Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

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

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

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

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

    We have a manual that explains all the features 

Records 1 - 20 / 43

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Rozendaal
Check title to add to marked list
Lumpy skin disease: de volgende nieuwkomer? : Nodulaire dermatose of "Knopvelsiekte"
Wuijckhuise, L. van; Rozendaal, Harry ; Schouten, M.G.C. ; Rijn, P.A. van - \ 2017
Tijdschrift voor Diergeneeskunde 142 (2017)5. - ISSN 0040-7453
Predicting the abundance of forest types across the eastern United States through inverse modelling of tree demography
Vanderwel, Mark C. ; Rozendaal, Danaë M.A. ; Evans, Margaret E.K. - \ 2017
Ecological Applications 27 (2017)7. - ISSN 1051-0761 - p. 2128 - 2141.
CAIN - demography - forest dynamics - global change - inverse modelling - range modelling - species distribution

Global environmental change is expected to induce widespread changes in the geographic distribution and biomass of forest communities. Impacts have been projected from both empirical (statistical) and mechanistic (physiology-based) modelling approaches, but there remains an important gap in accurately predicting abundance across species' ranges from spatial variation in individual-level demographic processes. We address this issue by using a cohort-based forest dynamics model (CAIN) to predict spatial variation in the abundance of six plant functional types (PFTs) across the eastern United States. The model simulates tree-level growth, mortality, and recruitment, which we parameterized from data on both individual-level demographic rates and population-level abundance using Bayesian inverse modelling. Across a set of 1 grid cells, we calibrated local growth, mortality, and recruitment rates for each PFT to obtain a close match between predicted age-specific PFT basal area in forest stands and that observed in 46,603 Forest Inventory and Analysis plots. The resulting models produced a strong fit to PFT basal area across the region (R2 = 0.66-0.87), captured successional changes in PFT composition with stand age, and predicted the overall stem diameter distribution well. The mortality rates needed to accurately predict basal area were consistently higher than observed mortality, possibly because sampling effects led to biased individual-level mortality estimates across spatially heterogeneous plots. Growth and recruitment rates did not show consistent directional changes from observed values. Relative basal area was most strongly influenced by recruitment processes, but the effects of growth and mortality tended to increase as stands matured. Our study illustrates how both top-down (population-level) and bottom-up (individual-level) data can be combined to predict variation in abundance from size, environmental, and competitive effects on tree demography. Evidence for how demographic processes influence variation in abundance, as provided by our model, can help in understanding how these forests may respond to future environmental change.

De grazers op de bodem
Smaal, Aad - \ 2017
Demographic Drivers of Aboveground Biomass Dynamics During Secondary Succession in Neotropical Dry and Wet Forests
Rozendaal, Danaë M.A. ; Chazdon, Robin L. ; Arreola-Villa, Felipe ; Balvanera, Patricia ; Bentos, Tony V. ; Dupuy, Juan M. ; Hernández-Stefanoni, J.L. ; Jakovac, Catarina C. ; Lebrija-Trejos, Edwin E. ; Lohbeck, Madelon ; Martínez-Ramos, Miguel ; Massoca, Paulo E.S. ; Meave, Jorge A. ; Mesquita, Rita C.G. ; Mora, Francisco ; Pérez-García, Eduardo A. ; Romero-Pérez, I.E. ; Saenz-Pedroza, Irving ; Breugel, Michiel van; Williamson, G.B. ; Bongers, Frans - \ 2017
Ecosystems 20 (2017)2. - ISSN 1432-9840 - p. 340 - 353.
Biomass accumulation - carbon sink - forest dynamics - Neotropics - second-growth tropical forest - species’ dominance - tree demography

