572 research outputs found
Supplemental Material - Practice of Supporting Family Caregivers of Patients with Life-Threatening Diseases: A Two-phase Study Among Healthcare Professionals
No full textSupplemental Material for Practice of Supporting Family Caregivers of Patients with Life-Threatening Diseases: A Two-phase Study Among Healthcare Professionals by Hinke E. Hoffstädt, MSc, Jannie A. Boogaard, PhD, Marcella C. Tam, MSc, Leti van Bodegom-Vos, PhD, Arianne Stoppelenburg, PhD, Iris D. Hartog, PhD, Yvette M. van der Linden, MD, PhD, and Jenny T. van der Steen, PhD, FGSA in American Journal of Hospice and Palliative Medicine®</p
Understanding the impact of main cell wall polysaccharides on the decomposition of ectomycorrhizal fungal necromass
No full textThe extramatrical mycelium of ectomycorrhizal fungi (EMF) is an important source of soil carbon and nitrogen. While the importance of recalcitrant compounds in the fungal cell wall has been explored earlier, the contribution of highly abundant but labile components, like glucans, and the role of their temporal dynamics during decomposition remains unknown. For the first time, we examined how the concentration of three main fungal cell wall components (chitin, melanin, glucans) in EMF necromass are related to necromass decomposition, over a period of 6 weeks. Although the initial concentrations of the three components were not good predictors of necromass loss, we found species-specific trends of chitin and glucans loss over time. The chitin concentration during decomposition was tightly linked to the weekly necromass degradation, with trends of chitin loss being dissimilar across fungal species. Chitin concentration was positively correlated with the mass loss in the first week, but in the remaining 5 weeks, it was found to be weakly negatively correlated with mass loss. The similarity in susceptibility to the decomposition of glucans and chitin likely compensates for the impacts of interspecific differences in their initial concentration, leading to overall similar decomposition patterns. Alternatively, other, non-measured, components (e.g., glycoproteins, N content) may contribute to explaining similar decomposition patterns. Our results indicate that ectomycorrhizal necromass decomposition processes differ from those of plant litter decomposition with, unlike in plants, differences in initial concentrations of major structural carbohydrates (e.g., glucans) being unrelated to differences in decomposition rates. These findings indicate that the decomposition of fungal material cannot be inferred from assumptions based on data provided by studies of plant decomposition.The Netherlands Organization for Scientific research, Grant/Award Number: 016.161.31
Upscaling methane emissions from rice paddies: problems and possibilities.
No full textGlobal methane emission estimates depend highly on the models, techniques, and databases used. Since emissions cannot be measured directly at large scales, it is impossible to judge which estimate is more realistic. In this paper, different aspects of uncertainty in upscaling methane emissions from rice paddies are discussed. These aspects are visualized by a case study on the spatial upscaling of methane emissions from the island of Java, Indonesia. The first aspect concerns process information. An approach to incorporate this information in a simplified but process-based way in predictive models is discussed. Sources of uncertainty include the methane emissions measurements, processes quantification, process simplification, and the use of data transfer functions. Data availability of input parameters, the second aspect, is uncertain because of differences between different data sources, the use of data sources for purposes not originally planned for, and the scale at which data are available. Data interpolation in combination with nonlinear model responses introduces scaling errors, the third aspect. Data accuracy introduced the highest uncertainties in emission estimates but is rarely accounted for in the estimation of global emissions
Genetic variation in pentraxin (PTX) 3 gene associates with PTX3 production and fertility in women
No full textPentraxin 3 (PTX3) plays an important role in innate immune responses and in female fertility, as discovered with studies in mice. However, the role of PTX3 in human fertility is unknown. Here, we report on a population-based study from a rural area of Upper East Ghana (n = 4346). We studied the association between the number of children given birth by women during their lifetime and ex vivo, lipopolysaccharide (LPS)-induced PTX3 production (n = 362). In addition, we studied the association of genetic variation in the PTX3 gene with PTX3 production (n = 617) and with female fertility (n = 1999). We found that ex vivo LPS-induced PTX3 production was associated with fertility (P = 0.040). Furthermore, we identified genetic variants in the PTX3 gene that influence PTX3 production, and also fertility. The strongest associations were observed for the rs6788044 single-nucleotide polymorphism (SNP). We found that carriers of this SNP had higher PTX3 production capacity (P = 0.003) and higher fertility (P = 0.043). The results reported here provide the first evidence, based on protein production and analysis of polymorphisms, that the long pentraxin PTX3 plays a role in female fertility in humans
N deposition and elevated CO2 on methane emissions: Differential responses of indirect effects compared to direct effects through litter chemistry feedbacks.
