62 research outputs found
How to evaluate the impact of citizen-science projects: The case of urban green projects in Suriname
“What did we contribute with our citizen science monitoring and how can we evaluate this?” is the question the project team of the Geo-Information Science and Earth Observation Faculty at University of Twente and Tropenbos Suriname are tackling in this report. The team conducted two projects on the role and use of urban green spaces in the Greater Paramaribo area, Suriname, from 2019 to 2022. One core activity was to set up citizen science-based monitoring of urban green space use and climate data in various locations across the city region. To scope different impact assessment approaches, this report summarises existing reviews on how to evaluate the impact of citizen science projects and related works and summarises key approaches on When and Why evaluate?, Who is evaluating?, What to evaluate?, How to evaluate? and How to communicate the findings? Then, the report applies our findings from the literature review as a framework to evaluate the citizen science part of the urban green projects in Paramaribo. We then report our findings on evaluating the experience of the citizen scientists, a science products inventory and educational materials we developed, a usability and usefulness analysis of the dashboard visualising the collected data and impact stories on how awareness among stakeholders might have changed.We reflected on our evaluation in two ways. First: What did we learn for future projects and creating actionable knowledge? We summarised these reflections with respect to interaction, sharing, geo-technology and viability and continuity. Second: What did we learn about evaluating a citizen science project
Tolerance to fusarium verticillioides infection and fumonisin accumulation in maize F1 hybrids and subsequent F2 populations
CITATION: Ouko, Abigael et al. 2020. Tolerance to fusarium verticillioides infection and fumonisin accumulation in maize F 1 hybrids and subsequent F 2 populations. Agronomy Journal, 112:2432–2444, doi.org/10.1002/agj2.20145.The original publication is available at: https://www.researchgate.netFusarium verticillioides causes Fusarium ear rot (FER) in maize (Zea mays L.), thus
reducing grain quality, yield, and contaminates grains with fumonisins. Grain infection
by these fungi occurs before harvest and selection of parental lines resistant to
fumonisin accumulation for breeding purposes is the most effective and environmentally
friendly control strategy for F. verticillioides. This study intended to evaluate F1
hybrids and F2 breeding populations in Kenya for improved resistance to FER and
fumonisin contamination. Trials were artificially inoculated and FER severity, F. verticillioides
accumulation, and fumonisin contamination were determined. Inheritance
of resistance was also determined in the F1 hybrids. CML444 × MIRTC5, R119W ×
CKL05015, and CML444 × CKL05015 exhibited little to no FER and had the least
fungal and fumonisin contamination, respectively. Inbred lines CML495, CKL05015,
and P502 had negative, significant general combining ability (GCA) estimates for
F. verticillioides colonization and fumonisin contamination, but positive, significant
GCA estimates for 1,000-kernel weight, respectively. The genotype × environment
interaction was the main source of variation observed in the F2 populations with
R119W × CKL05015 and CML444 × CKL05015 being the most tolerant to fungal
and fumonisin contamination in Kiboko and MIRTC5 × CML495 the most tolerant
in Katumani.Publisher's versio
Wnt signalling and cancer stem cells
[Abstract] Intracellular signalling mediated by secreted Wnt proteins is essential for the establishment of cell fates and proper tissue patterning during embryo development and for the regulation of tissue homeostasis and stem cell function in adult tissues. Aberrant activation of Wnt signalling pathways has been directly linked to the genesis of different tumours. Here, the components and molecular mechanisms implicated in the transduction of Wnt signal, along with important results supporting a central role for this signalling pathway in stem cell function regulation and carcinogenesis will be briefly reviewed.Ministerio de Ciencia e Innovación; SAF2008-0060
Environmental chemical stressors as epigenome modifiers:a new horizon in assessment of toxicological effects
