Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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What are the health effects of sodium?
Kersten, A.H. - \ 2019
Wageningen :
sodium - salt - nutrition and health - diet - intake
In this video we explain the health effects of your sodium intake.
The TeRiFiQ project : Combining technologies to achieve significant binary reductions in sodium, fat and sugar content in everyday foods whilst optimising their nutritional quality
Salles, C. ; Kerjean, J.R. ; Veiseth-Kent, E. ; Stieger, M. ; Wilde, P. ; Cotillon, C. - \ 2017
Nutrition Bulletin 42 (2017)4. - ISSN 1471-9827 - p. 361 - 368.
consumer - fat - food - perception - sodium - sugar
Most developed countries are confronted with rising rates of diseases related to unhealthy eating habits, particularly the excessive consumption of salt, saturated fat and free sugars. However, fat, sugars and salt in food influence not only its nutritional qualities but also its sensory properties, safety (e.g. shelf life) and affordability. The main challenge is to formulate healthier foods that are acceptable to consumers. In this context, the overall objective of TeRiFiQ was to achieve significant binary reductions in the salt-fat and sugar-fat contents of frequently consumed food products around Europe, while, at the same time, ensuring the products’ nutritional and sensorial qualities, safety and affordability for both industry and consumers was not compromised. TeRiFiQ addressed four major food categories: cheeses, processed meat, bakery and sauce products. Different strategies adapted to each food category were used to reduce the target ingredients. Significant reductions in the salt-fat and fat-sugar contents of a number of cheese, processed meat, bakery and sauce products were achieved, and these changes were found to be acceptable to consumers. The most promising reformulated food products were developed at the industrial scale.
Vascular effects of sodium and potassium intake
Gijsbers, Lieke - \ 2017
Wageningen University. Promotor(en): Marianne Geleijnse; Pieter van 't Veer. - Wageningen : Wageningen University - ISBN 9789463436267 - 161
sodium - potassium - vascular system - hypertension - blood pressure - mineral supplements - endothelium - blood vessels - heart rate - osmoregulation - human nutrition research - randomized controlled trials - cardiovascular diseases - natrium - kalium - vaatsysteem - hypertensie - bloeddruk - minerale supplementen - endotheel - bloedvaten - hartfrequentie - osmoregulatie - voedingsonderzoek bij de mens - gestuurd experiment met verloting - hart- en vaatziekten

Cardiovascular diseases (CVD) are the main cause of death worldwide. Annually, about 17.5 million people die from CVD, accounting for ~30% of deaths worldwide. Elevated blood pressure (BP) is a major risk factor for CVD and the largest single contributor to global mortality. BP is a modifiable risk factor that is largely determined by lifestyle factors, including diet. Dietary minerals, in particular sodium and potassium, play an important role in BP regulation. While adverse effects of sodium and beneficial effects of potassium on BP have repeatedly been shown in human intervention studies, evidence on other vascular effects of these dietary minerals is still scarce. Therefore, we investigated the BP effects of sodium and potassium intake in healthy humans in a broader (patho)physiological context, focusing also on endothelial function, arterial stiffness, fluid regulation and heart rate.

In Chapter 2, the effects of sodium and potassium supplementation on BP and arterial stiffness were examined by means of a randomized placebo-controlled crossover trial. Thirty-six untreated Dutch individuals with mildly elevated BP on a fully controlled diet that was relatively low in sodium (2-3 g/d) and potassium (2-3 g/d) received capsules with sodium (3 g/d), potassium (3 g/d) or placebo, for 4 weeks each, in random order. After each intervention, fasting office BP, 24-h ambulatory BP and measures of arterial stiffness were assessed. The results of this study showed that increased sodium intake strongly raised office and ambulatory systolic BP (7-8 mmHg) whereas increased potassium intake lowered systolic BP (3-4 mmHg). Potassium supplementation increased ambulatory HR, but office HR was not affected. Measures of arterial stiffness were not materially affected by increased sodium or potassium intake, possibly due to the relatively short intervention period.

In the same study we investigated the effects of increased sodium and potassium intake on the functional measure of endothelial function (flow-mediated dilation), and on a comprehensive set of biomarkers of endothelial dysfunction and low-grade inflammation (Chapter 3). Four weeks of supplemental sodium had no effect on brachial flow-mediated dilation, or on the blood biomarkers of endothelial dysfunction and low-grade inflammation, except for an increase in serum endothelin-1 (a biomarker of endothelial dysfunction). Potassium supplementation improved flow-mediated dilation by 1.2% and tended to lower the low-grade inflammation marker interleukin-8. This suggests that potassium may beneficially influence vascular health by improving endothelial function.

