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van der Heide T Govers LL de Fouw J Olff H van der Geest M van Katwijk MM Piersma T van de Koppel J Silliman BR Smolders AJ van Gils JA 《Science (New York, N.Y.)》2012,336(6087):1432-1434
Seagrasses evolved from terrestrial plants into marine foundation species around 100 million years ago. Their ecological success, however, remains a mystery because natural organic matter accumulation within the beds should result in toxic sediment sulfide levels. Using a meta-analysis, a field study, and a laboratory experiment, we reveal how an ancient three-stage symbiosis between seagrass, lucinid bivalves, and their sulfide-oxidizing gill bacteria reduces sulfide stress for seagrasses. We found that the bivalve-sulfide-oxidizer symbiosis reduced sulfide levels and enhanced seagrass production as measured in biomass. In turn, the bivalves and their endosymbionts profit from organic matter accumulation and radial oxygen release from the seagrass roots. These findings elucidate the long-term success of seagrasses in warm waters and offer new prospects for seagrass ecosystem conservation. 相似文献
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Inge M. Krijger Max Strating Marga van Gent-Pelzer Theo A.J. van der Lee Sara A. Burt Fleur H. Schroeten Robin de Vries Marieke de Cock Miriam Maas Bastiaan G. Meerburg 《Pest management science》2023,79(3):989-995
BACKGROUND
Resistance to rodenticides has been reported globally and poses a considerable problem for efficacy in pest control. The most-documented resistance to rodenticides in commensal rodents is associated with mutations in the Vkorc1 gene, in particular in codon 139. Resistance to anticoagulant rodenticides has been reported in the Netherlands since 1989. A study from 2013 showed that 25% of 169 Norway rats (Rattus norvegicus) had a mutation at codon 139 of the Vkorc1 gene. To gain insight in the current status of rodenticide resistance amongst R. norvegicus and house mice Mus musculus in the Netherlands, we tested these rodents for mutations in codon 139 of the Vkorc1 gene. In addition, we collected data from pest controllers on their use of rodenticides and experience with rodenticide resistance.RESULTS
A total of 1801 rodent samples were collected throughout the country consisting of 1404 R. norvegicus and 397 M. musculus. In total, 15% of R. norvegicus [95% confidence interval (CI): 13–17%] and 38% of M. musculus (95% CI: 33–43%) carried a genetic mutation at codon 139 of the Vkorc1 gene.CONCLUSION
This study demonstrates genetic mutations at codon 139 of the Vkorc1 gene in M. musculus in the Netherlands. Resistance to anticoagulant rodenticides is present in R. norvegicus and M. musculus in multiple regions in the Netherlands. The results of this comprehensive study provide a baseline and facilitate trend analyses of Vkorc1 codon 139 mutations and evaluation of integrated pest management (IPM) strategies as these are enrolled in the Netherlands. © 2022 The Dutch Pest and Wildlife. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献25.
Bekedam EK De Laat MP Schols HA Van Boekel MA Smit G 《Journal of agricultural and food chemistry》2007,55(3):761-768
The charge properties of melanoidins in high molecular weight (HMw) coffee brew fractions, isolated by diafiltration and membrane dialysis, were studied. Ion exchange chromatography experiments with the HMw fractions showed that coffee brew melanoidins were negatively charged whereas these molecules did not expose any positive charge at the pH of coffee brew. Fractions with different ionic charges were isolated and subsequently characterized by means of the specific extinction coefficient (K(mix 405nm)), sugar composition, phenolic group content, nitrogen content, and the arabinogalactan protein (AGP) specific Yariv gel-diffusion assay. The isolated fractions were different in composition and AGP was found to be present in one of the HMw fractions. The AGP accounted for 6% of the coffee brew dry matter and had a moderate negative charge, probably caused by the presence of uronic acids. As the fraction that precipitated with Yariv was brown (K(mix 405nm) = 1.2), compared to a white color in the green bean, it was concluded that these AGPs had undergone Maillard reaction resulting in an AGP-melanoidin complex. The presence of mannose (presumably from galactomannan) indicates the incorporation of galactomannans in the AGP-melanoidin complex. As the uronic acid content in the more negatively charged melanoidin-rich, AGP-poor HMw fractions decreased, it was hypothesized that acidic groups are formed or incorporated during melanoidin formation. 相似文献
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Bokken GC van Eerden E Opsteegh M Augustijn M Graat EA Franssen FF Görlich K Buschtöns S Tenter AM van der Giessen JW Bergwerff AA van Knapen F 《Veterinary parasitology》2012,184(2-4):126-132
