46 research outputs found

    Prospects of endosperm DNA in maize seed characterization

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    DNA based characterisation of maize germplasm has become the easiest and fastest approach to identify genetic diversity as compared to phenotyping. The conventional DNA source for genotyping is the leaf which required at least 2 weeks waiting period from seed planting to leaves sampling. This work exploits the use of endosperm DNA (EDNA) for the genotyping of maize germplasm. Maize endosperm was excised from maize seeds using pli¬ers, ground and used for Genomic DNA extraction (gDNA). Leaves DNA (LDNA) was also extracted concurrently. The extracted LDNA and EDNA were quantified and subjected to SSR-PCR. The mean concentrations of DNA extracted were 1575 ng/ul for the leaves and 526 ng/ul for endosperm. Though the difference in quantity of EDNA and LDNA were highly significant, the quality (A260/A280) for both EDNA and LDNA fall within 1.6-1.8 range of pure DNA index. SSR-PCR products using phi032 were similar for both EDNA and LDNA, indicating the usability of EDNA in genotyping. This seed based method of gDNA extraction takes less than 24 hours from sampling to quantification and genotyping. It also allows germination of sampled seeds, selection before planting, avoids the delay of planting and waiting in leaf sampling and saves field space

    Enhancing productivity of farmer-saved seed yam in Ghana: Positive selection and neem leaf powder factors

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    Recycling of diseased and pests infested seed yam ( Dioscorea spp.) has resulted in drastic yield reductions in yam production. The objective of this study was to determine the effect of positive selection on the quality of farmer-saved seed yam and also evaluate the effect of neem leaf powder in managing plant parasitic nematodes damage to yam. Two farming systems namely; Positive selection (PS) and Farmer practice (FP) and two soil amendment regimes; neem leaf powder at 20 g stand-1 (NA20) and no neem amendment (NA0) were tested on one variety of yam (Dente). A 2 x 2 x 1 factorial study, mounted on a randomised complete block design in a split plot arrangement was conducted in four replications. Positive selection occupied main plots; while Farmer practice occupied sub-plots. The study was conducted in eight communities located in two municipalities of Ghana, during 2015-2017. Parameters evaluated included Yam Mosaic Virus incidence and severity, incidence and severity of nematode cracks and galling on yam tubers, plant establishment and yield of yam. It was observed that Yam Mosaic Virus (YMV) disease incidence decreased from 38% in 2016 to 31% in 2017 in PS plots as a result of using virus-free planting materials. However, in FP plots, it increased from 67% in 2016 to 72% in 2017. Neem leaf powder amendment resulted in significantly (P< 0.05) low tuber galling (7%) compared with 40% in unamended plots. Similarly, PS plots yielded 7.7 t ha-1 compared to 5.9 t ha-1 in FP fields. In conclusion, Positive selection out-yielded FP by 30.5%; while PS-neem leaf powder interaction resulted in 38.5% over and above FP without neem amendment.Le recyclage des semences d\u2019igname ( Dioscorea spp.) contamin\ue9es par des maladies et des parasites a entra\ueen\ue9 une r\ue9duction drastique du rendement de la production d\u2019igname. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer l\u2019effet de la s\ue9lection positive sur la qualit\ue9 des semences d\u2019igname conserv\ue9es par les agriculteurs et \ue9galement d\u2019\ue9valuer l\u2019effet de la poudre de feuilles de neem dans la gestion des dommages caus\ue9s par les n\ue9matodes parasites des plantes. Deux syst\ue8mes agricoles \ue0 savoir; S\ue9lection positive (PS) et pratique paysanne (PF) et deux r\ue9gimes d\u2019amendement du sol; De la poudre de feuille de neem \ue0 20 g du stand-1 (NA20) et aucun amendement de neem (NA0) ont \ue9t\ue9 test\ue9s sur une vari\ue9t\ue9 d\u2019igname (Dente). Une \ue9tude factorielle de 2 x 2 x 1, mont\ue9e sur une dispositif en\ua0blocs al\ue9atoires complets dans un arrangement en parcelles divis\ue9es, a \ue9t\ue9 men\ue9e en quatre r\ue9p\ue9titions. S\ue9lection positive occup\ue9e parcelles principales; tandis que la pratique paysanne occupait des sous-parcelles. L\u2019\ue9tude a \ue9t\ue9 men\ue9e dans huit communaut\ue9s situ\ue9es dans deux municipalit\ue9s du Ghana en 2015-2017. Les param\ue8tres \ue9valu\ue9s comprenaient l\u2019incidence et la gravit\ue9 du virus de la mosa\uefque de l\u2019igname, l\u2019incidence et la gravit\ue9 des fissures de n\ue9matode et le grippage des tubercules de l\u2019igname, l\u2019\ue9tablissement de la plante et le rendement de l\u2019igname. Il a \ue9t\ue9 observ\ue9 que l\u2019incidence de la maladie caus\ue9e par le virus de la mosa\uefque \ue0 l\u2019igname (YMV) avait diminu\ue9 de 38% en 2016 \ue0 31% en 2017 dans les parcelles PS gr\ue2ce \ue0 l\u2019utilisation de mat\ue9riel de plantation d\ue9pourvu de virus. Cependant, dans les parcelles de PF, il est pass\ue9 de 67% en 2016 \ue0 72% en 2017. L\u2019amendement de poudre de feuille de Neem a entra\ueen\ue9 une r\ue9duction significative du galles des tubercules (P <0,05) (7%) par rapport \ue0 40% dans les parcelles non modifi\ue9es. De m\ueame, les parcelles de PS ont produit 7,7 t ha-1, contre 5,9 t ha-1 dans les champs de PF. En conclusion, la s\ue9lection positive a eu un rendement sup\ue9rieur de 30,5% \ue0 celui de la PF; tandis que l\u2019interaction de la poudre de feuille PS-neem a eu pour r\ue9sultat 38,5% de plus que FP sans amendement de nee

