scholarly journals Epidemic networks and potential sources of bacterial wilt infection in a potato seed network in Kenya.

Author(s):  
Sospeter Gachamba ◽  
Yan-ru Xing ◽  
Kelsey F. Andersen Onofre ◽  
Karen A. Garrett ◽  
Douglas W. Miano ◽  
...  

Abstract Potato seed systems in Kenya are largely informal, characterized by high seed degeneration due to the buildup of seed- and soil-borne diseases, including bacterial wilt caused by Ralstonia solanacearum. Informal sources of seed include neighbors, local markets and farmer-saved seed, and present a risk for spread and establishment of disease. To understand the larger context of potato disease risk in Kenya, we used network analysis to evaluate (1) epidemic risk through potato trade networks centered around East Africa, and (2) locations in East Africa likely to be particularly important for epidemic management because of their high potato cropland connectivity. We evaluated the interactions of the key stakeholders in a potato seed system and used network analysis to identify locations that are likely to be important for the spread of infection of R. solanacearum in a potato seed distribution network in Meru, Kenya. Household details, seed sources, quantities sold, pest incidence and management practices, knowledge about seed degeneration and farmers' sources of information on potato production were obtained and analyzed. The survey revealed that self-saved, neighbors, seed companies, friends, exchange, and markets are the main seed sources. Only 43% of total seed transacted was certified. Users of uncertified seeds have high disease risk, and this is an especially important risk if their roles in the network give them the potential to be 'superspreaders' of disease.

2018 ◽  
Vol 9 (2) ◽  
pp. 8 ◽  
Author(s):  
Doreen Akunda ◽  
Zhixia Chen ◽  
Simon Ndwiga Gikiri

Talent management and retention are increasingly seen as an essential practice in business sustainability strategies. It has since expanded from the sporting fraternity and the arts, particularly in the entertainment industry to become a global practice. This paper discusses the purpose and strategies used for talent management. Using a case study approach that combines the use of Reflexive Account (a retrospective analysis) and content analysis of firm reports, this paper identifies the Human Resource management practices implemented by one firm, MTN-Uganda as a case that provides human resource practitioners with evidence of the practical utility of various talent management and retention strategies. The primary sources of information used in reporting on the case were obtained through reflexive analysis (2012-2015) and content analysis of firm reports (2007-2018). Information gaps were filled in by contact and answered queries through the Department of Corporate Services at MTN Uganda.Although there are many strategies for implementing talent management programs, their success is primarily pegged on the use of a mixed approach, with the Human Resource functions being supported by other management divisions to realise the return on investment sought through the implementation of talent management programs.


2016 ◽  
Vol 19 (2) ◽  
pp. 29-41
Author(s):  
W. Pérez Barrera ◽  
M. Valverde Miraval ◽  
M. Barreto Bravo ◽  
J. Andrade-Piedra ◽  
G. A. Forbes

The major pests and diseases were identified and quantified on thirteen potato landraces and three bred varieties cultivated in Peru. Late blight (Phytophthora infestans) was the primary biotic constraint affecting plants before flowering with an average severity of 24%. No other pathogens caused severe foliar disease, but black scurf (Rhizoctonia solani) was relatively common on tubers of some genotypes with incidence ranging from 4.30 to 33.33%. The viruses most generally considered important in potato seed degeneration, PVY and PLRV, were extremely rare, with 1.11 and 0.12 % incidence, respectively. Other viruses considered mild, such as PVX and PVS, were more common, with incidence of 28.23 and 22.29 %, respectively. Potato flea beetle (Epitrix spp.), potato leaf beetle (Diabrotica spp.) and Andean potato weevil (Premnotrypes spp.) were common, with incidence of 28.14, 18.75 and 13.61%, respectively. Potato landraces known as Ishkupuru, Lengua de vaca, Chaulina, Chaulina Tajacaja and Negro cayash were identified as potentially resistant to P. infestans.


2021 ◽  
Vol 40 (1) ◽  
pp. 14-24
Author(s):  
Marianne Bracht ◽  
Fabiana Bacchini ◽  
Bosco Paes

PurposeEvaluate parental knowledge of respiratory syncytial virus (RSV) and other respiratory infections in preterm infants.DesignSurvey.SampleFive hundred and eighty-three parents of preterm infants with generalized, Canadian provincial representation.Main OutcomeKnowledge of RSV infection, sources of information, and parental understanding of disease risk.Results97.9 percent (571/583) of the parents had heard about RSV, since they all had a preterm infant. Sixty-one percent reported having good knowledge of RSV; 19.4 percent had very good knowledge; 19.7 percent had little or no awareness of RSV-related infection. Most (86.3 percent) believed that RSV illness was a very serious condition; 13 percent recognized that it could be a major problem for their child. Principal sources of information were the nurse, doctor and pamphlets. Over 480 participants cited 3 or more sources of additional information—Internet, social media platforms, and educational sessions. Respiratory syncytial virus prophylaxis was a priority, but knowledge regarding the eligibility criteria for prophylaxis is essential.


