Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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    Effect of Caffeinated Chewing Gum on Maximal Strength, Muscular Power, and Muscle Recruitment During Bench Press and Back Squat Exercises
    (MDPI (Basel, Switzerland), 2025-07-28) Ding L; Liu J; Ma Y; Lei T-H; Barnes M; Guo L; Chen B; Cao Y; Girard O
    Background/Objectives: This study aims to investigate the effects of caffeinated chewing gum on maximal strength, muscular power, and neural drive to the prime movers during bench press and back squat in resistance-trained men. Methods: Sixteen resistance-trained males participated in a double-blind, randomized trial, chewing either caffeinated gum (4 mg/kg) or placebo gum on two separate occasions, seven days apart. After chewing for 5 min, participants performed a maximal strength test followed by muscular power assessments at 25%, 50%, 75%, and 90% of their one-repetition maximum (1RM), completing with 3, 2, 1, and 1 repetition (s), respectively, for bench press and back squat. Surface electromyography data were recorded for each repetition. Results: Caffeinated gum did not significantly improve one-repetition maximum (1RM) for bench press (p > 0.05), but increased mean frequency (MF) and median frequency (MDF) in anterior deltoid, pectoralis major, and biceps brachii (all p < 0.05) compared to placebo. For back squat, 1RM increased with caffeinated gum, along with higher MF and MDF in vastus medialis (all p < 0.05). Caffeinated gum also improved mean and peak velocities, and mean and peak power outputs at 25–75% 1RM during the bench press (all p < 0.05), along with elevated MDF in pectoralis major and biceps brachii (all p < 0.05). Similar improvements were seen in mean and peak velocities during the back squat at 25–90% 1RM (all p < 0.05), along with higher MF and MDF in vastus medialis and increased normalized root mean square activity in gluteus maximus (all p < 0.05). Conclusions: Caffeinated chewing gum (4 mg/kg) enhanced muscular power (25–75% 1RM) in the bench press and improved maximal strength and muscular power (25–90% 1RM) in the back squat by increasing muscle recruitment in resistance-trained men.
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    Biochar can Increase Chinese Cabbage (Brassica oleracea L.) Yield, Decrease Nitrogen and Phosphorus Leaching Losses in Intensive Vegetable Soil
    (Tech Science Press, 16/08/2021) Sun H; Jeyakumar P; Xiao H; Li X; Liu J; Yu M; Rana P; Shi W
    There are few evidences on the effect of biochar on vegetable yield, nitrogen (N) and phosphorus (P) leaching losses under intensive vegetable production soil. The current field plot scale study evaluated responses of Chinese cabbage (Brassica oleracea L.) yield, N and P leaching losses using five N treatments of common N application rate according to local farmers’ practice (N100%), reducing 20% or 40% N fertilizer (N80% and N60%), and reducing 40% N fertilizer but incorporating 10 or 20 t/ha biochar (N60% + BC10 and N60% + BC20). Results showed that N80% and N60% decreased both the cabbage economic and leaf yields by 6.8%–36.3% and 27.4%–37.7%, respectively. Incorporation of biochar with reduced N fertilizer rates improved the cabbage yield, in particular the N60% + BC20 matched the yield that observed in N100% treatment. Enhanced N and P uptake capacities of cabbage shoot probably contributed the higher vegetable production under both biochar amendment schemes. Biochar application mitigated the NH+4-N and total P leaching losses by 20%–30% and 29%–32%, respectively, compared with their counterpart treatment N60%. Nevertheless, biochar exerted no influence on the NO–3-N leaching. In addition, soil organic matter content was recorded with 7.4%–28.7% higher following 10–20 t/ha bio-char application. In conclusion, biochar application can increase economic yield of cabbage via increasing N and P use efficiency, decrease N and P leaching losses, and improve soil quality in an intensive vegetable production system.
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    Functional response and prey stage preference of Neoseiulus barkeri on Trasonemus confuses
    (Systematic and Applied Acarology Society London, 23/11/2018) Li L; Jiao R; Lichen Y; He XZ; He L; Xu C; Zhang L; Liu J