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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    Care, commoning and collectivity: from grand domestic revolution to urban transformation
    Morrow, Oona ; Parker, Brenda - \ 2020
    Urban Geography (2020). - ISSN 0272-3638 - p. 1 - 18.
    Care - Cities - Commons - Feminist - Gender

    Given profound urban challenges amplified by COVID-19, we need to center anti-racist feminists’ lenses oncare, commoning, and collectivity in our cultivations and analyses of urban change. We join a chorus of feminists that critique the devaluation, erasure, and isolation of care in the cities that we build and the stories we tell about them. But this is well-traversed territory, the ‘me too’ tale of every feminist who dreamsa different city or kind of urban theory. So, we outline a research agenda rooted in intersectional feminist imaginations and transformations that live around us. Neither nomadic nor confined to the home, care, commoning and collectivity can be aspirational, spatial, and practical. Inspired by Dolores Hayden and intersectional feminists, we ask: What kinds of socio-spatial imaginations can produce just, sustainable cities and who makes them? What material practices enable social change and improve everyday life, and at what scales might struggles for just cities be waged?.

    “I prepared my own carrots”. The effect of participation in an out-of-home cooking session on Dutch 4–6-year-old children's vegetable consumption
    Zeinstra, Gertrude G. ; Vrijhof, Milou ; Kremer, Stefanie - \ 2020
    Food Quality and Preference 86 (2020). - ISSN 0950-3293
    Children's eating behaviour - Healthy diet - Intervention strategies - Involvement - Vegetable intake

    Involvement in vegetable preparation is thought to be an effective strategy to increase children's vegetable intake, but the evidence from experimental studies is scarce. A between-subject experiment was executed in a restaurant setting to investigate the effect of participation in vegetable preparation on 4–6-year-old children's vegetable intake. After a baseline evening meal, intervention children (N = 50) participated in a vegetable preparation session together with an enthusiastic chef. Control children (N = 51) participated in small groups in a book-reading activity. Subsequently, they ate an evening meal. Follow-up sessions at one month and three months were included to assess possible longer-term effects. Vegetable intake was the main outcome. Secondary outcomes were vegetable choice and involvement in food-related activities at home. For all four sessions, children's vegetable intake ranged between 50 and 60 g in both conditions (p > 0.05). Participation in carrot preparation did not increase children's vegetable intake. Involvement in food-related activities at home remained stable in the intervention group, whereas it decreased slightly in the control group (p = 0.01). A cluster analysis identified four distinct vegetable eating patterns over time, suggesting that there are different segments of children. To conclude, participating once in an out-of-home vegetable preparation session with an enthusiastic chef did not influence children's intake of a familiar vegetable, but it may support their general involvement in food-related activities at home.

    Does entry to center-based childcare affect gut microbial colonization in young infants?
    Hermes, Gerben D.A. ; Eckermann, Henrik A. ; Vos, Willem M. de; Weerth, Carolina de - \ 2020
    Scientific Reports 10 (2020)1. - ISSN 2045-2322

    Entry to center-based childcare (CC) at three months of life can be an important challenge for infants as it includes major stressors such as long maternal separations and frequently changing caregivers. Stress and the new environment may in turn alter the composition of the gut microbiota with possible implications for future health outcomes. As part of an ongoing longitudinal study, we investigated whether CC, as compared to being cared for by the parents at home, alters the composition of the gut microbiota, while accounting for known covariates of the infant gut microbiota. Stool samples of infants who entered CC (n = 49) and control infants (n = 49) were obtained before and four weeks after CC entrance. Using Redundancy analysis, Random Forests and Bayesian linear models we found that infant gut microbiota was not affected in a uniform way by entry to CC. In line with the literature, breastfeeding, birth mode, age, and the presence of siblings were shown to significantly impact the microbial composition.