The magnitude of the carbon sink in second-growth forests is expected to vary with successional biomass dynamics resulting from tree growth, recruitment, and mortality, and with the effects of climate on these dynamics. We compare aboveground biomass dynamics of dry and wet Neotropical forests, based on monitoring data gathered over 3–16 years in forests covering the first 25 years of succession. We estimated standing biomass, annual biomass change, and contributions of tree growth, recruitment, and mortality. We also evaluated tree species’ contributions to biomass dynamics. Absolute rates of biomass change were lower in dry forests, 2.3 and 1.9 Mg ha−1 y−1, after 5–15 and 15–25 years after abandonment, respectively, than in wet forests, with 4.7 and 6.1 Mg ha−1 y−1, in the same age classes. Biomass change was largely driven by tree growth, accounting for at least 48% of biomass change across forest types and age classes. Mortality also contributed strongly to biomass change in wet forests of 5–15 years, whereas its contribution became important later in succession in dry forests. Biomass dynamics tended to be dominated by fewer species in early-successional dry than wet forests, but dominance was strong in both forest types. Overall, our results indicate that biomass dynamics during succession are faster in Neotropical wet than dry forests, with high tree mortality earlier in succession in the wet forests. Long-term monitoring of second-growth tropical forest plots is crucial for improving estimates of annual biomass change, and for enhancing understanding of the underlying mechanisms and demographic drivers.

Biomass resilience of Neotropical secondary forests
Poorter, L. ; Bongers, F. ; Aide, T.M. ; Almeyda Zambrano, A.M. ; Balvanera, P. ; Becknell, J.M. ; Boukill, V. ; Brancalion, P.H.S. ; Jakovac, A.C. ; Braga Junqueira, A. ; Lohbeck, M.W.M. ; Pena Claros, M. ; Rozendaal, Danae - \ 2016
biomass - tropical forest - secondary succession - neotropics - rainfall - land use - soil fertility - carbon - mitigation
Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle1. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use2, 3, 4. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha−1), corresponding to a net carbon uptake of 3.05 Mg C ha−1 yr−1, 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha−1) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.
Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics
Chazdon, R.L. ; Broadbent, E.N. ; Rozendaal, Danae ; Bongers, F. ; Jakovac, A.C. ; Braga Junqueira, A. ; Lohbeck, M.W.M. ; Pena Claros, M. ; Poorter, L. - \ 2016
Science Advances 2 (2016)5. - ISSN 2375-2548 - 10 p.
Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km2 of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services.
Biomass resilience of Neotropical secondary forests
Poorter, Lourens ; Bongers, Frans ; Aide, T.M. ; Almeyda Zambrano, A.M. ; Balvanera, Patricia ; Jakovac, C.C. ; Braga Junqueira, A. ; Lohbeck, Madelon ; Penã-Claros, Marielos ; Rozendaal, D.M.A. - \ 2016
Nature 530 (2016)7589. - ISSN 0028-0836 - p. 211 - 214.

Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha-1), corresponding to a net carbon uptake of 3.05 Mg C ha 1 yr-1, 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha-1) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.

Long-term growth patterns of juvenile trees from a Bolivian tropical moist forest : Shifting investments in diameter growth and height growth
Rozendaal, D.M.A. ; During, H.J. ; Sterck, F.J. ; Asscheman, Daan ; Wiegeraad, Jeroen ; Zuidema, P.A. - \ 2015
Journal of Tropical Ecology 31 (2015)6. - ISSN 0266-4674 - p. 519 - 529.
allocation - allometry - Bolivia - diameter growth - height growth - juvenile trees - tree rings - tropical moist forest

Juvenile tropical trees grow from the shaded understorey to the high-light conditions of the canopy, but actual height growth trajectories towards the canopy remain unknown. Although height growth is the determining factor for reaching the canopy, investment in diameter growth is needed to sustain mechanical stability. We quantified variation in long-term juvenile tree growth patterns in diameter and height within three Bolivian moist forest species, and evaluated whether diameter growth and height growth were related. We reconstructed lifetime growth in diameter and height for 21-27 juvenile trees per species by measuring tree rings at various heights in the stem. Growth in diameter and height strongly varied among and within tree species. The light-demanding species Cedrelinga cateniformis needed just 6-19 y to reach a height of 3 m, while the more shade-tolerant species Clarisia racemosa and Peltogyne cf. heterophylla needed 8-39 y and 13-43 y, respectively. Diameter growth and height growth were not, or just weakly, positively related, and trees of the same height displayed a wide range in stem diameter. Our results indicate that trees of all three species shifted investment in diameter growth and height growth over time, most likely in response to variation in light levels.

