Effect of temperature on the in vitro multiplication of seven Radopholus similis isolates from different banana producing zones of the world

Une étude a été réalisée afin de comparer l'effet de la température sur le taux de multiplication de divers isolats du nématode #Radopholus similis en élevage monoxénique sur rondelles de carottes. Ces isolats ont été collectés sur racines de bananiers dans sept zones productrices du monde (Costa Rica, Martinique, Guadeloupe, Guinée, Côte d'Ivoire, Sri Lanka, et Queensland). Cette étude a été divisée en deux parties. Dans la première, les différents isolats ont été étudiés séparément, à quatre températures : 21, 24, 27 et 30°C. Dans la seconde, les sept isolats ont été étudiés en même temps à deux températures : 30 et 33°C. Les différents isolats se comportent de la même manière vis-à-vis de la température. La croissance des populations est très faible à 21°C et augmente fortement avec la température jusqu'à un maximum à 30°C pour chuter brusquement à 33°C. En revanche ces isolats se différencient par leur taux intrinsèque de multiplication, ceux de Côte d'Ivoire, du Costa Rica et de Guinée présentant les plus forts taux de multiplication. A l'opposé, les isolats de Martinique et du Queensland ont les taux les plus faibles. Ces résultats confirment la très forte diversité biologique au sein de l'espèce #Radopholus similis. (Résumé d'auteur

Phylodynamics reveals extinction-recolonization dynamics underpin apparently endemic vampire bat rabies in Costa Rica

Variation in disease incidence in wildlife is often assumed to reflect environmental or demographic changes acting on an endemic pathogen. However, apparent endemicity might instead arise from spatial processes that are challenging to identify from traditional data sources including time series and field studies. Here, we analysed longitudinal sequence data collected from rabies virus outbreaks over 14 years in Costa Rica, a Central American country that has recorded continuous vampire bat-transmitted rabies outbreaks in humans and livestock since 1985. We identified five phylogenetically distinct lineages which shared most recent common ancestors with viruses from North and South America. Bayesian phylogeographic reconstructions supported bidirectional viral dispersals involving countries to the north and south of Costa Rica at different time points. Within Costa Rica, viruses showed little contemporaneous spatial overlap and no lineage was detected across all years of surveillance. Statistical models suggested that lineage disappearances were more likely to be explained by viral extinctions than undetected viral circulation. Our results highlight the importance of international viral dispersal for shaping the burden of rabies in Costa Rica, suggest a Central American corridor of rabies virus invasions between continents, and show that apparent disease endemicity may arise through recurrent pathogen extinctions and reinvasions which can be readily detected in relatively small datasets by joining phylodynamic and modelling approaches

Visualization of 40 Years of Tropical Cyclone Positions and Their Rainfall

Correos de investigadores: [email protected] || [email protected] || [email protected] || [email protected] article focuses on a visualization of tropical cyclone track data occurring over a 40- year period (1970–2010) and their relationship with (extremely) heavy rainfall reported by 88 Central American weather stations. The purpose of the visualization is to associate the paths of tropical cyclones in oceanic areas with heavy rainfall inland. Thus, the potential for producing a set of rainfall patterns might somehow help in predicting where different impacts like flooding might occur when tropical cyclones develop in specific oceanic regions. The visualization will serve as a key tool for CIGEFI scientists to apply in their work to determine critical positions of the tropical cyclones associated with extremely heavy rainfall events at daily timescales.Universidad de Costa Rica/[805-B9-454]/UCR/Costa RicaUniversidad de Costa Rica/[805-C0-610]/UCR/Costa RicaUniversidad de Costa Rica/[EC-497]/UCR/Costa RicaUniversidad de Costa Rica/[805-A4-906]/UCR/Costa RicaUniversidad de Costa Rica/[805-C0-074]/UCR/Costa RicaUniversidad de Costa Rica/[805-A1-715]/UCR/Costa RicaUniversidad de Costa Rica/[805-B0-810]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de FísicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

Physical factors contributing to rural water supply functionality performance in Uganda

This report communicates the findings generated from one of the project surveys – deconstruction and forensic analysis of 50 individual water points in Uganda. The report presents the new data generated to Uganda’s groundwater resource potential; the nature and condition of hand-pump borehole installations; and the significance of both of these factors to service performance. Based on the evidence collected, the main physical factors affecting functionality performance within Uganda are the poor condition of handpump components, and the complex aquifer resource. The impact of these factors can be mitigated through appropriate material choice for handpump components (non GI), increased investment in borehole siting and testing, and adequate accessibility to repairs and maintenance capacity with breakdowns. These factors should not be considered to be the only driving forces of functionality outcomes in these regions of Uganda, however, and the results of this survey need to be examined alongside the wider project findings. Wider institutional arrangements, resources and dynamics, are likely to play a significant role in the implementation of appropriate borehole construction, siting and design; procurement processes; and the management capacity available for water points at national to local levels

Physical factors contributing to rural water supply functionality performance in Ethiopia

This report communicates the findings generated from one of the project surveys – deconstruction and forensic analysis of 50 individual water points in Ethiopia. The report presents the new data generated to Ethiopia’s groundwater resource potential; the nature and condition of hand-pump borehole installations; and the significance of both of these factors to service performance. Based on the evidence collected, the survey results indicate the main physical factors most likely to affect functionality performance within the Ethiopian Highlands are the relatively deep depth to groundwater and the poor condition of handpump components. The impact of these factors to functionality performance can be mitigated through appropriate pump technology choice (e.g. use of deeper handpump boreholes (HPB) lift design), handpump construction, and adequate accessibility to repairs and maintenance capacity with breakdowns. These factors should not, however, be considered to be the only driving forces of functionality outcomes in these regions of Ethiopia, and the results of this survey need to be examined alongside the wider project findings. Wider institutional arrangements, resources and dynamics, are likely to play a significant role in the implementation of appropriate borehole construction, siting and design; procurement processes; and the management capacity available for water points at national to local levels

