains reduced the lipopolysaccharide (LPS)-induced inflammatory response in BMDM, the effect of Lact. salivarius CECT5713 was more efficient, probably because of the production of higher amounts of IL-10 cytokine. In vivo assays in mice showed similar results; the consumption of Lact. fermentum CECT5716 enhanced the production of Th1 cytokines by spleen cells and increased the IgA concentration in faeces. However, the consumption of Lact. salivarius CECT5713 induced IL-10 production by spleen cells. Conclusion: Therefore, in general, the effect of Lact. fermentum CECT5716 is immunostimulatory in contrast to the anti-inflammatory effect of Lact. salivarius CECT5713. Significance and Impact of the Study: The results of this study show that two Lactobacillus strains isolated from breast milk can exert different and even opposing effects on immune response demonstrating the specificity of each strain.
Compensation for age-associated chemosensory losses and its effect on the pleasantness of a custard dessert and a tomato drink
Kremer, S. ; Bult, J.H.F. ; Mojet, J. ; Kroeze, J.H.A. - \ 2007
Appetite 48 (2007)1. - ISSN 0195-6663 - p. 96 - 103.
flavor amplification - elderly subjects - food preference - perception - young - texture - taste - consumption - enhancement - sensitivity
Differences between elderly subjects (n=52, 60¿85 years) and young subjects (n=55, 18¿35) in their food liking and their olfactory capability were investigated. Two food systems were used: custard desserts and tomato drinks. Flavor enhancement/enrichment, textural change, and/or irritant addition were incorporated as compensatory strategies into these foods. The addition of low concentrations of both cherry flavor and cream flavor to the custard desserts influenced their pleasantness for the majority of the elderly. The addition of cream topping increased the pleasantness of the custard desserts for both the elderly and the young. The elderly equally liked the tomato drinks with no or with low irritant addition, whereas the young generally disliked an irritant addition. However, the food liking of the elderly was not generally increased by these different compensatory strategies. Instead, subgroups were observed for each compensatory strategy, in which applied compensatory strategies led to an increase in product pleasantness. Age-associated losses in olfactory capabilities did not sufficiently explain differences in food liking, as only elderly with similar olfactory capabilities to the young demonstrated a liking of enhanced flavor. The present study does not support the assumption that age-associated impairment in olfactory capability will inevitably lead to changes in food liking.
Burkholderia phytofirmans sp. nov., a novel plant-associated bacterium with plant-beneficial properties
Sessitsch, A. ; Coenye, T. ; Sturz, A.V. ; Vandamme, P.A. ; Ait Barka, E. ; Salles, J.F. ; Elsas, J.D. van; Faure, D. ; Reiter, B. ; Glick, B.R. ; Wang-Pruski, G. ; Nowak, J. - \ 2005
International Journal of Systematic and Evolutionary Microbiology 55 (2005)3. - ISSN 1466-5026 - p. 1187 - 1192.
growth-promoting rhizobacteria - n-acylhomoserine lactones - in-vitro growth - cepacia complex - endophytic colonization - strain psjn - enhancement - resistance - potato - identification
A Gram-negative, non-sporulating, rod-shaped, motile bacterium, with a single polar flagellum, designated strain PsJNT, was isolated from surface-sterilized onion roots. This isolate proved to be a highly effective plant-beneficial bacterium, and was able to establish rhizosphere and endophytic populations associated with various plants. Seven related strains were recovered from Dutch soils. Based on 16S rRNA gene sequence data, strain PsJNT and the Dutch strains were identified as representing a member of the genus Burkholderia, as they were closely related to Burkholderia fungorum (98·7 %) and Burkholderia phenazinium (98·5 %). Analysis of whole-cell protein profiles and DNA¿DNA hybridization experiments confirmed that all eight strains belonged to a single species. Strain PsJNT had a DNA G+C content of 61·0 mol%. Only low levels of DNA¿DNA hybridization to closely related species were found. Qualitative and quantitative differences in fatty acid composition between strain PsJNT and closely related species were identified. The predominant fatty acids in strain PsJNT were 16 : 0, 18 : 17c and summed feature 3 (comprising 16 : 17c and/or iso-15 : 0 2-OH). Isolate PsJNT showed high 1-aminocyclopropane-1-carboxylate deaminase activity and is therefore able to lower the ethylene level in a developing or stressed plant. Production of the quorum-sensing signal compound 3-hydroxy-C8-homoserine lactone was detected. Based on the results of this polyphasic taxonomic study, strain PsJNT and the seven Dutch isolates are considered to represent a single, novel species, for which the name Burkholderia phytofirmans sp. nov. is proposed. The type strain is strain PsJNT (=LMG 22146T=CCUG 49060T)