Staff Publications

Staff Publications

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    '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.

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Collaboration between midwives and dietitians in improving dietary intake of low SES women
Super, S. ; Beulen, Y. ; Wagemakers, A. - \ 2019
European Journal of Public Health 29 (2019)Supplement_4. - ISSN 1101-1262 - p. 427 - 427.
A healthy dietary intake during pregnancy is important for maternal and child health. However, pregnant women with a low socioeconomic status (SES) are less likely to adhere to nutrition guidelines as compared to high SES groups. Midwives in the Netherlands experience limited opportunities to provide nutrition advice. Dietitians could play a role in providing nutrition advice to pregnant women, but collaborations between midwives and dietitians are limited. Therefore, this study aimed to investigate the opportunities and barriers for collaboration between midwives and dietitians in antenatal care for low SES women.
Questionnaires were administered amongst 134 dietitians to examine experiences of providing nutritional advice to pregnant women. Four focus groups were organised with midwives (2x) and dietitians (2x) to explore opportunities and barriers for collaboration.
Questionnaire results indicated that 73% of the dietitians like to see pregnant women more often in their practices and 78% feels the necessity to strengthen the collaboration with midwives. The focus groups showed that dietitians and midwives wish to strengthen the collaboration, but they also experience barriers: a focus on food risks rather than healthy nutrition in antenatal care, lack of referral procedures for women without medical necessity to see a dietitian, negative connotations with referring women to dietitians, and lack of time to discuss nutrition in consults by midwives.
Midwives and dietitians recognise the importance of strengthening collaborations, but in order to do so, several challenges need to be overcome. In a follow-up of this study, pressure cooker sessions will be conducted to design an integral strategy in antenatal care to empower women to improve dietary intake.
Key messages
There is a great potential to strengthen collaborations between midwives and dietitians in antenatal care to empower low SES pregnant women to improve dietary intake.
Several barriers need to be overcome to design in an integral strategy in antenatal care to improve the dietary intake of low SES pregnant women.
Protein hydrolysis and fermentation under methanogenic and acidifying conditions
Duong, Thu Hang ; Grolle, Katja ; Nga, Tran Thi Viet ; Zeeman, Grietje ; Temmink, Hardy ; Eekert, Miriam Van - \ 2019
Biotechnology for Biofuels 12 (2019)1. - ISSN 1754-6834
Amino acid fermentation - Hydrolysis - Methanogenic conditions - Non-methanogenic conditions - Proteins

Background: Many kinds of wastewaters contain appreciable quantities of protein. Anaerobic processes are suitable for the treatment of wastewater high in organics to achieve pollution control and recovery of energy as methane and hydrogen, or intermediates for production of biofuels and valuable biochemicals. A distinction between protein hydrolysis and amino acid fermentation, especially for dissolved proteins, is needed to target which one is truly rate-limiting and to effectively harvest bioproducts during anaerobic conversion of these wastewaters. This study explored mesophilic anaerobic hydrolysis and amino acid fermentation of gelatine, as a model for dissolved proteins, at pH 7 and at pH 5. Results: The results showed that at pH 7, protein hydrolysis (first-order rate of 0.15 h-1) was approximately 5 times faster than acidification of the hydrolysis products (first-order rate of 0.03 h-1), implying that not hydrolysis but acidification was the rate-limiting step in anaerobic dissolved protein degradation. This was confirmed by (temporary) accumulation of amino acids. Nineteen different amino acids were detected during the first 8 incubation hours of gelatine at neutral pH and the total chemical oxygen demand (COD) of these 19 amino acids was up to approximately 40% of the COD of the gelatine that was added. Protein hydrolysis at pH 5 was 2-25 times slower than at pH 7. Shifting the initial pH from neutral to acidic conditions (pH 5) inhibited protein degradation and changed the volatile fatty acids (VFA) product profile. Furthermore, the presence or absence of methanogenic activity did not affect the rates of protein hydrolysis and acidification. Conclusions: The findings in this study can help to set a suitable solid retention time to accomplish anaerobic degradation of protein-rich wastewaters in continuous reactor systems. For example, if the target is harvesting VFAs, methanogens can be washed-out for a shorter retention time while amino acid fermentation, instead of hydrolysis as assumed previously, will govern the design and solutions to improve the system dealing with dissolved proteins.[Figure not available: see fulltext].

Molecular Epidemiology of Ralstonia solanacearum Species Complex Strains Causing Bacterial Wilt of Potato in Uganda
Abdurahman, Abdulwahab ; Parker, Monica L. ; Kreuze, Jan ; Elphinstone, John G. ; Struik, Paul C. ; Kigundu, Andrew ; Arengo, Esther ; Sharma, Kalpana - \ 2019
Phytopathology 109 (2019)11. - ISSN 0031-949X - p. 1922 - 1931.
bacteriology - etiology - population biology

