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.

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Prevalence of dental disorders in degus and evaluation of diagnostic methods to determine dental disease and its prognosis
Bolhuis, Hester van; Hoffen, Lotte van; Zijll Langhout, Martine van; Engeldorp Gastelaars, Heleen van; Hendriks, Wouter ; Lamberts, Marnix ; Kik, Marja - \ 2017
Veterinary Record 181 (2017)23. - ISSN 0042-4900
apical elongation - calcium - malocclusion - octodon degus - phosphorus - radiography
Degus (Octodon degus) are prone to develop dental disease with deleterious health effects. The two studies reported here aimed to determine the prevalence of dental disorders in degus and to identify and evaluate diagnostic tools for determination of prognosis of these disorders. In study A, health data from 225 degus at AAP, Rescue Center for Exotic Animals in the Netherlands, were collated and the prevalence of dental disorders and differences in sex and age at clinical onset of symptoms associated with dental disorders were described. The prevalence was 34.7 per cent and higher (P<0.01) in males than in females. The occurrence of cheek teeth malocclusion was highly positively (P<0.0001) correlated to mortality. In study B, 36 skulls were examined by macroscopic evaluation, radiography and histology. Additionally, the calcium:phosphorus (Ca:P) of mandibular bone in degus with and without dental disorders were determined. There was no significant (P=0.10) difference in Ca:P between the two groups. Quantifying mandibular apical cheek teeth elongation via macroscopic evaluation was highly correlated (P<0.01) to the results obtained via radiography. Examination for apical elongation by palpation and diagnostic imaging should be included in routine health monitoring of degus. Apical elongation appeared to develop before coronal elongation and when cheek teeth malocclusion occurred, prognosis for recovery of dental disease was poor.
White root tips supply plants with oxygen, water and nutrients : healthy roots are fundamental for a healthy plant
Heuvelink, E. ; Kierkels, T. - \ 2016
In Greenhouses : the international magazine for greenhouse growers 5 (2016)3. - ISSN 2215-0633 - p. 44 - 45.
tuinbouw - glastuinbouw - worteloppervlak - wortelharen - wortels - wateropname (planten) - voedselopname - opname (uptake) - calcium - tomaten - pythium - plantenontwikkeling - horticulture - greenhouse horticulture - rhizoplane - root hairs - roots - water uptake - food intake - uptake - tomatoes - plant development
The main, most important function of roots belonging to horticultural crops is the uptake of water and nutrients. Healthy roots are essential for a healthy plant. After all, if the uptake of water and nutrients is not functioning properly, then other aspects also leave a lot to be desired
Mode of action of Bacillus licheniformis pectin methylesterase on highly methylesterified and acetylated pectins
Remoroza, C.A. ; Wagenknecht, M. ; Buchholt, H.C. ; Moerschbacher, B.M. ; Gruppen, H. ; Schols, H.A. - \ 2015
Carbohydrate Polymers 115 (2015). - ISSN 0144-8617 - p. 540 - 550.
sugar-beet pectins - aspergillus-niger - esterified oligogalacturonides - environmental-conditions - structural features - de-esterification - escherichia-coli - methyl esterase - degradation - calcium
A gene encoding a putative pectinesterase from Bacillus licheniformis DSM13 was cloned and expressed in Escherichia coli. The resulting recombinant enzyme (BliPME) was purified and characterized as a pectin methylesterase. The enzyme showed maximum activity at pH 8.0 and 50 °C. BliPME is able to release up to 100% of the methylesters from lime pectin (DM 34–76 ¿ DM 0) and up to 73% of all methylesters from SBPs (DM 30–73 ¿ DM 14). BliPME efficiently de-methylesterifies lemon pectins and SBPs in a blockwise manner and is quite tolerant towards the acetyl groups present within the SBPs. Detailed analysis of the BliPME-modified pectins using HILIC–MSn and the classical calcium reactivity measurement showed that the enzyme generates pectins with low methylesterification (lime and SBP) and high acetyl content (SBP) while creating blocks of nonmethylesterified galacturonic acid residues. The high activity of BliPME towards highly methylesterified and acetylated pectins makes this novel esterase more efficient in removing methylesters from highly esterified beet pectin compared to other PMEs, e.g. Aspergillus niger PME.