In a post-hoc analysis of the same study in 35 untreated individuals, the humoral effects of supplemental sodium and potassium were assessed using a panel of markers that are involved in osmoregulation and volume regulation (Chapter 4). Results showed that supplemental sodium increased plasma natriuretic peptides and plasma copeptin, and suppressed the renin-angiotensin system. Supplemental potassium decreased plasma MR-pro-ANP, increased plasma copeptin, and stimulated the renin-angiotensin system. These findings suggest that the mineral-induced changes in BP elicit several counter regulatory mechanisms to maintain volume homeostasis.

In Chapter 5, the effect of potassium supplementation on heart rate was assessed in a meta-analysis of 22 randomized, placebo-controlled trials in healthy adults. Overall, increasing potassium intake by 2-3 g/d for at least two weeks did not affect resting heart rate. 24-h Ambulatory heart rate was not significantly affected in subgroup analysis of 4 RCTs, including ours. Other subgroup analyses for characteristics of the study and study population also showed no significant effects, and there was no evidence for a dose-response relationship. These results suggest that increasing potassium intake is not expected to adversely affect heart rate in apparently healthy adults.

In Chapter 6, BP associations for sodium and potassium intake using different dietary assessment methods were examined. Data of 993 healthy Dutch adults not on antihypertensive medication were analyzed using a cross-sectional approach. Sodium and potassium intake were estimated from two non-consecutive 24-h urinary samples (considered as the gold standard), two non-consecutive web-based 24-h recalls, and a validated 180-item food frequency questionnaire (FFQ). This study showed no significant associations of sodium intake with BP, regardless of the dietary assessment method used. Potassium intake estimated from 24-h urine and FFQ was inversely associated with BP (~1.5 mmHg reduction per 1 g/d increment). This suggests that dietary assessment methods in cross-sectional studies may be inadequate for estimating the association of sodium intake with BP, but may yield reliable results for potassium intake.

As discussed in Chapter 7, the studies presented in this thesis indicate that increasing sodium intake from a recommended level to a level that is common in Western societies for four weeks strongly raises BP in individuals with an untreated mildly elevated BP. The results for endothelial function and arterial stiffness are inconclusive, and hence more (longer-term) studies are warranted. Increasing the intake of potassium lowers BP and improves endothelial function, even in individuals on a relatively low-sodium diet. Both sodium and potassium intake affected fluid parameters, likely indicating that compensatory responses are stimulated to maintain body fluid balance. Although in our RCT ambulatory heart rate was increased after supplemental potassium, the meta-analysis showed that increasing potassium intake is unlikely to affect heart rate in apparently healthy adults. When evaluating the effectiveness of sodium and potassium intake on cardiovascular health, results obtained from observational studies should be interpreted with caution, particularly for sodium intake.

Around the world people consume on average 9-12 g of salt and 2-4 g of potassium on a daily basis. A more optimal intake of sodium and potassium can be achieved through adherence to dietary guidelines and product reformulation by food industry. This could reduce BP by more than 10 mmHg and lower the number of cardiovascular deaths by at least one-quarter in Western populations.

Nieuwe voedingsschema’s phalaenopsis voor veranderde teeltwijze : recirculatie, productieverhoging, teeltverkorting
Kromwijk, Arca ; Blok, Chris - \ 2016
horticulture - greenhouse horticulture - pot plants - phalaenopsis - recirculating systems - cropping systems - nutrients - crop production - urea - sodium - zinc - crop growth stage - agricultural research

De teelt van phalaenopsis is in de afgelopen vijftien jaar zo sterk veranderd, dat de praktijk niet goed meer uit de voeten kon met de voedingsschema’s uit de jaren negentig. Onderzoekers van Wageningen UR Glastuinbouw hebben daarom nieuwe schema’s ontwikkeld, die inmiddels op grote schaal toepassing vinden. Het gaat om schema’s voor opkweek (vegetatief) en afkweek (generatief) in bedrijfssituaties met en zonder recirculatie.

Nieuwe ionenwisselaar verwijdert 98% van nitraat uit spuiwater : door terugwinnen stikstof voldoen aan lozingsnormen
Ruijven, Jim van - \ 2016
horticulture - greenhouse horticulture - water management - drainage water - ion exchange - ion exchange treatment - technology - agricultural research - nitrogen - sodium - minerals - ion exchange resins - standards - eu regulations

Door nitraat te verwijderen uit spuiwater, kun je voldoen aan de lozingsregels voor 2027. Die zijn immers geënt op stikstofnormen. De teler zou echter nog meer hebben aan verwijdering van natrium, omdat hij dan langer kan recirculeren. Een nieuwe techniek, afkomstig uit Zuid-Afrika, biedt op beide vlakken veel perspectieven.