Bacterial wilt (BW) caused by the Ralstonia solanacearum species complex (RSSC) is a serious threat to potato production in Uganda. However, little is known about the extent of the disease and the type of the pathogen strains involved. A nationwide survey was conducted to study BW prevalence and incidence in potato, and potato tuber and stem samples of potential alternative hosts were collected for pathogen isolation. DNA was extracted from pure cultures for genetic diversity studies. The pathogen was phylotyped by multiplex PCR; then, a subset of isolates was typed at sequevar level. Isolates of the same sequevar were then haplotyped using multilocus tandem repeat sequence typing (TRST) schemes. BW prevalence and incidence in potato farms were 81.4 and 1.7%, respectively. Three RSSC phylotypes were identified, with the majority of the strains belonging to Phylotype II (80%) followed by Phylotype I (18.5%) and III (1.5%). Phylotype I strains belonged to Sequevar 31, and Phylotype II strains belonged to Sequevar 1. Potato-associated Phylotype II Sequevar 1 strains were more diverse (27 TRST haplotypes) than nonpotato Phylotype I (5 TRST haplotypes). Mapping of TRST haplotypes revealed that three TRST haplotypes of Phylotype II Sequevar 1 strains play an important epidemiological role in BW of potato in Uganda being disseminated via latently infected seed.[Formula: see text]

De toegankelijkheid van Jufferswaardin Renkum : bezoekaantallen, burgerparticipatie en communicatie
Goossen, C.M. ; Dekker, Lianne - \ 2019
Wageningen : Wageningen University & Research, Wetenschapswinkel (Wetenschapswinkel Rapport 353) - ISBN 9789463950435 - 87
This report discusses the results of the stakeholder analysis and the amount of recreational visits that was counted in the Natura 2000 area of the Jufferswaard in the period 2018-2019. The Jufferswaard, a 31 ha floodplain in the municipality of Renkum, is an area where recreation can take place. There are 55,000 visits a year, mainly from residents of the neighbouring villages of Renkum and Heelsum. On average there are 150 visits per day, mainly between 12.00 and 14.00. Sundays are by far the busiest days. In the future, on a beautiful and dry Sunday in the second half of February, the Pilot Group will be able to count 1 hour between 15.00 and 16.00 of the outgoing visit at each entrance gate. Based on the key figures from this study, the annual visit can then be roughly estimated. This is an inexpensive way for the Pilot Group to monitor the annual visit. According to the Pilogroep (a group of active citizens), the accessibility of the walking paths could be improved. They also have wishes for the preservation of cultural history in the area. These wishes are not directly shared by the owner of the Jufferswaard: Staatsbosbeheer. Other stakeholders are also active: the municipality of Renkum, the province of Gelderland, the Vallei and Veluwe Water Board and the nearby Parenco paper factory. The stakeholder analysis looked at what wishes were involved and how much influence the various stakeholders have. The wishes for the area were explained on the basis of nature images consisting of different management. The inhabitants of the municipality of Renkum were also heard by means of a survey in which they were asked about their wishes, nature images and recreational motives. It appears that although the nature images of the most important stakeholders, the Pilot Group and Staatsbosbeheer, differ, a compromise can be reached on the wishes of the Jufferswaard. This requires an improvement in communication on both sides. For the Pilot Group it is important that they present an unambiguous vision to the other stakeholders, and forStaatsbosbheer it is important that they communicate more from the experience of nature, because this is closer to the image of nature of recreational users. In this way the tension we see in de Jufferswaard between a more hierarchical role for the manager, who has to comply with statutory agreements, and citizens’ initiatives that expect a more collaborative and responsive role or demand a more effective role for the managers and the government, can be resolved. A situation can then be created that leads to cooperation on the basis of communication, understanding and trust in which the Pilot Group is heard and in which Staatsbosbeheer can benefit from the involvement of the Pilot Group. This could ultimately lead to a kind of management covenant. It is very positive for the Pilot Group that it is deploying its waste disposal activities (and thus taking a great deal of the work out of the hands of Staatsbosbeheer as manager) to show that it is in the process of putting into practice one of the most important wishes of the inhabitants and of the stakeholders. Through a networking and cooperative management style, Staatsbosbeheer can fulfill the desired “experiencing nature together”. The results of this project can serve as an example for other Natura 2000 floodplains in the Netherlands with similar issues and tensions between management styles.
In silico-guided engineering of Pseudomonas putida towards growth under micro-oxic conditions
Kampers, Linde F.C. ; Heck, Ruben G.A. van; Donati, Stefano ; Saccenti, Edoardo ; Volkers, Rita J.M. ; Schaap, Peter J. ; Suarez-Diez, Maria ; Nikel, Pablo I. ; Martins Dos Santos, Vitor A.P. - \ 2019
Microbial Cell Factories 18 (2019)1. - ISSN 1475-2859 - 1 p.
Anaerobiosis - Comparative genomics - Constraint-based metabolic modelling - Domainome analysis - Microbial physiology - Synthetic biology

BACKGROUND: Pseudomonas putida is a metabolically versatile, genetically accessible, and stress-robust species with outstanding potential to be used as a workhorse for industrial applications. While industry recognises the importance of robustness under micro-oxic conditions for a stable production process, the obligate aerobic nature of P. putida, attributed to its inability to produce sufficient ATP and maintain its redox balance without molecular oxygen, severely limits its use for biotechnology applications. RESULTS: Here, a combination of genome-scale metabolic modelling and comparative genomics is used to pinpoint essential [Formula: see text]-dependent processes. These explain the inability of the strain to grow under anoxic conditions: a deficient ATP generation and an inability to synthesize essential metabolites. Based on this, several P. putida recombinant strains were constructed harbouring acetate kinase from Escherichia coli for ATP production, and a class I dihydroorotate dehydrogenase and a class III anaerobic ribonucleotide triphosphate reductase from Lactobacillus lactis for the synthesis of essential metabolites. Initial computational designs were fine-tuned by means of adaptive laboratory evolution. CONCLUSIONS: We demonstrated the value of combining in silico approaches, experimental validation and adaptive laboratory evolution for microbial design by making the strictly aerobic Pseudomonas putida able to grow under micro-oxic conditions.

