120 results on '"Gort, G."'
Search Results
2. Do organic inputs matter - a meta-analysis of additional yield effects for arable crops in Europe
- Author
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Hijbeek, R., van Ittersum, M.K., ten Berge, H.F.M., Gort, G., Spiegel, H., and Whitmore, A.P.
- Published
- 2017
3. Effects of seasonality and previous logging on faecal helminth-microbiota associations in wild lemurs
- Author
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de Winter, I. I., Umanets, A., Gort, G., Nieuwland, W. H., van Hooft, P., Heitkönig, I. M. A., Kappeler, P. M., Prins, H. H. T., and Smidt, H.
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- 2020
- Full Text
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4. Morphological adaptation of rumen papillae during the dry period and early lactation as affected by rate of increase of concentrate allowance
- Author
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Dieho, K., Bannink, A., Geurts, I.A.L., Schonewille, J.T., Gort, G., and Dijkstra, J.
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- 2016
- Full Text
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5. Enhancement of crop photosynthesis by diffuse light: quantifying the contributing factors
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Li, T., Heuvelink, E., Dueck, T. A., Janse, J., Gort, G., and Marcelis, L. F. M.
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- 2014
6. Cortisol-binding globulin and meat quality in five European lines of pigs
- Author
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Geverink, N.A., Foury, A., Plastow, G.S., Gil, M., Gispert, M., Hortos, M., Font i Furnols, M., Gort, G., Moisan, M.P., and Mormede, P.
- Subjects
Meat -- Comparative analysis ,Swine -- Comparative analysis ,Zoology and wildlife conservation - Abstract
The gene (Cbg) encoding cortisol-binding globulin (CBG) has been proposed as a candidate gene to explain genetic variation in cortisol secretion and carcass composition in pigs. The objective of this study was to evaluate the association between CBG and pork quality in 5 European breeding lines, Pietrain, Large White (LW), and Landrace purebred lines, a Duroc synthetic line, and a Meishan (MS) x LW advanced intercross. Cortisol-binding globulin maximum binding capacity (CBG-Bmax) was twice as high (P < 0.05) in MS x LW pigs compared with the other lines. There was no (P [greater than or equal to] 0.364) association between CBG-Bmax and carcass quality traits in Pietrain gilts, but CBG-Bmax was associated with increased loin yields in LW (P = 0.010) and Landrace (P = 0.103) gilts, decreased ham yields (P = 0.082) in Duroc gilts, and increased fat depth (P = 0.064) and leaf fat (P = 0.001) in MS x LW gilts. There was no association between CBG-Bmax and pork quality traits in Pi6train (P [greater than or equal to] 0.269) and Duroc (P [greater than or equal to] 0.114) gilts. Conversely, CBG-Bmax was associated with lighter (higher [L.sup.*] values; P < 0.05) pork in Landrace gilts, as well as lower (P [less than or equal to] 0.055) ultimate pH in the LM and semimembranosus, and a tendency for lower (P = 0.095) [L.sup.*] values of pork from LW gilts. Within MS x LW pigs, CBG-Bmax was associated with increased drip loss (P=0.001) and decreased i.m. fat in the semimembranosus (P = 0.005). Because drip loss is an economically important pork quality trait, results of this study could be used in the selection of improved water-holding capacity of pork from synthetic lines involving the MS breed. Key words: cortisol-binding globulin, drip loss, gilt, meat quality, pork
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- 2006
7. Comparison of Cultivars of Ornamental Crop Gerbera jamesonii on Production of Spider Mite-Induced Volatiles, and Their Attractiveness to the Predator, Phytoseiulus persimilis
- Author
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Krips, O. E., Willems, P. E. L., Gols, R., Posthumus, M. A., Gort, G., and Dicke, M.
- Published
- 2001
- Full Text
- View/download PDF
8. The reproductive phenology of blackbuck: influence of seasonal nutritional resources and flexible lactation as an adaptive strategy.
- Author
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Priyadarshini, K. V. R., Gort, G., Rice, C. G., and Yoganand, K.
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PHENOLOGY , *LACTATION , *ANIMAL weaning , *LACTATION in cattle , *BIOMASS , *FOOD quality - Abstract
Seasonality poses significant nutritional constraints for ungulates. Consequently, most ungulates time their energy‐demanding events like calving and lactation to the availability of abundant and high‐quality nutritional resources. We investigated the reproductive phenology of blackbuck, Antilope cervicapra, in relation to resource seasonality, in a semi‐arid grassland in western India. We examined whether the body condition of females, forage abundance and forage quality influenced the timing of blackbuck reproduction. We also used a conceptual model to explore whether blackbuck use behavioural adaptations in maternal care as an adaptive strategy to buffer the high nutritional demands of lactation. Blackbuck showed biannual calving, which occurred before (pre‐monsoon) and after the rains (post‐monsoon). We found statistically significant relationships, albeit small effect sizes, of body condition, forage abundance (biomass) and moisture content of grasses on the proportion of lactating females. The biannual reproductive phenology seems more complex than a simple relationship of reproduction with body condition and optimal nutrition supply. In the conceptual model based on our data, we propose that blackbuck females shortened their lactation time and weaned their calves sooner during the pre‐monsoon calving to coincide with a period of optimal food quality, thus, ensuring sufficient nutrition for both weanlings and allowing the females to regain body reserves, whereas, resource availability during the post‐monsoon calving likely allowed females to invest in longer lactation, weaning the calves later, as compared to the pre‐monsoon calving season. Thereby, blackbuck may be maintaining biannual calving and thus increase their lifetime reproductive output. [ABSTRACT FROM AUTHOR]
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- 2022
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9. Interlaboratory comparison of methods to quantify microsclerotia of Verticillium dahliae in soil
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Termorshuizen, A.J., Davis, J.R., Gort, G., Harris, D.C., Huisman, O.C., Lazarovitis, G., Locke, T., Vara, J.M. Melero, Mol, L., Paplomatas, E.J., Platt, H.W., Powelson, M., Rouse, D.I., Rowe, R.C., and Tsror, L.
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Soils -- Analysis ,Plant diseases -- Research ,Biological sciences - Abstract
A study was conducted to analyze different techniques for determining Verticillium dahliae in soil. Fourteen soil samples were examined in a blinded fashion by research groups in seven nations. Results indicated that techniques based on plating dry soil samples supported higher numbers of V. dahliae than those supporting plating of an aqueous soil suspension. Findings also showed that dry plating assays were more accurate than wet plating assays.
- Published
- 1998
10. Individual differences in behaviour, physiology and pathology in breeding gilts housed in groups or stalls
- Author
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Geverink, N.A., Schouten, W.G.P., Gort, G., and Wiegant, V.M.
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- 2003
- Full Text
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11. Individual differences in aggression and physiology in peri-pubertal breeding gilts
- Author
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Geverink, N.A., Schouten, W.G.P., Gort, G., and Wiegant, V.M.
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- 2002
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12. Nutritional plasticity of the black soldier fly (Hermetia illucens) in response to artificial diets varying in protein and carbohydrate concentrations.
- Author
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Barragan-Fonseca, K.B., Gort, G., Dicke, M., and van Loon, J.J.A.
- Published
- 2021
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13. Nano- and microplastics affect the composition of freshwater benthic communities in the long term.
- Author
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Redondo-Hasselerharm, P. E., Gort, G., Peeters, E. T. H. M., and Koelmans, A. A.
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PLASTIC marine debris , *BENTHIC ecology , *PHYSICAL & theoretical chemistry , *MULTIWALLED carbon nanotubes , *WATER quality management , *ESTUARINE sediments , *COMMUNITIES - Abstract
The article presents a study on nano- and microplastics affect the composition of freshwater benthic communities in the long term. Topics discussed include the presence of nano- and microplastics in the environment, nescience with respect to in situ effects is disturbing; long-term implications under ecologically realistic conditions are particularly important for the risk assessment of nano- and microplastics; and effects of five concentrations of nano- and microplastics.
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- 2020
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14. Behavioural responses of Ixodes ricinus nymphs to carbon dioxide and rodent odour.
- Author
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VAN DUIJVENDIJK, G., GORT, G., SPRONG, H., and TAKKEN, W.
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CASTOR bean tick , *CARBON dioxide , *RODENT odor , *OLFACTOMETRY , *ECTOPARASITES , *ANIMAL behavior - Abstract
Many haematophagous ectoparasites use carbon dioxide (CO2) and host odour to detect and locate their hosts. The tick Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) walks only small distances and quests in vegetation until it encounters a host. The differential effects of CO2 and host odour on the host-finding behaviour of I. ricinus have, however, never been clarified and hence represent the subject of this study. The effects of CO2 and odour from bank voles on the activation and attraction of I. ricinus nymphs were analysed in a Y-tube olfactometer. Carbon dioxide evoked a response in the absence and presence of host odour, but did not attract nymphs. Host odour, however, did not evoke a response but did attract nymphs in the absence and presence of CO2. The current results show that CO2 is an activator, but not an attractant, and that host odour is an attractant, but not an activator, of I. ricinus nymphs, and provide ecological insights into the host-finding behaviour of I. ricinus. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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15. Quantification of motility of carabid beetles in farmland.