Recirculatie bij Phalaenopsis technisch goed haalbaar : Investeringsdrempel voor hergebruik drainwater ligt hoog
Arkesteijn, Marleen ; Kromwijk, J.A.M. - \ 2016
Onder Glas 13 (2016)1. - p. 9 - 11.
tuinbouw - glastuinbouw - waterbeheer - potplanten - drainagewater - hergebruik van water - phalaenopsis - gewaskwaliteit - emissiereductie - normen - stikstof - mest - natrium - zink - ijzer - horticulture - greenhouse horticulture - water management - pot plants - drainage water - water reuse - crop quality - emission reduction - standards - nitrogen - manures - sodium - zinc - iron
Hergebruik van drainwater bij phalaenopsis heeft geen nadelige effecten voor de plantengroei. Dat is de eindconclusie uit het onderzoek dat het afgelopen jaar is uitgevoerd en dat de gewascoöperatie Potorchidee deels financierde. De gewascoöperatie is tevreden en wil het komende jaar een vervolgonderzoek naar het effect van gecontroleerd vrijkomende meststoffen. Hiermee kunnen ook niet recirculerende telers een stap zetten.
Measurement errors in dietary assessment using duplicate portions as reference method
Trijsburg, L.E. - \ 2016
Wageningen University. Promotor(en): Pieter van 't Veer; Anouk Geelen; Jeanne de Vries. - Wageningen : Wageningen University - ISBN 9789462576421 - 128 p.
diet studies - nutritional assessment - questionnaires - reference standards - correction factors - validity - body mass index - regression analysis - food intake - food - protein - potassium - sodium - energy intake - methodology - dieetstudies - voedingstoestandbepaling - vragenlijsten - referentienormen - correctiefactoren - geldigheid - quetelet index - regressieanalyse - voedselopname - voedsel - eiwit - kalium - natrium - energieopname - methodologie

Measurement errors in dietary assessment using duplicate portions as reference method

Laura Trijsburg

Background: As Food Frequency Questionnaires (FFQs) are subject to measurement error, associations between self-reported intake by FFQ and outcome measures should be corrected for measurement error with data from a reference method. Whether the correction is adequate depends on the characteristics of the reference method used in the validation study. The duplicate portion method (DP), compared to the often used 24h recall (24hR), seems a promising reference method as correlated errors between FFQ and DP, such as memory bias, errors in portion size estimations and food composition databases, are not expected.

Aim: This thesis aimed to determine the validity of the DP compared to the 24hR as a reference method for FFQ validation. The second aim was to explore the validity of nutrient densities for DP, 24hR and FFQ. The third aim was to determine the factors associated with misreporting of energy, protein and potassium as estimated by DP, 24hR and FFQ.

Methods: Within the DuPLO-study, a Dutch validation study which is part of the NQplus study, two DPs, two FFQs, two blood and urinary biomarkers and one to fifteen 24hRs (web-based and/or telephone-based) were collected in 198 subjects, within 1.5 years. Also, one or two doubly labelled water measurements were available for 69 participants. Multivariate measurement error models were used to assess proportional scaling bias, error correlations with the FFQ, validity coefficients and attenuation factors. Furthermore linear regression analysis was used to determine the association between misreporting and various factors.

Results: The DP was less influenced by proportional scaling bias, had lower correlated errors with the FFQ and showed higher attenuation factors than the 24hR for potassium, sodium and protein. Also, the DP seemed a better reference method than the 24hR for the assessment of validity coefficients for the FFQ for various fatty acids. The attenuation factors for the FFQ, using either the DP or 24hR as reference method, agreed reasonably well. Furthermore, the DP showed, when using plasma fatty acids as reference, slightly better ranking of participants according to their intake of n-3 fatty acids (0.33) and the n‑3/LA ratio (0.34) than the 24hR (0.22 and 0.24, respectively). Less group level bias was observed for protein and sodium densities compared to their absolute intakes for FFQ, 24hR and DP, but not for potassium. Overall the validity coefficients and attenuation factors for DP, 24hR and FFQ did not improve for nutrient densities compared to absolute intakes, except for the attenuation factor for sodium density. Lastly, BMI proved to be the most consistent determinant associated with misreporting (group level bias) of energy, protein and potassium for DP, 24hR and FFQ. Men tended to underreport protein by the DP, FFQ and 24hR and persons of older age underreported potassium but only by the 24hR and FFQ. Other explorative determinants did not show a consistent association with misreporting of energy or nutrients by the different dietary assessment methods.