2020 ◽  
Vol 12 (9) ◽  
pp. 3580
Author(s):  
Shiferaw Tafesse ◽  
Rico Lie ◽  
Barbara van Mierlo ◽  
Paul C. Struik ◽  
Berga Lemaga ◽  
...  

Collective action is required to deal with various complex agricultural problems such as invasive weeds and plant diseases that pose a collective risk to farmers. Monitoring systems could help to stimulate collective action and avoid free-riding. The paper develops a novel framework consisting of essential elements of a monitoring system for managing a complex disease like bacterial wilt in potato crops. The framework is used to explore how seed potato cooperatives in Ethiopia operationalised the essential elements of a monitoring system and identifies which challenges remain to be overcome. Data were collected through in-depth interviews, reflective workshops, participant observation, and document analysis. We found that the cooperatives had organised a self-monitoring system to monitor disease occurrence and the disease management practices of their members. Monitoring committees were in charge of the data collection and enforcement of sanctions on farmers who did not adhere to the cooperatives’ bylaws. The main challenges included the dependency on visual observation, which does not disclose latent infections, limited financial incentives for the monitoring committee members, lack of trust, weak peer monitoring, and the social and ecological interdependency between producers of ware and seed potatoes. Suggestions are provided to strengthen the monitoring systems of farmers’ seed potato cooperatives in Ethiopia. In addition, we discuss the broader value of our novel framework for describing and analysing monitoring systems for future research and intervention.


2020 ◽  
Vol 3 ◽  
pp. 251581632097208
Author(s):  
Pengfei Zhang ◽  
Santosh Bhaskarabhatla

Background: Twitter is a leading microblogging platform, with over 126 million daily active users as of 2019, which allows for large-scale analysis of tweets related to migraine. June 2020 encompassed the National Migraine and Headache Awareness Month in the United States and the American Headache Society’s virtual annual conference, which offer opportunities for us to study online migraine advocacy. Objective: We aim to study the content of individual tweets about migraine, as well as study patterns of other topics that were discussed in those tweets. In addition, we aim to study the sources of information that people reference within their tweets. Thirdly, we want to study how online awareness and advocacy movements shape these conversations about migraine. Methods: We designed a Twitter robot that records all unique public tweets containing the word “migraine” from May 8th, 2020 to June 23rd, 2020, within a 400 km radius of New Brunswick, New Jersey, United States. We built two network analysis models, one for the months of May 2020 and June 2020. The model for the month of May served as a control group for the model for the month of June, the Migraine Awareness Month. Our network model was developed with the following rule: if two hashtag topics co-exist in a single tweet, they are considered nodes connected by an edge in our network model. We then determine the top 30 most important hashtags in the month of May and June through applications of degree, between-ness, and closeness centrality. We also generated highly connected subgraphs (HCS) to categorize clusters of conversations within each of our models. Finally, we tally the websites referenced by these tweets during each month and categorized these websites according to the HCS subgroups. Results: Migraine advocacy related tweets are more popular in June when compared to May as judged by degree and closeness centrality measurements. They remained unchanged when judged by between-ness centralities. The HCS algorithm categorizes the hashtags into a large single dominant conversation in both months. In each of the months, advocacy related hashtags are apart of each of the dominant conversation. There are more hashtag topics as well as more unique websites referenced in the dominant conversation in June than in May. In addition, there are many smaller subgroups of migraine-related hashtags, and in each of these subgroups, there are a maximum of two websites referenced. Conclusion: We find a network analysis approach to be fruitful in the area of migraine social media research. Migraine advocacy tweets on Twitter not only rise in popularity during migraine awareness month but also may potentially bring in more diverse sources of online references into the Twitter migraine conversation. The smaller subgroups we identified suggest that there are marginalized conversations referencing a limited number of websites, creating a possibility of an “echo chamber” phenomenon. These subgroups provide an opportunity for targeted migraine advocacy. Our study therefore highlights the success as well as potential opportunities for social media advocacy on Twitter.