Responsible innovation and agricultural sustainability: lessons from genetically modified crops’
Macnaghten, Philip - \ 2019
In: International Handbook on Responsible Innovation / van Schomberg, R., Hankins, J., Edward Elgar - ISBN 9781784718855 - p. 285 - 307.
Although scientists and policymakers frequently see genetically modified (GM) crops as part of the solution to the global ‘grand challenge’ of agricultural sustainability, all too commonly they have been viewed as part of the problem. They have been met with resistance by a variety of social actors, their regulation has been challenged as inadequate, even biased, and their consumption recurrently rejected by consumers as not delivering a societal benefit. In this chapter I examine the case of GM crops and how an analysis of the controversy investigated through the lens of responsible innovation can cast light on the conditions under which innovations in the agricultural sciences can become responsive to this important global challenge. First, I set out a brief context to GM crops within the grand challenge of agricultural sustainability. Second, I examine empirical research on the socio-political impacts of GM crops in Brazil, India and Mexico, exploring the views of farmers, scientists and publics. Third, in response to the clear absence of authoritative governance that is identified across these three diverse geopolitical contexts, I explore the potential of frameworks of responsible innovation to reconfigure the debate on the governance of GM foods and crops, and to provide new pathways to move it away from its current polemic and impasse. I conclude with a modest set of recommendations.
Inbreeding depression due to recent and ancient inbreeding in Dutch Holstein-Friesian dairy cattle
Doekes, Harmen P. ; Veerkamp, Roel F. ; Bijma, Piter ; Jong, Gerben de; Hiemstra, Sipke J. ; Windig, Jack J. - \ 2019
Genetics, Selection, Evolution 51 (2019)1. - ISSN 0999-193X - 16 p.

BACKGROUND: Inbreeding decreases animal performance (inbreeding depression), but not all inbreeding is expected to be equally harmful. Recent inbreeding is expected to be more harmful than ancient inbreeding, because selection decreases the frequency of deleterious alleles over time. Selection efficiency is increased by inbreeding, a process called purging. Our objective was to investigate effects of recent and ancient inbreeding on yield, fertility and udder health traits in Dutch Holstein-Friesian cows. METHODS: In total, 38,792 first-parity cows were included. Pedigree inbreeding ([Formula: see text]) was computed and 75 k genotype data were used to compute genomic inbreeding, among others based on regions of homozygosity (ROH) in the genome ([Formula: see text]). RESULTS: Inbreeding depression was observed, e.g. a 1% increase in [Formula: see text] was associated with a 36.3 kg (SE = 2.4) decrease in 305-day milk yield, a 0.48 day (SE = 0.15) increase in calving interval and a 0.86 unit (SE = 0.28) increase in somatic cell score for day 150 through to 400. These effects equalled - 0.45, 0.12 and 0.05% of the trait means, respectively. When [Formula: see text] was split into generation-based components, inbreeding on recent generations was more harmful than inbreeding on more distant generations for yield traits. When [Formula: see text] was split into new and ancestral components, based on whether alleles were identical-by-descent for the first time or not, new inbreeding was more harmful than ancestral inbreeding, especially for yield traits. For example, a 1% increase in new inbreeding was associated with a 2.42 kg (SE = 0.41) decrease in 305-day fat yield, compared to a 0.03 kg (SE = 0.71) increase for ancestral inbreeding. There were no clear differences between effects of long ROH (recent inbreeding) and short ROH (ancient inbreeding). CONCLUSIONS: Inbreeding depression was observed for yield, fertility and udder health traits. For yield traits and based on pedigree, inbreeding on recent generations was more harmful than inbreeding on distant generations and there was evidence of purging. Across all traits, long and short ROH contributed to inbreeding depression. In future work, inbreeding depression and purging should be assessed in more detail at the genomic level, using higher density information and genomic time series.