Conclusion: With respect to error correlations and attenuation factors the DP performed slightly better than the 24hR as a reference method for validating FFQs in epidemiological research. Furthermore, the use of nutrient densities does not necessarily improve the validity of the dietary intake estimates from DP, 24hR and FFQ. Moreover, it was shown that BMI is an important determinant of misreporting of energy, protein and potassium for these three assessment methods.

Recirculatie bij Cymbidium
Kromwijk, J.A.M. ; Voogt, W. - \ 2015
cymbidium - zoutgehalte - teeltsystemen - glastuinbouw - tuinbouw - recirculatiesystemen - natrium - proeven - monitoring - salinity - cropping systems - greenhouse horticulture - horticulture - recirculating systems - sodium - trials
Tot voor kort had het gewas Cymbidium een vrijstelling voor recirculatie vanwege de zoutgevoeligheid van het gewas en lage EC in de gift. Daardoor is er weinig kennis en ervaring met recirculatie. Voor Cymbidium is nog niet bekend wat de effecten van Natrium zijn. Daarom is onderzoek gestart om vast te stellen bij welk Natriumniveau in de voeding nadelige effecten op gaan treden.
Natriumgevoeligheid en recirculatie bij Cymbidium. Tussenrapport na 1e teeltjaar : Behoud plantgezondheid en voorkomen groeiremming bij hergebruik drainwater
Kromwijk, J.A.M. ; Voogt, W. - \ 2015
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1371) - 24
teelt onder bescherming - glastuinbouw - cymbidium - recirculatiesystemen - emissie - natrium - drainagewater - groei - kwaliteit - gewaskwaliteit - protected cultivation - greenhouse horticulture - recirculating systems - emission - sodium - drainage water - growth - quality - crop quality
In the Netherlands, the government and horticultural industry have agreed to lower the emission of nutrients to the environment. Until recently no drain water was reused in the cultivation of Cymbidium orchids as growers were allowed to discharge the drain water when a sodium level of more than 0 mmol/l was reached. As reusing drain water is a new phenomenon for Cymbidium, growers are now faced with a lack of knowledge on the effects of drain water reuse. Therefore a trial was started to investigate the effect of sodium accumulation on crop growth and flowering in two varieties of Cymbidium. Different sodium concentrations are given while maintaining the EC at 0.8. These sodium treatments have a lower “nutritional EC” than the control treatment without sodium. As of February 2015 unusual symptoms in the leaves emerged at the two highest levels of sodium resulting in dead leaf tips / leaves. This is potassium deficiency, induced by the lower potassium concentration in the nutritional solution and by inhibition of the potassium uptake by a high sodium concentration. In the first year of cultivation, sodium accumulation had no effect on production as the flower stalks were already induced before the start of the treatments. Cymbidium is a perennial crop in which negative effects on production and quality take a long time to become visible, so the experiment will be continued into a second year of cultivation. This research is funded by the Cymbidium growers in the Netherlands, Product Board for Horticulture and Top Sector Horticulture and Propagation Materials.
Root zone salinity and sodicity under seasonal rainfall due to feedback of decreasing hydraulic conductivity
Zee, S.E.A.T.M. van der; Shah, S.H.H. ; Vervoort, R.W. - \ 2014
Water Resources Research 50 (2014)12. - ISSN 0043-1397 - p. 9432 - 9446.
soil-moisture dynamics - irrigation - infiltration - variability - management - california - transport - quality - systems - sodium
Soil sodicity, where the soil cation exchange complex is occupied for a significant fraction by Na+, may lead to vulnerability to soil structure deterioration. With a root zone flow and salt transport model, we modeled the feedback effects of salt concentration (C) and exchangeable sodium percentage (ESP) on saturated hydraulic conductivity Ks(C, ESP) for different groundwater depths and climates, using the functional approach of McNeal (1968). We assume that a decrease of Ks is practically irreversible at a time scale of decades. Representing climate with a Poisson rainfall process, the feedback hardly affects salt and sodium accumulation compared with the case that feedback is ignored. However, if salinity decreases, the much more buffered ESP stays at elevated values, while Ks decreases. This situation may develop if rainfall has a seasonal pattern where drought periods with accumulation of salts in the root zone alternate with wet rainfall periods in which salts are leached. Feedback that affects both drainage/leaching and capillary upward flow from groundwater, or only drainage, leads to opposing effects. If both fluxes are affected by sodicity-induced degradation, this leads to reduced salinity (C) and sodicity (ESP), which suggests that the system dynamics and feedback oppose further degradation. Experiences in the field point in the same direction.