- Author
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Allema, A.B., van der Werf, W., Groot, J.C.J., Hemerik, L., Gort, G., Rossing, W.A.H., and van Lenteren, J.C.
- Subjects
INSECT ecology ,GROUND beetles ,INSECT populations ,HABITATS ,META-analysis - Abstract
Quantification of the movement of insects at field and landscape levels helps us to understand their ecology and ecological functions. We conducted a meta-analysis on movement of carabid beetles (Coleoptera: Carabidae), to identify key factors affecting movement and population redistribution. We characterize the rate of redistribution using motility μ (L2 T−1), which is a measure for diffusion of a population in space and time that is consistent with ecological diffusion theory and which can be used for upscaling short-term data to longer time frames. Formulas are provided to calculate motility from literature data on movement distances. A field experiment was conducted to measure the redistribution of mass-released carabid, Pterostichus melanarius in a crop field, and derive motility by fitting a Fokker–Planck diffusion model using inverse modelling. Bias in estimates of motility from literature data is elucidated using the data from the field experiment as a case study. The meta-analysis showed that motility is 5.6 times as high in farmland as in woody habitat. Species associated with forested habitats had greater motility than species associated with open field habitats, both in arable land and woody habitat. The meta-analysis did not identify consistent differences in motility at the species level, or between clusters of larger and smaller beetles. The results presented here provide a basis for calculating time-varying distribution patterns of carabids in farmland and woody habitat. The formulas for calculating motility can be used for other taxa. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
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16. Assess ecosystem resilience: Linking response and effect traits to environmental variability.
- Author
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Sterk, M., Gort, G., Klimkowska, A., van Ruijven, J., van Teeffelen, A.J.A., and Wamelink, G.W.W.
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CLIMATE change , *EUTROPHICATION , *BIOTIC communities , *STATISTICAL correlation , *PREDICTION models , *WETLANDS - Abstract
Abstract: Disturbances, nature as well as human, are putting constant pressure on ecosystems. These include small scale disturbances like a falling tree, but also large scale disturbances like eutrophication and climate change. Resilience is a useful indicator to assess whether an ecosystem has the capacity to maintain functioning with environmental variability. In this study we tested whether plant functional traits can be distinguished to develop a response-and-effect framework for general predictions concerning resilience. We defined response traits to assess the system's resistance to disturbance, and effect traits to assess its recovery after disturbance. We used a dataset with 932 vegetation plots containing 104 species from a selected wetland area in The Netherlands. The environmental variability was related to response traits and the response traits to effect traits with RLQ analysis, fourth-corner analysis and Spearman's rank correlation. As a result, combinations of traits that specify effects of environmental change on ecosystem resilience were found. A strong resistance to environmental variability was shown, and consequently, a positive effect on resilience. Due to correlations between response and effect traits, combinations of traits were identified having a variable effect on the resilience of the system. In this way this study argues to further develop a response-and-effect framework to understand and assess ecosystem resilience. The selection of traits is system-specific, and therefore, one should only select those response and effect traits that differentiate between response to environmental variability and effects on ecosystem functioning. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
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17. Lactulose as a marker of intestinal barrier function in pigs after weaning.
- Author
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Wijtten, P. J. A., Verstijnen, J. J., van Kempen, T. A. T. G., Perdok, H. B., Gort, G., and Verstegen, M. W. A.
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LACTULOSE ,PEROXIDASE ,SWINE ,INTESTINAL diseases ,BOWEL obstructions - Abstract
Intestinal barrier function in pigs after weaning is almost exclusively determined in terminal experiments with Using chambers. Alternatively, the recovery in urine of orally administered lactulose can be used to assess intestinal permeability in living animals. This experiment was designed to study the barrier function of the small intestine of pigs over time after weaning. The aim was to relate paracellular barrier function (measured by lactulose recovery in the urine) with macromolecular transport [measured by horseradish peroxidase (HRP) using Ussing chambers] and bacterial translocation to assess whether lactulose recovery is related to possible causes of infection and disease. Forty gonadectomized male pigs (6.7 ± 0.6 kg) were weaned (d 0) at a mean age of 19 d, fitted with urine collection bags, and individually housed. Pigs were dosed by oral gavage with a marker solution containing lactulose (disaccharide) and the monosaccharides L-rhamnose, 3-0rnethylglucose, and D-xylose at 2 h and at 4, 8, and 12 d after weaning. The recovery of sugars in the urine was determined over 18 h after each oral gavage. The day after each permeability test, the intestines of 10 pigs were dissected to determine bacterial translocation to the mesenteric lymph nodes and jejunal permeability for HRP in Ussing chambers. Recovery of L-rharnnose in urine was affected by feed intake and by the time after weaning (P < 0.05). Recovery of lactulose from the urine was greater (P 0.05) at 4, 8, and 12 d after weaning compared with the first day after weaning and was negatively correlated with feed intake (r = -0.63, P < 0.001). The mean translocation of aerobic bacteria to the mesenteric lymph nodes was greater at 5 and 13 d after weaning compared with d 1 (P < 0.05). Lactulose recovery showed no correlation with permeability for HRP nor with bacterial translocation (P> 0.05). Although both lactulose recovery and bacterial translocation increased over time after weaning, lactulose recovery did not correlate with the permeability for HRP nor bacterial translocation within a pig (P> 0.05). Therefore, we conclude that lactulose recovery in the urine of pigs after weaning is not associated with risk factors for infections. However, it appears to be possible to measure paracellular barrier function with orally administered lactulose in pigs shortly after weaning. Further studies will reveal whether this variable is relevant for the long-term performance or health of pigs after weaning. [ABSTRACT FROM AUTHOR]
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- 2011
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18. Reduced competitive ability due to Wolbachia infection in the parasitoid wasp Trichogramma kaykai.
- Author
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Huigens, M. E., Hohmann, C. L., Luck, R. F., Gort, G., and Stouthamer, R.
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HYMENOPTERA ,PARTHENOGENESIS in animals ,PARASITOIDS ,WASPS ,INFECTION ,INSECT sex ratio - Abstract
Several hymenopteran parasitoids are infected with parthenogenesis-inducing (PI) Wolbachia. Infected wasps produce daughters instead of sons from unfertilized eggs. Thus far, little is known about the direct effects of PI Wolbachia on their host's fitness. Here, we report reduced competitive ability due to Wolbachia infection in a minute parasitoid wasp, Trichogramma kaykai Pinto and Stouthamer (Hymenoptera: Trichogrammatidae). Immature survival of infected individuals in a host parasitized by a single infected female, laying a normal clutch of eggs, was lower than those parasitized by a single uninfected individual. When the offspring of infected and uninfected females shared the same host, the infected immatures had significantly lower survival rates than their uninfected counterparts. The survival rate of infected immatures was higher when they competed with other infected immatures from a different infected parent than in competition with uninfected immatures of conspecific wasps. Thus, the host Trichogramma can suffer a substantial reduction in fitness when it is infected with the PI Wolbachia. We discuss why such a reduction is to be expected when populations of infected and uninfected individuals co-occur, and how the reduced competitive ability of PI Wolbachia influences the spread of the bacteria in the field. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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19. Effects of Trypanosoma vivax infection during pregnancy on feed intake, nitrogen retention and liveweight changes in West African Dwarf ewes.
- Author
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Akinbamijo, O. O., Reynolds, L., and Gort, G.
- Abstract
The effects of infection with T. vivax in mid- or late pregnancy on food intake and utilization, liveweight changes, abortion rate and lamb growth rate were investigated in West African Dwarf ewes at lbadan, Nigeria in 1990. Rate of liveweight gain by ewes infected during mid-pregnancy (IMH) was16 g/day compared with 33 and 37 g/day for the uninfected ewes offered medium (CM) or high (CH) plane diets. Although digestibility coefficients were not affected, intake of digestible organic matter was higher in CH ewes than in IMH and CM ewes. Nitrogen retention at mid-pregnancy on a metabolic size basis was higher in CH ewes than in CM and IMH ewes.Lamb birth weight and survival rate were lower in infected ewes. Ewes infected in mid-pregnancy (IMH) and in late pregnancy (ILH) had mean birth weights of 1·4 and 1·0 kg compared with CM and CH ewes, which had mean birth weights of 1·9 and 2·0 kg respectively. Observed survival rates were 63, 15, 75 and 80% for lambs nursed by IMH, ILH, CM and CH ewes respectively. During the first 6 weeks postpartum, lamb growth rate in all groups did not differ. However, during weeks 7–12 postpartum, lambs nursed by IMH ewes had significantly lower growth rates. Weaning weight was also lower in lambs from IMH (5·0 kg) dams than in lambs from CM and CH dams (7·1 kg). Infection during late pregnancy was more severe and all infected ewes lost weight due to reduced feed intake and fever. T. vivax infection in sheep is responsible for reproductive wastage, abortion, poor lamb growth and ewe mortality. [ABSTRACT FROM PUBLISHER]
- Published
- 1994
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20. A critical look at the TNM classification for laryngeal carcinoma.