How clusters create shared value in rural areas: An examination of six case studies

The main aim of this paper is to demonstrate that clusters can support the sustainable development of rural areas through the creation of shared value. This is done via the close examination of six different cases of rural clusters in Greece, Italy, Germany, Poland, Denmark, and Sweden. Qualitative as well as quantitative data were taken from the clusters, which demonstrated that their main business approaches naturally coincided with the creation of economic, social, and environmental benefits for the local communities in which they operated. The case clusters were created in a top-down manner, aimed at boosting regional R&D activities and making the local economy more competitive and more sustainable. However, private initiative took over and al-lowed these clusters to flourish because meeting the regions’ economic, social, and environmental needs successfully coincided with the target of the clusters’ own development and profitability. The results show that clusters, with their potential for shared value creation, can constitute a powerful engine for the revitalisation and development of rural areas, addressing the significant challenges which they are currently facing

Improvement of diaphragmatic performance through orthotopic application of decellularized extracellular matrix patch.

AbstractMuscle tissue engineering can provide support to large congenital skeletal muscle defects using scaffolds able to allow cell migration, proliferation and differentiation. Acellular extracellular matrix (ECM) scaffold can generate a positive inflammatory response through the activation of anti-inflammatory T-cell populations and M2 polarized macrophages that together lead to a local pro-regenerative environment. This immunoregulatory effect is maintained when acellular matrices are transplanted in a xenogeneic setting, but it remains unclear whether it can be therapeutic in a model of muscle diseases. We demonstrated here for the first time that orthotopic transplantation of a decellularized diaphragmatic muscle from wild animals promoted tissue functional recovery in an established atrophic mouse model. In particular, ECM supported a local immunoresponse activating a pro-regenerative environment and stimulating host muscle progenitor cell activation and migration. These results indicate that acellular scaffolds may represent a suitable regenerative medicine option for improving performance of diseased muscles

Drinking water quality from rural handpump-boreholes in Africa

Groundwater provides a vital source of drinking water for rural communities in many parts of Africa, particularly in the dry season when there are few safe alternative sources. This paper summarises results from a study (n = 428) assessing dry season water quality, both microbiological and inorganic chemistry, in handpump equipped boreholes (HPBs) across the Ethiopia Highlands (n = 142), Malawi (n = 162) and Uganda (n = 124) using a stratified, randomised sampling design. This study seeks to examine general water quality by randomly sampling rural groundwater supplies across larger areas with different geology and climate. The majority, 72%, of HPBs surveyed provide good quality dry season drinking water as defined by WHO drinking water quality criteria. Within this overall picture, the most notable constraints were from thermotolerant coliforms (TTCs), which exceeded the WHO drinking water guideline of zero colony forming units (cfu/100 ml) in 21% of sites (range 0–626 cfu/100 ml). TTC contamination was found to have a significant and positive correlation with annual average rainfall (ρ = 0.2, p = 0.00003). Across all three countries, WHO health based chemical drinking water quality values were exceeded at 9% of sites and were found for manganese (4%), fluoride (2.6%) and nitrate (2.5%); arsenic concentrations were below the guideline value of 10 μg l−1 (range 400 μg l−1) found in drinking water sources in Uganda challenges the decision by WHO not to formalise a health-based guideline for Mn. While the overall level of microbiological contamination from HPBs is low, results from this study strongly suggest that at a national and regional level, microbiological contamination rather than chemical contamination will provide a greater barrier to achieving targets set for improved drinking water quality under the UN-SDG 6. Efforts should be made to ensure that boreholes are properly sited and constructed effectively to reduce pathogen contamination

The Human Pancreas as a Source of Protolerogenic Extracellular Matrix Scaffold for a New-generation Bioartificial Endocrine Pancreas

OBJECTIVES: Our study aims at producing acellular extracellular matrix scaffolds from the human pancreas (hpaECMs) as a first critical step toward the production of a new-generation, fully human-derived bioartificial endocrine pancreas. In this bioartificial endocrine pancreas, the hardware will be represented by hpaECMs, whereas the software will consist in the cellular compartment generated from patient's own cells. BACKGROUND: Extracellular matrix (ECM)-based scaffolds obtained through the decellularization of native organs have become the favored platform in the field of complex organ bioengineering. However, the paradigm is now switching from the porcine to the human model. METHODS: To achieve our goal, human pancreata were decellularized with Triton-based solution and thoroughly characterized. Primary endpoints were complete cell and DNA clearance, preservation of ECM components, growth factors and stiffness, ability to induce angiogenesis, conservation of the framework of the innate vasculature, and immunogenicity. Secondary endpoint was hpaECMs’ ability to sustain growth and function of human islet and human primary pancreatic endothelial cells. RESULTS: Results show that hpaECMs can be successfully and consistently produced from human pancreata and maintain their innate molecular and spatial framework and stiffness, and vital growth factors. Importantly, hpaECMs inhibit human naïve CD4+ T-cell expansion in response to polyclonal stimuli by inducing their apoptosis and promoting their conversion into regulatory T cells. hpaECMs are cytocompatible and supportive of representative pancreatic cell types. DISCUSSION: We, therefore, conclude that hpaECMs has the potential to become an ideal platform for investigations aiming at the manufacturing of a regenerative medicine-inspired bioartificial endocrine pancreas