Association of dietary pattern and body weight with blood pressure in Jiangsu Province, China
Qin, Y. ; Boonstra, A. ; Pan, X. ; Zhao, J. ; Yuan, B. ; Dai, Yue ; Zhou, M. ; Geleijnse, J.M. ; Kok, F.J. ; Shi, Z. - \ 2014
BMC Public Health 14 (2014). - ISSN 1471-2458 - 16 p.
randomized controlled-trials - public-health - global burden - risk-factors - meat intake - mass index - hypertension - sodium - adults - metaanalysis
Background To identify risk factors, associations between dietary patterns, body mass index (BMI), and hypertension in a Chinese population. Methods Dietary intake was assessed in 2518 adults by a 3-day 24 h recall and a food frequency questionnaire. Salt and oil intake was assessed by weighing records. Four dietary patterns were identified using principal component analysis. Overweight and obesity was determined according to the Chinese cut-offs for BMI. High blood pressure was defined as systolic blood pressure¿=¿140 mmHg and/or diastolic blood pressure¿=¿90 mmHg. Prevalence ratios (PR) were calculated using Poisson regression. Results Of the subjects, 26.7% had high blood pressure. Subjects with overweight and obesity were more likely to have high blood pressure than those with normal weight (PR, 95% CI: 1.60, 1.40-1.87; 2.45, 2.11-2.85, respectively). Subjects with a ‘traditional’ dietary pattern were more likely to have high blood pressure (P for trend¿=¿0.001), whereas those with a ‘macho’ or ‘sweet tooth’ dietary pattern were less likely to have high blood pressure (P for trend¿=¿0.004 and ¿9 g/d, and blood pressure increased with salt intake (P for trend
Eicosapentaenoic acid free fatty acid prevents and suppresses colonic neoplasia in colitis-associated colorectal cancer acting on Notch signaling and gut microbiota
Piazzi, G. ; Argenio, G. D'; Prossomariti, A. ; Lembo, V. ; Mazzone, G. ; Candela, M. ; Biagi, E. ; Brigidi, P. ; Vitaglione, P. ; Fogliano, V. ; Angelo and others, L. D' - \ 2014
International Journal of Cancer 135 (2014)9. - ISSN 0020-7136 - p. 2004 - 2013.
inflammatory-bowel-disease - dietary fish-oil - intestinal microbiota - mouse model - docosahexaenoic acid - mice - sodium - cells - differentiation - chemoprevention
Inflammatory bowel diseases are associated with increased risk of developing colitis-associated colorectal cancer (CAC). Epidemiological data show that the consumption of ¿-3 polyunsaturated fatty acids (¿-3 PUFAs) decreases the risk of sporadic colorectal cancer (CRC). Importantly, recent data have shown that eicosapentaenoic acid-free fatty acid (EPA-FFA) reduces polyp formation and growth in models of familial adenomatous polyposis. However, the effects of dietary EPA-FFA are unknown in CAC. We tested the effectiveness of substituting EPA-FFA, for other dietary fats, in preventing inflammation and cancer in the AOM-DSS model of CAC. The AOM-DSS protocols were designed to evaluate the effect of EPA-FFA on both initiation and promotion of carcinogenesis. We found that EPA-FFA diet strongly decreased tumor multiplicity, incidence and maximum tumor size in the promotion and initiation arms. Moreover EPA–FFA, in particular in the initiation arm, led to reduced cell proliferation and nuclear ß-catenin expression, whilst it increased apoptosis. In both arms, EPA-FFA treatment led to increased membrane switch from ¿-6 to ¿-3 PUFAs and a concomitant reduction in PGE2 production. We observed no significant changes in intestinal inflammation between EPA-FFA treated arms and AOM-DSS controls. Importantly, we found that EPA-FFA treatment restored the loss of Notch signaling found in the AOM-DSS control and resulted in the enrichment of Lactobacillus species in the gut microbiota. Taken together, our data suggest that EPA-FFA is an excellent candidate for CRC chemoprevention in CAC.
Recirculatie potorchidee 2. Natrium
Blok, C. ; Kromwijk, J.A.M. - \ 2014
Wageningen UR / Glastuinbouw Waterproof
potplanten - orchidales - hergebruik van water - natrium - opname (uptake) - effecten - waterkwaliteit - plantenvoeding - gewasanalyse - pot plants - water reuse - sodium - uptake - effects - water quality - plant nutrition - plant analysis
Planten nemen zo min mogelijk natrium (Na) op. Als het gehalte in het aanvoer water hoger is dan de plantopname, leidt recirculatie van drainwater tot het oplopen van het natriumgehalte in het substraat en in de voedingsoplossing. De grenswaarde voor natrium en de opname van natrium kunnen per gewas sterk verschillen. Voor potorchideeën is nog niet bekend bij welke natriumgehalten negatieve effecten optreden.