- Author
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Karim, A. B. M. F., Kralendonk, J. H., Njo, K. H., Tabak, J. M., Gort, G., and Karim, A B
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- 1990
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21. Dispersal and survival of Anopheles funestus and A. gambiae s.l. (Diptera: Culicidae) during the rainy season in southeast Tanzania.
- Author
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Takken, W., Charlwood, J.D., Billingsley, P.F., and Gort, G.
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- 1998
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22. Analysing host location in Uscana lariophaga (Hymenoptera: Trichogrammatidae), an egg parasitoid of bruchids (Coleoptera: Bruchidae), using Cox's proportional hazards model.
- Author
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Ormel, G.J., Gort, G., and van Alebeek, F.A.N.
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- 1995
- Full Text
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23. Monitoring habitat types by the mixed multinomial logit model using panel data.
- Author
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Brus, D.J., Slim, P.A., Gort, G., Heidema, A.H., and van Dobben, H.
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ENVIRONMENTAL monitoring , *HABITATS , *PANEL analysis , *ECOLOGICAL mapping , *SOIL ecology - Abstract
Habitats in the Wadden Sea, a world heritage area, are affected by land subsidence resulting from natural gas extraction and by sea level rise. Here we describe a method to monitor changes in habitat types by producing sequential maps based on point information followed by mapping using a multinomial logit regression model with abiotic variables of which maps are available as predictors. In a 70 ha study area a total of 904 vegetation samples has been collected in seven sampling rounds with an interval of 2–3 years. Half of the vegetation plots was permanent, violating the assumption of independent data in multinomial logistic regression. This paper shows how this dependency can be accounted for by adding a random effect to the multinomial logit (MLN) model, thus becoming a mixed multinomial logit (MMNL) model. In principle all regression coefficients can be taken as random, but in this study only the intercepts are treated as location-specific random variables (random intercepts model). With six habitat types we have five intercepts, so that the number of extra model parameters becomes 15, 5 variances and 10 covariances. The likelihood ratio test showed that the MMNL model fitted significantly better than the MNL model with the same fixed effects. McFadden- R 2 for the MMNL model was 0.467, versus 0.395 for the MNL model. The estimated coefficients of the MMNL and MNL model were comparable; those of altitude, the most important predictor, differed most. The MMNL model accounts for pseudo-replication at the permanent plots, which explains the larger standard errors of the MMNL coefficients. The habitat type at a given location-year combination was predicted by the habitat type with the largest predicted probability. The series of maps shows local trends in habitat types most likely driven by sea-level rise, soil subsidence, and a restoration project. We conclude that in environmental modeling of categorical variables using panel data, dependency of repeated observations at permanent plots should be accounted for. This will affect the estimated probabilities of the categories, and even stronger the standard errors of the regression coefficients. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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24. Interaction between dietary content of protein and sodium chloride on milk urea concentration, urinary urea excretion, renal recycling of urea, and urea transfer to the gastrointestinal tract in dairy cows.
- Author
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Spek, J. W., Bannink, A., Gort, G., Hendriks, W. H., and Dijkstra, J.
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LOW-protein diet , *DAIRY cattle feeding & feeds , *UREA content of milk , *UREA in the body , *GASTROINTESTINAL system - Abstract
Dietary protein and salt affect the concentration of milk urea nitrogen (MUN; mg of N/dL) and the relationship between MUN and excretion of urea nitrogen in urine (UUN; g of N/d) of dairy cattle. The aim of the present study was to examine the effects of dietary protein and sodium chloride (NaCl) intake separately, and their interaction, on MUN and UUN, on the relationship between UUN and MUN, on renal recycling of urea, and on urea transfer to the gastrointestinal tract. Twelve second-parity cows (body weight of 645 ± 37 kg, 146 ± 29 d in milk, and a milk production of 34.0 ± 3.28 kg/d), of which 8 were previously fitted with a rumen cannula, were fitted with catheters in the urine bladder and jugular vein. The experiment had a split-plot arrangement with dietary crude protein (CP) content as the main plot factor [116 and 154 g of CP/kg of dry matter (DM)] and dietary NaCl content as the subplot factor (3.1 and 13.5 g of Na/kg of DM). Cows were fed at 95% of the average ad libitum feed intake of cows receiving the low protein diets. Average MUN and UUN were, respectively, 3.90 mg of N/dL and 45 g of N/d higher for the high protein diets compared with the low protein diets. Compared with the low NaCl diets, MUN was, on average, 1.74 mg of N/dL lower for the high NaCl diets, whereas UUN was unaffected. We found no interaction between dietary content of protein and NaCl on performance characteristics or on MUN, UUN, urine production, and renal clearance characteristics. The creatinine clearance rate was not affected by dietary content of protein and NaCl. Urea transfer to the gastrointestinal tract, expressed as a fraction of plasma urea entry rate, was negatively related to dietary protein, whereas it was not affected by dietary NaCl content. We found no interaction between dietary protein and NaCl content on plasma urea entry rate and gastrointestinal urea entry rate or their ratio. The relationship between MUN and UUN was significantly affected by the class variable dietary NaCl content: UUN = -17.7 ± 7.24 + 10.09 ± 1.016 x MUN + 2.26 ± 0.729 x MUN (for high NaCl); R² = 0.85. Removal of the MUN x NaCl interaction term lowered the coefficient of determination from 0.85 to 0.77. In conclusion, dietary protein content is positively related to MUN and UUN, whereas dietary NaCl content is negatively correlated to MUN but NaCl content is not related to UUN. We found no interaction between dietary protein and NaCl content on performance, MUN, UUN, or renal urea recycling, nor on plasma urea entry rate and urea transfer to the gastrointestinal tract. For a proper interpretation of the relationship between MUN and UUN, the effect of dietary NaCl should be taken into account, but we found no evidence that the effect of dietary NaCl on MUN is dependent on dietary protein content. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
25. Effect of sodium chloride intake on urine volume, urinary urea excretion, and milk urea concentration in lactating dairy cattle.
- Author
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Spek, J. W., Bannink, A., Gort, G., Hendriks, W. H., and Dijkstra, J.
- Subjects
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COMPOSITION of milk , *UREA , *HOLSTEIN-Friesian cattle , *SODIUM , *CREATININE - Abstract
Milk urea nitrogen (MUN; mg of N/dL) has been shown to be related to excretion of urinary urea N (UUN; g of N/d) and total excretion of urinary N (UN; g of N/d) in dairy cows. In the present experiment, it was hypothesized that MUN and the relationship between MUN and UUN or UN is affected by urine volume as a result of dietary sodium chloride intake. Twelve lactating Holstein-Friesian dairy cows (mean ± SD: milk production 28.1 ± 3.23 kg/d and 190 ± 41 d in milk), of which 4 were fitted with catheters in the urine bladder and jugular vein, were randomly assigned to 4 dietary levels of sodium chloride (3, 9, 14, and 19 g of Na/kg of DM) according to a triple 4 × 4 Latin square design. Cows were fed at 95% of ad libitum intake, excluding salt addition. Milk was analyzed for MUN and protein content; urine was analyzed for total N, urea, and creatinine content; feces were analyzed for total N and DM content; and blood plasma was analyzed for urea and creatinine content. Creatinine clearance rate (CCR; L/min) and renal urea reabsorption ratio were estimated based on plasma concentrations of urea and creatinine, and total excretion of urea and creatinine in urine. Intake of DM and N, milk production, and milk protein content were (mean ± SD), on average, 21.4 ± 1.24 kg/d, 522 ± 32.0 g/d, 25.4 ± 2.53 kg/d, and 3.64 ± 0.186%, respectively. A linear relationship was found between Na intake and urine production [urine (kg/d; mean ± SE) = 7.5 ± 4.33 + 0.136 ± 0.0143 × Na intake (g/d)] and between Na intake and MUN [MUN (mg/ dL; mean ± SE) = 13.5 ± 0.35 - 0.0068 ± 0.00104 × Na intake (g/d)]. Despite the decrease in MUN with increased Na intake, UN excretion increased linearly with Na intake. Excretion of UUN was not affected by dietary Na content. A linear plateau relationship was observed between CCR and renal urea reabsorption. An increase in CCR coincided with an increase in calculated renal urea reabsorption until a CCR breakpoint value (mean ± SD) of 1.56 ± 0.063 L/min was reached. We conclude that Na intake is negatively related to MUN, whereas UUN is not affected. Variation in mineral intake levels that affect urine volume should, therefore, be taken into account when using MUN as an indicator of UUN in dairy cattle. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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26. Individual differences in behavioral and physiological responses to restraint stress in pigs
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Geverink, N.A., Schouten, W.G.P., Gort, G., and Wiegant, V.M.