    Effects of Early and Current Environmental Enrichment on Behavior and Growth in Pigs
    Luo, Lu ; Reimert, Inonge ; Middelkoop, Anouschka ; Kemp, Bas ; Bolhuis, J.E. - \ 2020
    Frontiers in Veterinary Science 7 (2020). - ISSN 2297-1769
    behavior - early life - environmental enrichment - feed intake - growth - pigs

    Enriched environments are known to beneficially affect the behavior of pigs, as compared with barren pens. The influence of enrichment may, however, depend on pigs' early life housing experiences. The aim of this study was to investigate the long-term effects of early and later life environmental enrichment on behavior and growth in pigs with different coping styles. Pigs were housed in either barren pens or in larger pens enriched with rooting substrates from birth, and half of them experienced a housing switch, i.e., a loss or gain of enrichment, at 7 weeks of age, creating four treatment groups. Home pen behavior and body weight were recorded until 19 weeks of age. Pigs were classified as reactive or proactive based on a backtest at 2 weeks of age. Enrichment increased time spent exploring, chewing, and play and decreased oral manipulation of penmates and pen-directed exploring and chewing. Behavior of pigs that switched from barren to enriched pens or vice versa reflected not only their actual environment, but also their early life housing. As early and later life enrichment affected most behaviors in opposite directions, effects of enrichment, or lack thereof, after the switch were more pronounced in pigs that had experienced a different early life condition. For instance, pigs experiencing an upgrade from barren to enriched pens seemed to “catch-up” by showing more exploration and play. Conversely, pigs exposed to a downgrade displayed more oral manipulation of penmates than ones kept barren throughout, which particularly held for pigs with a reactive coping style. Effects of early life and current housing on several other behaviors depended on coping style too. Pigs housed in enriched conditions appeared better able to cope with weaning than barren housed pigs, as they gained more weight and had higher feed intake post-weaning. Barren housed pigs had a lower body weight than enriched pigs just before the switch, after which growth was mainly determined by actual housing, with enriched kept pigs having a higher feed intake and body weight. Thus, not only current housing conditions, but also a (mis)match with the early life environment may affect behavior and growth of pigs.

    Assessing spatial resolution, acquisition time and signal-to-noise ratio for commercial microimaging systems at 14.1, 17.6 and 22.3 T
    Krug, Julia R. ; Schadewijk, Remco van; Vergeldt, Frank J. ; Webb, Andrew G. ; Groot, Huub J.M. de; Alia, A. ; As, Henk Van; Velders, Aldrik H. - \ 2020
    Journal of Magnetic Resonance 316 (2020). - ISSN 1090-7807
    Limit of detection - Magnetic resonance microscopy - Signal-to-noise ratio - Ultra-high field strength

    This work provides a systematic comparison of the signal-to-noise ratio (SNR), spatial resolution, acquisition time and metabolite limits-of-detection for magnetic resonance microscopy and spectroscopy at three different magnetic field strengths of 14.1 T, 17.6 T and 22.3 T (the highest currently available for imaging), utilizing commercially available hardware. We find an SNR increase of a factor 5.9 going from 14.1 T to 22.3 T using 5 mm radiofrequency (saddle and birdcage) coils, which results in a 24-fold acceleration in acquisition time and deviates from the theoretically expected increase of factor 2.2 due to differences in hardware. This underlines the importance of not only the magnetic field strengths but also hardware optimization. In addition, using a home-built 1.5 mm solenoid coil, we can achieve an isotropic resolution of (5.5 µm)3 over a field-of-view of 1.58 mm × 1.05 mm × 1.05 mm with an SNR of 12:1 using 44 signal averages in 58 h 34 min acquisition time at 22.3 T. In light of these results, we discuss future perspectives for ultra-high field Magnetic Resonance Microscopy and Spectroscopy.

    What happens in Europe stays in Europe : apparent evolution by an invader does not help at home
    Pal, Robert W. ; Maron, John L. ; Nagy, David U. ; Waller, Lauren P. ; Tosto, Ambra ; Liao, Huixuan ; Callaway, Ragan M. - \ 2020
    Ecology (2020). - ISSN 0012-9658
    biogeography - common garden experiment - competition - EICA hypothesis - invasion - reintroduction - Solidago gigantea - transcontinental research