Uitspoeling van zouten in een kasgrond: Onderzoek aan uitspoeling aan grondkolommen met natriumchloride- en natriumsulfaattoediening
Voogt, W. ; Steenhuizen, J.W. ; Winkel, A. van; Bosch, C.J.W. - \ 2013
Bleiswijk : Wageningen UR Glastuinbouw (Rapporten WUR GTB 1260) - 40
kassen - bodemonderzoek - percolatie - zouten - natrium - chloor - laboratoriumproeven - irrigatie - meting - uitspoelen - glastuinbouw - greenhouses - soil testing - percolation - salts - sodium - chlorine - laboratory tests - irrigation - measurement - leaching - greenhouse horticulture
Dit onderzoek is gefinancierd door het Ministerie van Economische Zaken, in het kader van het BO programma “Biologische Landbouw/thema Duurkas” en “Duurzame bodem”
Niet kunstmest, maar water is belangrijkste bron van natrium (Wim Voogt zet de situatie uiteen)
Staalduinen, J. van; Voogt, W. - \ 2013
Onder Glas 10 (2013)5. - p. 53 - 53.
glastuinbouw - waterkwaliteit - natrium - irrigatie - bemesting - mineralenopname - kasgewassen - snijbloemen - groenten - greenhouse horticulture - water quality - sodium - irrigation - fertilizer application - mineral uptake - greenhouse crops - cut flowers - vegetables
Intensief recirculeren spaart water en meststoffen, maar soms is spuien noodzakelijk. Een oplopend natriumcijfer is een belangrijke aanleiding om recirculatie- en spoelwater te lozen. Blijkens onderzoek bevat het uitgangswater vaak veel natrium. Meestal meer dan er via meststoffen het bedrijf binnenkomt. Wim Voogt van Wageningen UR Glastuinbouw is gespecialiseerd in meststoffen en zet de situatie uiteen.
Glastuinbouw Waterproof: Haalbaarheidsstudie valorisatie van concentraatstromen (WP6) Fase 2 - Desktop studie afzetmogelijkheden van concentraat als meststof voor andere teelten
Balendonck, J. ; Feenstra, L. ; Os, E.A. van; Lans, C.J.M. van der - \ 2012
Bleiswijk : Wageningen UR Glastuinbouw (Rapporten GTB 1204) - 87
afvalwaterbehandeling - afvalwater - stikstof - fosfaten - natrium - substraten - teeltsystemen - vloeibare meststoffen - concentraten - economische haalbaarheid - milieuwetgeving - methodologie - Nederland - waste water treatment - waste water - nitrogen - phosphates - sodium - substrates - cropping systems - liquid manures - concentrates - economic viability - environmental legislation - methodology - Netherlands
Dit rapport geeft de resultaten van een desktop studie naar de haalbaarheid van valorisatie van stikstof-, fosfaat- en natriumrijke afvalwaterstromen uit de substraatteelt. Afzetroutes voor grondteelten, substraatteelten en aquacultuur zijn geëvalueerd door te kijken naar de gewenste samenstelling, logistiek, wetgeving, markt en implementatie termijn. Milieuwetgeving stelt dat hergebruik mag als het om dezelfde toepassing gaat. Voor hergebruik in een andere teelt, buiten het eigen bedrijf, is een vergunning nodig. Om transportkosten te besparen moet de afvalwaterstroom hoog geconcentreerd en het liefst dichtbij afgezet worden. Nutriëntenrijke drijfmest is op de markt een grote concurrent. Bewerking is vaak nodig omdat afnemers eigen kwaliteitseisen stellen. Met geavanceerde oxidatie, elektrochemische flocculatie en O3 met actief kool kunnen ziektekiemen en gewasbeschermingsmiddelen deels verwijderd worden. Met nano-filtratie en elektrodialyse kan tot op zekere hoogte de nutriëntensamenstelling aangepast worden. Voor de korte termijn worden kansen gezien voor de afzet naar meststoffenleveranciers van vloeibare meststoffen en de bemesting van grasland. Voor de langere termijn zijn er kansen voor toepassing als aanvullende bemesting bij zout-tolerante teelten, mits uit onderzoek economisch interessante rassen daarvoor beschikbaar komen. Ook de algenteelt voor biobrandstof zou op termijn een markt kunnen vormen. Er moet wel gezocht worden naar het type alg dat optimaal presteert.
Glastuinbouw Waterproof: Haalbaarheidsstudie valorisatie van concentraatstromen (WP6) Fase 1 - Desktop studie “Scenario’s”
Balendonck, J. ; Feenstra, L. - \ 2012
Bleiswijk : Wageningen UR Glastuinbouw (Rapporten GTB 1203) - 96
afvalwater - afvalwaterbehandeling - stikstof - fosfaten - natrium - substraten - recirculatiesystemen - gesloten systemen - hergebruik van water - methodologie - waterzuivering - glastuinbouw - waste water - waste water treatment - nitrogen - phosphates - sodium - substrates - recirculating systems - closed systems - water reuse - methodology - water treatment - greenhouse horticulture