- Subjects
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SWINE , *PIGLETS , *HYDROCORTISONE , *ANIMAL behavior - Abstract
Several recent studies on pigs have demonstrated a relationship between the degree of resistance displayed early in life in a so-called backtest and a variety of behavioural and physiological responses in piglets and young fattening pigs. To study whether pigs with diverging responses in the backtest, i.e., high-resisting (HR) and low-resisting (LR) pigs, differ also in adulthood in their responses to an acute stressor, adult nulliparous HR (n=36) and LR gilts (n=36) housed in groups or stalls were challenged by 5-min fixation with a nose sling. During the first minute of restraint, HR gilts vocalised significantly more than LR gilts. Over the whole 5-min period, HR gilts tended to vocalise more than LR gilts. Housing or backtest type did not affect immediate cortisol increase (Δ(−5 min; 15 min)). At t=45 min, cortisol concentrations in HR gilts but not in LR gilts were still higher than at t=−5 min. Heart rate quickly decreased during the first min of restraint and remained fairly constant thereafter. Estimated heart rate after 5 min of nose sling was significantly lower in HR gilts compared to LR gilts. Housing or backtest type did not affect heart rate variability indices. The results support the idea that the backtest relates to individual characteristics, which at an adult age also seem to play a role in the regulation of certain behavioral and physiological responses to short-term stress. [Copyright &y& Elsevier]
- Published
- 2002
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27. Estimation of photosynthesis parameters for a modified Farquhar–von Caemmerer–Berry model using simultaneous estimation method and nonlinear mixed effects model
- Author
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Qian, T., Elings, A., Dieleman, J.A., Gort, G., and Marcelis, L.F.M.
- Subjects
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PHOTOSYNTHESIS , *MULTILEVEL models , *CARBOXYLATION , *PHYSIOLOGICAL effects of light , *PHYSIOLOGICAL effects of temperature , *ELECTRON transport , *RIBULOSE bisphosphate carboxylase , *PARAMETER estimation , *PLANT photorespiration , *PLANTS - Abstract
Abstract: The aims of this paper was to modify the photosynthesis model of Farquhar, von Caemmerer and Berry (FvCB) to be able to predict light dependency of the carboxylation capacity (V c ) and to improve the prediction of temperature dependency of the maximum carboxylation capacity (V cmax) and the maximum electron transport rate (J max). The FvCB model was modified by adding a sub-model for Ribulose-1,5-bisphosphate carboxylase (Rubisco) activation and validating the parameters for temperature dependency of V cmax and J max. Values of parameters for temperature dependency of V cmax and J max were validated and adjusted based on data of the photosynthesis response to temperature. Parameter estimation was based on measurements under a wide range of environmental conditions, providing parameters with broad validity. The simultaneous estimation method and the nonlinear mixed effects model were applied to ensure the accuracy of the parameter estimation. The FvCB parameters, V cmax, J max, α (the efficiency of light energy conversion), θ (the curvature of light response of electron transport), and R d (the non-photorespiratory CO2 release) were estimated and validated on a dataset from two other years. Observations and predictions matched well (R 2 =0.94). We conclude that incorporating a sub-model of Rubisco activation improved the FvCB model through predicting light dependency of carboxylation rate; and that estimating V cmax, J max, α, θ, and R d requires data sets of both CO2 and light response curves. [Copyright &y& Elsevier]
- Published
- 2012
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28. Effect of response to backtest and housing condition on cell-mediated and humoral immunity in adult pigs
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Geverink, N.A., Parmentier, H.K., de Vries Reilingh, G., Schouten, W.G.P., Gort, G., and Wiegant, V.M.
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- *
CELLULAR immunity , *DRUG resistance , *IMMUNE response , *PLACEBOS - Abstract
Several recent studies in juvenile pigs demonstrated a relationship between the degree of resistance displayed early in life in a so-called “backtest” and parameters of cell-mediated and humoral immunity. Some of the immune characteristics were reported to depend on the interaction between backtest classification and housing system. In the present study, the effects of backtest classification and housing condition on immune reactivity in adult gilts were examined. At 10 and 17 days of age, female piglets were subjected to the backtest. In this test, each piglet is restrained on its back for 1 min and the number of escape attempts is scored. Pigs classified as high resisting (HR) or low resisting (LR) were selected and housed in groups of six gilts. At 7 months of age, half of the gilts were housed in individual stalls. At 12 months of age, gilts were challenged by immunization with DNP-KLH. Control gilts were treated similarly with a placebo. Blood samples were drawn prior to immunization (Day 0) and weekly thereafter until Day 28. No significant effects of backtest type on cellular and humoral responses against KLH were found. Furthermore, being housed in stalls as compared to groups had no consequences for the immune response and did not induce differences between HR and LR gilts. Differences in behavior and physiology found previously between HR and LR gilts, particularly in gilts in stall housing, may thus be of relatively little importance for immune-related health. [Copyright &y& Elsevier]
- Published
- 2004
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29. Corrigendum to “Estimation of photosynthesis parameters for a modified Farquhar–von Caemmerer–Berry model using simultaneous estimation method and nonlinear mixed effects model” [Environ. Exp. Bot. 82 (2012) 66–73].
- Author
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Qian, T., Elings, A., Dieleman, J.A., Gort, G., and Marcelis, L.F.M.
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- *
PHOTOSYNTHESIS , *ESTIMATION theory , *NONLINEAR statistical models - Published
- 2016
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30. Performance, egg quality and organ traits of laying hens fed black soldier fly larvae products.
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Dörper A, Gort G, van Harn J, Oonincx DGAB, Dicke M, and Veldkamp T
- Subjects
- Animals, Female, Ovum physiology, Animal Nutritional Physiological Phenomena, Random Allocation, Chickens physiology, Animal Feed analysis, Larva physiology, Larva growth & development, Diet veterinary, Simuliidae physiology
- Abstract
Due to consumer demands and institutional pressure, the egg production sector, is looking for alternative protein sources for laying hen feed to support more sustainable, circular production. black soldier fly (BSF) larvae could be used as a protein source. In addition to protein the larvae contain large quantities of fat and can either be fed to laying hens unprocessed (alive) or processed (meal and oil). The current study was performed with 560 Brown Nick laying hens from 20 to 27 wk of age. The laying hens were divided over 5 treatments, each replicated 8 times. Treatments consisted of standard laying hen feed (control) and standard feed in which soybean meal was partly exchanged with live BSF larvae or BSF larvae meal and oil combined, at 2 inclusion levels. During the experiment production parameters, egg-quality, and length and weight of various organs were measured. Laying hens fed BSF larvae products consumed less feed compared to those of the control group. Most egg production parameters were similar, however laying hens fed diets with BSF larvae meal plus oil produced eggs with lower egg weight during the last 2 wk of the experiment, compared to the control group. All egg-quality characteristics remained the same across treatments, except for darker yolk colors when feeding BSF meal and oil and high inclusion of live BSF larvae. This is a favorable characteristic for European consumers. The weight of intestinal organs was largely unaffected by the treatments. The jejunum and ileum weight of laying hens fed live larvae was lower compared to the control group. As FCRs were similar or improved compared to the control group, we assume that nutrient utilization was not impaired. For most detected differences the type of BSF larvae product (live larvae or meal plus oil) rather than inclusion level was of significance., Competing Interests: DISCLOSURES The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Marcel Dicke reports financial support was provided by Dutch Research Council. The project is funded by the Dutch Research Council (NWO; NWA programme, InsectFeed project, NWA.1160.18.144). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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31. Spatial and temporal variation of five different pathogens and symbionts in Ixodes ricinus nymphs in the Netherlands.