Impact of vertebrate communities on Ixodes ricinus-borne disease risk in forest areas
Takumi, Katsuhisa ; Sprong, Hein ; Hofmeester, Tim R. - \ 2019
Parasites & Vectors 12 (2019)1. - ISSN 1756-3305
Anaplasma phagocytophilum - Borrelia burgdorferi (s.l.) - Borrelia miyamotoi - Ixodes ricinus - Lyme borreliosis - Neoehrlichia mikurensis - Transmission dynamics - Vector-borne disease

Background: The density of questing ticks infected with tick-borne pathogens is an important parameter that determines tick-borne disease risk. An important factor determining this density is the availability of different wildlife species as hosts for ticks and their pathogens. Here, we investigated how wildlife communities contribute to tick-borne disease risk. The density of Ixodes ricinus nymphs infected with Borrelia burgdorferi (sensu lato), Borrelia miyamotoi, Neoehrlichia mikurensis and Anaplasma phagocytophilum among 19 forest sites were correlated to the encounter probability of different vertebrate hosts, determined by encounter rates as measured by (camera) trapping and mathematical modeling. Result: We found that the density of any tick life stage was proportional to the encounter probability of ungulates. Moreover, the density of nymphs decreased with the encounter probability of hare, rabbit and red fox. The density of nymphs infected with the transovarially-transmitted B. miyamotoi increased with the density of questing nymphs and the encounter probability of bank vole. The density of nymphs infected with all other pathogens increased with the encounter probability of competent hosts: bank vole for Borrelia afzelii and N. mikurensis, ungulates for A. phagocytophilum and blackbird for Borrelia garinii and Borrelia valaisiana. The negative relationship we found was a decrease in the density of nymphs infected with B. garinii and B. valaisiana with the encounter probability of wood mouse. Conclusions: Only a few animal species drive the densities of infected nymphs in forested areas. There, foxes and leporids have negative effects on tick abundance, and consequently on the density of infected nymphs. The abundance of competent hosts generally drives the abundances of their tick-borne pathogen. A dilution effect was only observed for bird-associated Lyme spirochetes.[Figure not available: see fulltext.]

Dairy farmers' strategies in four European countries before and after abolition of the milk quota
Klopčič, Marija ; Kuipers, Abele ; Malak-Rawlikowska, Agata ; Stalgiene, Aldona ; Ule, Anita ; Erjavec, Karmen - \ 2019
Land Use Policy 88 (2019). - ISSN 0264-8377
Dairy farmers - EU countries - Milk quota abolition - Strategies

In recent years, the European Union (EU) dairy sector has experienced considerable changes, triggering heavily fluctuating milk prices and a crash in milk prices in 2015/2016. These changes were forcing dairy farmers to respond by reconsidering their strategy. Since there is a lack of insight into how farmers were adjusting their strategies to the new circumstances, this study aimed to fill the gap by conducting a survey on farmers’ development plans in three Central and Eastern European countries (Poland, Lithuania and Slovenia) with different farming systems and one Western European country with a well-developed dairy sector (the Netherlands) before (2010 and 2013) and one year after the EU milk quota was abolished (2016). Groups of farmers with similar strategies were identified using principle component analysis and cluster analysis. Differences in strategies between years and countries were studied. The results reveal three main strategies in the analysed years: expansion, specialisation, and wait and see. Six farmer clusters were then identified. The cluster of Growers was largest, corresponding to the strategies of expansion and specialisation in dairy production. The share of Growers was increasing in Poland and the Netherlands and falling in Lithuania and Slovenia, probably due to the strong market orientation and good dairy production conditions in the aforementioned countries. The share of farmers in the Wait and See cluster grew significantly from 2013 to 2016 in all countries. These farmers considered the economic environment as too uncertain for further development at the time. The share of Diversifiers was rather stable within each country over the years. The share of Chain integrators, namely those who look for cooperation with other parties in the chain, was larger in good years and the share of Co-operators, who prefer to cooperate with other farmers, was larger in difficult market times. The cluster of Movers had the largest farms. On average, larger farms with somewhat younger farmers opted for growth, chain integration or moving and somewhat older farmers with smaller farms for a (temporary) stand-still. But considerable differences in the number of farmers per cluster over the years were found. Less than half the farmers were consistent in their development direction after 3 years, due to fluctuating prices and changing policies. Wait and See farmers were the most consistent. Policymakers and advisory services should consider farm strategies according to national specificities. Most farmers follow a strategy of expansion, while a smaller group of them were more concerned and act cautiously in a difficult market or policy situation. However, many farmers appeared to change their opinion on the self-chosen direction from time to time due to the varying circumstances. This instability in strategy choice makes future decision-making a fluid matter and not really consistent with well-designed planning.

Pathogen suppression by microbial volatile organic compounds in soils
Boer, Wietse de; Li, Xiaogang ; Meisner, Annelein ; Garbeva, Paolina - \ 2019
FEMS microbiology ecology 95 (2019)8. - ISSN 0168-6496
disease suppression - fungistasis - microbial interactions - soil atmosphere - soil microbial community - sustainable management strategies - volatile organic compounds

There is increasing evidence that microbial volatile organic compounds (mVOCs) play an important role in interactions between microbes in soils. In this minireview, we zoom in on the possible role of mVOCs in the suppression of plant-pathogenic soil fungi. In particular, we have screened the literature to see what the actual evidence is that mVOCs in soil atmospheres can contribute to pathogen suppression. Furthermore, we discuss biotic and abiotic factors that influence the production of suppressive mVOCs in soils. Since microbes producing mVOCs in soils are part of microbial communities, community ecological aspects such as diversity and assembly play an important role in the composition of produced mVOC blends. These aspects have not received much attention so far. In addition, the fluctuating abiotic conditions in soils, such as changing moisture contents, influence mVOC production and activity. The biotic and abiotic complexity of the soil environment hampers the extrapolation of the production and suppressing activity of mVOCs by microbial isolates on artificial growth media. Yet, several pathogen suppressive mVOCs produced by pure cultures do also occur in soil atmospheres. Therefore, an integration of lab and field studies on the production of mVOCs is needed to understand and predict the composition and dynamics of mVOCs in soil atmospheres. This knowledge, together with the knowledge of the chemistry and physical behaviour of mVOCs in soils, forms the basis for the development of sustainable management strategies to enhance the natural control of soil-borne pathogens with mVOCs. Possibilities for the mVOC-based control of soil-borne pathogens are discussed.

