Increased light-use efficiency sustains net primary productivity of shaded coffee plants in agroforestry system.

In agroforestry systems, shade trees strongly affect the physiology of the undergrown crop. However, a major paradigm is that the reduction in absorbed photosynthetically active radiation is, to a certain extent, compensated by an increase in light-use efficiency, thereby reducing the difference in net primary productivity between shaded and non-shaded plants. Due to the large spatial heterogeneity in agroforestry systems and the lack of appropriate tools, the combined effects of such variables have seldom been analysed, even though they may help understand physiological processes underlying yield dynamics. In this study, we monitored net primary productivity, during two years, on scales ranging from individual coffee plants to the entire plot. Absorbed radiation was mapped with a 3D model (MAESPA). Light-use efficiency and net assimilation rate were derived for each coffee plant individually. We found that although irradiance was reduced by 60% below crowns of shade trees, coffee light-use efficiency increased by 50%, leaving net primary productivity fairly stable across all shade levels. Variability of aboveground net primary productivity of coffee plants was caused primarily by the age of the plants and by intraspecific competition among them (drivers usually overlooked in the agroforestry literature) rather than by the presence of shade trees.

Incorrect evaluation of the frequency of malnutrition and of its screening in hospitalized children by health care professionals.

RATIONALE, AIMS AND OBJECTIVES: Malnutrition screening is essential to detect and to treat patients with stunting or wasting. The aim was to evaluate the subjective perception of frequency and assessment of malnutrition by health care professionals. RESEARCH METHODS AND PROCEDURES: In a paediatric university hospital, a cross-sectional survey was conducted with a Likert scale approach to health care professionals and compared with objective measurements on a given day of frequency of malnutrition and of its screening. RESULTS: 279 health care professionals participated. The malnutrition rate, estimated versus measured, was 16.8% and 34.8%, respectively. Conversely, the estimated frequency of malnutrition screening versus measured frequency was 80.6% versus 43.1%, respectively. Furthermore, the perception of health care professionals did not differ depending on their professional category or speciality. CONCLUSIONS: In conclusion, health care staff underestimates the prevalence of malnutrition in children by half and overestimates the frequency of appropriate screening practices for detection of malnutrition. This flawed/unreliable perception may disrupt both screening and the management of malnourished children. There is an urgent need to find out the reasons behind these errors caused by subjective perception in order to develop appropriate educational training to remedy the situation.