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Hartemink N, Gort G, Krawczyk AI, Fonville M, van Vliet AJH, Takken W, and Sprong H
- Abstract
The incidence of diseases caused by pathogens transmitted by the tick Ixodes ricinus vary over time and space through incompletely understood mechanisms. An important determinant of the disease risk is the density of infected ticks, which is the infection prevalence times the density of questing ticks. We therefore investigated the spatial and temporal variation of four pathogens and one of the most abundant symbionts in Ixodes ricinus in questing nymphs over four years of monthly collections in 12 locations in the Netherlands. The infection prevalence of all microbes showed markedly different patterns with significant spatial variation for Borrelia burgdorferi ( s.l. ), Neoehrlichia mikurensis , Rickettsia helvetica , and Midichloria mitochondrii , significant seasonal variation of B. burgdorferi ( s.l. ), N. mikurensis , and M. mitochondrii and a significant interannual variation of R. helvetica . Despite its ubiquitous presence, no spatio-temporal variation was observed for the infection prevalence of B. miyamotoi . The variation in infection prevalence was generally smaller than the variation in the density of nymphs, which fluctuated substantially both seasonally and between locations. This means that the variation in the densities of infected nymphs for all pathogens was mostly the result of the variation in densities of nymphs. We also investigated whether there were positive or negative associations between the symbionts, and more specifically whether ticks infected with vertically transmitted symbionts like M. mitochondrii and R. helvetica , have a higher prevalence of horizontally transmitted symbionts, such as B. burgdorferi ( s.l. ) and N. mikurensis . We indeed found a clear positive association between M. mitochondrii and B. burgdorferi ( s.l. ). The positive association between R. helvetica and B. burgdorferi ( s.l. ) was less clear and was only shown in two locations. Additionally, we found a clear positive association between B. burgdorferi ( s.l. ) and N. mikurensis , which are both transmitted by rodents. Our longitudinal study indicated strong between-location variation, some seasonal patterns and hardly any differences between years for most symbionts. Positive associations between symbionts were observed, suggesting that infection with a (vertically transmitted) symbiont may influence the probability of infection with other symbionts, or that there is a common underlying mechanism (e.g. feeding on rodents)., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)
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- 2024
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32. The small hive beetle's capacity to disperse over long distances by flight.
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Cornelissen B, Ellis JD, Gort G, Hendriks M, van Loon JJA, Stuhl CJ, and Neumann P
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- Animals, Animal Distribution, Bees physiology, Temperature, Wind, Coleoptera physiology, Flight, Animal physiology, Introduced Species
- Abstract
The spread of invasive species often follows a jump-dispersal pattern. While jumps are typically fostered by humans, local dispersal can occur due to the specific traits of a species, which are often poorly understood. This holds true for small hive beetles (Aethina tumida), which are parasites of social bee colonies native to sub-Saharan Africa. They have become a widespread invasive species. In 2017, a mark-release-recapture experiment was conducted in six replicates (A-F) using laboratory reared, dye-fed adults (N = 15,690). Honey bee colonies were used to attract flying small hive beetles at fixed spatial intervals from a central release point. Small hive beetles were recaptured (N = 770) at a maximum distance of 3.2 km after 24 h and 12 km after 1 week. Most small hive beetles were collected closest to the release point at 0 m (76%, replicate A) and 50 m (52%, replicates B to F). Temperature and wind deviation had significant effects on dispersal, with more small hive beetles being recaptured when temperatures were high (GLMM: slope = 0.99, SE = 0.17, Z = 5.72, P < 0.001) and confirming the role of wind for odour modulated dispersal of flying insects (GLMM: slope = - 0.39, SE = 0.14, Z = - 2.90, P = 0.004). Our findings show that the small hive beetles is capable of long-distance flights, and highlights the need to understand species specific traits to be considered for monitoring and mitigation efforts regarding invasive alien species., (© 2024. The Author(s).)
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- 2024
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33. Effects of different black soldier fly larvae products on slow-growing broiler performance and carcass characteristics.
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Dörper A, Berman HM, Gort G, van Harn J, Dicke M, and Veldkamp T
- Subjects
- Male, Animals, Larva chemistry, Animal Feed analysis, Diet veterinary, Chickens metabolism, Diptera chemistry
- Abstract
Black soldier fly (BSF) larvae have gained significant attention as ingredients for poultry feed to improve value chain circularity and sustainability. Black soldier fly larvae contain bioactive compounds which can potentially improve broiler health and thereby performance. However, the functionality of bioactive compounds likely depends on how larvae are processed prior to feeding and to which extent larvae products are included in the diet. This may explain the variable results reported in literature on broiler performance and carcass characteristics when feeding them different types of BSF larvae products at different inclusion levels. Therefore, the present research aimed to investigate the effects of different BSF larvae products and inclusion levels in diets on performance and carcass characteristics of slow-growing broilers. The experiment started with 1,728 one-day-old slow-growing male broilers (Hubbard JA757). Nine dietary treatments were used, each replicated eight times. One group of broilers was given a control diet. The following BSF larvae products were investigated: live larvae, a combination of BSF larvae meal and oil mimicking the nutritional composition of the live larvae, and BSF larvae meal and oil separately. All insect products were tested at two inclusion levels. All diet programs were nutritionally comparable (isoenergetic and based on balanced levels of digestible essential amino acids). During the 7-wk trial, several performance parameters and carcass characteristics were measured. The results show that comparable or better broiler performance was achieved with the inclusion of BSF larvae products in the diets compared to the control. Based on the feed conversion ratio (FCR), the unprocessed larvae product and the highest inclusion level led to the most favorable results. Carcass characteristics remained unchanged when BSF larvae products were used in the diets compared to the control group, indicating favorable production output. The BSF larvae products investigated seem suitable feed ingredients for broilers at the current levels tested, generating performance benefits., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2024
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34. Effects of far-red light on the behaviour and reproduction of the zoophytophagous predator Macrolophus pygmaeus and its interaction with a whitefly herbivore.
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Meijer D, Hopkoper S, Weldegergis BT, Westende WV, Gort G, van Loon JJA, and Dicke M
- Subjects
- Animals, Plants, Reproduction, Light, Herbivory, Heteroptera
- Abstract
Plants can detect neighbouring plants through a reduction in the ratio between red and far-red light (R:FR). This provides a signal of plant-plant competition and induces rapid plant growth while inhibiting defence against biotic stress, two interlinked responses designated as the shade avoidance syndrome (SAS). Consequently, the SAS can influence plant-herbivore interactions that could cascade to higher trophic levels. However, little is known about how the expression of the SAS can influence tritrophic interactions. We investigated whether changes in R:FR affect the emission of herbivore-induced plant volatiles (HIPVs), and whether these changes influence the attraction of the zoophytophagous predator Macrolophus pygmaeus. We also studied how the expression of the SAS and subsequent inhibition of plant defences affects the reproduction of M. pygmaeus in both the presence and absence of the greenhouse whitefly (WF) (Trialeurodes vaporariorum) as arthropod prey. The results show that changes in R:FR have little effect on HIPV emissions and predator attraction. However, a reduction in R:FR leads to increased reproduction of both the predator and the WFs. We discuss that shade avoidance responses can increase the population development of M. pygmaeus through a combination of reduced plant defences and increased herbivore densities., (© 2023 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.)
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- 2024
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35. When nudgees become nudgers: Exploring the use of self-nudging to promote fruit intake.
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van Rookhuijzen M, de Vet E, Gort G, and Adriaanse MA
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- Humans, Diet, Healthy, Feeding Behavior, Fruit, Health Promotion methods
- Abstract
The current study explored (1) the immediate and prolonged effects of self-nudges promoting fruit intake in the home environment, (2) whether the effect of self-nudges on fruit intake persists after self-nudges are no longer used (i.e. a temporal spillover effect) and (3) whether self-nudges can install healthy eating habits that, in turn, explain the temporal spillover effect. Participants (N = 331) were randomly assigned to either a control or self-nudge condition in which they had to choose a self-nudge promoting fruit consumption for 8 weeks. Thereafter, participants were asked to remove the self-nudge for 1 week to assess a possible temporal spillover effect. Results showed a positive effect of the self-nudges on fruit consumption right after implementation that continued during the 8 weeks in which the self-nudge was implemented, which was accompanied by an increase in fruit intake habit strength. However, a mixed picture emerged regarding the temporal spillover effect and no support was found for a mediation effect of habit strength. Although this study is only a first exploration of self-nudging to increase healthy food consumption, results indicate that self-nudging may be a promising extension of traditional nudging that can influence behaviour beyond out-of-home settings., (© 2023 The Authors. Applied Psychology: Health and Well-Being published by John Wiley & Sons Ltd on behalf of International Association of Applied Psychology.)
- Published
- 2023
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36. Pesticide residues with hazard classifications relevant to non-target species including humans are omnipresent in the environment and farmer residences.