    Some invasive plant species rapidly evolve greater size and/or competitive ability in their nonnative ranges. However, it is not well known whether these traits transfer back to the native range, or instead represent genotype-by-environment interactions where traits are context specific to communities in the new range where the evolution occurred. Insight into transferability vs. context specificity can be tested using experiments performed with individuals from populations from the native and nonnative ranges of exotic invasive species. Using a widespread invasive plant species in Europe, Solidago gigantea, we established reciprocal common garden experiments in the native range (Montana, North America; n = 4) and the nonnative range (Hungary, Europe; n = 4) to assess differences in size, vegetative shoot number, and herbivory between populations from the native and nonnative ranges. In a greenhouse experiment, we also tested whether the inherent competitive ability of genotypes from 15 native and 15 invasive populations differed when pitted against 11 common native North American competitors. In common gardens, plants from both ranges considered together produced five times more biomass, grew four times taller, and developed five times more rhizomes in the nonnative range garden compared to the native range garden. The interaction between plant origin and the common garden location was highly significant, with plants from Hungary performing better than plants from Montana when grown in Hungary, and plants from Montana performing better than plants from Hungary when grown in Montana. In the greenhouse, there were no differences in the competitive effects and responses of S. gigantea plants from the two ranges when grown with North American natives. Our results suggest that S. gigantea might have undergone rapid evolution for greater performance abroad, but if so, this response does not translate to greater performance at home.

    Policy Brief No. 15: Flood-resilient cities start at home
    Hartmann, Thomas ; Doorn-Hoekveld, Willemijn van; Rijswick, Marleen van; Spit, T.J.M. - \ 2020
    IWRA (IWRA Policy Brief, Blue Series 15) - 4 p.
    Higher Serum Vitamin D Concentrations Are Longitudinally Associated with Better Global Quality of Life and Less Fatigue in Colorectal Cancer Survivors up to 2 Years after Treatment
    Koole, Janna L. ; Bours, Martijn J.L. ; Roekel, Eline H. van; Breedveld-Peters, José J.L. ; Duijnhoven, Fränzel J.B. van; Ouweland, Jody van den; Breukink, Stéphanie O. ; Janssen-Heijnen, Maryska L.G. ; Keulen, Eric T.P. ; Weijenberg, Matty P. - \ 2020
    Cancer Epidemiology Biomarkers & Prevention 29 (2020)6. - ISSN 1055-9965 - p. 1135 - 1144.

    BACKGROUND: Vitamin D status may be an important determinant of health-related quality of life of colorectal cancer survivors. The current study investigated longitudinal associations between serum 25-hydroxyvitamin D3 (25OHD3) concentrations and quality of life in stage I-III colorectal cancer survivors up to 2 years after treatment. METHODS: Patients with colorectal cancer (n = 261) were included upon diagnosis. Home visits (including blood sampling) were performed at diagnosis and at 6 weeks, 6 months, 1 year, and 2 years after treatment. Serum 25OHD3 concentrations were measured using LC/MS-MS and adjusted for season. Validated questionnaires were used to assess global quality of life and cognitive functioning (EORTC-QLQ-C30), fatigue (EORTC-QLQ-C30 and Checklist Individual Strength, CIS), and depression and anxiety (Hospital Anxiety and Depression Scale). Statistical analyses were performed using linear mixed models and adjusted for sex, age, time since diagnosis, therapy, comorbidities, physical activity, and body mass index. RESULTS: At diagnosis, 45% of patients were vitamin D deficient (<50 nmol/L). After treatment, 25OHD3 concentrations increased on average with 3.1 nmol/L every 6 months. In confounder-adjusted models, 20 nmol/L increments in 25OHD3 were longitudinally associated with increased global quality of life [β 2.9; 95% confidence interval (CI), 1.5-4.3] and reduced fatigue (EORTC-QLQ-C30 subscale: β -3.5; 95% CI, -5.3 to -1.8 and CIS: β -2.8; 95% CI, -4.7 to -0.9). Observed associations were present both within and between individuals over time. CONCLUSIONS: Higher concentrations of 25OHD3 were longitudinally associated with better global quality of life and less fatigue in colorectal cancer survivors. IMPACT: This study suggests that higher 25OHD3 concentrations may be beneficial for colorectal cancer survivors. Future intervention studies are needed to corroborate these findings.