Positiebepaling van residuen van gewasbeschermingsmiddelen in de vrucht
Jong, P.F. de; Rozendaal, E. - \ 2011
fruitteelt - appels - residuen - gewasproductie - kwaliteitszorg - landbouwkundig onderzoek - methodologie - innovaties - fruit growing - apples - residues - crop production - quality management - agricultural research - methodology - innovations
Doelstelling van het onderzoek is doorde verbeterde kennis van waar residuen van gewasbeschermingsmiddelen zich bevinden in de vrucht kan er gewerkt worden aan het verwijderen van deze residuen van de vrucht.
Gebiedsuitvoeringsprogramma groene diensten Gemeenten Aalten, Oost Gelre en Winterswijk
Rozendaal, W.J.B. ; Tol, M. van der; Korevaar, H. - \ 2011
Dronten : Aequator
Minder en anders bemesten : onderzoeksresultaat tuinbouw op klei. Rozendaal, courgette 2008
Timmermans, B.G.H. ; Burgt, G.J.H.M. van der; Berg, C. ter; Staps, S. - \ 2010
[Driebergen] : Louis Bolk Instituut (Publicatie / Louis Bolk Instituut nr. 2010-025 LbP) - 32 p.
bemesting - biologische landbouw - courgettes - vollegrondsgroenten - vollegrondsteelt - cultuurmethoden - groenbemesters - stikstof - veldproeven - fertilizer application - organic farming - marrows - field vegetables - outdoor cropping - cultural methods - green manures - nitrogen - field tests
Op een kleigrond werd in samenwerking met een tuinbouwer een systeem ontwikkeld voor de teelt van courgette na gras/klaver voorvrucht. Het betreft de teelt op bedden met een aangepaste bemesting. De resultaten laten zien dat het systeem voor courgette nog niet bedrijfsklaar is. De praktijkbehandeling had in eerste instantie grotere planten en een hogere opbrengst. Dit had te maken met meer beschikbaar N in een wat vroeger stadium van het groeiseizoen. In een later stadium had vooral de behandeling van courgette na gras/klaver op gespitte en gefreesde bedden in de gras/klaver een hogere opbrengst dan die van de praktijkbehandeling. Hierdoor was in totaal de opbrengst van de courgette praktijk vergelijkbaar met die van de courgette na gras/klaver op gespitte en gefreesde bedden. We concluderen dat de courgetteteelt verder geoptimaliseerd kan worden wat betreft timing van de beschikbaar komende stikstof.
Minder en anders bemesten : onderzoeksresultaat tuinbouw op klei, Rozendaal, kool 2010
Timmermans, B.G.H. ; Burgt, G.J.H.M. van der - \ 2010
[Driebergen] : Louis Bolk Instituut (Publicatie / Louis Bolk Instituut nr. 2010-027 LbP) - 30 p.
bemesting - biologische landbouw - koolsoorten - stikstof - cultuurmethoden - vollegrondsteelt - vollegrondsgroenten - lichte-matig zware kleigronden - veldproeven - fertilizer application - organic farming - cabbages - nitrogen - cultural methods - outdoor cropping - field vegetables - clay loam soils - field tests
De onderzoeksvraag was om een stap te maken naar de ontwikkeling van een teeltsysteem voor witte kool, geteeld op bedden gefreesd in grasklaver, met aangepaste bemesting. De behandelingen betroffen voorvrucht grasklaver, voorvrucht courgette (bedden die al een jaar oud waren), beiden met drie N-niveaus. De grasklaver stroken naast de kool werden tijdens de teelt gemaaid en ingezet als maaimeststof. Als vergelijking is er een praktijkbehandeling meegenomen, met voorvrucht grasklaver die ondergeploegd is met varkensdrijfmest. De resultaten laten zien dat het systeem voor witte kool nog niet bedrijfsklaar is. De praktijkbehandeling had een veel hogere opbrengst dan de witte kool op de bedden. Dit had te maken met een lager niveau van beschikbaar stikstof in de proef, maar ook met een systeemverschil: de combinatie van frezen in plaats van ploegen, concurrentie van de grasklaver met de randrijen van de witte kool op de bedden, en minder koolplanten per hectare. Geconcludeerd wordt dat de teelt geoptimaliseerd dient te worden met een hogere en andere bemesting en bredere bedden waarop de kool verbouwd wordt. Verder wordt geconcludeerd dat vers gemaaide grasklaver, gedurende de teelt ingezet als maaimeststof, weinig bijdraagt aan de stikstof beschikbaarheid.
Minder en anders bemesten : onderzoeksresultaten tuinbouw op klei. Rozendaal, courgette 2009