Factors contributing to the variation in feline urinary oxalate excretion
Dijcker, J.C. ; Hagen-Plantinga, E.A. ; Everts, H. ; Queau, Y. ; Biourge, V.C. ; Hendriks, W.H. - \ 2014
Journal of Animal Science 92 (2014)3. - ISSN 0021-8812 - p. 1029 - 1036.
glycolate excretion - dietary-protein - ascorbic-acid - calcium - cats - hydroxyproline - vitamin-b-6 - fructose - requirement - absorption
This study aimed to identify factors (season, animal, and diet) contributing to the variation in urinary oxalate (Uox) excretion rate, Uox concentration, and urine volume in healthy adult cats. A data set (1,940 observations) containing information on Uox excretion rate of 65 cats fed 252 diets (i.e., each diet was fed to a group of 6 to 8 cats), with known dietary oxalate concentrations, collected over a 6 yr period at a feline nutrition facility, were retrospectively analyzed. Data related to season, animal (i.e., age, gender, body weight, and breed), and diet (i.e., nutrient content) characteristics were subjected to stepwise multivariate regression analysis to identify factors significantly correlated to Uox excretion rate (µmol/(kg BW0.67·d)) and concentration (mmol/L) as well as urine volume (mL/(kg BW0.67·d)). Independent factors significantly (P <0.05) associated with lower Uox concentration (mmol/L) included greater ash, Ca, and Na intake and lower nitrogen-free extract, total dietary fiber, P, and oxalate intake, and a body weight
Is calciuminname een goede indicator voor voedingskwaliteit?
Groot, C.P.G.M. de - \ 2014
VoedingsMagazine (2014)3. - ISSN 0922-8012 - p. 23 - 23.
calcium - inname - voeding en gezondheid - voedingsstoffen - voedingsgewoonten - voedselkwaliteit - ingestion - nutrition and health - nutrients - feeding habits - food quality
In Nutrition Today publiceerden dr. Karen Lafferty en collega's een secundaire analyse van zes studies naar de relatie tussen calciuminname en de voedingskwaliteit bij vrouwen. Deelneemsters aan deze studies waren meisjes en vrouwen in de leeftijd van 14 tot 86 jaar. Degenen met een lage calciuminname bleken gemiddeld ook een lage inname te hebben van elf andere nutriënten. Van degenen met een hogere calciuminname bleek slechts 7,7% een voeding van slechte kwaliteit te hebben.
Influence of C16:0 and long-chain saturated fatty acids on normal variation of bovine milk fat triacylglycerol structure
Tzompa Sosa, D.A. ; Aken, G.A. van; Hooijdonk, A.C.M. van; Valenberg, H.J.F. van - \ 2014
Journal of Dairy Science 97 (2014)7. - ISSN 0022-0302 - p. 4542 - 4551.
regiospecific analysis - infant formulas - positional distribution - stereospecific analysis - magnesium bromide - palmitic acid - triglycerides - parameters - calcium - rats
Fatty acids (FA) are nonrandomly distributed within milk fat triacylglycerols (TAG). Moreover, the structure of milk fat TAG differs with feeding regimens. So far, nothing is known about the variation of milk fat TAG structure among individual cows. A deep understanding of the normal variation of TAG structures and the relationships between milk fat FA profile and its TAG structure could help to better control functional and compositional differences between milk fats from various sources and to increase the knowledge on milk fat synthesis. The focus of the present study was to determine the regiospecific TAG structure of individual samples of winter milk fat from Dutch Holstein-Friesian cows with a wide variation of FA profiles and with 2 diacylglycerol acyltransferase 1 (DGAT1) genotypes: DGAT1 K232A genotype AA and DGAT1 K232A genotype KK. From an initial set of 1,918 individual milk fat samples, 24 were selected. The selected samples had a wide range of FA composition and had either DGAT1 K232A genotype AA or KK. The structure analysis was done with a regiospecific approach. This analysis is based on the acyl degradation of TAG by a Grignard reagent and further isolation of sn-2 monoacylglycerols by thinlayer chromatography. An intra- and interpositional approach was used to study the structural variation. With the intrapositional approach, the amount of an FA at the secondary (sn-2) and primary (sn-1,3) positions was related to its total amount in the TAG. With the interpositional approach, the proportion of C8:0, C10:0, C14:1 cis-9, C16:1 cis-9, and C18:1 cis-9 at sn-2 was positively correlated with the amount of C16:0 in the triacylglycerol; in contrast, saturated C14:0, C16:0, and long-chain saturated FA (C14:0–C18:0) were negatively correlated. These observations suggest that the amount of long-chain saturated FA in TAG influences the positioning of other FA in the TAG. With an interpositional approach, the DGAT1 polymorphism had a significant effect on the proportional positioning of C16:0 at sn-2. These results provide a new direction to controlling functional and compositional differences between milk fats.
