235130 research outputs found
Sort by
Reverse genetics system for shuni virus, an emerging orthobunyavirus with zoonotic potential
Get PDFThe genus Orthobunyavirus (family Peribunyaviridae, order Bunyavirales) comprises over 170 named mosquito- and midge-borne viruses, several of which cause severe disease in animals or humans. Their three-segmented genomes enable reassortment with related viruses, which may result in novel viruses with altered host or tissue tropism and virulence. One such reassortant, Schmallenberg virus (SBV), emerged in north-western Europe in 2011. Shuni virus (SHUV) is an orthobunyavirus related to SBV that is associated with neurological disease in horses in southern Africa and recently caused an outbreak manifesting with neurological disease and birth defects among ruminants in Israel. The zoonotic potential of SHUV was recently underscored by its association with neurological disease in humans. We here report a reverse genetics system for SHUV and provide first evidence that the non-structural (NSs) protein of SHUV functions as an antagonist of host innate immune responses. We furthermore report the rescue of a reassortant containing the L and S segments of SBV and the M segment of SHUV. This novel reverse genetics system can now be used to study SHUV virulence and tropism, and to elucidate the molecular mechanisms that drive reassortment events.</p
Metagenomic-and cultivation-based exploration of anaerobic chloroform biotransformation in hypersaline sediments as natural source of chloromethanes
Get PDFChloroform (CF) is an environmental contaminant that can be naturally formed in various environments ranging from forest soils to salt lakes. Here we investigated CF removal potential in sediments obtained from hypersaline lakes in Western Australia. Reductive dechlorination of CF to dichloromethane (DCM) was observed in enrichment cultures derived from sediments of Lake Strawbridge, which has been reported as a natural source of CF. No CF removal was observed in abiotic control cultures without artificial electron donors, indicating biotic CF dechlorination in the enrichment cultures. Increasing vitamin B12 concentration from 0.04 to 4 µM in enrichment cultures enhanced CF removal and reduced DCM formation. In cultures amended with 4 µM vitamin B12 and13C labelled CF, formation of13CO2 was detected. Known organohalide-respiring bacteria and reductive dehalogenase genes were neither detected using quantitative PCR nor metagenomic analysis of the enrichment cultures. Rather, members of the order Clostridiales, known to co-metabolically transform CF to DCM and CO2, were detected. Accordingly, metagenome-assembled genomes of Clostridiales encoded enzymatic repertoires for the Wood-Ljungdahl pathway and cobalamin biosynthesis, which are known to be involved in fortuitous and nonspecific CF transformation. This study indicates that hypersaline lake microbiomes may act as a filter to reduce CF emission to the atmosphere.</p
Amino acid and energy requirements of growing-finishing pigs kept under low and high sanitary conditions
Get PDFThe present study was performed to evaluate the effects of dietary energy source (starch vs fat) and of increased levels of dietary energy and essential amino acids (EAA), related to the assumed increased EAA and energy requirements in immune stimulated pigs, on the growth performance of growing-finishing (GF) pigs under low sanitary conditions (LSC), in which the immune system of the pigs was activated, or under high sanitary conditions (HSC) resulting in a lower state of activation of the immune system. The trial was conducted with 408 male pigs (Tempo boar x (York x Dutch Landrace) sow) during the weaner, grower and finisher phase. Piglets were weaned at an age of four weeks and followed till delivery to the slaughterhouse. In a 2 × 2 × 2 factorial design, pigs were allocated to either high sanitary conditions (HSC) or low sanitary conditions (LSC). A contrast in sanitary conditions was generated by imposing to the pigs differences in strategy for vaccination against pathogens, cleaning and hygiene protocol, antibiotic treatment and deworming. During the growing and finishing period, pigs had ad libitum access to one of four experimental diets, a diet with starch as main energy source or a diet with fat and starch as main energy source, each diet having either basal energy and EAA concentrations (B diet) or increased concentrations in energy and EAA (I diet). The levels of supplementation of EAA and energy in the I diets compared to the B diets were based on a model that calculated the effects of low sanitary conditions on the EAA and energy requirements of pigs. At an age of nine weeks, pigs were moved to the rooms for GF pigs. The HSC GF pigs were fed a starter diet during the first five weeks, followed by a grower diet for four weeks and then a finisher diet till delivery to the slaughterhouse. The LSC GF pigs were fed a starter diet during six weeks, followed by a grower diet for four weeks and then a finisher diet till delivery to the slaughterhouse. In all pens, 8 or 9 GF pigs were housed
De biodiversiteitsmonitor voor beloning van boeren voor biodiversiteitsverbetering