Timmermans, B. ; Burgt, G.J.H.M. van der; Berg, C. ter; Staps, S. - \ 2010
[Driebergen] : Louis Bolk Instituut (Publicatie / Louis Bolk Instituut nr. 2010-026 LbP) - 40 p.
bemesting - biologische landbouw - courgettes - vollegrondsgroenten - vollegrondsteelt - lichte-matig zware kleigronden - veldproeven - fertilizer application - organic farming - marrows - field vegetables - outdoor cropping - clay loam soils - field tests
In het kader van het project Minder en Anders Bemesten is op het bedrijf van Jan en Hans van Lierop een vervolgonderzoek uitgevoerd. In een veldexperiment in herhalingen is getracht de productie van courgette gelijkmatiger in het seizoen te verdelen door op twee peilers te steunen: een bescheiden bemesting om de productie in het begin van het seizoen te verhogen, en grasklaver als voorvrucht om de productie verderop in het seizoen te verhogen. De resultaten tonen dat deze aanpak werkt: met een relatief kleine bemesting is er geen sprake van een verlaagde opbrengst in de eerste helft van de productieperiode. Verder is de bodemstructuur verbeterd door de grasklaver en is de mestgift lager dan anders het geval zou zijn geweest.
Minder en anders bemesten 2009; Courgette met gras/klaver voorvrucht, tussen in bedden gefreesde gras/klaver bij Hans en Jan Rozendaal
Timmermans, B. ; Staps, J.J.M. ; Berg, C. ter; Bruinenberg, R. - \ 2009
Driebergen : Louis Bolk Instituut
Leaf size and leaf display of thirty-eight tropical tree species
Poorter, L. ; Rozendaal, D.M.A. - \ 2008
Oecologia 158 (2008)1. - ISSN 0029-8549 - p. 35 - 46.
light capture efficiency - rain-forest - shade-tolerance - corners rules - crown architecture - biomass investment - dependent changes - deciduous trees - woody-plants - carbon gain
Trees forage for light through optimal leaf display. Effective leaf display is determined by metamer traits (i.e., the internode, petiole, and corresponding leaf), and thus these traits strongly co-determine carbon gain and as a result competitive advantage in a light-limited environment. We examined 11 metamer traits of sun and shade trees of 38 coexisting moist forest tree species and determined the relative strengths of intra- and interspecific variation. Species-specific metamer traits were related to two variables that represent important life history variation; the regeneration light requirements and average leaf size of the species. Metamer traits varied strongly across species and, in contrast to our expectation, showed only modest changes in response to light. Intra- and interspecific responses to light were only congruent for a third of the traits evaluated. Four traits, amongst which leaf size, specific leaf area (SLA), and leaf area ratio at the metamer level (LAR) showed even opposite intra- and interspecific responses to light. Strikingly, these are classic traits that are thought to be of paramount importance for plant performance but that have completely different consequences within and across species. Sun trees of a given species had small leaves to reduce the heat load, but light-demanding species had large leaves compared to shade-tolerants, probably to outcompete their neighbors. Shade trees of a given species had a high SLA and LAR to capture more light in a light-limited environment, whereas shade-tolerant species have well-protected leaves with a low SLA compared to light-demanding species, probably to deter herbivores and enhance leaf lifespan. There was a leaf-size-mediated trade-off between biomechanical and hydraulic safety, and the efficiency with which species can space their leaves and forage for light. Unexpectedly, metamer traits were more closely linked to leaf size than to regeneration light requirements, probably because leaf-size-related biomechanical and vascular constraints limit the trait combinations that are physically possible. This suggests that the leaf size spectrum overrules more subtle variation caused by the leaf economics spectrum, and that leaf size represents a more important strategy axis than previously thought
Plasticity in leaf traits of 38 tropical tree species in response to light; relationships with light demand and adult stature.
