scholarly journals A risk assessment framework for seed degeneration: Informing an integrated seed health strategy for vegetatively-propagated crops

2017 ◽  
Author(s):  
S. Thomas-Sharma ◽  
J. Andrade-Piedra ◽  
M. Carvajal Yepes ◽  
J. F. Hernandez Nopsa ◽  
M. J. Jeger ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Low Income ◽  
Performance Outcomes ◽  
Parameter Estimates ◽  
Assessment Framework ◽  
Worst Case ◽  
Health Strategy ◽  
Seed Health ◽  
On Farm ◽  
Seed Degeneration

ABSTRACTPathogen build-up in vegetative planting material, termed seed degeneration, is a major problem in many low-income countries. When smallholder farmers use seed produced on-farm or acquired outside certified programs, it is often infected. We introduce a risk assessment framework for seed degeneration, evaluating the relative performance of individual and combined components of an integrated seed health strategy. The frequency distribution of management performance outcomes was evaluated for models incorporating biological and environmental heterogeneity, with the following results. (1) On-farm seed selection can perform as well as certified seed, if the rate of success in selecting healthy plants for seed production is high; (2) When choosing among within-season management strategies, external inoculum can determine the relative usefulness of ‘incidence-altering management’ (affecting the proportion of diseased plants/seeds) and rate-altering management (affecting the rate of disease transmission in the field); (3) Under severe disease scenarios, where it is difficult to implement management components at high levels of effectiveness, combining management components can produce synergistic benefits and keep seed degeneration below a threshold; (4) Combining management components can also close the yield gap between average and worst-case scenarios. We also illustrate the potential for expert elicitation to provide parameter estimates when data are unavailable.

scholarly journals A Risk Assessment Framework for Seed Degeneration: Informing an Integrated Seed Health Strategy for Vegetatively Propagated Crops

2017 ◽  
Vol 107 (10) ◽  
pp. 1123-1135 ◽  
Author(s):  
S. Thomas-Sharma ◽  
J. Andrade-Piedra ◽  
M. Carvajal Yepes ◽  
J. F. Hernandez Nopsa ◽  
M. J. Jeger ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Low Income ◽  
Performance Outcomes ◽  
Parameter Estimates ◽  
Assessment Framework ◽  
Worst Case ◽  
Health Strategy ◽  
Seed Health ◽  
On Farm ◽  
Seed Degeneration

Pathogen buildup in vegetative planting material, termed seed degeneration, is a major problem in many low-income countries. When smallholder farmers use seed produced on-farm or acquired outside certified programs, it is often infected. We introduce a risk assessment framework for seed degeneration, evaluating the relative performance of individual and combined components of an integrated seed health strategy. The frequency distribution of management performance outcomes was evaluated for models incorporating biological and environmental heterogeneity, with the following results. (1) On-farm seed selection can perform as well as certified seed, if the rate of success in selecting healthy plants for seed production is high; (2) when choosing among within-season management strategies, external inoculum can determine the relative usefulness of ‘incidence-altering management’ (affecting the proportion of diseased plants/seeds) and ‘rate-altering management’ (affecting the rate of disease transmission in the field); (3) under severe disease scenarios, where it is difficult to implement management components at high levels of effectiveness, combining management components can be synergistic and keep seed degeneration below a threshold; (4) combining management components can also close the yield gap between average and worst-case scenarios. We also illustrate the potential for expert elicitation to provide parameter estimates when empirical data are unavailable.[Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals An integrated seed health strategy and phytosanitary risk assessment: Potato in the Republic of Georgia

2021 ◽  
Vol 191 ◽  
pp. 103144
Author(s):  
Kelsey F. Andersen Onofre ◽  
Gregory A. Forbes ◽  
Jorge L. Andrade-Piedra ◽  
Chris E. Buddenhagen ◽  
James C. Fulton ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Republic Of Georgia ◽  
Health Strategy ◽  
Seed Health ◽  
The Republic

scholarly journals Seed degeneration in potato: the need for an integrated seed health strategy to mitigate the problem in developing countries

2015 ◽  
Vol 65 (1) ◽  
pp. 3-16 ◽  
Author(s):  
S. Thomas-Sharma ◽  
A. Abdurahman ◽  
S. Ali ◽  
J. L. Andrade-Piedra ◽  
S. Bao ◽  
...  
Keyword(s):  
Developing Countries ◽  
Health Strategy ◽  
Seed Health ◽  
Seed Degeneration

