Attenuated Sympathetic Baroreflex Sensitivity Evoked by Acute Mental Stress but not Prolonged Sleep Restriction in Healthy Adults

Sleep restriction and psychological stress have both been found to increase the risk of hypertension. To understand how these factors affect blood pressure, the sympathetic baroreflex sensitivity (sBRS) was measured throughout 1) 10 minutes of mental stress and 2) after a period of consecutive sleep restriction. A randomized cross-over study design was used to evaluate these effects in14 healthy, young adults. Continuous muscle sympathetic nerve activity was measured along with continuous realtime blood pressure and heart rate to evaluates RS. Mental stress included 5 minutes of a mental arithmetic task followed by a Stroop color-word test, while sleep restriction testing involved 4 hours of sleep per night for 14 or 19 days with a4-night acclimation period. Acute mental stress appeared to reduce baroreflex function compared to baseline, especially during the initial 5 minutes of mental stress testing. However, sBRS did not show any significant action between restricted sleep conditions and mental stress. This shows that sBRS is attenuated early during mental stress but returns to baseline quickly in young, healthy adults

Managing Phenol Contents in Crop Plants by Phytochemical Farming and Breeding—Visions and Constraints

Two main fields of interest form the background of actual demand for optimized levels of phenolic compounds in crop plants. These are human health and plant resistance to pathogens and to biotic and abiotic stress factors. A survey of agricultural technologies influencing the biosynthesis and accumulation of phenolic compounds in crop plants is presented, including observations on the effects of light, temperature, mineral nutrition, water management, grafting, elevated atmospheric CO2, growth and differentiation of the plant and application of elicitors, stimulating agents and plant activators. The underlying mechanisms are discussed with respect to carbohydrate availability, trade-offs to competing demands as well as to regulatory elements. Outlines are given for genetic engineering and plant breeding. Constraints and possible physiological feedbacks are considered for successful and sustainable application of agricultural techniques with respect to management of plant phenol profiles and concentrations