    Interdisciplinary communication and collaboration as key to improved nutritional care of malnourished older adults across health‐care settings – A qualitative study
    Verwijs, Marije H. ; Puijk‐Hekman, Saskia ; Heijden, Ellen ; Vasse, Emmelyne ; Groot, Lisette C.P.G.M. ; Schueren, Marian A.E. - \ 2020
    Health Expectations (2020). - ISSN 1369-6513
















    Background
    Malnutrition is a risk factor for impaired functionality and independence. For optimal treatment of malnourished older adults (OA), close collaboration and communication between all stakeholders involved (OA, their caregivers and health‐care and welfare professionals) is important. This qualitative study assesses current collaboration and communication in nutritional care over the continuum of health‐care settings and provides recommendations for improvement.
    Methods
    Eleven structured focus group interviews and five individual interviews took place in three regions across the Netherlands from November 2017 until February 2018, including OA, caregivers and health‐care and welfare professionals. Various aspects of collaboration and communication between all stakeholders were discussed. Interviews were transcribed and analysed using a thematic approach.
    Results
    Six main themes emerged: causes of malnutrition, knowledge and awareness, recognition and diagnosis of malnutrition, communication, accountability and food preparation and supply. Physical and social aspects were recognized as important risk factors for malnutrition. Knowledge and awareness regarding malnutrition were acknowledged as being insufficient among all involved. This may impair timely recognition and diagnosis. Responsibility for nutritional care and its communication to other disciplines are low. Food preparation and supply in hospitals, rehabilitation centres and home care are below expected standards.
    Conclusion
    Many stakeholders are involved in nutritional care of OA, and lack of communication and collaboration hinders continuity of nutritional care over health‐care settings. Lack of knowledge is an important risk factor. Establishing one coordinator of nutritional care is suggested to improve collaboration and communication across health‐care settings.
    Improving dietary intake during lunch through the provision of a healthy school lunch at Dutch primary schools : Design of a pretest-posttest effectiveness study
    Kleef, Ellen Van; Rongen, Frédérique C. ; Vingerhoeds, Monique H. ; Dijkstra, Coosje ; Seidell, Jaap C. - \ 2020
    BMC Public Health 20 (2020)1. - ISSN 1471-2458
    Primary school - School lunch - School-based intervention - Vegetables

    Background: Since there is a shift from eating lunch at home to eating lunch at primary schools in the Netherlands, providing a school lunch may be an important opportunity to improve the diet quality of Dutch children. Therefore, the aim of this Healthy School Lunch project is to encourage healthy eating behavior of children at primary schools by offering a healthy school lunch, based on the guidelines for a healthy diet. In this study, two research questions will be addressed. The first research question is: What and how much do children consume from a self-served school lunch and how do they evaluate the lunch? The second research question is: Do children compensate healthier school lunches by eating less healthy outside school hours? The purpose of this paper is to report the rationale and study design of this study. Methods: In the Healthy School Lunch project children in grades 5-8 (aged 8-12 years) of three primary schools in the Netherlands will receive a healthy school lunch for a 6-month period. To answer research question 1, lunch consumption data will be collected at baseline and again at 3- A nd 6-months. This will be measured with lunch photos and questionnaires among children. To answer the second research question, a quasi-experimental, pre-test post-test intervention-comparison group design (3 intervention schools and 3 comparison schools) will be carried out. Potential compensation effects will be measured with a single brief questionnaire among parents at the three intervention and three comparison schools at month 6 of the lunch period. The school lunch will also be evaluated by parents (discussion groups) and teachers and support staff (brief questionnaires). Discussion: Results of this study will provide valuable information to influence future school lunch interventions and policies. Trial registration: This study is registered at the Netherlands trial register (NTR): Trialregister.nl, Trial NL7402 (NTR7618), registered retrospectively at 2018-11-13.