Antenatal iron supplementation and birth weight in conditions of high exposure to infectious diseases
Verhoef, Hans ; Mwangi, Martin N. ; Cerami, Carla ; Prentice, Andrew M. - \ 2019
BMC Medicine 17 (2019). - ISSN 1741-7015
Anaemia - Birthweight - Iron - Malaria - Plasmodium - Pregnancy

Background: A recent cohort study among Papua New Guinean women surprisingly showed iron deficiency during pregnancy to be associated with increased birth weight. These findings seemingly contradict previous trial evidence that iron supplementation leads to increased birth weight, particularly in iron-deficient women, and hence require explanation. Main text: We have re-analysed data from a previous trial in Kenya and demonstrated that, because women who were initially iron deficient respond better to iron supplementation, they show an increase in birthweight. There is evidence that this benefit is decreased in iron-replete women, possibly due to the adverse effects of haemoconcentration that can impair oxygen and nutrient transfer across the placenta. The Papua New Guinean results might be explained by a similar differential response to the iron supplements that they all received. Conclusions: Antenatal iron supplementation should ideally be administered in conjunction with measures to prevent, diagnose and treat malaria given the propensity of pathogenic microorganisms to proliferate in iron-supplemented individuals. However, even where services to prevent and treat malaria are poor, current evidence supports the conclusion that the benefits of universal iron supplementation outweigh its risks. Please see related article: Please see related article:

Attitudes and perceptions of Dutch companion animal veterinarians towards antimicrobial use and antimicrobial resistance
Hopman, Nonke E.M. ; Mughini-Gras, Lapo ; Speksnijder, David C. ; Wagenaar, Jaap A. ; Geijlswijk, Ingeborg M. van; Broens, E.M. - \ 2019
Preventive Veterinary Medicine 170 (2019). - ISSN 0167-5877
Antimicrobial use - Companion animal - Explanatory variable - Prescribing behaviour - Veterinary medicine

Antimicrobial use (AMU) in humans and animals facilitates the emergence of antimicrobial resistance (AMR). With increasing AMR being recognised as a major global threat for public health, responsible AMU is strongly advocated in both human and veterinary medicine. Knowledge on factors influencing antimicrobial prescribing behaviour of companion animal veterinarians is needed to promote responsible AMU in companion animals and to improve compliance with current legislation and guidelines. The present study aimed to quantitively investigate attitudes and perceptions of companion animal veterinarians towards AMU and AMR and to identify associations with demographic characteristics as possible explanatory variables. A self-administered questionnaire was developed based upon an earlier qualitative interview study, and 1608 potential participants (i.e. practising companion animal veterinarians) were invited. The questionnaire included questions addressing general descriptives of the respondents and questions with 6-point Likert scale statements, to assess attitudes towards AMU, AMR, factors influencing antimicrobial prescribing, and possible options to support responsible AMU. The response rate was 32% (22% when complete questionnaires considered). Categorical Principal Component Analysis (CATPCA) was conducted on 76 Likert scale questions. This resulted in a final model with 37 questions explaining 38.7% of the variance of the question scores, with three underlying dimensions (“attitudinal profiles”). Additionally, general descriptives were added to the CATPCA as possible explanatory variables. The first dimension, related to “social responsibility” was positively associated with veterinarians working in clinics dedicated to companion animals, with veterinarians working in a referral clinic, and with more experienced veterinarians. The second dimension was related to “scepticism”, which was positively associated with being a male veterinarian and with more experienced veterinarians. The third dimension was related to “risk avoidance”, especially regarding surgical procedures, and was negatively associated with veterinarians working in clinics in urban areas and with veterinarians working part-time. Antimicrobial prescribing behaviour was self-reported to be well considered, and respondents did not see economic drivers as important influencing factors. The unwillingness of owners and financial constraints were perceived as important barriers for performing further diagnostics. To improve AMU, a multifaceted approach, taking differences between companion animal veterinarians (e.g., in experience and gender) and differences in work situation (e.g., full-time versus part-time) into account, should be directed at companion animal veterinarians and owners. Moreover, a joint and comprehensive effort of several stakeholders, like veterinary nurses, guideline developers, pharmaceutical industry, and providers of diagnostics, is needed to optimise AMU in companion animals.