Evaluation of using spot urine to replace 24 h urine sodium and potassium excretions
Hooft Van Huysduynen, E.J.C. ; Hulshof, P.J.M. ; Lee, L. van; Geelen, A. ; Feskens, E.J.M. ; Veer, P. van 't; Woerkum, C.M.J. van; Vries, J.H.M. de - \ 2014
Public Health Nutrition 17 (2014)11. - ISSN 1368-9800 - p. 2505 - 2511.
24-hour - collections - completeness - creatinine - magnesium - calcium - samples - marker - acid
Objective The most accurate method to estimate Na and K intakes is to determine 24 h urinary excretions of these minerals. However, collecting 24 h urine is burdensome. Therefore it was studied whether spot urine could be used to replace 24 h urine samples. Design Participants collected 24 h urine and kept one voiding sample separate. Na, K and creatinine concentrations were analysed in both 24 h and spot urine samples. Also 24 h excretions of Na and K were predicted from spot urine concentrations using the Tanaka and Danish methods. Setting In 2011 and 2012, urine samples were collected and brought to the study centre at Wageningen University, the Netherlands. Subjects Women (n 147) aged 19–26 years. Results According to p-aminobenzoic acid excretions, 127 urine collections were complete. Correlations of Na:creatinine, K:creatinine and Na:K between spot urine and 24 h urine were 0·68, 0·57 and 0·64, respectively. Mean 24 h Na excretion predicted with the Tanaka method was higher (difference 21·2 mmol/d, P
Nanospheres of alginate prepared through w/o emulsification and internal gelation with nanoparticles of CaCO3
Paques, J.P. ; Sagis, L.M.C. ; Rijn, C.J.M. van; Linden, E. van der - \ 2014
Food Hydrocolloids 40 (2014). - ISSN 0268-005X - p. 182 - 188.
drug-delivery - beads - microcapsules - release - calcium - islets - encapsulation - particles - chitosan - size
Gelled nanospheres of alginate are prepared through a single step technique involving emulsification and gelation. CaCO3 nanoparticles, together with glucono delta-lactone (GDL), are dispersed in an alginate solution, which is subsequently dispersed in an oil phase and followed by gelation of the alginate spheres. Rheology and pH time dependence are determined during gelation of macroscopic alginate gels. The results are used to optimize CaCO3/alginate mass ratio and GDL/CaCO3 molar ratio in the recipe for formation of the alginate spheres. It is found that nanoparticles of CaCO3 result in smaller alginate spheres and reduces the gelation time significantly, compared to microparticles of CaCO3. Cryo-SEM and light microscopy confirmed the formation of gelled alginate spheres below 10 µm with majority of spheres smaller than 2 µm and even spheres below 200 nm are observed. The extension into the nano range, the reduction in gelation time, and the possibility of a final internal pH around 6 all significantly extend the range of applications for these alginate nanospheres.
Variation in phosphorus content of milk from dairy cattle as affected by differences in milk composition
Klop, G. ; Ellis, J.L. ; Blok, M.C. ; Brandsma, G.G. ; Bannink, A. ; Dijkstra, J. - \ 2014
The Journal of Agricultural Science 152 (2014)5. - ISSN 0021-8596 - p. 860 - 869.