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Management of root-knot nematodes on Yam with Trichoderma viride

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    Root-knot nematodes (Meloidogyne spp.) are one of the most   economically damaging agents on yam producing fields which could lead to 100 % yield loss. The use of biocontrol agents such as fungi is among the sustainable methods recommended to manage the menace of rootknot nematode infection on yams. The potential of three isolates of Trichoderma virideto reduce soil populations of Meloidogyne spp. was evaluated at three yam producing locations in Ghana. Trichoderma viride was isolated from soil sampled from Atebubu (A), Kintampo (K) and Wenchi (W). Trichoderma viride suspensions at a concentration of 1.7 x 107spores/ml isolate was inoculated on three yam varieties one month after planting. Inoculation of T. viride resulted in significant reduction in Meloidogyne populations at all the locations on all the three yam varieties. At Atebubu, all the three isolates (A, K, W) reduced Meloidogyne populations by 78.8%, 66.8% and 66.2% respectively on Pona. Higher suppressive effects of 90% and 85.6% were achieved by isolate K on Afebetua at Atebubu and Kintampo respectively. Isolates A recorded the minimum control effect of 30.4% on Afebetua at Wenchi. No nematodes were recovered from the peels of inoculated tubers at harvest. Key words: Dioscorea rotundata, Meloidogyne spp, Root-knot nematodes, Trichoderma viride Gestion des nématodes cécidogènes à Trichoderma virideLes nématodes à galles (Meloidogyne spp.) sont l'un des agents les plus dommageables sur le plan économique dans les champs des producteurs d'igname, ce qui pourrait entraîner une perte de rendement de 100%. L'utilisation d'agents de lutte biologique tels que les champignons est parmi les méthodes durables recommandées pour gérer la menace de l'infection par les nématodes cécidogènes sur les ignames. Le potentiel de trois isolats de Trichoderma virideto réduit les populations de Meloidogyne spp. a été évalué dans trois sites de production qui vient d'ignames au Ghana. Trichoderma viride a été isolé à partir du sol échantillonné à partir d'Atebubu (A), Kintampo (K) et Wenchi (W). Des suspensions de Trichoderma viride à une concentration de 1,7 x 107spores / ml d'isolat ont été inoculées sur trois variétés d'ignames un mois après la plantation. L'inoculation de T. viride a entraîné une réduction significative des populations de Meloidogyne à tous les emplacements sur les trois variétés d'ignames. A Atebubu, tous les trois isolats (A, K, W) ont réduit les populations de Meloidogyne de 78,8%, 66,8% et 66,2% respectivement sur Pona. Des effets suppresseurs plus élevés de 90% et 85,6% ont été obtenus par l'isolat K sur Afebetua à Atebubu et Kintampo respectivement. Les isolats A ont enregistré l'effet de contrôle minimum de 30,4% sur Afebetua à Wenchi. Aucun nématode n'a été récupéré des pelures des tubercules inoculés lors de la récolte.Mots-clés: Dioscorea rotundata, Meloidogyne spp, Nématodes à galles, Trichoderma

    Annotation and anonymity: Playful photo-sharing by visiting groups of teenagers

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    This paper investigates the playful photo taking behaviour of teenagers during group visits to two touristic public events (an airshow and a guided tour of a museum). These studies provide the feedback for the iterative development of a smartphone based anonymous image annotation and sharing application. The resulting implications for the design of such photo systems are examined, specifically the appropriateness of opportunistic upload for social media. Playfulness in photography has many implications regarding wider social behaviours. Comic annotations provide the ability to create humorous reinterpretations of photos, and the presence of humour and in-jokes affect the makeup of the audience with whom a group would like to share. It is counter-productive that an application encouraging such limiting behaviours may conflict with the open nature of touristic events. In addition, the shared images have an ephemeral quality and are therefore of transient value (compared to more tangible souvenirs), and their production through the application can ultimately distract from the experience of the visit itself.The authors gratefully thank all participants, the reviewers, and the financial support received from the RCUK Horizon Digital Economy Research Hub Grant EP/G065802/1.This is the author accepted manuscript. The final version is available from ACM via http://dx.doi.org/10.1145/2832932.283295
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