Nucleic acid lateral flow assays using a conjugate of a DNA binding protein and carbon nanoparticles
Aktas, Gülsen Betül ; Wichers, Jan H. ; Skouridou, Vasso ; Amerongen, Aart van; Masip, Lluis - \ 2019
Microchimica acta 186 (2019)7. - ISSN 0026-3672
Enzyme conjugate - Escherichia coli - Immunochromatographic test - Nucleic acid lateral flow assay - Signal enhancement - Single-chain Cro

Nucleic acid lateral flow assays (NALFA) are often performed with gold nanoparticles. These are typically associated with ligand-labeled PCR amplicons via affinity interactions of adsorbed/conjugated proteins. Otherwise, they are conjugated to specific ssDNA sequences that hybridize to the target sequence. To avoid the need to generate ssDNA and to reduce the costs associated with primer labeling and antibody use, NALFA assays were developed that allow the direct detection of PCR amplicons using conjugates of a DNA binding protein with carbon nanoparticles (CNPs). The target gene encoding 16S ribosomal RNA of Escherichia coli was amplified by PCR using a single fluorophore-labeled forward primer and a reverse primer extended with the binding sequence of the bacteriophage lambda Cro repressor protein. Three different detection approaches were evaluated: (a) scCro/CNPs conjugate (black color), (b) HRP-scCro enzyme conjugate (red color), and (c) HRP-scCro/CNPs conjugate for dual color development. The limits of detection were between 6.9 and 10.4 ng of PCR product for all three approaches. These correspond to 3.0 to 4.5 × 103 CFU·mL−1. The single-step scCro/CNP approach proved to be the fastest one to perform and gave no false-positive signals. It also showed a broad dynamic range even though the signal intensities were lower compared to the enzyme-amplified tests. However, the latter ones produced some background signal. In our perception, the application of scCro in lateral flow assays to bind dsDNA appears to be an excellent alternative to the use of small tags that have to be chemically linked to synthetic primers. Finally, the approach is generic because any primer sequence can be extended with the specific scCro binding sequence. [Figure not available: see fulltext.].

Recent Advances in Forest Observation with Visual Interpretation of Very High-Resolution Imagery
Schepaschenko, Dmitry ; See, Linda ; Lesiv, Myroslava ; Bastin, Jean-François ; Mollicone, Danilo ; Tsendbazar, Nandin-Erdene ; Bastin, Lucy ; McCallum, Ian ; Laso Bayas, Juan Carlos ; Baklanov, Artem ; Perger, Christoph ; Dürauer, Martina ; Fritz, Steffen - \ 2019
Surveys in Geophysics 40 (2019)4. - ISSN 0169-3298 - p. 839 - 862.
The land area covered by freely available very high-resolution (VHR) imagery has grown dramatically over recent years, which has considerable relevance for forest observation and monitoring. For example, it is possible to recognize and extract a number of features related to forest type, forest management, degradation and disturbance using VHR imagery. Moreover, time series of medium-to-high-resolution imagery such as MODIS, Landsat or Sentinel has allowed for monitoring of parameters related to forest cover change. Although automatic classification is used regularly to monitor forests using medium-resolution imagery, VHR imagery and changes in web-based technology have opened up new possibilities for the role of visual interpretation in forest observation. Visual interpretation of VHR is typically employed to provide training and/or validation data for other remote sensing-based techniques or to derive statistics directly on forest cover/forest cover change over large regions. Hence, this paper reviews the state of the art in tools designed for visual interpretation of VHR, including Geo-Wiki, LACO-Wiki and Collect Earth as well as issues related to interpretation of VHR imagery and approaches to quality assurance. We have also listed a number of success stories where visual interpretation plays a crucial role, including a global forest mask harmonized with FAO FRA country statistics; estimation of dryland forest area; quantification of deforestation; national reporting to the UNFCCC; and drivers of forest change.
Change Detection in Satellite Image Time Series for Continuous Land Cover Map Updating
Masiliunas, D. ; Tsendbazar, N.E. ; Herold, M. ; Lesiv, Myroslava ; Verbesselt, J. - \ 2019
Land cover monitoring is an integral part of land management. Many stakeholders, such as land owners, governments, NGOs and international organisations are interested in keeping track of changes on the ground, so that these changes could be managed. This can be done using land cover maps, however, most land cover maps are only produced for a single date. For example, the GLC2000 product was produced with the intention of representing the global land cover in the year 2000. Yet, the target of land cover monitoring is the land cover change over time, which is an indicator of ongoing processes on the ground.

One way to express land cover change is by producing multiple single-date maps, and analysing the differences between them. However, if the probability that the pixel belongs to a certain class is close between two classes, then even a small change in model input data may cause the prediction to shift to a different land cover class.

In this study, we propose to update land cover maps by performing change detection on time series of satellite imagery. If there is an abrupt change in seasonal pattern in the time series of a pixel, then a land cover class transition is likely to have occurred at that location. Only areas with detected change need to be updated for producing the next iteration of the map, making it more consistent over time, and taking less computational effort to reclassify the map. In addition, performing change detection allows us to avoid extracting temporal features for classification from periods of change. If no land cover change happened, then it is possible to use a longer history period for extracting temporal features, therefore increasing the robustness and accuracy of the classification model (see Figure 1). However, a limitation of using change detection for map updating is that we assume that the original land cover map is accurate and can be used as a basemap for updating, which may not always be the case.