2019 ◽  
Vol 20 (2) ◽  
pp. 305-318
Author(s):  
Rachael Vriezen ◽  
Jan M. Sargeant ◽  
Ellen Vriezen ◽  
Charlotte B. Winder ◽  
Annette M. O'Connor

AbstractTo implement effective stewardship in food animal production, it is essential that producers and veterinarians are aware of preventive interventions to reduce illness in livestock. Systematic reviews and meta-analyses (SR/MA) provide transparent, replicable, and quality-assessed overviews. At present, it is unknown how many SR/MA evaluate preventive antibiotic use or management practices aimed at reducing disease risk in animal agriculture. Further, the quality of existing reviews is unknown. Our aim was to identify reviews investigating these topics and to provide an assessment of their quality. Thirty-eight relevant reviews were identified. Quality assessment was based on the AMSTAR 2 framework for the critical appraisal of systematic reviews. The quality of most of the reviews captured was classified as critically low (84.2%, n = 32/38), and only a small percentage of the evaluated reviews did not contain critical weaknesses (7.9%, n = 3/38). Particularly, a small number of reviews reported the development of an a priori protocol (15.8%, n = 6/38), and few reviews stated that key review steps were conducted in duplicate (study selection/screening: 26.3%, n = 10/38; data extraction: 15.8%, n = 6/38). The development of high-quality reviews summarizing evidence on approaches to antibiotic reduction is essential, and thus greater adherence to quality conduct guidelines for synthesis research is crucial.


2020 ◽  
Author(s):  
Robert Burtscher ◽  
Taher Kahil ◽  
Mikhail Smilovic ◽  
Diana Luna ◽  
Jenan Irshaid ◽  
...  

<p>Food security has long been a challenge for East Africa region and is becoming a pressing issue for the coming decades because food demand is expected to increase considerably following rapid population and income growth. Agricultural production in the region is thus required to intensify, in a sustainable way, to keep up with food demand. However, many challenges face the sustainable intensification of the agricultural production including low productivity, inadequate management, small scale operations, and large climate variability. Several pilot initiatives, that involves a bundle of land and water management practices, have been introduced in the region to tackle such challenges. However, their large-scale implementation remains limited. In the framework of a research project which is jointly implemented by the International Institute for Applied System Analysis (IIASA), the Lake Victoria Basin Commission (LVBC) and the International Crops Research Institute for Semi-Arid Tropics (ICRISAT), we analyse up scaling opportunities for water and land management practices for the sustainable and resilient intensification of rice and fodder production systems in the extended Lake Victoria Basin in East Africa. The expected outcome of this project is to provide an improved understanding of up scaling of such practices through model simulations and integrated analysis of political economy aspects, governance and social and gender dimensions.</p><p>This paper presents an integrated upscaling modeling framework that combines biophysical suitability analysis and economic optimization. Several production system options (i.e., management practices) for rice intensification are examined at high-spatial resolution (0.5°x0.5°) in the extended Lake Victoria basin. The suitability analysis identifies suitable area for the production system options based on a combination of various biophysical factors such as climate, hydrology, vegetation and soil properties using the Global Agroecological Zones (GAEZ) model and the Community Water Model (CWaTM). The economic optimization identifies the optimal combination of those production systems that maximizes their overall contribution to agricultural economic benefits having satisfied various technical and resource constraints including commodity balance, land availability and suitability, water availability, labor availability and capital constraints. A set of socioeconomic (e.g., impact of population and income growth on food demand and agricultural productivity) and climate change (e.g., impact on water resources availability) scenarios based on combinations of the Shared Socioeconomic Pathways (SSPs), Representative Concentration Pathways (RCPs), and co-developed bottom-up policy scenarios, through stakeholders’ engagement with the Basin Commission (LVBC), have been utilized to simulate the modeling framework. Results of this study show the existence of significant opportunities for the sustainable intensification of rice production in East Africa. Moreover, the study identifies the key biophysical and economic factors that could enable the upscaling of sustainable land and water management practices for rice production in the region. Overall, this study demonstrates the capacity of the proposed upscaling modeling framework as a system approach to address the linkages between the intensification of agricultural production and the sustainable use of natural resources.</p>


2016 ◽  
Vol 86 (3) ◽  
pp. 247-259 ◽  
Author(s):  
Emma L. Davis ◽  
Colin J. Courtney Mustaphi ◽  
Amber Gall ◽  
Michael F.J. Pisaric ◽  
Jesse C. Vermaire ◽  
...  