Rozendaal, D.M.A. ; Hurtado, V.H. ; Poorter, L. - \ 2006
Functional Ecology 20 (2006)2. - ISSN 0269-8463 - p. 207 - 216.
rain-forest trees - photosynthetic acclimation - alocasia-macrorrhiza - relative importance - optical-properties - shade tolerance - nitrogen-use - plant - growth - allocation
1. The sun¿shade acclimation and plasticity of 16 functional leaf traits of 38 tropical tree species were studied in relation to their light demand, maximum adult stature and ontogenetic changes in crown exposure. 2. Species differed significantly in all leaf traits, which explained a large part of the observed variation (average R2 = 0·72). Light had a significant effect on 12 traits and species showed a similar proportional response to light, indicating that the species ranking in trait performance is largely maintained in different light environments. 3. Specific leaf area, leaf nutrient content and chlorophyll : nitrogen ratio showed the largest plasticity to irradiance. These traits are important for maximizing growth in different light conditions because they are closely linked to the photosynthetic capacity and carbon balance of the plant. 4. Plasticity is generally thought to be greatest for pioneer species that occupy early successional habitats with a large variation in irradiance. This hypothesis was rejected because short-lived pioneers showed the lowest plasticity to irradiance. 5. An alternative hypothesis states that plasticity is largest for tall species that experience large ontogenetic changes in irradiance during their life cycle. Yet plasticity was barely related to adult stature or ontogenetic changes in crown exposure. Short-lived pioneers that experience consistently high light levels did have low plasticity, but shade-tolerant species that experience consistently low light levels had high plasticity. 6. Tropical rainforest species show a large variation in plasticity. Plasticity is a compromise between many factors and constraints, and all of these may explain the observed patterns to some extent.
Effect of an enriched drink on cognitive function in frail elderly persons
Wouters-Wesseling, W. ; Wagenaar, L. ; Rozendaal, M. ; Deijen, J.B. ; Groot, C.P.G.M. de; Bindels, J.G. ; Staveren, W.A. van - \ 2005
Journals of Gerontology. Series A: Biological Sciences & Medical Sciences 60 (2005)2. - ISSN 1079-5006 - p. 265 - 270.
mini-mental-state - nutritional-status - methylmalonic acid - plasma homocysteine - dietary-intake - b-vitamins - supplementation - performance - population - impairment
Many elderly persons report that they have difficulties learning new things and remembering names, plans, and conversations. Because decreased cognitive function in elderly persons is potentially related to their poor nutritional status, provision of essential nutrients may improve cognitive function. The authors wanted to determine whether consumption of an enriched drink, including moderate doses of all essential micronutrients, improves cognitive function in frail elderly persons. Methods. Frail, white adults (n = 101) who were aged 65 years or older with a body mass index ¿25 kg/m 2 were selected for this randomized, double-blind, placebo-controlled trial. They received either an enriched drink or a placebo product for 6 months. Before and after the intervention, participants' cognitive function was assessed (word learning test [WLT], WLT delayed, category fluency [CF] for animals and professions, and recognition memory test for words [RMTW]) and blood biochemical analyses (vitamin B12, homocysteine) were performed. Results. Sixty-seven residents completed the study period. After 6 months, significant differences were noted in changes of the WLT (0.9 ± 0.3 vs-0.1 ± 0.3; p = .014) and CF professions (1.2 ± 0.7 vs -0.6 ± 0.5; p = .017) in the supplement group (n = 34) compared with the placebo group (n = 33). No significant differences were observed in WLT delayed, RMTW, and CF animals. The plasma vitamin B12 concentration increased (105 ± 50 vs 8 ± 16; p = .003) and the homocysteine concentration decreased (-6.3 ± 5.9 vs -0.3 ± 2.9; p = .000) in the supplement group compared with the placebo group. Conclusions. This study contributes to the evidence that nutritional supplementation may improve neuropsychological performance in frail elderly persons.