Risk assessment of Campylobacter species in shellfish: identifying the unknown

1997 ◽  
Vol 35 (11-12) ◽  
pp. 29-34 ◽  
Author(s):  
P. Teunis ◽  
A. Havelaar ◽  
J. Vliegenthart ◽  
G. Roessink
Keyword(s):  
Risk Assessment ◽  
Quantitative Risk Assessment ◽  
Contamination Level ◽  
Risk Of Infection ◽  
Worst Case ◽  
Considerable Uncertainty ◽  
Risk Estimates ◽  
Consumption Data ◽  
Campylobacter Infection ◽  
Campylobacter Spp

Shellfish are frequently contaminated by Campylobacter spp, presumably originating from faeces from gulls feeding in the growing or relaying waters. The possible health effects of eating contaminated shellfish were estimated by quantitative risk assessment. A paucity of data was encountered necessitating many assumptions to complete the risk estimate. The level of Campylobacter spp in shellfish meat was calculated on the basis of a five-tube, single dilution MPN and was strongly season-dependent. The contamination level of mussels (<1/g) appeared to be higher than in oysters. The usual steaming process of mussels was found to completely inactivate Campylobacter spp so that risks are restricted to raw/undercooked shellfish. Consumption data were estimated on the basis of the usual size of a portion of raw shellfish and the weight of meat/individual animal. Using these data, season-dependent dose-distributions could be estimated. The dominant species in Dutch shellfish is C. lari but little is known on its infectivity for man. As a worst case assumption, it was assumed that the infectivity was similar to C. jejuni. A published dose-response model for Campylobacter-infection of volunteers is available but with considerable uncertainty in the low dose region. Using Monte Carlo simulation, risk estimates were constructed. The consumption of a single portion of raw shellfish resulted in a risk of infection of 5–20% for mussels (depending on season; 95% CI 0.01–60%). Repeated (e.g. monthly) exposures throughout a year resulted in an infection risk of 60% (95% CI 7–99%). Risks for oysters were slightly lower than for mussels. It can be concluded that, under the assumptions made, the risk of infection with Campylobacter spp by eating of raw shellfish is substantial. Quantitative risk estimates are highly demanding for the availability and quality of experimental data, and many research needs were identified.

scholarly journals Risk Assessment Framework to Avoid Serial Failure for New Technical Solutions Applied to the Construction of a CLT Structure Resilient to Climate

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 247
Author(s):  
Charlotte Svensson Tengberg ◽  
Carl-Eric Hagentoft
Keyword(s):  
Risk Assessment ◽  
Success Factors ◽  
Real Life ◽  
Qualitative Assessment ◽  
Technical Solution ◽  
Functional Requirements ◽  
Assessment Framework ◽  
Construction Period ◽  
Design Build ◽  
Technical Solutions

Design-build contractors are challenged with the task of minimizing failure risks when introducing new technical solutions or adapting technical solutions to new conditions, e.g., climate change. They seem to have a disproportional trust in suppliers and their reference cases and might not have adequate resources or methodologies for sufficient evaluation. This creates the potential for serial failures to spread in the construction industry. To mitigate this, it was suggested that a predefined risk assessment framework should be introduced with the aim of providing a prequalification and requirements for the use of the technical solution. The objectives of this paper are to develop a comprehensive risk assessment framework and to explore the framework’s potential to adequately support the design-build contractor’s decisions. The framework uses qualitative assessment, relying on expert workshops and quantitative assessments, with a focus on simulation and probabilities. Tollgates are used to communicate risk assessments to the contractor. The framework is applied to a real-life case study of construction with a CLT-structure for a Swedish design-build contractor, where exposure to precipitation during construction is a key issue. In conclusion, the chosen framework was successful in a design-build contractor context, structuring the process and identifying difficulties in achieving the functional requirements concerning moisture. Three success factors were: documentation and communication, expert involvement, and the use of tollgates. Recommendations to the design-build contractor on construction of CLT structure are to keep construction period short and to use full weather protection on site.

A Hybrid Fuzzy Risk Assessment Framework for Determining Building Demolition Safety Index

2021 ◽  
Vol 25 (4) ◽  
pp. 1144-1162
Author(s):  
Milad Alipour-Bashary ◽  
Mehdi Ravanshadnia ◽  
Hamidreza Abbasianjahromi ◽  
Ehsan Asnaashari
Keyword(s):  
Risk Assessment ◽  
Assessment Framework ◽  
Safety Index ◽  
Fuzzy Risk Assessment ◽  
Building Demolition
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