No full textEen van de oplossingsrichtingen voor herstel van biodiversiteit op het boerenland is het belonen van bijdragen van boeren aan biodiversiteit. De Biodiversiteitsmonitor Melkveehouderij kan daarvoor een belangrijk instrument zijn, ook omdat het een centrale rol speelt in het Deltaplan biodiversiteitsherstel. De biodiversiteitsmonitor maakt de prestaties van boeren voor biodiversiteit inzichtelijk aan de hand van zeven kritische prestatie indicatoren (KPI’s). De indicatoren sturen integraal naar biodiversiteitsverbetering en kunnen mogelijk gebruikt worden om boeren te belonen voor hun prestaties. Maar bij welke waarden van de KPI’s is sprake van herstel van biodiversiteit? En bij welke waarden kunnen we spreken over een ecologisch optimum? Het Wereld Natuurfonds en Rabobank vroegen Wageningen Environmental Research en het Louis Bolk Instituut om drempel- en streefwaarden te bepalen voor de KPI’s
Corporate Responsibility for Human Rights in Assam Tea Plantations - A Business and Human Rights Approach
No full textThis paper explores how UK-based companies deal with their responsibility to respect the human rights of Assam (India) tea plantations workers. Using publicly available corporate reports and other documents, it investigates how companies approach, and communicate on, their potential human rights impacts. It highlights the gap between well-documented human rights issues on the ground and corporate reports on these issues. It aims to answer the following research question: in a context where the existence of human rights violations at the end of the supply chain is well-documented, how do companies reconcile their possible connection with those violations and the corporate responsibility to respect human rights under the United Nations Guiding Principles on Business and Human Rights? The paper reveals the weakness of the current CSR approach from the perspective of rights-holders. It supports a business and human rights approach, one that places the protection of human rights at its core
Convivial Greenstreets: A Concept for Climate-Responsive Urban Design
No full textThis paper presents a conceptual framework for using “convivial greenstreets” (CG) as a resource for climate adaptation. When applied consistently, CG can become an emerging green practice with a positive impact on urban adaptation to climate change: CG may provide localized climate amelioration in ways that support social engagement outdoors. However, as spontaneous phenomena, CG should neither become an academic nor an aesthetic prescriptive tool. How then can CG be used as an active resource for urban adaptation to climate change while avoiding these two potential pitfalls? To explore this question, we present the concept of CG and the ways it can be situated in theoretical urbanism and analogous urban morphologies. We profile the CG inventory corpus and conceptualization that has taken place to date and expand them through a climate-responsive urban design lens. We then discuss how CG and climate-responsive urban design can be brought together while preventing the academization and aestheticizing of the former. This discussion is illustrated with a group of visualizations. We conclude by submitting that climate-responsive urban design and extensive and robust CG practices can co-operate to promote more resilient communities and urban climates. Finally, the conceptual framework herein sets an agenda for future research
Climate-resilient horticulture for sustainable county development in Kenya
No full textClimate change presents one of the greatest challenges to the productivity and sustainable growth of the agricultural sector in Kenya due to extreme events such as droughts and floods as well as changes in temperature. Horticultural crops are particularly sensitive to climate change because of their high water demand and strict temperature requirements. Increased or decreased rainfall and increased temperature result in drought or flooding, lack of water for irrigation, and pests and diseases epidemic can affect the suitability of areas for growing horticultural crops. Understanding the impacts of climate for a given crop under specific conditions is key to supporting further development of the horticulture sector. While horticulture is a priority economic subsector in many counties, it is not known how the counties position themselves with regard to dealing with climate change threats in the sector. A review of the literature shows how climate change significantly affects the performance of horticultural crops across a variety of climatic zones and that counties need to be better prepared to address these effects. Horticulture covers myriad crops (including fruits and vegetables), which are affected by climate change in different ways. Seasonal patterns, both for temperature as well as (onset of) rainfall are changing. Temperature thresholds for specific crops are being exceeded, while some areas are now more favourable for growing certain crops where previously temperatures were too low. Suboptimal temperatures affect both the yield and quality of produce. The horticulture sector has also experienced incidences of pests, such as Tuta absoluta on tomato; climate change is a confounding factor to the spread and establishment of these pests. Agriculture which is highly affected by climate change is devolved to counties; as such, policies relevant to it are expected to be implemented at county level. An analysis of the County Integrated Development Plans