    A cross-sectional comparison of meal delivery options in three international cities
    Poelman, Maartje P. ; Thornton, Lukar ; Zenk, Shannon N. - \ 2020
    European Journal of Clinical Nutrition (2020). - ISSN 0954-3007

    Background/Objectives: The recent upsurge in online food delivery options has reshaped the food market. The aim of this study was to examine between-city differences and within-city socioeconomic differences in the number of online meal delivery options, meal types, and meal prices. Subjects/Methods: A cross-sectional study was conducted in three international cities within high-income countries. Across 10 sampled addresses in Chicago (USA), Amsterdam (The Netherlands), and Melbourne (Australia), meal delivery options provided by a major international meal delivery company were sampled. Bonferroni adjusted Chi2-tests were conducted to assess between-city differences as well as within-city socioeconomic differences in price levels. Results: Across the 10 sampled addresses in each city, there were n = 1668 delivery options in Chicago, n = 1496 in Amsterdam and n = 1159 in Melbourne. In total, 10,220 keywords (representing 148 different meal types) were recorded across all 4323 delivery options. In all three cities, burgers, pizza and Italian were in the top 10 of most advertised meals. Compared with Amsterdam, healthy and meat-free meals were less commonly advertised in Chicago and Melbourne. In Chicago, the number of delivery options for addresses in the most disadvantaged and least disadvantaged neighborhoods were similar. In Amsterdam and Melbourne, a greater number of options was available for the addresses in the least disadvantaged neighborhoods. Conclusions: This study highlights the vast number of meal delivery options individuals can source when at home via a meal delivery service, noting the number differs across and within cities. In each city, most food types available for delivery were not considered healthy.

    Developing a Business and Human Rights Treaty: Lessons from the Deep Seabed Mining Regime Under the United Nations Convention on the Law of the Sea
    Bernaz, Nadia ; Pietropaoli, Irene - \ 2020
    Business and Human Rights Journal (2020). - ISSN 2057-0198 - 21 p.
    This article delves into the deep seabed mining regime under the United Nations Convention on the Law of the Sea (UNCLOS) with a view to inform the negotiating process of the proposed business and human rights (BHR) treaty. It highlights points of convergence and divergence between the two regulatory regimes and explores how the BHR treaty negotiations could draw from the deep seabed mining regime with regard to the responsibility and liability of states and corporations. In particular, it suggests that a BHR treaty could incorporate some of the arrangements of UNCLOS to address state obligations and direct corporate human rights obligations, both of a general and specific nature, including the obligation to carry out human rights due diligence. The article also proposes a mechanism of responsibility and liability of states and corporations under the future BHR treaty going beyond UNCLOS and embracing residual liability for home and/or host states
    Movement ecology of large herbivores in African savannas: current knowledge and gaps
    Owen-Smith, Norman ; Hopcraft, Grant ; Morrison, Thomas ; Chamaillé-Jammes, Simon ; Hetem, Robyn ; Bennitt, Emily ; Langevelde, Frank Van - \ 2020
    Mammal Review 50 (2020)3. - ISSN 0305-1838 - p. 252 - 266.
    Africa - daily activity - home range - migration - population dispersion - predation - ungulates

    Nearly 90% of the world's large herbivore diversity occurs in Africa, yet there is a striking dearth of information on the movement ecology of these organisms compared to herbivores living in higher latitude ecosystems. The environmental context for movements of large herbivores in African savanna ecosystems has several distinguishing features. African large herbivores move in landscapes with high spatiotemporal variability, low predictability, seasonal restrictions in surface water as well as food resources, and exposure to a diverse assemblage of competitors, predators, and pathogens. These features influence mobility, diel activity routines, home-range fidelity, and exposure to predation. We review the knowledge that has been gained about the movements of African herbivores from Global Positioning System (GPS) telemetry and identify important gaps in knowledge that exist. Topics addressed include seasonal movement patterns, daily activity schedules, space utilisation, water dependency, responses to risks of predation, pathogen transmission, social affiliations, and local population density determination. While the growing number of GPS telemetry studies has addressed a wide range of topics in Africa, they remain fragmentary in terms of places and species represented. Most research has been focussed on three species, and practices for data sharing and analysis should be improved. African landscapes are changing perhaps faster than any other region on Earth, with rapidly expanding human populations, massive infrastructure development projects, and changes in climatic regimes. There is a crucial need to establish relationships between herbivore movements and their changing environments, especially in Africa where most of the world's large herbivore diversity resides.