No full textIncreases in atmospheric CO2 concentration and N deposition are expected to affect methane (CH4) production in soils and emission to the atmosphere, directly through increased plant litter production and indirectly through changes in substrate quality. We examined how CH4 emission responded to changes in litter quality under increased N and CO2, beyond differences in CH4 resulting from changes in litter production. We used senesced leaves from 13C-labeled plants of Molinia caerulea grown at elevated and ambient CO2 and affected by N fertilization to carry out two experiments: a laboratory litter incubation and a pot experiment. N fertilization increased N and decreased C concentrations in litter whereas elevated CO2 decreased litter quality as reflected in litter C and N concentrations and in the composition of lignin and saturated fatty acids within the litter. In contrast to our expectations, CH4 production in the laboratory incubation decreased when using litter from N-fertilized plants as substrate, whereas litter from elevated CO2 had no effect, compared to controls without N and at ambient CO2. Owing to high within-treatment variability in CH4 emissions, none of the treatment effects were reflected in the pot experiment. C mineralization rates were not affected by any of the treatments. The decrease in CH4 emissions due to indirect effects of N availability through litter quality changes (described here for the first time) contrast direct effects of N fertilization on CH4 production. The complex interaction of direct effects with indirect effects of increased N on litter quality may potentially result in a net decrease in CH4 emissions from wetlands in the long term.Fil: Pancotto, Veronica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Bodegom, P. M. van. University Of Amsterdam; Países BajosFil: Hal, J. van. University Of Amsterdam; Países BajosFil: Logtestijn, R. S. P. van. University Of Amsterdam; Países BajosFil: Blokker, P.. University Of Amsterdam; Países BajosFil: Toet, S.. University Of Amsterdam; Países Bajos. University Of York; Reino UnidoFil: Aerts, R.. University Of Amsterdam; Países Bajo
Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger observatory with zenith angles up to 80 degrees
No full textK. B. Barber, J. A. Bellido, S. G. Blaess, R.W. Clay, M. J. Cooper, B. R. Dawson, T. D. Grubb, T. A. Harrison, G. C. Hill, M. Malacari, P. H. Nguyen, S. J. Saffi, J. Sorokin, P. Van Bodegom are members of the Pierre Auger CollaborationWe present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60° and 80°. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in the 98E > 8 EeV energy bin, with an amplitude for the first harmonic in right ascension r1α = (4.4 ± 1.0) × 10-2, that has a chance probability P (≥1α) = 6.4 × 10-5, reinforcing the hint previously reported with vertical events alone.A. Aab ... K. B. Barber ... J. A. Bellido ... S. G. Blaess ... R.W. Clay ... M. J. Cooper ... B. R. Dawson ... T. D. Grubb ... T. A. Harrison ... G. C. Hill ... M. Malacari ... P. H. Nguyen ... S. J. Saffi ... J. Sorokin ... P. Van Bodegom et al. (Pierre Auger Collaboration
Partitioning the impact of environmental drivers and species interactions in dynamic aquatic communities
No full text© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Musters, C. J. M., Ieromina, O., Barmentlo, S. H., Hunting, E. R., Schrama, M., Cieraad, E., Vijver, M. G., & van Bodegom, P. M. Partitioning the impact of environmental drivers and species interactions in dynamic aquatic communities. Ecosphere, 10(11), (2019): e02910, doi:10.1002/ecs2.2910.Temperate aquatic communities are highly diverse and seasonally variable, due to internal biotic processes and environmental drivers, including human‐induced stressors. The impact of drivers on species abundance is supposed to differ fundamentally depending on whether populations are experiencing limitations, which may shift over the season. However, an integrated understanding of how drivers structure communities seasonally is currently lacking. In order to partition the effect of drivers, we used random forests to quantify interactions between all taxa and environmental factors using macrofaunal data from 18 agricultural ditches sampled over two years. We found that, over the agricultural season, taxon abundance became increasingly better predicted by the abundances of co‐occurring taxa and nutrients compared to other abiotic factors, including pesticides. Our approach provides fundamental insights in community dynamics and highlights the need to consider changes in species interactions to understand the effects of anthropogenic stressors.The authors are grateful to B. Schaub of Water Board Rijnland for his help, E. Gertenaar for assistance in the fieldwork, M. Wouterse for DOC measurements, and B. Koese for help with taxonomic identification of macrofaunal samples. CM designed the study, did the statistical modeling and analyses, and wrote the draft paper; OI did field sampling and taxonomic identification and constructed the datasets; OI and HB structured the data; EH, MS, ES, MV, and PvB contributed to the study design and the conceptual improvement of the manuscript; all authors substantially revised the subsequent drafts