- Author
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Silva V, Gai L, Harkes P, Tan G, Ritsema CJ, Alcon F, Contreras J, Abrantes N, Campos I, Baldi I, Bureau M, Christ F, Mandrioli D, Sgargi D, Pasković I, Polić Pasković M, Glavan M, Hofman J, Huerta Lwanga E, Norgaard T, Bílková Z, Osman R, Khurshid C, Navarro I, de la Torre A, Sanz P, Ángeles Martínez M, Dias J, Mol H, Gort G, Martins Figueiredo D, Scheepers PTJ, Schlünssen V, Vested A, Alaoui A, and Geissen V
- Subjects
- Humans, Farmers, Crops, Agricultural, Dust, Soil, Water, Environmental Monitoring, Pesticide Residues, Pesticides
- Abstract
Intensive and widespread use of pesticides raises serious environmental and human health concerns. The presence and levels of 209 pesticide residues (active substances and transformation products) in 625 environmental samples (201 soil, 193 crop, 20 outdoor air, 115 indoor dust, 58 surface water, and 38 sediment samples) have been studied. The samples were collected during the 2021 growing season, across 10 study sites, covering the main European crops, and conventional and organic farming systems. We profiled the pesticide residues found in the different matrices using existing hazard classifications towards non-target organisms and humans. Combining monitoring data and hazard information, we developed an indicator for the prioritization of pesticides, which can support policy decisions and sustainable pesticide use transitions. Eighty-six percent of the samples had at least one residue above the respective limit of detection. One hundred residues were found in soil, 112 in water, 99 in sediments, 78 in crops, 76 in outdoor air, and 197 in indoor dust. The number, levels, and profile of residues varied between farming systems. Our results show that non-approved compounds still represent a significant part of environmental cocktails and should be accounted for in monitoring programs and risk assessments. The hazard profiles analysis confirms the dominance of compounds of low-moderate hazard and underscores the high hazard of some approved compounds and recurring "no data available" situations. Overall, our results support the idea that risk should be assessed in a mixture context, taking environmentally relevant mixtures into consideration. We have uncovered uncertainties and data gaps that should be addressed, as well as the policy implications at the EU approval status level. Our newly introduced indicator can help identify research priority areas, and act as a reference for targeted scenarios set forth in the Farm to Fork pesticide reduction goals., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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37. Pairwise ratio-based differential abundance analysis of infant microbiome 16S sequencing data.
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Mildau K, Te Beest DE, Engel B, Gort G, Lambert J, Swinkels SHN, and van Eeuwijk FA
- Abstract
Differential abundance analysis of infant 16S microbial sequencing data is complicated by challenging data properties, including high sparsity, extreme dispersion and the relative nature of the information contained within the data. In this study, we propose a pairwise ratio analysis that uses the compositional data analysis principle of subcompositional coherence and merges it with a beta-binomial regression model. The resulting method provides a flexible and easily interpretable approach to infant 16S sequencing data differential abundance analysis that does not require zero imputation. We evaluate the proposed method using infant 16S data from clinical trials and demonstrate that the proposed method has the power to detect differences, and demonstrate how its results can be used to gain insights. We further evaluate the method using data-inspired simulations and compare its power against related methods. Our results indicate that power is high for pairwise differential abundance analysis of taxon pairs that have a large abundance. In contrast, results for sparse taxon pairs show a decrease in power and substantial variability in method performance. While our method shows promising performance on well-measured subcompositions, we advise strong filtering steps in order to avoid excessive numbers of underpowered comparisons in practical applications., (© The Author(s) 2023. Published by Oxford University Press on behalf of NAR Genomics and Bioinformatics.)
- Published
- 2023
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38. Stone tools improve diet quality in wild monkeys.
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Izar P, Peternelli-Dos-Santos L, Rothman JM, Raubenheimer D, Presotto A, Gort G, Visalberghi EM, and Fragaszy DM
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- Animals, Carbohydrates, Cebus physiology, Diet, Feeding Behavior physiology, Haplorhini, Lipids, Hominidae, Tool Use Behavior physiology
- Abstract
Tool use is a fundamental feature of human evolution. Stone tools are in the archaeological record from 3.4 Ma, even before Homo,
1 and the use of stone tools probably predated the split between hominins and panins.2 Using tools (hereafter, tooling cf Fragaszy and Mangalam3 ) is hypothesized to have improved hominins' foraging efficiency or access to high-quality foods.4-7 This hypothesis is supported if feeding with tools positively contributes to diet quality in extant non-human primates or if foraging efficiency is increased by tooling. However, the contribution of tooling to non-human primates' foraging success has never been investigated through a direct analysis of nutritional ecology.8 , 9 We used multi-dimensional nutritional geometry to analyze energy and macronutrients (nonstructural carbohydrates, lipids, and protein) in the diets of wild capuchin monkeys (Sapajus libidinous) that routinely crack palm nuts with stone hammers.10 , 11 We show that eating nuts obtained through tooling helps monkeys to achieve more consistent dietary intakes. Tooling increased the net energy gain by 50% and decreased the proportion of fiber ingested by 7%. Tooling also increased the daily non-protein energy intake. By contrast, protein intake remained constant across foraging days, suggesting a pattern of macronutrient regulation called protein prioritization, which is also found in contemporary humans.8 , 9 In addition, tooling reduced dispersion in the ratio of protein to non-protein energy, suggesting a role in macronutrient balancing. Our findings suggest that tooling prior to tool making could have substantially increased the nutritional security of ancestral hominins, sowing the seeds for cultural development.5 , 7 VIDEO ABSTRACT., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 Elsevier Inc. All rights reserved.)- Published
- 2022
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39. Adaptation by Type V-A and V-B CRISPR-Cas Systems Demonstrates Conserved Protospacer Selection Mechanisms Between Diverse CRISPR-Cas Types.
- Author
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Wu WY, Jackson SA, Almendros C, Haagsma AC, Yilmaz S, Gort G, van der Oost J, Brouns SJJ, and Staals RHJ
- Subjects
- CRISPR-Cas Systems genetics, DNA, Endonucleases genetics, Gene Editing, CRISPR-Associated Proteins genetics, CRISPR-Associated Proteins metabolism
- Abstract
Adaptation of clustered regularly interspaced short palindromic repeats (CRISPR) arrays is a crucial process responsible for the unique, adaptive nature of CRISPR-Cas immune systems. The acquisition of new CRISPR spacers from mobile genetic elements has previously been studied for several types of CRISPR-Cas systems. In this study, we used a high-throughput sequencing approach to characterize CRISPR adaptation of the type V-A system from Francisella novicida and the type V-B system from Alicyclobacillus acidoterrestris . In contrast to other class 2 CRISPR-Cas systems, we found that for the type V-A and V-B systems, the Cas12 nucleases are dispensable for spacer acquisition, with only Cas1 and Cas2 (type V-A) or Cas4/1 and Cas2 (type V-B) being necessary and sufficient. Whereas the catalytic activity of Cas4 is not essential for adaptation, Cas4 activity is required for correct protospacer adjacent motif selection in both systems and for prespacer trimming in type V-A. In addition, we provide evidence for acquisition of RecBCD-produced DNA fragments by both systems, but with spacers derived from foreign DNA being incorporated preferentially over those derived from the host chromosome. Our work shows that several spacer acquisition mechanisms are conserved between diverse CRISPR-Cas systems, but also highlights unexpected nuances between similar systems that generally contribute to a bias of gaining immunity against invading genetic elements.
- Published
- 2022
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40. Seasonal dynamics of tick burden and associated Borrelia burgdorferi s.l. and Borrelia miyamotoi infections in rodents in a Dutch forest ecosystem.
- Author
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van Duijvendijk G, Krijger I, van Schaijk M, Fonville M, Gort G, Sprong H, and Takken W
- Subjects
- Animals, Ecosystem, Female, Forests, Male, Murinae, Nymph, Seasons, Borrelia, Borrelia Infections, Borrelia burgdorferi, Ixodes, Lyme Disease
- Abstract
Ixodes ricinus ticks transmit Borrelia burgdorferi sensu lato (s.l.) as well as Borrelia miyamotoi. Larvae become infected when feeding on infected rodents, with horizontal transmission of B. burgdorferi and horizontal and vertical transmission of B. miyamotoi. We studied seasonal dynamics of infection rates of I. ricinus and their rodent hosts, and hence transmission risk of these two distinctly different Borrelia species. Rodents were live-trapped and inspected for ticks from May to November in 2013 and 2014 in a forest in The Netherlands. Trapped rodents were temporarily housed in the laboratory and detached ticks were collected. Borrelia infections were determined from the trapped rodents and collected ticks. Borrelia burgdorferi s.l. and B. miyamotoi were found in ticks as well as in rodents. Rodent density was higher in 2014, whereas tick burden as well as the Borrelia infection rates in rodents were higher in 2013. The density of B. miyamotoi-infected nymphs did not differ between the years. Tick burdens were higher on Apodemus sylvaticus than on Myodes glareolus, and higher on males than on females. Borrelia-infection rate of rodents varied strongly seasonally, peaking in summer. As the larval tick burden also peaked in summer, the generation of infected nymphs was highest in summer. We conclude that the heterogeneity of environmental and host-specific factors affects the seasonal transmission of Borrelia spp., and that these effects act more strongly on horizontally transmitted B. burgdorferi spp. than on the vertically transmitted B. miyamotoi., (© 2022. The Author(s).)
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- 2022
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41. Effect of Type of Cow-Calf Contact on Health, Blood Parameters, and Performance of Dairy Cows and Calves.