    Spatial geochemistry influences the home range of elephants
    Sach, Fiona ; Yon, Lisa ; Henley, Michelle D. ; Bedetti, Anka ; Buss, Peter ; Boer, Willem Frederik de; Dierenfeld, Ellen S. ; Gardner, Amanda ; Langley-Evans, Simon C. ; Hamilton, Elliott ; Lark, Murray ; Prins, Herbert H.T. ; Swemmer, Anthony M. ; Watts, Michael J. - \ 2020
    Science of the Total Environment 729 (2020). - ISSN 0048-9697
    Elephant movement - Loxodonta africana - Minerals - Mining - Potentially toxic elements

    The unique geochemistry surrounding the Palabora Mining Company (PMC) land may act as a micronutrient hotspot, attracting elephants to the area. The PMC produces refined copper and extracts phosphates and other minerals. Understanding the spatial influence of geochemistry on the home range size of African elephants is important for elephant population management and conservation. The home ranges of collared elephants surrounding the PMC were significantly smaller (P = 0.001) than conspecifics in surrounding reserves, suggesting that their resource needs were met within these smaller areas. Environmental samples (soil, water and plants) were analysed from the mine area and along six transects radiating from the mine centre. Tail hair and faecal samples from elephants at the PMC, and conspecifics within the surrounding area were analysed. All samples were analysed for minerals essential to health and potentially toxic elements (PTEs; As, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se, U, V and Zn). Results show that the geochemistry at the PMC is different compared to surrounding areas, with significant elevations seen in all analysed minerals and PTEs in soil closer to the mine, thereby drawing the elephants to the area. Additionally significant elevations were seen in elements analysed in water and vegetation samples. Elephant tail hair from elephants at the mine was significantly greater in Cd, whilst Mg, P, Cu, As, Cd, Pb and U concentrations were significantly greater in elephant faecal samples at the mine compared to the non-mine samples. When micronutrient hotspots overlap with human activity (such as mining), this can lead to poor human-elephant coexistence and thus conflict. When managing elephant populations, the influence of mineral provision on elephant movement must be considered. Such detailed resource information can inform conservation efforts for coordinated programmes (UN SDGs 15 and 17) and underpin sustainable economic activity (UN SDG 8, 11 and 12).

    Home range and Long-Range Movements of the Nile Crocodile in Relation to the Anthropogenic pressure, Lake Nasser, Egypt
    Ezat, M. ; Naguib, M. ; Langevelde, F. van - \ 2020
    In: Wias Annual Conference 2020 WIAS - p. 76 - 76.
    Movements of animals determine and reflect home ranges and social interactions, provide insights into resource requirements and habitat usage, and allow to make predictions about individual and population responses to disturbances. The size, location and shape of a home range reflects an animals’ behavioural decisions as it searches for food, nesting sites, shelter and mates. Understanding movement behaviour and social structures is seen as prerequisite for effective conservation and management actions, particularly for apex predators with large home ranges because of their influence on lower trophic levels. The Nile crocodile Crocodylus niloticus is the second world’s largest reptile and the most iconic animal along the Nile. The Nile crocodile inhabits threatened wetlands and it is an important indicator species of environmental conditions. Lake Nasser in Egypt is the largest man-made lake world-wide and contains a large, but decreasing population providing unique opportunities to study their ecology and behaviour under fully free ranging conditions.However, despite its remote location, the crocodiles of Lake Nasser compete with local fishermen. Local crocodile populations become therefore increasingly threatened asmany individuals are killed every year, often by local fishermen. Yet, little is known about the behaviour and ecology of Nile crocodile and consequently local conservation programs lack information on the spatial distribution of crocodiles and whether they indeed consume fish in the same areas in which fishermen harvest their fish. Home ranges of Nile crocodiles generally centre around suitable basking sites in winter and expand to include favourable breeding (mating and nesting) and foraging sites in summer. However, these long-range movement are only anecdotally described and without determining factors that could explain these movements, e.g. the anthropogenic pressures in the lake. The aim of this PhD project is thus is to obtain fundamental insights into the distribution and movements of fully free ranging GPS tagged Nile crocodiles by determining their home ranges and long-range movements. In particular, determining seasonal changes in habitat use and movements to and from nesting sites is important to also understand the ecological requirements and to understand where and when crocodiles are exposed to threats by,for instance fishermen or changing water levels that effects the availability of the nesting habitat
    Stay and help or go (to help)? - Cooperative breeding in white-crested helmetshrikes
    Kuspiel, Miriam ; Kingma, Sjouke ; Bebbington, Kat ; Naguib, M. - \ 2020
    In: Wias Annual Conference 2020 WIAS - p. 75 - 75.
    Why would an individual forego or delay its own reproduction and instead help raising the offspring of others? Numerous studies have already established concepts and models addressing these questions. Yet the reasons for and forms of cooperative breeding can greatly vary between species, and various theoretical concepts on group and individual benefits lack practical evidence from the field. We will thus investigate social organization and dispersal in white-crested helmetshrikes Prionops plumatus. This bird species has rarely been studied, yet observations like same-sex offspring dispersing and founding a new group together prove it to be a fascinating system to unravel direct and indirect benefits of cooperative breeding tactics. We thus plan to 1) investigate the cooperative breeding system and dispersal patterns in white-crested helmetshrikes with modern techniques, 2)test group augmentation theories and cost-benefit trade-offs for staying versus dispersing in a new study system and 3) investigate the effect of gradual and abrupt environmental changes on group stability, home ranges, dispersal and reproductive success. We collect data in the Mbuluzi Game Reserve in eSwatini where approximately 30 wild groups of white-crested helmetshrikes live, using a combination of genetic and observational approaches.Our findings will contribute to the understanding of cooperative breeding in non-human animals.
    Optimisation and field validation of odour-baited traps for surveillance of Aedes aegypti adults in Paramaribo, Suriname
    Visser, Tessa M. ; Cock, Marieke P. De; Hiwat, Hélène ; Wongsokarijo, Merril ; Verhulst, Niels O. ; Koenraadt, Constantianus J.M. - \ 2020
    Parasites & Vectors 13 (2020)1. - ISSN 1756-3305
    Aedes aegypti - Carbon dioxide - Host-seeking - Odour-baited traps - Odour-blends - Trapping