In eukaryotic cells, chromatin transformation from euchromatin into heterochromatin as a means of controlling gene expression and replication has been known as the ?accessibility hypothesis?. The interplay of epigenetic changes including histone modifications, DNA methylation, RNA interference (RNAi) and other functional epigenetic components are intricate. It is believed that these changes are well-programmed, inherited and can be modified by environmental contaminant stressors. Environmentally-driven epigenetic alterations during development, e.g. embryonic, foetal or neonatal stage, may influence disease susceptibility in adulthood. Therefore, understanding how epigenome modifications develop in response to environmental chemicals and, how epigenetic-xenobiotic interactions influence human health will shed new insights into gene-environment interactions in the epidemiology of several diseases including cancer. In this review, we consider studies of chemical modifiers including nutritional and xenobiotic effects on epigenetic components in vitro or in vivo. By examining the most-studied epigenome modifications and how their respective roles are interlinked, we highlight the central role of xenbiotic-modified epigenetic mechanisms. A major requirement will be to study and understand effects following environmentally-relevant exposures. We suggest that the study of epigenetic toxicology will open up new opportunities to devise strategies for the prevention or treatment of at-risk populations
Evaluation of Agronomic Characteristics, Disease Incidence, Yield Performance, and Aflatoxin Accumulation among Six Peanut Varieties (Arachis hypogea L.) Grown in Kenya
Diseases contribute to attainment of less than 50% of the local groundnut potential yield in Kenya. This study aimed to evaluate the agronomic characteristics (flowering and germination), disease incidence, yield performance (biomass, harvest index, 100-pod, 100-seed, and total pod weight), and aflatoxin accumulation in six peanut varieties. A field experiment was conducted using four newly improved peanut varieties: CG9, CG7, CG12, and ICGV-SM 90704 (Nsinjiro), and two locally used varieties: Homabay local (control) and 12991, and in a randomized complete block design with three replications. The disease identification followed the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT) rating scale and further isolation of fungal contaminants was conducted by a direct plating technique using potato dextrose agar. The aflatoxin levels in the peanuts were determined after harvesting using the ultrahigh performance liquid chromatography and fluorescence detection (UHPLC-FLD) technique. ICGV-SM 90704 showed the least average disease incidence of 1.31 ± 1.75%, (P < 0.05); the lowest total aflatoxin levels (1.82 ± 1.41 μg kg−1) with a range 0.00–0.85 μg kg−1 for total aflatoxins and a range 0.00–1.24 μg kg−1 for Aflatoxin B1. The locally used varieties (12991 and the control) revealed the highest disease incidence (5.41 ± 8.31% and 7.41 ± 1.88%), respectively. ICGV-SM 90704 was the best performing among all the six varieties with an average total pod weight (9.22 ± 1.19 kg), 100-pod weight (262.93 ± 10.8 g), and biomass of (27.21 ± 5.05 kg) per row. The 12991 variety and the control showed the least total pod weight (1.60 ± 0.28 and 1.50 ± 1.11 kg, respectively) (P = 0.0001). The newly improved varieties showed lower disease rates, low levels of aflatoxins, and higher yields than the locally used varieties
Epidemiological connectivity between humans and animals across an urban landscape
Urbanization is predicted to be a key driver of disease emergence through human exposure to novel, animal-borne pathogens. However, while we suspect that urban landscapes are primed to expose people to novel animal-borne diseases, evidence for the mechanisms by which this occurs is lacking. To address this, we studied how bacterial genes are shared between wild animals, livestock, and humans (n = 1,428) across Nairobi, Kenya—one of the world’s most rapidly developing cities. Applying a multilayer network framework, we show that low biodiversity (of both natural habitat and vertebrate wildlife communities), coupled with livestock management practices and more densely populated urban environments, promotes sharing of Escherichia coli–borne bacterial mobile genetic elements between animals and humans. These results provide empirical support for hypotheses linking resource provision, the biological simplification of urban landscapes, and human and livestock demography to urban dynamics of cross-species pathogen transmission at a landscape scale. Urban areas where high densities of people and livestock live in close association with synanthropes (species such as rodents that are more competent reservoirs for zoonotic pathogens) should be prioritized for disease surveillance and control
Epidemiological connectivity between humans and animals across an urban landscape