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Wenker ML, Verwer CM, Bokkers EAM, Te Beest DE, Gort G, de Oliveira D, Koets A, Bruckmaier RM, Gross JJ, and van Reenen CG
- Abstract
Prolonged cow-calf contact (CCC) could potentially improve dairy calf welfare. However, it is currently unknown how different types of CCC affect animals' biological functions. We evaluated health and performance parameters of dairy calves and their dams, where calves: (i) had no contact with their dam (NC), in which the calf was removed from the dam directly after birth ( n = 10); (ii) were allowed to have partial contact (PC) with their dam, in which the calf was housed in a calf pen adjacent to the cow area allowing physical contact on the initiative of the dam but no suckling ( n = 18); (iii) were allowed to have full contact (FC) with their dam, including suckling, in which calves were housed together with their dams in a free-stall barn ( n = 20). Throughout the first 7 weeks postpartum, data were collected on the health status, fecal microbiota, hematological profile, immune and hormonal parameters, and growth rates of calves, and on the health status, metabolic responses, and performance of dams. Overall, FC calves had more health issues ( P = 0.02) and a tendency for higher antibiotic usage ( P = 0.0 7) than NC calves. Additionally, FC calves showed elevated levels of erythrocytes, hematocrit, hemoglobin, and leukocytes on day 49 compared to NC calves ( P < 0.001). Calf fecal microbiota changed over time, and we found preliminary evidence that fecal microbiota is affected by the type of CCC, as reflected by differences in relative abundances of taxa including Lactobacillus in FC calves compared to NC and PC calves except on days 7 and 66. The FC calves had a greater average daily gain in body weight than NC and PC calves ( P = 0.002). Cow health was not affected by the type of CCC, although in the first 7 weeks of lactation FC cows had a lower machine-gained milk yield accompanied by a lower fat percentage than NC and PC cows ( P < 0.001). These results indicate that full contact posed a challenge for calf health, presumably because the housing conditions of FC calves in this experimental context were suboptimal. Secondly, ad libitum suckling leads to higher weight gains and negatively affected milk fat content besides machine-gained yields. More research into strategies to improve cow-calf housing and management in CCC systems is warranted., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling Editor declared a past co-authorship with one of the authors, EB., (Copyright © 2022 Wenker, Verwer, Bokkers, te Beest, Gort, de Oliveira, Koets, Bruckmaier, Gross and van Reenen.)
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- 2022
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42. Plasticity in induced resistance to sequential attack by multiple herbivores in Brassica nigra.
- Author
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de Bobadilla MF, Van Wiechen R, Gort G, and Poelman EH
- Subjects
- Animals, Herbivory, Insecta, Mustard Plant, Aphids, Hymenoptera
- Abstract
In nature, plants interact with multiple insect herbivores that may arrive simultaneously or sequentially. There is extensive knowledge on how plants defend themselves against single or dual attack. However, we lack information on how plants defend against the attack of multiple herbivores that arrive sequentially. In this study, we investigated whether Brassica nigra L. plants are able to defend themselves against caterpillars of the late-arriving herbivore Plutella xylostella L., when plants had been previously exposed to sequential attack by four other herbivores (P. xylostella, Athalia rosae, Myzus persicae and Brevicoryne brassicae). We manipulated the order of arrival and the history of attack by four herbivores to investigate which patterns in sequential herbivory determine resistance against the fifth attacker. We recorded that history of sequential herbivore attack differentially affected the capability of B. nigra plants to defend themselves against caterpillars of P. xylostella. Caterpillars gained less weight on plants attacked by a sequence of four episodes of attack by P. xylostella compared to performance on plants that were not previously damaged by herbivores. The number of times the plant was attacked by herbivores of the same feeding guild, the identity of the first attacker, the identity and the guild of the last attacker as well as the order of attackers within the sequence of multiple herbivores influenced the growth of the subsequent herbivory. In conclusion, this study shows that history of sequential attack is an important factor determining plant resistance to herbivores., (© 2021. The Author(s).)
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- 2022
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43. Two-year effects of the community-based overweight and obesity intervention program Gezond Onderweg! (GO!) in children and adolescents living in a low socioeconomic status and multi-ethnic district on Body Mass Index-Standard Deviation Score and quality of life.
- Author
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Lek D, Haveman-Nies A, Bezem J, Zainalabedin S, Schetters-Mouwen S, Saat J, Gort G, Roovers L, and van Setten P
- Abstract
Background: In most childhood obesity interventions, disadvantaged groups are underrepresented, and results are modest and not maintained. A long-term collaborative community-based approach is necessary to reach out to children from multi-ethnic backgrounds and achieve sustainable behavior change, resulting in sustained Body Mass Index-Standard Deviation Score (BMI-SDS) reductions. The objective is to determine the effects of GO! on BMI-SDS and Health-Related Quality of Life (HRQoL) for children and adolescents having overweight or obesity., Methods: A prospective, longitudinal cohort study was used to collect two-year follow-up data from November 2014 to July 2019. Children and adolescents (4-19 years old) from the low socioeconomic status and multi-ethnic district of Malburgen in the Dutch city of Arnhem were included. 178 children having overweight or obesity were recruited, with 155 children measured at baseline and after two years as a minimum, while 23 were lost to follow up. Participants attending the program for over six months were defined as completers (n=107) and participants attending the program for less than six months were defined as non-completers (n=48). The child health coach (CHC) acts as a central care provider in the collaborative community with healthcare providers from both medical and social fields. This coach coordinates, monitors and coaches healthy lifestyles, while increasing self-management for both children and parents. This is done in a customized and neighborhood-oriented manner and provided by all the stakeholders involved in GO!. The main outcomes are the change in BMI-SDS scores and HRQoL scores reported by participants., Findings: After 24 months, completers showed a decrease in BMI-SDS of -0·32 [95% CI: -0·42, -0·21], compared with -0·14 [95% CI: -0·29, 0·01] for non-completers (adjusted for gender and ethnicity; P=0.036). While 25% suffered from overweight and 75% from obesity at the start, following the intervention 5% showed normal weight, with 33% overweight and 62% with obesity. HRQoL reported by participants improved over time, showing no differences between completers and non-completers, gender and ethnicity after two years., Interpretation: Our results suggest that the GO! program might be effective in reaching out and reducing BMI-SDS for participants in a low socioeconomic status and multi-ethnic district over a two-year period. We noticed also trends to beneficial shifts in obesity grades. HRQoL improved regardless of the participation rate, gender and ethnic background. In light of the study limitations, further studies are needed to corroborate our observations., Funding: Dullerts-foundation, Nicolai Broederschap foundation, Burger en Nieuwe weeshuis foundation, Rijnkind foundation, Arnhems Achterstandswijken foundation, Menzis-foundation, the municipalities of Arnhem, Rheden, Overbetuwe and Lingewaard, the Association of Dutch municipalities, and Province of Gelderland., Competing Interests: We declare no competing interests., (© 2021 The Authors.)
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- 2021
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44. Insect species richness affects plant responses to multi-herbivore attack.
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Fernández de Bobadilla M, Bourne ME, Bloem J, Kalisvaart SN, Gort G, Dicke M, and Poelman EH
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- Animals, Larva, Mustard Plant, Phloem, Herbivory, Moths
- Abstract
Plants are often attacked by multiple insect herbivores. How plants deal with an increasing richness of attackers from a single or multiple feeding guilds is poorly understood. We subjected black mustard (Brassica nigra) plants to 51 treatments representing attack by an increasing species richness (one, two or four species) of either phloem feeders, leaf chewers, or a mix of both feeding guilds when keeping total density of attackers constant and studied how this affects plant resistance to subsequent attack by caterpillars of the diamondback moth (Plutella xylostella). Increased richness in phloem-feeding attackers compromised resistance to P. xylostella. By contrast, leaf chewers induced a stronger resistance to subsequent attack by caterpillars of P. xylostella while species richness did not play a significant role for chewing herbivore induced responses. Attack by a mix of herbivores from different feeding guilds resulted in plant resistance similar to resistance levels of plants that were not previously exposed to herbivory. We conclude that B. nigra plants channel their defence responses stronger towards a feeding-guild specific response when under multi-species attack by herbivores of the same feeding guild, but integrate responses when simultaneously confronted with a mix of herbivores from different feeding guilds., (© 2021 The Authors New Phytologist © 2021 New Phytologist Foundation.)
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- 2021
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45. Female emancipation in a male dominant, sexually dimorphic primate under natural conditions.