    Background: Emerging arboviral diseases like Zika, dengue and chikungunya that are transmitted by Aedes aegypti mosquitoes, are increasingly threatening human health. Blends of human-like synthetic chemical attractants can be used to attract host-seeking mosquitoes. The aim of this study was to test new combinations of traps and odour baits in the laboratory, followed by testing the best candidates in the field to improve Ae. aegypti monitoring and surveillance. Methods: First, the BG-Suna trap was evaluated for capturing laboratory-reared Ae. aegypti by testing normal and inverted positions in screen cage tests. Secondly, the attractiveness of the MB5 blend, CO2, and their combination was tested. Thirdly, we tested the attractiveness of different trap types (BG-Suna, BG-Sentinel, MM-X and CDC light trap). Finally, we confirmed laboratory results in the field in Paramaribo, Suriname, using the MB5 and BG-Lure odour blends, CO2 and the BG-Sentinel and BG-Bowl trap using a Latin Square design. Results: The MB5 blend in combination with CO2 outperformed traps baited only with CO2 or MB5 in screen cage tests (P < 0.0001). The BG-Sentinel trap performed equally well as the inverted BG-Suna and was taken to the field (P = 0.729). In the field, we captured Ae. aegypti, Cx. quinquefasciatus and Cx. nigripalpus. We confirmed the laboratory results and found that the combination of the MB5 blend and CO2 almost doubled Ae. aegypti female captures (P = 0.004) and more than doubled Culex spp. female captures (P = 0.005) compared to using only CO2. Interestingly, the MB5 blend outperformed the commercially available BG-Lure, in the BG-Sentinel (P < 0.001). The BG-Bowl also attracted Ae. aegypti when baited with the MB5 blend in similar numbers as the BG-Sentinel baited with the MB5 (P = 0.362). Conclusions: Our study demonstrated that the BG-Sentinel trap baited with the MB5 blend and CO2 outperforms the current golden standard (BG-Sentinel trap with BG-Lure) for monitoring Ae. aegypti females and males, in both laboratory and field experiments. The BG-Bowl baited with the MB5 blend is a good candidate for home use. Finally, the results show that CO2 is an indispensable component of the attractive blend.[Figure not available: see fulltext.]

