Collection of Data on Pesticides in Maize and Tomato in Africa: Protocol for Africa Pesticide Residue Survey Study.

Pesticide use has grown rapidly in West Africa over the past decades. Regulatory capacity has not kept pace with the rapid proliferation of pesticide products and on-farm use. As a result, health and environmental impacts from the growing use of pesticides, despite their potential importance to food safety, remain largely unmonitored, underreported, and poorly understood by key stakeholders. This study protocol was the document for conducting a pesticide survey study to identify the most critically emerging pesticides across the Continent of Africa. Multiple countries were selected in this study to represent the north, east, south, and west regions of Africa. Two food commodities, maize and tomato, were chosen to monitor the pesticide level for food safety. This study protocol describes the fieldwork and laboratory work per the standards of Good Laboratory Practices (GLP) and ISO-17025 and US EPA 860 Residue Chemistry Guidelines but the survey study performed was not considered as a GLP or ISO 17025 study. This is because many steps were not able to be closely monitored per the GLP requirements. This protocol describes the requirements for a pesticide residue study in food collected from local markets. This protocol describes the test commodities, sampling methods, sample transfer/shipping, storage stability, sample analysis, sample disposal, and documentation and record keeping.

Muscle architecture and shape changes in the gastrocnemii of active younger and older adults.

When muscles contract and change length, they also bulge in thickness and/or width. These shape changes extend the functional range of skeletal muscle by allowing individual muscle fibres to shorten at different velocities than the whole muscle. Age-related differences in muscle architecture and tissue properties influence how older muscles change shape and architecture during contractions, yet this remains unexplored in active older adults. The aim of this study was to quantify and compare in vivo muscle architecture and shape changes in the medial (MG) and lateral (LG) gastrocnemii of active younger and older adults during isometric plantarflexion contractions. Fifteen younger (21 ±â€¯2y) and 15 older (70 ±â€¯3y) participants performed contractions at 20%, 40%, 60%, 80%, and 100% of maximum voluntary contraction (MVC). B-mode ultrasound was used to measure fascicle length, pennation angle and muscle thickness in MG and LG. We found no influence of age on changes in normalized fascicle length and thickness, or absolute change in pennation angle during contractions. With increasing contraction level, MG and LG fascicle shortening (P < 0.001) and rotation (P < 0.001) increased. However, the change in muscle thickness increased at higher contraction levels in LG, and not MG. Similarly, increased changes in pennation angle were associated with increased muscle thickness in LG, but not MG at 80% and 100% MVC. These results suggest that (1) gastrocnemii shape changes are similar in active older and younger adults at matched levels of effort, and (2) the relationship between pennation angle and muscle thickness can differ between synergistics (LG and MG) and across contraction levels.