Avian influenza A virus (H7N7) associated with human conjunctivitis and a fatal case of acute respiratory distress syndrome.
Fouchier, R.A.M. ; Schneeberger, P.M. ; Rozendaal, F.W. ; Broekman, J.M. ; Kemink, S.A.G. ; Munnster, V. ; Kuiken, T. ; Rimmelzwaan, G.F. ; Schutten, M. ; Doornum, G.J.J. van; Koch, G. ; Bosman, A. ; Koopmans, M. ; Osterhaus, A.D.M.E. - \ 2004
Proceedings of the National Academy of Sciences of the United States of America 101 (2004)5. - ISSN 0027-8424 - p. 1356 - 1361.
h5n1 virus - hong-kong - hemagglutinin - infection - amplification - replication - diagnosis - emergence - sequence - assay
Highly pathogenic avian influenza A viruses of subtypes H5 and H7 are the causative agents of fowl plague in poultry. Influenza A viruses of subtype H5N1 also caused severe respiratory disease in humans in Hong Kong in 1997 and 2003, including at least seven fatal cases, posing a serious human pandemic threat. Between the end of February and the end of May 2003, a fowl plague outbreak occurred in The Netherlands. A highly pathogenic avian influenza A virus of subtype H7N7, closely related to low pathogenic virus isolates obtained from wild ducks, was isolated from chickens. The same virus was detected subsequently in 86 humans who handled affected poultry and in three of their family members. Of these 89 patients, 78 presented with conjunctivitis, 5 presented with conjunctivitis and influenza-like illness, 2 presented with influenza-like illness, and 4 did not fit the case definitions. Influenza-like illnesses were generally mild, but a fatal case of pneumonia in combination with acute respiratory distress syndrome occurred also. Most virus isolates obtained from humans, including probable secondary cases, had not accumulated significant mutations. However, the virus isolated from the fatal case displayed 14 amino acid substitutions, some of which may be associated with enhanced disease in this case. Because H7N7 viruses have caused disease in mammals, including horses, seals, and humans, on several occasions in the past, they may be unusual in their zoonotic potential and, thus, form a pandemic threat to humans
De Europese rivierkreeft (Astacus astacus) in 2002 : Inventarisaties in 2002
Niewold, F.J.J. - \ 2003
Wageningen : Centrum Ecosystemen - 11
aquatische ecologie - rivierkreeft - stilstaand water - inventarisaties - veluwe - gelderland - aquatic ecology - crayfish - standing water - inventories
In opdracht van het Waterschap Rijn en IJssel en mede gefinancierd door de Provincie Gelderland worden door Alterra de activiteiten in het kader van behoud en bescherming van de Europese rivierkreeft in de periode 2001-2003 mede voorbereid, begeleid, uitgevoerd en gerapporteerd. Dit rapport beschrijft de resultaten van de inventarisaties in 2002. Tijdens de vorige inventarisatie in het najaar van 2001 bleek dat de twee kolonies van de Europese rivierkreeft aslacus astacus in en langs de Rozendaalse Beek te Rozendaal en Velp als gevolg van een massale sterfte waren verdwenen. Er zijn sterke aanwijzingen dat hier de kreeftenpest heeft toegeslagen, maar de mogelijke bron kon niet worden achterhaald. In de enige nog resterende populatie in Nederland in een vijver op het Landgoed Warnsborn zijn tijdens een nachtelijke inventarisatie ronde 86 kreeften waargenomen.
Stadsranden, rood èn groen
Eijk, S. van; Rozendaal, W.J.B. - \ 2003
Topos : periodiek over landschapsarchitectuur, ruimtelijke planning en sociaal-ruimtelijke analyse 13 (2003)1. - ISSN 1572-302X - p. 42 - 45.
stadsrandgebieden - ruimtelijke ordening - landgebruik - stedelijke gebieden - nederland - urban hinterland - physical planning - land use - urban areas - netherlands
Op het raakvlak van stad en land bevindt zich een gebied waarin vele, zowel rode als groene processen een rol spelen. De vraag wordt gesteld, hoe de stadsrand vorm gegeven zou kunnen worden om ruimtelijke kwaliteit te waarborgen, conform vijfde nota ruimtelijke ordening
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.