    The ecology of wild zebra finch song – why do they sing?
    Loning, Hugo ; Griffith, Simon C. ; Naguib, M. - \ 2020
    In: Wias Annual Conference 2020 WIAS - p. 35 - 35.
    The zebra finch Taeniopygia guttata is the most studied songbird in the lab but the functions of their song in the wild, Australia’s arid zone, remain unclear. Like many songbirds,male zebra finches sing to attract a female. However, unlike the typically studied songbirds,zebra finches are nomadic birds that live in fission-fusion societies. They pair early in life (sometimes <100 days) and have extremely faithful monogamous relations. Nevertheless,males sing throughout their life. So why do zebra finches sing? In this talk I present data collected at Fowlers Gap Arid Zone Research Station in New South Wales, Australia, home of the world’s only nest box breeding population of zebra finches. Using advanced audio recording techniques and standard behavioural observations, I show that zebra finchessing uncharacteristically soft and that they sing in a variety of contexts, such as in groups at social areas. By studying this lab ‘supermodel’ in the wild, where it evolved, this research may bridge the gap between our understanding of this species in the lab and birdsong in general, already one of the best studied model systems for animal communication.
    A multi-method approach to explore environmental governance: a case study of a large, densely populated dry forest region of the neotropics
    Siegmund-Schultze, Marianna - \ 2020
    Environment, Development and Sustainability (2020). - ISSN 1387-585X
    Caatinga - Constellation analysis - Land use change - Multi-level governance - Social–ecological systems - System dynamics

    Semiarid regions are often secondary on the national to global (scientific) agenda, especially if abundant vegetation elsewhere draws attention and the local population is considered backwards thinking and poverty-stricken. The Caatinga, our case study, is such a region, home to millions of Brazilians and a vast biodiversity. Unfortunately, a widely uncoordinated land use change and biodiversity decline are happening, while farmers’ livelihoods are at risk. We hypothesize substantial weaknesses in the current governance practices. To explore governance of the less noticed region, we conducted interviews and field visits and complemented the findings with the literature and internet resources. Our multi-method approach combines the social–ecological systems framework with constellation analysis and dynamic modeling. The aim was to understand the current state of governance in the region and identify clues for more sustainable land management. The use and conservation of Caatinga are negotiated at multiple levels, which are only sporadically interlinked. The conversion of forest land into alternative land uses shifts and shares responsibility among different sectors, while cross-sectoral cooperation is rarely observed. The region and its population face massive prejudices. Obstructing attitudes, such as thinking in dichotomies, and paternalistic and opportunistic approaches, are being addressed by some new coalitions taking alternative action. It is unlikely that these isolated initiatives will converge by themselves to a larger transformation toward sustainable resource use. There is a need to bring the dispersed actions in a more focused and coordinated approach, integrating socioeconomic and ecological concerns, values, and partnerships.

    Homegarden commercialization: extent, household characteristics, and effect on food security and food sovereignty in Rural Indonesia
    Abdoellah, Oekan S. ; Schneider, Mindi ; Nugraha, Luthfan Meilana ; Suparman, Yusep ; Voletta, Cisma Tami ; Withaningsih, Susanti ; Parikesit, A.A. ; Heptiyanggit, Amanda ; Hakim, Lukmanul - \ 2020
    Sustainability Science 15 (2020). - ISSN 1862-4065 - p. 797 - 815.
    Homegardens have long been recognized for contributing to household food security, nutritional status, and ecological sustainability in especially poor, rural areas in low-income countries. However, as markets and policies drive the commercialization of food and farming systems, and of rural livelihoods in general, it becomes increasingly difficult for small-holder farmers to maintain homegarden plots. Rather than autonomous spaces to grow food for self-consumption, farmers are transforming the land around their dwellings into an income-generating space by planting commercial crops for sale in urban and processing markets. The objective of this study was to examine homegarden commercialization in the Upper Citarum Watershed of West Java, Indonesia, and its effects on food security and food sovereignty. We employed a mixed-method approach to survey 81 village households involved in agricultural production. For quantitative analysis, we calculated a “homegarden commercialization index,” and developed indicator frameworks to examine relationships between commercialization, household food security, and food-related decision-making. Accompanied by insights from qualitative interviews, our results show that homegardens are highly commercialized, which contributes to the spread of monocultural production in the region. We argue that homegardens should be included and supported in food, agricultural, health, environmental, and rural development policy, in Indonesia and generally.
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