Parrots and Palms: Analyzing Data to Determine Best Management Strategies and Sustainable Harvest Levels

This exercise1 presents a scenario and raw data on a realistic conflict between parrot conservation and palm tree harvest. It requires that students analyze data very comparable to what would be gathered in the field, to: 1) construct a life tables for the palm and parrot, 2) extract vital statistics about both the palm and parrot population from the life tables, 3) estimate maximum sustainable yield for both species, and 4) make a decision about the sustainability of harvest intensity. It illustrates the importance of data analysis skills for conservation

Meal Timing Regulates the Human Circadian System

Circadian rhythms, metabolism and nutrition are intimately linked [1, 2], although effects of meal timing on the human circadian system are poorly understood. We investigated the effect of a 5-hour delay in meals on markers of the human master clock and multiple peripheral circadian rhythms. Ten healthy young men undertook a 13-day laboratory protocol. Three meals (breakfast, lunch, dinner) were given at 5-hour intervals, beginning either 0.5 (early) or 5.5 (late) hours after wake. Participants were acclimated to early meals and then switched to late meals for 6 days. After each meal schedule, participants' circadian rhythms were measured in a 37-hour constant routine that removes sleep and environmental rhythms while replacing meals with hourly isocaloric snacks. Meal timing did not alter actigraphic sleep parameters before circadian rhythm measurement. In constant routines, meal timing did not affect rhythms of subjective hunger and sleepiness, master clock markers (plasma melatonin and cortisol), plasma triglycerides, or clock gene expression in whole blood. Following late meals, however, plasma glucose rhythms were delayed by 5.69 ± 1.29 hours (p < 0.001) and average glucose concentration decreased by 0.27 ± 0.05 mM (p < 0.001). In adipose tissue, PER2 mRNA rhythms were delayed by 0.97 ± 0.29 hours (p < 0.01), indicating that human molecular clocks may be regulated by feeding time and could underpin plasma glucose changes. Timed meals therefore play a role in synchronising peripheral circadian rhythms in humans, and may have particular relevance for patients with circadian rhythm disorders, shift workers, and transmeridian travellers

The effect of plant-based dietary patterns on blood pressure : a systematic review and meta-analysis of controlled intervention trials

OBJECTIVES. The consumption of strict vegetarian diets with no animal products is associated with low blood pressure (BP). It is not clear whether less strict plant-based diets (PBDs) containing some animal products exert a similar effect. The main objective of this meta-analysis was to assess whether PBDs reduce BP in controlled clinical trials. METHODS. We searched Cumulative Index to Nursing and Allied Health Literature, Medline, Embase, and Web of Science to identify controlled clinical trials investigating the effect of plant-based diets on BP. Standardised mean differences in BP and 95% C.I. were pooled using a random effects model. Risk of bias, sensitivity, heterogeneity and publication bias were assessed. RESULTS. Of the 790 studies identified, 41 clinical trials met the inclusion criteria (8,416 participants of mean age 49.2 yrs). In the pooled analysis, PBDs were associated with lower systolic BP (DASH -5.53 mmHg [95% C.I. -7.95, -3.12], Mediterranean -0.95 mmHg [-1.70, -0.20], Vegan -1.30 mmHg [-3.90, 1.29], Lacto-ovo vegetarian -5.47 mmHg [-7.60, -3.34], Nordic -4.47 mmHg [-7.14, -1.81], high-fiber -0.65 mmHg [-1.83, 0.53], high fruit and vegetable -0.57 mmHg [-7.45, 6.32]. Similar effects were seen on diastolic BP. There was no evidence of publication bias and some heterogeneity was detected. The certainty of the results is high for the lacto-ovo vegetarian and DASH diets, moderate for the Nordic and Mediterranean diets, low for the vegan diet, and very low for the high fruit and vegetable and high-fiber diets. CONCLUSION. PBDs with limited animal products lower both systolic and diastolic BP, across sex and body mass index