environmental-impact - methane production - blood-plasma - beef-cattle - cows - excretion - prediction - magnesium - calcium
In view of environmental concerns with regard to phosphorus (P) pollution and the expected global P scarcity, there is increasing interest in improving P utilization in dairy cattle. In high-producing dairy cows, P requirements for milk production comprise a significant fraction of total dietary P requirements. Although variation in P content of milk can affect the efficiency of P utilization for milk production (i.e. the fraction of ingested P that is incorporated in milk), this variation is poorly understood. It was hypothesized that the P content of milk is related to both milk protein and milk lactose content, but not necessarily to milk fat content. Three existing experiments comprising individual animal data on milk yield and fat, protein, lactose and P content of milk (in total 278 observations from 121 cows) were analysed to evaluate this hypothesis using a mixed model analysis. The models including the effects of both protein and lactose content of milk yielded better prediction of milk P content in terms of root-mean-square prediction error (RMSPE) and concordance correlation coefficient (CCC) statistics than models with only protein included as prediction variable; however, estimates of effect sizes varied between studies. The inclusion of milk fat content in equations already including protein and lactose did not further improve prediction of milk P content. Equations developed to describe the relationship between milk protein and lactose contents (g/kg) and milk P content (g/kg) were: (Expt 1) P in milk=-0·44(±0·179)+0·0253(±0·00300)×milk protein+0·0133(±0·00382)×milk lactose (RMSPE: 5·2%; CCC: 0·71); (Expt 2) P in milk=-0·26 (±0·347)+0·0174(±0·00328)×milk protein+0·0143 (±0·00611)×milk lactose (RMSPE: 6·3%; CCC: 0·40); and (Expt 3) P in milk=-0·36(±0·255)+0·0131(±0·00230)×milk protein+0·0193(±0·00490)×milk lactose (RMSPE: 6·5%; CCC: 0·55). Analysis of the three experiments combined, treating study as a random effect, resulted in the following equation to describe the same relationship as in the individual study equations: P in milk=-0·64(±0·168)+0·0223(±0·00236)×milk protein+0·0191(±0·00316)×milk lactose (RMSPE: 6·2%; CCC: 0·61). Although significant relationships between milk protein, milk lactose and milk P were found, a considerable portion of the observed variation remained unexplained, implying that factors other than milk composition may affect the P content of milk. The equations developed may be used to replace current fixed milk P contents assumed in P requirement systems for cattle.
The effect of dietary hydroxyproline and dietary oxalate on urinary oxalate excretion in cats
Dijcker, J.C. ; Plantinga, E.A. ; Thomas, D.G. ; Queau, Y. ; Biourge, V.C. ; Hendriks, W.H. - \ 2014
Journal of Animal Science 92 (2014). - ISSN 0021-8812 - p. 577 - 584.
lactic-acid bacteria - oxalobacter-formigenes - primary hyperoxaluria - feline uroliths - adult cats - calcium - rats - dogs - metabolism - canine
In humans and rodents, dietary hydroxyproline (hyp) and oxalate intake affect urinary oxalate (Uox) excretion. Whether Uox excretion occurs in cats was tested by feeding diets containing low oxalate (13 mg/100g DM) with high (Hhyp-Lox), moderate (Mhyp-Lox), and low hyp (Lhyp-Lox) concentrations (3.8, 2.0 and 0.2 g/100g DM, respectively), and low hyp with high oxalate (93 mg/100g DM; Lhyp-Hox) to 8 adult, female cats in a 48-d study using a Latin square design. Cats were randomly allocated to 1 of the four 12-d treatment periods and fed according to individual energy needs. Feces and urine were collected quantitatively using modified litter boxes during the final 5 d of each period. Feces were analyzed for oxalate and Ca, and urine for specific density, pH, oxalate, Ca, P, Mg, Na, K, ammonia, citrate, urate, sulphate, and creatinine. Increasing hyp intake (0.2, 2.0, and 3.8 g/100g DM) resulted in increased Uox excretion (Lhyp-Lox vs. Mhyp-Lox vs. Hhyp-Lox, P <0.05), and the linear dose-response equation was: Uox (mg ¿d(-1)) = 5.62 + 2.10 x g hyp intake/d (r(2) = 0.56; P <0.001). Increasing oxalate intake from 13 to 93 mg/100g DM did not affect Uox excretion, but resulted in an increase in fecal oxalate output (P <0.001) and positive oxalate balance (32.20 ± 2.06 mg¿d(-1)). The results indicate that the intestinal absorption of the supplemental oxalate, and thereby its contribution to Uox, was low (5.90 ± 5.24%). Relevant increases in endogenous Uox excretion were achieved by increasing dietary hyp intake. The hyp-containing protein sources should be minimized in Ca ox urolith preventative diets until their effect on Uox excretion is tested. The oxalate content (up to 93 mg/100g DM) in a diet with moderate Ca content does not contribute to Uox content.
The use of predefined diet quality scores in the context of CVD risk during urbanization in the South African Prospective Urban and Rural Epidemiological (PURE) study
Dolman, R.C. ; Wentzel-Viljoen, E. ; Jerling, J.C. ; Feskens, E.J.M. ; Kruger, A. ; Pieters, M. - \ 2014
Public Health Nutrition 17 (2014)8. - ISSN 1368-9800 - p. 1706 - 1716.