Fungal communities are passengers in community development of dune ecosystems, while bacteria are not
No full textAn increasing number of studies of above-belowground interactions provide a fundamental basis for our understanding of the coexistence between plant and soil communities. However, we lack empirical evidence to understand the directionality of drivers of plant and soil communities under natural conditions: 'Are soil microorganisms driving plant community functioning or do they adapt to the plant community?' In a field experiment in an early successional dune ecosystem, we manipulated soil communities by adding living (i.e., natural microbial communities) and sterile soil inocula, originating from natural ecosystems, and examined the annual responses of soil and plant communities. The experimental manipulations had a persistent effect on the soil microbial community with divergent impacts for living and sterile soil inocula. The plant community was also affected by soil inoculation, but there was no difference between the impacts of living and sterile inocula. We also observed an increasing convergence of plant and soil microbial composition over time. Our results show that alterations in soil abiotic and biotic conditions have long-term effects on the composition of both plant and soil microbial communities. Importantly, our study provides direct evidence that soil microorganisms are not "drivers" of plant community dynamics. We found that soil fungi and bacteria manifest different community assemblies in response to treatments. Soil fungi act as "passengers," that is, soil microorganisms reflect plant community dynamics but do not alter it, whereas soil bacteria are neither "drivers" nor "passengers" of plant community dynamics in early successional ecosystems. These results are critical for understanding the community assembly of plant and soil microbial communities under natural conditions and are directly relevant for ecosystem management and restoration.Environmental BiologyPlant science
Global patterns of vascular plant alpha diversity
No full textSabatini FM, Jiménez-Alfaro B, Jandt U, Chytrý M, Field R, Kessler M, Lenoir J, Schrodt F, Wiser SK, Arfin Khan MAS, Attorre F, Cayuela L, De Sanctis M, Dengler J, Haider S, Hatim MZ, Indreica A, Jansen F, Pauchard A, Peet RK, Petřík P, Pillar VD, Sandel B, Schmidt M, Tang Z, van Bodegom P, Vassilev K, Violle C, Alvarez-Davila E, Davidar P, Dolezal J, Hérault B, Galán-de-Mera A, Jiménez J, Kambach S, Kepfer-Rojas S, Kreft H, Lezama F, Linares-Palomino R, Monteagudo Mendoza A, N'Dja JK, Phillips OL, Rivas-Torres G, Sklenář P, Speziale K, Strohbach BJ, Vásquez Martínez R, Wang HF, Wesche K, Bruelheide
Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above 10(17.8) eV
No full textK.B. Barber, J.A. Bellido, S. Blaess, R.W. Clay, M.J. Cooper, B.R. Dawson, T.D. Grubb, T.A. Harrison, G. C. Hill, M. Malacari, P. Nguyen, S.J. Saffi, J. Sorokin, P. van Bodegom are members of The Pierre Auger CollaborationWe report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 1017.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is described in detail as well as the experimental cross-checks and systematic uncertainties. Furthermore, we discuss the detector acceptance and the resolution of the Xmax measurement and provide parametrizations thereof as a function of energy. The energy dependence of the mean and standard deviation of the Xmax distributions are compared to air-shower simulations for different nuclear primaries and interpreted in terms of the mean and variance of the logarithmic mass distribution at the top of the atmosphere.A. Aab ... K.B. Barber ... J.A. Bellido ... S. Blaess ... R.W. Clay ... M.J. Cooper ... B.R. Dawson ... T.D. Grubb ... T.A. Harrison ... G. C. Hill ... M. Malacari ... P. Nguyen ... S.J. Saffi ... J. Sorokin ... P. van Bodegom ... et al. ... (Pierre Auger Collaboration
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