The aim of this study was to examine the dynamics of parasite specific antibody development in Trichinella spiralis and Toxoplasma gondii co-infections in pigs and to compare these with antibody dynamics in T. spiralis and T. gondii single infections. In this experiment, fifty-four pigs were divided into five inoculated groups of ten animals, and one control group of four animals. Two groups were inoculated with a single dose of either T. gondii tissue cysts or T. spiralis muscle larvae, one group was inoculated simultaneously with both parasites and two groups were successively inoculated at an interval of four weeks. Specific IgG responses to the parasites were measured by ELISA. T. gondii burden was determined by MC-PCR carried out on heart muscle and T. spiralis burden by artificial digestion of diaphragm samples. Specific IgG responses to T. gondii and T. spiralis in single and simultaneously inoculated animals showed a respective T. gondii and T. spiralis inoculation effect but no significant interaction of these parasites to the development of specific antibodies with the serum dilutions used. Moreover, our data showed that the specific IgG response levels in groups of animals successively or simultaneously co-infected were independent of a respective previous or simultaneous infection with the other parasite. Additionally, no differences in parasite burden were found within groups inoculated with T. gondii and within groups inoculated with T. spiralis. Conclusively, for the infection doses tested in this experiment, the dynamics of specific antibody development does not differ between single and simultaneous or successive infection with T. gondii and T. spiralis. However, lower parasitic doses and other ratios of doses, like low-low, low-high and high-low of T. gondii and T. spiralis in co-infection, in combination with other time intervals between successive infections may have different outcomes and should therefore be studied in further detail. 相似文献
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Opsteegh M Haveman R Swart AN Mensink-Beerepoot ME Hofhuis A Langelaar MF van der Giessen JW 《Preventive veterinary medicine》2012,104(3-4):317-326
Cats, as definitive hosts, play an important role in the transmission of Toxoplasma gondii. To determine the seroprevalence and risk factors for T. gondii infection in Dutch domestic cats, serum samples of 450 cats were tested for T. gondii antibodies by indirect ELISA. Binary mixture analysis was used to estimate the seroprevalence, the optimal cut-off value and the probability of being positive for each cat. The seroprevalence was estimated at 18.2% (95% CI: 16.6-20.0%) and showed a decrease with age in very young cats, an increase up to about 4 years old and ranged between 20 and 30% thereafter. Hunting (OR 4.1), presence of a dog in the household (OR 2.1), former stray cat (OR 3.3) and feeding of raw meat (OR 2.7) were identified as risk factors by multivariable logistic regression analysis. Prevalence differences were estimated by linear regression on the probabilities of being positive and used to calculate the population attributable fractions for each risk factor. Hunting contributed most to the T. gondii seroprevalence in the sampled population (35%). 相似文献
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Felines are the key species in the epidemiology of Toxoplasma gondii infection, as they are the definitive host of the parasite and are the only species that can shed resistant oocysts in the environment. Different assays are in use for the detection of antibodies against T. gondii in cats. However, assay validation studies are limited. For that reason it was our aim to first evaluate 6 serological tests (one commercial and 2 in-house ELISAs, ImmunoComb, IFAT and MAT) for antibodies (IgG) against T. gondii in cats by Bayesian modeling. Factors associated with seropositivity were evaluated by bivariable and multivariable methods. The test evaluation indicated the commercial ELISA had the highest Youden Index. The estimated sensitivity ranged between 95.7% and 97.1% and the specificity between 97.3% and 97.6%. Using this commercial ELISA 111 out of 236 cats (47%) were positive for T. gondii antibodies. Two peaks in the percentage of strong positive samples (S/P≥200) were observed, around 10-months-old and 8-years-old. In bivariable analysis the seroprevalence was significantly higher in adult cats, cats with mixed diet, with outdoor access, in cats from a rural area and in cats from centre and north-western Romania. Adult age (adults: OR 6.98; 95% CI: 2.02-24.14 and geriatrics (cats older than 10-years): OR 12.01; 95% CI: 1.60-90.15) and outdoor access (OR 6.38; 95% CI: 2.32-17.53) remained significant risk factors in the multivariable logistic regression analysis. Our results suggest that T. gondii infection is common in household cats in Romania, and especially in those with outdoor access. 相似文献
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Florian Hirsch Anna Schneider Marieke van der Maaten-Theunissen Ernst van der Maaten Christin Räbiger Alexandra Raab Thomas Raab 《植物养料与土壤学杂志》2023,186(4):417-427