cardiovascular-disease - nutrition transition - income countries - blood-pressure - beta-carotene - lung-cancer - population - metaanalysis - mortality - calcium
Objective Urbanization is generally associated with increased CVD risk and accompanying dietary changes. Little is known regarding the association between increased CVD risk and dietary changes using approaches such as diet quality. The relevance of predefined diet quality scores (DQS) in non-Western developing countries has not yet been established. Design The association between dietary intakes and CVD risk factors was investigated using two DQS, adapted to the black South African diet. Dietary intake data were collected using a quantitative FFQ. CVD risk was determined by analysing known CVD risk factors. Setting Urban and rural areas in North West Province, South Africa. Subjects Apparently healthy volunteers from the South African Prospective Urban and Rural Epidemiological (PURE) study population (n 1710). Results CVD risk factors were significantly increased in the urban participants, especially women. Urban men and women had significantly higher intakes of both macro- and micronutrients with macronutrient intakes well within the recommended CVD guidelines. While micronutrient intakes were generally higher in the urban groups than in the rural groups, intakes of selected micronutrients were low in both groups. Both DQS indicated improved diet quality in the urban groups and good agreement was shown between the scores, although they seemed to measure different aspects of diet quality. Conclusions The apparent paradox between improved diet quality and increased CVD risk in the urban groups can be explained when interpreting the cut-offs used in the scores against the absolute intakes of individual nutrients. Predefined DQS as well as current guidelines for CVD prevention should be interpreted with caution in non-Western developing countries.
Low vitamin D status is associated with reduced muscle mass and impaired physical performance in frail elderly people
Tieland, C.A.B. ; Brouwer, E.M. ; Nienaber-Rousseau, C. ; Loon, L.J.C. van; Groot, C.P.G.M. de - \ 2013
European Journal of Clinical Nutrition 67 (2013). - ISSN 0954-3007 - p. 1050 - 1055.
randomized controlled-trial - parathyroid-hormone levels - nursing-home residents - older men - women - population - determinants - strength - calcium - 25-hydroxyvitamin-d
Background/Objectives: Serum 25-hydroxyvitamin D (25(OH)D) status has been associated with muscle mass, strength and physical performance in healthy elderly people. Yet, in pre-frail and frail elderly people this association has not been studied. The objective of this study was to explore the association between vitamin D intake and serum 25(OH)D status with muscle mass, strength and physical performance in a pre-frail and frail elderly population. Subjects/Methods: This cross-sectional study included 127 pre-frail and frail elderly people in The Netherlands. Whole body and appendicular lean mass (ALM) (dual energy X-ray absorptiometry), leg strength (one repetition maximum), handgrip strength and physical performance (short physical performance battery) were measured, and blood samples were collected for the assessment of serum 25(OH)D status (liquid chromatography-tandem mass spectrometry). In addition, habitual dietary intake (3-day food records) and physical activity data (accelerometers) were collected. Results: In total, 53% of the participants had a serum 25(OH)D level below 50¿nmol/l. After adjustment for confounding factors, 25(OH)D status was associated with ALM (ß=0.012, P=0.05) and with physical performance (ß=0.020, P0.05). Conclusion: In this frail elderly population, 25(OH)D status is low and suggests a modest association with reduced ALM and impaired physical performance. In addition, vitamin D intake tended to be associated with impaired physical performance. Our findings highlight the need for well-designed intervention trials to assess the impact of vitamin D supplementation on 25(OH)D status, muscle mass and physical performance in pre-frail and frail elderly people
Oxygen activation of Apo-oberlin-Coelenterazine Complex
Eremeeva, E. ; Natashin, P.V. ; Song, L. ; Zhou, Y. ; Berkel, W.J.H. van; Liu, Z.J. ; Vysotski, E.S. - \ 2013
ChemBioChem 14 (2013)6. - ISSN 1439-4227 - p. 739 - 745.
green-fluorescent protein - jellyfish clytia-gregaria - crystal-structure - ca2+-discharged photoprotein - angstrom resolution - recombinant obelin - molecular-oxygen - aequorin - calcium - bioluminescence
Ca2+-regulated photoproteins use a noncovalently bound 2-hydroperoxycoelenterazine ligand to emit light in response to Ca2+ binding. To better understand the mechanism of formation of active photoprotein from apoprotein, coelenterazine and molecular oxygen, we investigated the spectral properties of the anaerobic apo-obelin–coelenterazine complex and the kinetics of its conversion into active photoprotein after exposure to air. Our studies suggest that coelenterazine bound within the anaerobic complex might be a mixture of N7-protonated and C2(-) anionic forms, and that oxygen shifts the equilibrium in favor of the C2(-) anion as a result of peroxy anion formation. Proton removal from N7 and further protonation of peroxy anion and the resulting formation of 2-hydroperoxycoelenterazine in obelin might occur with the assistance of His175. It is proposed that this conserved His residue might play a key role both in formation of active photoprotein and in Ca2+-triggering of the bioluminescence reaction.