De waterkwaliteitsnormen voor emissie van gewasbeschermingsmiddelen en nutriënten worden in een aantal glastuinbouwgebieden in Nederland overschreden. Hoewel glastuinbouwbedrijven met substraatteelt al recirculatie moeten toepassen, wordt er naast bedrijfsafvalwater ook spuiwater (drainwater) geloosd dat als gevolg van de accumulatie van zouten (natrium), groeiremmende stoffen of vanwege de risico’s op ziekten in het wortelmilieu niet meer kan worden hergebruikt. Het project “Glastuinbouw Waterproof substraatteelt - waterkringloopsluiting op bedrijfsniveau” wil een oplossing voor het lozen van de glastuinbouw genereren door het ontwikkelen van een systeem van waterkringloopsluiting voor substraatteelt. Het doel is om de genoemde emissies van nutriënten en gewasbeschermingsmiddelen naar het oppervlaktewater of riool te voorkomen door het hergebruik van drainwater te maximaliseren en het restantwater te zuiveren en valoriseren. Hierbij staat een integrale aanpak centraal met aandacht voor het opheffen groeiremming (werkpakket 1 +2), optimalisatie bemesting (werkpakket 3 + 4) en waterkringloopsluiting door waterzuivering en valorisatie van concentraatstromen (werkpakket 5 + 6). Door de betrokkenheid van de sector in het project zal de te ontwikkelen oplossing een brede acceptatie en implementatie in de glastuinbouwsector moeten krijgen. Dit rapport presenteert de uitkomsten van de haalbaarheidsstudie van Fase 1 van werkpakket 6 die tot doel heeft om onderwerpen en technieken te selecteren en te evalueren die in de volgende fase van het onderzoek kunnen worden onderzocht en ontwikkeld naar toepassing voor de opwerking van de concentraatstromen. De haalbaarheidsstudie is gestart met het opstellen van een overzicht van de hoeveelheid en samenstelling van de huidige afvalwaterstroom en het concentraat van WP5, waarin voor de modelgewassen roos, paprika, gerbera en tomaat, drie verschillende concepten zijn geformuleerd.
Variation in rumen fermentation and the rumen wall during the transition period in dairy cows
Bannink, A. ; Gerrits, W.J.J. ; France, J. ; Dijkstra, J. - \ 2012
Animal Feed Science and Technology 172 (2012)1-2. - ISSN 0377-8401 - p. 80 - 94.
subacute ruminal acidosis - chain fatty-acids - veal calf diets - early lactation - carbohydrate-composition - metabolic disorders - absorption - ph - adaptation - sodium
Strong adaptive changes occur in the peri-parturient dairy cow related to a marked rise in dry matter intake and alteration in diet composition after calving. Early lactation dairy cattle are susceptible to metabolic disorders and impaired rumen function during the transition period, with detrimental effects on cow performance. For a quantitative understanding of the dietary effects on rumen function, several classes of influencing factors can be distinguished (intrinsic degradation characteristics of feed, characteristics of microbial activity, rumen fermentation conditions, rumen wall function). Interpretation of experimental results requires all these factors to be taken into consideration simultaneously. This contribution aimed to review the capacity of the rumen wall to adapt to the marked increase in feed intake by the post-parturient dairy cow. While the principle of distinct adaptations of the post-parturient rumen wall is generally accepted, literature is not always conclusive about the size of the effects. Virtually all studies on adaptation of the post-parturient rumen wall were performed post-mortem and with isolated tissue in vitro. Therefore, an in vivo trial with twelve rumen fistulated dairy cows is presented to support and discuss the various factors involved in this review. A faster (in 10 d) versus a slower (in 20 d) increment of starch-rich concentrate intake after calving was evaluated for effects on adaptive response of rumen epithelia and altered rumen functioning up to twelve weeks after calving. Results showed transient changes in rumen epithelia and suggest a different adaptive response of rumen epithelia during the first weeks of lactation due to differences in supplemental concentrate feeding. No evidence was found for any detrimental effect of a fast increment of concentrate intake on dry matter intake, rumen fermentation, and cow performance. Results in literature either confirm or contradict these findings, and they attribute either a more important role to molecular mechanisms in rumen epithelia or to cell proliferation and epithelial morphology. The different research methods adopted and the high variability of results obtained with this type of research strongly limit our understanding of the relative importance of cell metabolic changes, epithelia proliferation and rumen wall morphology. In conclusion, the ruminal epithelia in the peri-parturient cow responds in a coordinated manner to rapid dietary changes which is of high significance to maintain normal rumen function