AbstractLong-term records of wildfires and their controlling factors are important sources of information for informing land management practices. Here, dendrochronology and lake sediment analyses are used to develop a 3500-yr fire and vegetation history for a montane forest in Jasper National Park, Alberta, Canada. The tree-ring record (AD 1771-2012) indicates that this region historically experienced a mixed-severity fire regime, and that effective fire suppression excluded widespread fire events from the study area during the 20th century. A sediment core collected from Little Trefoil Lake, located near the Jasper townsite, is analyzed for subfossil pollen and macroscopic charcoal (>150 μm). When comparing the tree-ring record to the 3500-yr record of sediment-derived fire events, only high-severity fires are represented in the charcoal record. Comparisons between the charcoal record and historical climate and pollen data indicate that climate and vegetation composition have been important controls on the fire regime for most of the last 3500 yr. Although fire frequency is presently within the historical range of variability, the fire return interval of the last 150 yr is longer than expected given modern climate and vegetation conditions, indicating that humans have become the main control on fire activity around Little Trefoil Lake.


Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 372-372 ◽  
Author(s):  
A. T. Thera ◽  
B. J. Jacobsen ◽  
O. T. Neher

Ralstonia solanacearum (Smith) Yabuuchi et al. causes bacterial wilt worldwide on a wide range of plant species. In Mali, the disease is commonly found on potato (Solanum tuberosum L.), tomato (Lycopersicon esculentum var. esculentum L.), pepper (Capsicum annuum L.), eggplant (Solanum melongena L.), tobacco (Nicotiana tabacum L.), and peanut (Arachis hypogaea L.). Determination of race and biovar is critical for development of potato seed certification programs for management of the disease. Isolates (25) of R. solanacearum were obtained from wilting potato, pepper, eggplant, tobacco, and tomato plants collected from fields near Baguineda, Sonityeni, Sotuba, Sikasso, and Kolikoro. Isolations were made from bacterial streaming by dilution plating on triphenyl tetrazolium chloride medium (TZC) (2). Characteristic colonies were selected and identified by ELISA or Immunostrips (Pathoscreen Rs, Agdia Inc., Elkhart, IN). These isolates were used in host range studies and hypersensitivity (HR) tests on tobacco (cv. xanthi) (3) and tested for their ability to produce acids on Ayers basal media amended with disaccharide and hexose alcohol carbon sources (1). These isolates caused characteristic wilt 40 days postinoculation on greenhouse-grown tobacco (cv. Xanthi), peanut (cv. 4610), and tomato (cv. Roma VF) plants when stems of five plants of each host were syringe inoculated with 0.1 ml of a 1 × 109 CFU/ml of bacteria. Plants inoculated with sterile distilled water remained symptomless and R. solanacearum was reisolated from infected plants on TZC and identified with Immunostrips. All HR tests were negative. Infection of peanut, tobacco, and tomato and the results of the HR tests indicated that all isolates were Race 1 and no significant variation was noted between isolates. Acid was produced from the hexose alcohols: mannitol, sorbitol, and dulcitol; and the disaccharides: cellobiose, lactose, and maltose. This indicated that all isolates were biovar 3, the same as a known Race 1 strain from tobacco (MSU Plant Pathology teaching collection) (1). To assess relative distribution of R. solanacearum, 20 soil samples collected from potato fields in the vicinity of Baguineda, Kati, Koulikoro, and Sikasso were placed in pots (30 × 25 cm) under shade cloth at the IER Station in Sotuba and planted with 30-day-old tobacco plants. After 90 days, infected plants (35 to 100% infection) were found in all soils. Infected plants exhibited classical wilt symptoms and tested positive for R. solanacearum infections as confirmed by Immunostrip tests. Six of nine surface water samples taken near potato fields in Baguineda, Sikasso, Mopti, and Koulikoro tested positive for the presence of R. solanacearum by an Agdia Inc. enrichment kit and ELISA. A weed, Commelina forskalaei (Vahl), collected by Farako creek near Sikasso tested positive in the Immunostrip test even though no symptoms were obvious. No attempt was made to characterize the race, biovar, or phylotype of the soil, water, and weed isolates. To our knowledge, this is the first time that the race and biovar of R. solanacearum from Mali has been reported and the wide distribution of this pathogen in Malian soils and surface water has been demonstrated. It is significant that we did not detect Race 3 biovar 2, which is subject to quarantine and biosecurity regulations. References: (1) A. C. Hayward. J. Bacteriol. 27:265, 1964. (2) A. Kelman. Phytopathology 44:693, 1954. (3) J. Lozano and L. Sequeira. Phytopathology 60:833, 1970.


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