Plasma 25(OH)vitamin D and the risk of breast cancer in the european prospective investigation into cancer and nutrition (EPIC): A nested case-control study
Kühn, T. ; Kaaks, R. ; Becker, S. ; Eomois, P.P. ; Clavel-Chapelon, F. ; Kvaskoff, M. ; Dossus, L. ; Duijnhoven, F.J.B. van - \ 2013
International Journal of Cancer 133 (2013)7. - ISSN 0020-7136 - p. 1689 - 1700.
d-binding protein - circulating vitamin-d - french e3n cohort - postmenopausal women - nurses health - serum-levels - association - prevention - calcium - time
Experimental evidence suggests that vitamin D might play a role in the development of breast cancer. Although the results of case–control studies indicate that circulating 25-hydroxyvitamin D [25(OH)D] is inversely associated with the risk of breast cancer, the results of prospective studies are inconsistent. A case–control study embedded in the European Prospective Investigation into Cancer and Nutrition (EPIC) was carried out comprising 1,391 incident breast cancer cases and 1,391 controls. Multivariable conditional logistic regression models did not reveal a significant overall association between season-standardized 25(OH)D levels and the risk of breast cancer (ORQ4–Q1 [95% CI]: 1.07 [0.85–1.36], ptrend = 0.67). Moreover, 25(OH)D levels were not related to the risks of estrogen receptor positive tumors (ORQ4–Q1 [95% CI]: 0.97 [0.67–1.38], ptrend = 0.90) and estrogen receptor negative tumors (ORQ4–Q1 [95% CI]: 0.97 [0.66–1.42], ptrend = 0.98). In hormone replacement therapy (HRT) users, 25(OH)D was significantly inversely associated with incident breast cancer (ORlog2 [95% CI]: 0.62 [0.42–0.90], p = 0.01), whereas no significant association was found in HRT nonusers (ORlog2 [95% CI]: 1.14 [0.80–1.62], p = 0.48). Further, a nonsignificant inverse association was found in women with body mass indices (BMI) <25 kg/m2 (ORlog2 [95% CI]: 0.83 [0.67–1.03], p = 0.09), as opposed to a borderline significant positive association in women with BMI = 25 kg/m2 (ORlog2 [95% CI]: 1.30 [1.0–1.69], p = 0.05). Overall, prediagnostic levels of circulating 25(OH)D were not related to the risk of breast cancer in the EPIC study. This result is in line with findings in the majority of prospective studies and does not support a role of vitamin D in the development of breast cancer
Many physiogene problems due to poor calcium distribution : Balance can be restored at night
Heuvelink, E. ; Kierkels, T. - \ 2013
In Greenhouses : the international magazine for greenhouse growers 2 (2013)2. - ISSN 2215-0633 - p. 10 - 11.
calcium - calciumabsorptie - plantenfysiologie - groenteteelt - siergewassen - neusrot - worteldruk - nacht - groenten - kasgewassen - glastuinbouw - calcium absorption - plant physiology - vegetable growing - ornamental crops - blossom-end rot - root pressure - night - vegetables - greenhouse crops - greenhouse horticulture
Dry, brown areas (blossom end rot) on tomatoes and peppers; tipburn on lettuce and Chinese cabbage; dry edges on the young leaves and flower leaves of poinsettias; malformed spathe leaves on anthurium. Many such physiogene deviations are related to calcium. They aren’t always caused by a deficiency but can be due to poor calcium distribution in the plant. Many sorts of circumstances influence the dispersal of calcium.
Interpreting experimental data on egg production - applications of dynamic differential equations
France, J. ; Lopez, S. ; Kebreab, E. ; Dijkstra, J. - \ 2013
Poultry Science 92 (2013)9. - ISSN 0032-5791 - p. 2498 - 2508.