To see if this method is viable and scalable, we compared the performance of three time series break detection algorithms: strucchange::breakpoints, BFAST Monitor and annual t-test. The algorithms were run over the time series of vegetation indices derived from MODIS 250 m data over the entire continent of Africa. A computer cluster hosted by VITO was used for this big data processing task. This was done in the context of the Copernicus Global Land System: Dynamic Land Cover (CGLS-LC100) land cover project.

In order to validate the algorithm performance, the CGLS-LC100 project is collecting reference points from Africa. Land cover change is identified through image interpretation of very high resolution imagery, as well as Sentinel-2 images and NDVI profiles. Once the reference data is collected, algorithm performance will be assessed using confusion matrix statistics, such as sensitivity, specificity, false positive rate, likelihood ratio for positive tests and positive predictive value.

Preliminary results from West African drylands show that land cover change is an uncommon phenomenon, as only 3.4% of the 1010 reference points show change. All of the tested algorithms tended to overestimate the detected change in this region. The annual t-test algorithm was the fastest, but it does not provide any temporal metrics, only whether there was a break in time series over a chosen year. In contrast, strucchange::breakpoints provides the estimated day of year when a break in the time series is detected. BFAST Monitor is in between, in that it gives a rough estimate of when the break occurred within a particular year.

Once additional reference data about land cover change is collected, we will investigate options to further tune the algorithms to detect land cover change, so that it would improve the classification accuracy of the final land cover map for a given year. This will also reduce the data amounts that need reprocessing each year to produce an updated map. Limiting the amount of data to process is becoming more important, as land cover maps move into higher spatial resolution, e.g. 20 m resolution based on Sentinel-2 imagery.

The framework set in this study is independent of a particular satellite sensor, and so the findings are applicable to all land cover maps that are in an operational phase, i.e. are regularly updated. Due to the scalability of the approach, the methods have the potential to improve the accuracy of both local-scale and global-scale land cover classification products, as well as make them easier to update.
Rurality and multi-level governance : Marginal rural areas inciting community governance
Bock, Bettina B. - \ 2019
In: The Routledge Companion to Rural Planning Taylor and Francis Inc. - ISBN 9781138104051 - p. 103 - 113.
In the late 1990s, the shift of power from government to governance was a critical subject of academic debate. In the rural context, studies focused on the role of governance in endogenous models of development. The discussion centred on the opportunities for development from bottom-up and based on local resources, the danger of elite groups’ dominance and the legitimacy of rural governance within a representative democracy society. Changes in the governing of rural areas have continued ever since and proceeded in the same direction. They reflect the continuous withdrawal of the state from public tasks in the aftermath of the financial crisis and as part of welfare state reforms. Lack of public funds is one driver of this development, yet this is – again – presented as an opportunity for citizen empowerment. Marginal rural areas are affected in a particular way; because of the diminishing support from central governments, active citizens play an increasingly important role in maintaining vital services. In a way they may, hence, be considered as natural laboratories for testing and understanding the opportunities and limits of multilevel governance. This chapter looks into the development of thought about rural governance in relation to rural development. In sketches how research and theory developed since the 1990s, appointing and discussing the most important strands of thought in rural governance literature. It then focuses on current research in marginal rural areas where we see a broad spectrum of multilevel governance mechanisms, before the conclusions regarding the characteristics of current multi-level governance, its functioning and its results.
Fostering Community Values through Meal Sharing with Strangers
Veen, E.J. - \ 2019
Sustainability 11 (2019)7. - ISSN 2071-1050 - 14 p.
commodification - community self-organization - rules of engagement - trust - sharing economy
This paper studies a Dutch meal sharing platform in order to understand what it means to engage in face-to-face sharing with strangers and what the performance of such transactions entails. I hypothesize that this meal sharing platform is a form of community self-organization, aiming to replace the anonymity of the food system by the creation of community relations through sharing. I used semistructured interviews, participant observations, and autoethnography to investigate the social aspects involved in this type of sharing. Focusing on rules of engagement, trust, exchange, and commodification, I argue that while first encounters in stranger food sharing may be awkward, people enter the transaction from a perspective of trust. While sharing meals through this platform is a form of true sharing and no direct reciprocity is required, consumers see their appreciation for the meals as a way to reciprocate. In that sense, positive reviews consolidate the relations between cook and consumer. Money also plays an important role in the transaction, enabling it to take place as it clarifies roles and responsibilities and shows genuine interest. However, commodification also means that users are looking for value for money, while simultaneously they expect the price to reflect the initiative’s “noncommercialness”. I conclude that there is a clear social element in this particular type of meal sharing that distinguishes it from more mainstream economic transactions. Being based on real connections, this particular performance of sharing is a way to socialize the economy, and to tackle local community problems. View Full-Text
Evaluating the Healthy Futures Nearby Program: Protocol for Unraveling Mechanisms in Health-Related Behavior Change and Improving Perceived Health Among Socially Vulnerable Families in the Netherlands
Hogeling, Lette ; Vaandrager, Lenneke ; Koelen, Maria - \ 2019
JMIR Research Protocols 8 (2019)4. - ISSN 1929-0748
Background: The persistence of health inequalities within high-income societies such as the Netherlands indicates the importance of researching effective ways to reduce those inequalities. Multiple strategies for reducing health inequalities have been identified. Specifically targeting health-related behaviors among lower socioeconomic status groups is one of those strategies. All in all, it seems relatively clear what types of approaches in general lead to health-related behavior change. However, it is still unclear how these approaches, in interaction with context, trigger a specific desired change. In the Netherlands, the private funding organization, Fonds NutsOhra, funded 46 small-scale projects under the umbrella of the Healthy Futures Nearby program. The projects aim to reduce vulnerable families’ health deprivation by triggering lifestyle changes.