Predicting urinary creatinine excretion and its usefulness to identify incomplete 24h urine collections
Keyzer, W. de; Huybrechts, I. ; Dekkers, A.L.M. ; Geelen, A. ; Crispim, S.P. ; Hulshof, P.J.M. ; Andersen, L.F. ; Rehurkova, I. ; Ruprich, J. ; Volatier, J.L. ; Maele, G. van; Slimani, N. ; Veer, P. van 't; Boer, E. de; Henauw, S. de - \ 2012
The British journal of nutrition 108 (2012)6. - ISSN 0007-1145 - p. 1118 - 1125.
4-aminobenzoic acid - european centers - completeness - potassium - diet - validation - stability - recalls - protein - sodium
Studies using 24 h urine collections need to incorporate ways to validate the completeness of the urine samples. Models to predict urinary creatinine excretion (UCE) have been developed for this purpose; however, information on their usefulness to identify incomplete urine collections is limited. We aimed to develop a model for predicting UCE and to assess the performance of a creatinine index using para-aminobenzoic acid (PABA) as a reference. Data were taken from the European Food Consumption Validation study comprising two non-consecutive 24 h urine collections from 600 subjects in five European countries. Data from one collection were used to build a multiple linear regression model to predict UCE, and data from the other collection were used for performance testing of a creatinine index-based strategy to identify incomplete collections. Multiple linear regression (n 458) of UCE showed a significant positive association for body weight (ß = 0·07), the interaction term sex × weight (ß = 0·09, reference women) and protein intake (ß = 0·02). A significant negative association was found for age (ß = - 0·09) and sex (ß = - 3·14, reference women). An index of observed-to-predicted creatinine resulted in a sensitivity to identify incomplete collections of 0·06 (95 % CI 0·01, 0·20) and 0·11 (95 % CI 0·03, 0·22) in men and women, respectively. Specificity was 0·97 (95 % CI 0·97, 0·98) in men and 0·98 (95 % CI 0·98, 0·99) in women. The present study shows that UCE can be predicted from weight, age and sex. However, the results revealed that a creatinine index based on these predictions is not sufficiently sensitive to exclude incomplete 24 h urine collections.
Comparison of various models to describe the charge-pH dependence of poly(acrylic acid)
Lützenkirchen, J. ; Male, J. van; Leermakers, F.A.M. ; Sjöberg, S. - \ 2011
Journal of Chemical and Engineering Data 56 (2011)4. - ISSN 0021-9568 - p. 1602 - 1612.
ion-binding - electrolyte-solutions - monte-carlo - polyelectrolytes - adsorption - molecules - constants - titration - sodium - simulations
The charge of poly(acrylic acid) (PAA) in dilute aqueous solutions depends on pH and ionic strength. We report new experimental data and test various models to describe the deprotonation of PAA in three different NaCl concentrations. A simple surface complexation approach is found to be very successful: the constant capacitance model requires one pKa value and one capacitance for excellent fits to the data, with both parameters depending on ionic strength. The use of a self-consistent set of diffuse double layer parameters with one pKa for flat, spherical, and cylindrical geometry does not result in a satisfactory description of the data, and a number of adjustments to that model were tested to improve the fit. The basic Stern model (BSM) was tested with both plate and cylinder geometry. The cylinder geometry along with strong electrolyte binding was found to be superior to a similar approach involving weak electrolyte binding both in terms of goodness of fit and self-consistency of the parameters. The third approach, the non-ideal competitive consistent adsorption-Donnan (NICCA-Donnan) model, involving one functional group, allows an excellent description of the experimental data. Finally, the polyacid chain was modeled using a mechanistically more realistic self-consistent field (SCF) approach, which allows for radially inhomogeneous distributions of the charges and radial variations in the polymer density and electrostatic potential, while the functional groups can be in protonated, deprotonated, or complexed states. One functional group was insufficient for a satisfactory description of the data. With two segments (one monoprotic, the other diprotic) a reasonable description of the data, including the ionic strength dependence, is achieved, and the tendency of the size of the macro-ion with pH and ionic strength is as expected. This model has the fewest adjustable parameters and is considered the most realistic and comprehensive among the models tested
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