drosophila-melanogaster - gastrointestinal-tract - quantitative genetics - mathematical-models - phosphorus - calcium - absorption - fertility - algorithm
This contribution focuses on applying mathematical models based on systems of ordinary first-order differential equations to synthesize and interpret data from egg production experiments. Models based on linear systems of differential equations are contrasted with those based on nonlinear systems. Regression equations arising from analytical solutions to linear compartmental schemes are considered as candidate functions for describing egg production curves, together with aspects of parameter estimation. Extant candidate functions are reviewed, a role for growth functions such as the Gompertz equation suggested, and a function based on a simple new model outlined. Structurally, the new model comprises a single pool with an inflow and an outflow. Compartmental simulation models based on nonlinear systems of differential equations, and thus requiring numerical solution, are next discussed, and aspects of parameter estimation considered. This type of model is illustrated in relation to development and evaluation of a dynamic model of calcium and phosphorus flows in layers. The model consists of 8 state variables representing calcium and phosphorus pools in the crop, stomachs, plasma, and bone. The flow equations are described by Michaelis-Menten or mass action forms. Experiments that measure Ca and P uptake in layers fed different calcium concentrations during shell-forming days are used to evaluate the model. In addition to providing a useful management tool, such a simulation model also provides a means to evaluate feeding strategies aimed at reducing excretion of potential pollutants in poultry manure to the environment.
Effect of soybean processing on content and bioaccessibility of folate, vitamin B12 and isoflavones in tofu and tempe
Mo, H. ; Kariluoto, S. ; Piironen, V. ; Zhu, Y. ; Sanders, M.G. ; Vincken, J.P. ; Wolkers-Rooijackers, J.C.M. ; Nout, M.J.R. - \ 2013
Food Chemistry 141 (2013)3. - ISSN 0308-8146 - p. 2418 - 2425.
solid-substrate fermentation - folic-acid - in-vitro - gastrointestinal model - nutritional value - binding protein - bioavailability - rats - calcium - women
Purpose - To compare the content of bioaccessible folate, vitamin B12, and isoflavones in tofu and tempe, as influenced by soybean variety and food processing, particularly fermentation. Principal results - Raw soybeans contained 2207–2671 µg/kg (dry matter) folate, cooked tempe 1493–4143, and cooked tofu 968–1273 µg/kg, the difference was attributed to the fermentation in tempe. Vitamin B12 was detected only in tempe (0.16–0.72 µg/kg). Isoflavone aglycones were formed during soaking of soybeans, with only minor differences between the contents in cooked tempe (average 1922–2968 µg/kg) or tofu (1667–2782 µg/kg) but strongly depending on bean variety. Conclusions - Folate and vitamin B12 contents were mainly influenced by microbial activity during fermentation, whereas isoflavone aglycone content was determined by bean variety. Tofu had lower folate and vitamin B12, but equal isoflavone contents as tempe. Bioaccessibility of folate (80–100%) and isoflavone aglycones (100%) were high
Biomarkers of Dairy Fatty Acids and Risk of Cardiovascular Disease in the Multi-Ethnic Study of Atherosclerosis
Oliveira Otto, M.C. de; Nettleton, J.A. ; Lemaitre, R.N. ; Steffen, L.M. ; Kromhout, D. ; Rich, R.L. ; Tsai, M.Y. ; Jacobs, D.R. ; Mozaffarian, D. - \ 2013
Journal of the American Heart Association 2 (2013). - ISSN 2047-9980 - 11 p.
intima-media thickness - physical-activity - dietary patterns - plasma-lipids - milk-fat - hypertension - women - association - calcium - mesa
Background Evidence regarding the role of dairy fat intake in cardiovascular disease (CVD) has been mixed and inconclusive. Most earlier studies have used self-reported measures of dietary intake and focused on relatively racially homogeneous populations. Circulating biomarkers of dairy fat in a multiethnic cohort provide objective measures of dairy fat intake and facilitate conclusions relevant to populations with different diets and susceptibility to CVD. Methods and Results In a multiethnic cohort of 2837 US adults aged 45 to 84 years at baseline (2000–2002), phospholipid fatty acids including 15:0, 14:0, and trans-16:1n7 were measured using standardized methods, and the incidence of CVD prospectively adjudicated. Self-reported whole-fat dairy and butter intakes had strongest associations with 15:0, rather than 14:0 or trans-16:1n7. In multivariate models including demographics and lifestyle and dietary habits, each SD-unit of 15:0 was associated with 19% lower CVD risk (hazard ratio [95% CI] 0.81 [0.68 to 0.98]) and 26% lower coronary heart disease (CHD) risk (0.74 [0.60 to 0.92]). Associations were strengthened after mutual adjustment for 14:0 and trans-16:1n-7 and were similar after adjustment for potential mediators. Plasma phospholipid 14:0 and trans-16:1n-7 were not significantly associated with incident CVD or CHD. All findings were similar in white, black, Hispanic, and Chinese American participants. Conclusion Plasma phospholipid 15:0, a biomarker of dairy fat, was inversely associated with incident CVD and CHD, while no association was found with phospholipid 14:0 and trans-16:1n-7. These findings support the need for further investigation of CVD effects of dairy fat, dairy-specific fatty acids, and dairy products in general
Bemesting Alstroemeria: Invloed van EC en K:Ca verhoudingin de teelt van Alstroemeria op kokossubstraat
Helm, F.P.M. van der; Labrie, C.W. ; Mourik, N.M. van; Groot, M. de; Voogt, W. - \ 2013
Bleiswijk : Wageningen UR Glastuinbouw (Rapporten WUR GTB 1249) - 74
alstroemeria - alstroemeriaceae - bemesting - teelt - substraten - kokosnootproducten - elektrische geleidbaarheid - kalium - calcium - glastuinbouw - nederland - fertilizer application - cultivation - substrates - coconut products - electrical conductivity - potassium - greenhouse horticulture - netherlands
In 2010 is budget beschikbaar gesteld door het Productschap Tuinbouw voor een 2 jaar durend onderzoek om te bepalen wat de juiste verhouding K:Ca bij verschillende EC-niveau’s is gedurende het jaar. Er is een twee jaar durende kasproef uitgevoerd waarin een K:Ca verhouding van 5:1, 1:1 en 1:3 is gerealiseerd bij een EC van 2 (laag) en 3 (hoog) mS/ cm. In het onderzoek gaf de hoge EC op een kokossubstraat bij een K:Ca verhouding van 1:1 of lager betrouwbaar meer productie in stuks en in kilo’s geoogst gewicht dan een lage EC. De productie bij een K:Ca verhouding van 5:1 was altijd lager, de EC had hierop geen invloed. Daarnaast was bij een hoge EC en een K:Ca verhouding van 1:3 in de voedingsoplossing zowel productie en takgewicht per 80 cm het hoogste. Ook was de lengte van het gewas in de zomer duidelijk hoger als gevolg van een lagere K:Ca in de voedingsoplossing. Met het oog op ziektegevoeligheid gaf een voedingsoplossing met een K:Ca verhouding van 1:3 een robuuster gewas dat minder vatbaar was voor vochtblaadjes en bloemschade door klimaat wisselingen en hoge instraling. Daarnaast was bij hoge EC het gewas gevoeliger voor vochtblaadjes, maar dit effect was minder sterk dan het effect van een hoge K:Ca verhouding. Ten slotte gaf de lage EC in dit onderzoek meer problemen met uitval door Fusarium.
Photosynthetic thermotolerance of woody savanna species in China is correlated with leaf life span.
Zhang, J.L. ; Poorter, L. ; Hao, G.Y. ; Cao, K.F. - \ 2012
Annals of Botany 110 (2012)5. - ISSN 0305-7364 - p. 1027 - 1033.
valley-savanna - heat tolerance - fluorescence - evolution - calcium - stress - plants - area - consequences - temperatures
Background and Aims Photosynthetic thermotolerance (PT) is important for plant survival in tropical and sub-tropical savannas. However, little is known about thermotolerance of tropical and sub-tropical wild plants and its association with leaf phenology and persistence. Longer-lived leaves of savanna plants may experience a higher risk of heat stress. Foliar Ca is related to cell integrity of leaves under stresses. In this study it is hypothesized that (1) species with leaf flushing in the hot-dry season have greater PT than those with leaf flushing in the rainy season; and (2) PT correlates positively with leaf life span, leaf mass per unit area (LMA) and foliar Ca concentration ([Ca]) across woody savanna species. Methods The temperature-dependent increase in minimum fluorescence was measured to assess PT, together with leaf dynamics, LMA and [Ca] for a total of 24 woody species differing in leaf flushing time in a valley-type savanna in south-west China. Key Results The PT of the woody savanna species with leaf flushing in the hot-dry season was greater than that of those with leaf flushing in the rainy season. Thermotolerance was positively associated with leaf life span and [Ca] for all species irrespective of the time of flushing. The associations of PT with leaf life span and [Ca] were evolutionarily correlated. Thermotolerance was, however, independent of LMA. Conclusions Chinese savanna woody species are adapted to hot-dry habitats. However, the current maximum leaf temperature during extreme heat stress (44·3 °C) is close to the critical temperature of photosystem II (45·2 °C); future global warming may increase the risk of heat damage to the photosynthetic apparatus of Chinese savanna species.
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