showed that horticulture is a high-value subsector that plays a major role in generating revenue for county development. Most counties have prioritized horticulture and made substantial investments. Climate change is acknowledged as a threat to different sectors, but there is only scant analysis of the factors causing it, effects it will have and proposed responses to it. Farmers and crop officers from Kiambu and Kajiado counties are aware of climate change and its effects on horticulture. However, understanding of the relationship between cause and effect and of possible mitigating actions is weak. We observed that at all levels, in the field as well as at county level, preparedness for climate change is low and government support to the farmers is also limited. Due attention and informed decision-making based on, for example the Kenya Climate Atlas that is currently being developed, is required
Application of the Natural Capital Model to assess changes in ecosystem services from changes in green infrastructure in Amsterdam
No full textThis paper demonstrates the utility of local models for assessing ecosystem services to support urban planning. It does so by application of the NC-Model, a spatially-explicit set of models for assessing ecosystem services in the Netherlands, to assess changes in ecosystem services in the Municipality of Amsterdam given the implementation of strategies from the Green Quality Impulse. The Green Quality Impulse is a spatial plan that envisions the development of Amsterdam's green infrastructure by 2025 to support the needs of Amsterdam's growing population. The NC-Model was implemented to spatially quantify six ecosystem services within a ‘business-as-usual’ scenario (only residential and population expansion considered) and three scenarios that capture changes in green infrastructure from the implementation of strategies from the Green Quality Impulse. Incorporation of local knowledge and data enabled quantification of ecosystem services at a high spatial resolution and identification of key factors that influence ecosystem service delivery. Such an approach can support urban planners who wish to better-understand the mechanism by which green infrastructure generates value for urban dwellers, to develop scientifically-sound spatial strategies that optimize ecosystem service supply and use, and to further communicate this information to decision-makers, investors, and local inhabitants in an accessible manner.</p
Aanbevelingen voor directe kwantificering van broeikasgas-balansen van natte natuurgebieden : Technische adviesmemo
No full textEr is een groeiend belang om van alle typen landoppervlak de bijdrages aan de broeikasgasbalans te kwantificeren. Voor landelijke en internationale rapportage is het nodig om goed onderbouwde broeikasgas-kengetallen te produceren voor de diverse sectoren en landschapstypen. De broeikasgasbalans betreft opname en uitstoot van CO2 en CH4, en uitstoot van N2O. CO2 wordt in natuur opgenomen bij fotosynthese en groei van planten, en uitgestoten door dezelfde planten, maar ook door bodemorganismen, dieren en via chemische oxidatie van organische stof. In een ecosysteem waar de biomassa toeneemt, wordt over het algemeen netto CO2 vastgelegd, en omgekeerd is een degraderend systeem of een systeem waar de bodem is verstoord vaak een bron van CO2 naar de atmosfeer. Methaan wordt meestal uitgestoten in zuurstofloze, natte omgevingen (bv moerassen), en in mindere mate weer geoxideerd (dus opgenomen) waar de bodem zuurstofrijk is. N2O wordt vooral uitgestoten in (te) voedselrijke omgeving, en is voor natuurgebieden waarschijnlijk minder relevant
Editorial Seed Science and Technology Volume 48 Issue 1 (2020)
No full textThis issue of Seed Science and Technology contains a number of interesting papers worth giving additional attention. There are five papers that deal with analysis and breaking of seed dormancy, an important issue, not only for commercial practice and breeding, but also for regeneration of habitats and safeguarding biodiversity. One paper in this issue describes how mucilage production by seeds can aid in overcoming drought stress during germination of seeds from a desert plant. Combatting seed borne diseases remains an important issue. One paper describes how treatment with a combination of two fungicides proved to be effective against seed transmitted seedling blight in Norway spruce. Another paper demonstrates a method to combat a seedtransmitted bacterial infection with watermelon in the seedling stage. Seed vigour tests are needed to give a better estimation of differences between seed lots regarding field emergence. A faster vigour test for tobacco seeds is proposed in a paper in this issue. Even traditional ISTA germination tests may be improved, asdemonstrated in a paper for spinach seeds, where especially large seeds can be sensitive to a high moisture level in the tests. Instruments initially used in high-technology industries or in medical care sometimes find their wayto seed science applications. An example described in this issue is the use of 3D X-ray computed tomography, which enables rapid non-destructive analyses of the morphology of individual seeds, which can be correlated with germination behaviour. Another paper is on the use of multispectral imaging for seed purity analysis with alfalfa seed lots