Objective: This study aimed to outline and justify the protocol for the overall evaluation of the program. The evaluation aimed to find out to what extent and how the small-scale projects and approaches within the program affect (or not) health-related behaviors and improve perceived health.

Methods: The approach to the overall evaluation of the 46 projects builds on a combination of 3 frequently used evaluation models; it is theory-based, realist informed, and uses a mixed methodology design. Methods include analysis of quantitative project data, document analysis, focus groups, and interviews. A study design has been drawn up that values and uses the multifaceted development of the projects and the influence this might have on implementation and project outcomes. Also, it respects the complex nature of the projects and is suited to studying health promotion mechanisms in depth. Finally, it optimizes the usage of all—quantitative and qualitative—project evaluation data available.

Results: This study protocol included the design of at least 4 different studies. The results will hence provide information on (1) building and defining theories of change in health promotion practice, (2) mechanisms at work in promotion of healthy behavior among vulnerable families, (3) what works and what does not in professionals’ practices in health promotion among those vulnerable groups, and (4) what works and what does not in health promotion projects with a participatory approach. In addition, data will be collected on the overall effectiveness of the 46 initiatives. Data collection started in 2016. Data analysis is currently underway, and the first results are expected to be submitted for publication in 2019.

Conclusions: This overall evaluation provides a unique opportunity. The diversity of projects allows for a study protocol that answers in greater depth questions of how specific health promotion approaches work while also elucidating their effectiveness in a more traditional way. Using a theory-based complexity-sensitive approach that is mainly realist informed, this study also provides an opportunity to see whether combining assumptions from different evaluation perspectives yields relevant information.
Temporal Limits of Visual Motion Processing: Psychophysics and Neurophysiology
Borghuis, Bart G. ; Tadin, Duje ; Lankheet, Martin J.M. ; Lappin, Joseph S. ; Grind, Wim A. van de - \ 2019
Vision 3 (2019)1. - ISSN 2411-5150 - 17 p.
Under optimal conditions, just 3–6 ms of visual stimulation suffices for humans to see motion. Motion perception on this timescale implies that the visual system under these conditions reliably encodes, transmits, and processes neural signals with near-millisecond precision. Motivated by in vitro evidence for high temporal precision of motion signals in the primate retina, we investigated how neuronal and perceptual limits of motion encoding relate. Specifically, we examined the correspondence between the time scale at which cat retinal ganglion cells in vivo represent motion information and temporal thresholds for human motion discrimination. The timescale for motion encoding by ganglion cells ranged from 4.6 to 91 ms, and depended non-linearly on temporal frequency, but not on contrast. Human psychophysics revealed that minimal stimulus durations required for perceiving motion direction were similarly brief, 5.6–65 ms, and similarly depended on temporal frequency but, above ~10%, not on contrast. Notably, physiological and psychophysical measurements corresponded closely throughout (r = 0.99), despite more than a 20-fold variation in both human thresholds and optimal timescales for motion encoding in the retina. The match in absolute values of the neurophysiological and psychophysical data may be taken to indicate that from the lateral geniculate nucleus (LGN) through to the level of perception little temporal precision is lost. However, we also show that integrating responses from multiple neurons can improve temporal resolution, and this potential trade-off between spatial and temporal resolution would allow for loss of temporal resolution after the LGN. While the extent of neuronal integration cannot be determined from either our human sychophysical or neurophysiological experiments and its contribution to the measured temporal resolution is unknown, our results demonstrate a striking similarity in stimulus dependence between the temporal fidelity established in the retina and the temporal limits of human motion discrimination.
Everyday Encounters in the Shopping Mall: (Un)Making Boundaries in the Divided Cities of Johannesburg and Mostar
Aceska, Ana ; Heer, Barbara - \ 2019
Anthropological Forum : a journal of social anthropology and comparative sociology 29 (2019)1. - ISSN 0066-4677 - p. 47 - 61.
divided cities - everyday encounters - Johannesburg - Mostar - Shopping malls - urban marginality

The many studies that see shopping malls as places of power, control and exclusion have often neglected the potential of malls as places of encounters. Drawing on ethnographic data from the divided cities of Johannesburg in South Africa and Mostar in Bosnia–Herzegovina, we examine the ways in which urban dwellers who enter the mall from a marginalised position–poor black urban dwellers at a regional, middle class and white-dominated mall in Johannesburg and Bosniak city dwellers at a mall located in the Croat part of Mostar–use the mall, what kind of relations they build to others and how they rework boundaries of race, class, religion and ethnicity at the mall. Rather than being spaces that strengthen and reproduce centre–margins relations, urban dwellers appropriate them as places where these relations become reworked.

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