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Izar P, Fernández-Bolaños M, Seex L, Gort G, Suscke P, Tokuda M, Mendonça-Furtado O, Verderane MP, and Hemelrijk CK
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- Aggression, Animals, Female, Male, Dominance-Subordination, Sapajus physiology, Sexual Behavior, Animal
- Abstract
In most group-living animals, a dominance hierarchy reduces the costs of competition for limited resources. Dominance ranks may reflect prior attributes, such as body size, related to fighting ability or reflect the history of self-reinforcing effects of winning and losing a conflict (the winner-loser effect), or both. As to prior attributes, in sexually dimorphic species, where males are larger than females, males are assumed to be dominant over females. As to the winner-loser effect, the computational model DomWorld has shown that despite the female's lower initial fighting ability, females achieve some degree of dominance of females over males. In the model, this degree of female dominance increases with the proportion of males in a group. This increase was supposed to emerge from the higher fraction of fights of males among themselves. These correlations were confirmed in despotic macaques, vervet monkeys, and in humans. Here, we first investigate this hypothesis in DomWorld and next in long-term data of 9,300 observation hours on six wild groups of robust capuchin monkeys (Sapajus libidinosus; S. nigritus, and S. xanthosternos) in three Brazilian sites. We test whether both the proportion of males and degree of female dominance over males are indeed associated with a higher relative frequency of aggression among males and a higher relative frequency of aggression of females to males. We confirm these correlations in DomWorld. Next, we confirm in empirical data of capuchin monkeys that with the proportion of males in the group there is indeed an increase in female dominance over males, and in the relative frequency of both male-male aggression and aggression of females to males and that the female dominance index is significantly positively associated with male male aggression. Our results reveal that adult sex ratio influences the power relation between the sexes beyond predictions from socioecological models., Competing Interests: The authors have declared that no competing interests exist.
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- 2021
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46. Seasonal patterns and spatial variation of Borrelia burgdorferi (sensu lato) infections in Ixodes ricinus in the Netherlands.
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Hartemink N, van Vliet AJH, Gort G, Gassner F, Jacobs F, Fonville M, Takken W, and Sprong H
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- Animals, Borrelia classification, Borrelia genetics, Borrelia isolation & purification, Borrelia burgdorferi classification, Borrelia burgdorferi genetics, Borrelia burgdorferi isolation & purification, Ixodes growth & development, Netherlands, Nymph growth & development, Nymph microbiology, Seasons, Borrelia burgdorferi physiology, Ixodes microbiology
- Abstract
Background: The incidence of Lyme borreliosis varies over time and space through as yet incompletely understood mechanisms. In Europe, Lyme borreliosis is caused by infection with a Borrelia burgdorferi (s.l.) genospecies, which is primarily transmitted by a bite of Ixodes ricinus nymphs. The aim of this study was to investigate the spatial and temporal variation in nymphal infection prevalence of B. burgdorferi (s.l.) (NIP), density of questing nymphs (DON) and the resulting density of infected nymphs (DIN)., Methods: We investigated the infection rates in I. ricinus nymphs that were collected monthly between 2009 and 2016 in 12 locations in the Netherlands. Using generalized linear mixed models, we explored how the NIP, DON and DIN varied during the seasons, between years and between locations. We also determined the genospecies of the Borrelia infections and investigated whether the genospecies composition differed between locations., Results: The overall NIP was 14.7%. A seasonal pattern in infection prevalence was observed, with higher estimated prevalences in the summer than in the spring and autumn. This, combined with higher nymphal densities in summer, resulted in a pronounced summer peak in the estimated DIN. Over the 7.5-year study period, a significant decrease in infection prevalence was found, as well as a significant increase in nymphal density. These two effects appear to cancel each other out; the density of infected nymphs, which is the product of NIP × DON, showed no significant trend over years. Mean infection prevalence (NIP, averaged over all years and all months) varied considerably between locations, ranging from 5 to 26%. Borrelia genospecies composition differed between locations: in some locations almost all infections consisted of B. afzelii, whereas other locations had more diverse genospecies compositions., Conclusion: In the Netherlands, the summer peak in DIN is a result of peaks in both NIP and DON. No significant trend in DIN was observed over the years of the study, and variations in DIN between locations were mostly a result of the variation in DON. There were considerable differences in acarological risk between areas in terms of infection prevalence and densities of ticks as well as in Borrelia genospecies composition.
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- 2021
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47. Characterization of the Habitat- and Season-Independent Increase in Fungal Biomass Induced by the Invasive Giant Goldenrod and Its Impact on the Fungivorous Nematode Community.
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Harkes P, van Heumen LJM, van den Elsen SJJ, Mooijman PJW, Vervoort MTW, Gort G, Holterman MHM, van Steenbrugge JJM, Quist CW, and Helder J
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Outside its native range, the invasive plant species giant goldenrod ( Solidago gigantea ) has been shown to increase belowground fungal biomass. This non-obvious effect is poorly characterized; we don't know whether it is plant developmental stage-dependent, which fractions of the fungal community are affected, and whether it is reflected in the next trophic level. To address these questions, fungal assemblages in soil samples collected from invaded and uninvaded plots in two soil types were compared. Although using ergosterol as a marker for fungal biomass demonstrated a significant increase in fungal biomass, specific quantitative PCR (qPCR) assays did not point at a quantitative shift. MiSeq-based characterization of the belowground effects of giant goldenrod revealed a local increase of mainly Cladosporiaceae and Glomeraceae. This asymmetric boost in the fungal community was reflected in a specific shift in the fungivorous nematode community. Our findings provide insight into the potential impact of invasive plants on local fungal communities.
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- 2021
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48. Impact of plastic mulch film debris on soil physicochemical and hydrological properties.
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Qi Y, Beriot N, Gort G, Huerta Lwanga E, Gooren H, Yang X, and Geissen V
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- Agriculture, Ecosystem, Hydrology, Plastics, Soil, Soil Pollutants
- Abstract
The plastic mulch films used in agriculture are considered to be a major source of the plastic residues found in soil. Mulching with low-density polyethylene (LDPE) is widely practiced and the resulting macro- and microscopic plastic residues in agricultural soil have aroused concerns for years. Over the past decades, a variety of biodegradable (Bio) plastics have been developed in the hope of reducing plastic contamination of the terrestrial ecosystem. However, the impact of these Bio plastics in agroecosystems have not been sufficiently studied. Therefore, we investigated the impact of macro (around 5 mm) and micro (<1 mm) sized plastic debris from LDPE and one type of starch-based Bio mulch film on soil physicochemical and hydrological properties. We used environmentally relevant concentrations of plastics, ranging from 0 to 2% (w/w), identified by field studies and literature review. We studied the effects of the plastic residue on a sandy soil for one month in a laboratory experiment. The bulk density, porosity, saturated hydraulic conductivity, field capacity and soil water repellency were altered significantly in the presence of the four kinds of plastic debris, while pH, electrical conductivity and aggregate stability were not substantially affected. Overall, our research provides clear experimental evidence that microplastics affect soil properties. The type, size and content of plastic debris as well as the interactions between these three factors played complex roles in the variations of the measured soil parameters. Living in a plastic era, it is crucial to conduct further interdisciplinary studies in order to have a comprehensive understanding of plastic debris in soil and agroecosystems., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2020
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49. Corrigendum: Dynamics of Intersexual Dominance and Adult Sex- Ratio in Wild Vervet Monkeys.
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Hemelrijk CK, Wubs M, Gort G, Botting J, and van de Waal E
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[This corrects the article DOI: 10.3389/fpsyg.2020.00839.]., (Copyright © 2020 Hemelrijk, Wubs, Gort, Botting and van de Waal.)
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- 2020
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50. Efficacy of Management and Monitoring Methods to Prevent Post-Harvest Losses Caused by Rodents.
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Krijger IM, Gort G, Belmain SR, Groot Koerkamp PWG, Shafali RB, and Meerburg BG
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The presence of pest rodents around food production and storage sites is one of many underlying problems contributing to food contamination and loss, particularly influencing food and nutrition security in low-income countries. By reducing both pre- and post-harvest losses by rodents, millions of food-insecure people would benefit. As there are limited quantitative data on post-harvest rice losses due to rodents, our objectives were to assess stored rice losses in local households from eight rural communities and two rice milling factories in Bangladesh and to monitor the effect of different rodent control strategies to limit potential losses. Four treatments were applied in 2016 and 2017, (i) untreated control, (ii) use of domestic cats, (iii) use of rodenticides, (iv) use of snap-traps. In total, over a two-year period, 210 rodents were captured from inside people's homes, with Rattus rattus trapped most often ( n = 91), followed by Mus musculus ( n = 75) and Bandicota bengalensis ( n = 26). In the milling stations, 68 rodents were trapped, of which 21 were M. musculus , 19 R. rattus , 17 B. bengalensis , 8 Rattus exulans , and 3 Mus terricolor . In 2016, losses from standardised baskets of rice within households were between 13.6% and 16.7%. In 2017, the losses were lower, ranging from 0.6% to 2.2%. Daily rodent removal by trapping proved to be most effective to diminish stored produce loss. The effectiveness of domestic cats was limited.
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- 2020
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