Urbanization is predicted to be a key driver of disease emergence through human exposure to novel, animal-borne pathogens. However, while we suspect that urban landscapes are primed to expose people to novel animal-borne diseases, evidence for the mechanisms by which this occurs is lacking. To address this, we studied how bacterial genes are shared between wild animals, livestock, and humans (n = 1,428) across Nairobi, Kenya—one of the world’s most rapidly developing cities. Applying a multilayer network framework, we show that low biodiversity (of both natural habitat and vertebrate wildlife communities), coupled with livestock management practices and more densely populated urban environments, promotes sharing of Escherichia coli–borne bacterial mobile genetic elements between animals and humans. These results provide empirical support for hypotheses linking resource provision, the biological simplification of urban landscapes, and human and livestock demography to urban dynamics of cross-species pathogen transmission at a landscape scale. Urban areas where high densities of people and livestock live in close association with synanthropes (species such as rodents that are more competent reservoirs for zoonotic pathogens) should be prioritized for disease surveillance and control
Implementation of a comprehensive program including psycho-social and treatment literacy activities to improve adherence to HIV care and treatment for a pediatric population in Kenya
BACKGROUND: To achieve good clinical outcomes with HAART, patient adherence to treatment and care is a key factor. Since the literature on how to care for pediatric HIV patients is limited, we describe here adherence interventions implemented in our comprehensive care program in a resource-limited setting in Kenya. METHODS: We based our program on factors reported to influence adherence to HIV care and treatment. We describe, in detail, our program with respect to how we adapted our clinical settings, implemented psycho-social support activities for children and their caregivers and developed treatment literacy for children and teenagers living with HIV/AIDS. RESULTS: This paper focused on the details of the program, with the treatment outcomes as secondary. However, our program appeared to have been effective; for 648 children under 15 years of age who were started on HAART, the Kaplan-Meier mortality survival estimate was 95.27% (95%CI 93.16-96.74) at 12 months after the time of initiation of HAART. CONCLUSION: Our model of pediatric HIV/AIDS care, focused on a child-centered approach with inclusion of caregivers and extended family, addressed the main factors influencing treatment adherence. It appeared to produce good results and is replicable in resource-limited settings
Inhibition of Fibroblast Growth by Notch1 Signaling Is Mediated by Induction of Wnt11-Dependent WISP-1
Fibroblasts are an integral component of stroma and important source of growth factors and extracellular matrix (ECM). They play a prominent role in maintaining tissue homeostasis and in wound healing and tumor growth. Notch signaling regulates biological function in a variety of cells. To elucidate the physiological function of Notch signaling in fibroblasts, we ablated Notch1 in mouse (Notch1Flox/Flox) embryonic fibroblasts (MEFs). Notch1-deficient (Notch1−/−) MEFs displayed faster growth and motility rate compared to Notch1Flox/Flox MEFs. Such phenotypic changes, however, were reversible by reconstitution of Notch1 activation via overexpression of the intracellular domain of Notch1 (NICD1) in Notch1-deficient MEFs. In contrast, constitutive activation of Notch1 signaling by introducing NICD1 into primary human dermal fibroblasts (FF2441), which caused pan-Notch activation, inhibited cell growth and motility, whereas cellular inhibition was relievable when the Notch activation was countered with dominant-negative mutant of Master-mind like 1 (DN-MAML-1). Functionally, “Notch-activated” stromal fibroblasts could inhibit tumor cell growth/invasion. Moreover, Notch activation induced expression of Wnt-induced secreted proteins-1 (WISP-1/CCN4) in FF2441 cells while deletion of Notch1 in MEFs resulted in an opposite effect. Notably, WISP-1 suppressed fibroblast proliferation, and was responsible for mediating Notch1's inhibitory effect since siRNA-mediated blockade of WISP-1 expression could relieve cell growth inhibition. Notch1-induced WISP-1 expression appeared to be Wnt11-dependent, but Wnt1-independent. Blockade of Wnt11 expression resulted in decreased WISP-1 expression and liberated Notch-induced cell growth inhibition. These findings indicated that inhibition of fibroblast proliferation by Notch pathway activation is mediated, at least in part, through regulating Wnt1-independent, but Wnt11-dependent WISP-1 expression
Dose-dependent alcohol-induced alterations in chromatin structure persist beyond the window of exposure and correlate with fetal alcohol syndrome birth defects
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