Seasonality affects dietary diversity of school-age children in northern Ghana.

BACKGROUND AND OBJECTIVES: Dietary diversity score (DDS) is relatively easy to measure and is shown to be a very useful indicator of the probability of adequate micronutrient intake. Dietary diversity, however, is usually assessed during a single period and little is known about the effect of seasonality on it. This study investigates whether dietary diversity is influenced by seasonality. METHODS: Two cross-sectional surveys were conducted in two different seasons-dry season (October 2010) and rainy season (May 2011) among the same school-age children (SAC) in two rural schools in northern Ghana. The study population consisted of 228 school-age children. A qualitative 24-hour dietary recall was conducted in both seasons. Based on 13 food groups, a score of 1 was given if a child consumed a food item belonging to a particular food group, else 0. Individual scores were aggregated into DDS for each child. Differences in mean DDS between seasons were compared using linear mixed model analysis. RESULTS: The dietary pattern of the SAC was commonly plant foods with poor consumption of animal source foods. The mean DDS was significantly higher (P < 0.001) in the rainy season (6.95 ± 0.55) compared to the dry season (6.44 ± 0.55) after adjusting for potential confounders such as age, sex, occupation (household head and mother) and education of household head. The difference in mean DDS between dry and rainy seasons was mainly due to the difference in the consumption of Vitamin A-rich fruits and vegetables between the seasons. While vitamin A-rich fruits (64.0% vs. 0.9%; P < 0.0001) and vitamin A rich dark green leafy vegetables (52.6% vs. 23.3%, P < .0001) were consumed more during the rainy season than the dry season, more children consumed vitamin A-rich deep yellow, orange and red vegetables during the dry season than during the rainy season (73.7% vs. 36.4%, P <0.001). CONCLUSION: Seasonality has an effect on DDS and may affect the quality of dietary intake of SAC; in such a context, it would be useful to measure DDS in different seasons. Since DDS is a proxy indicator of micronutrient intake, the difference in DDS may reflect in seasonal differences in dietary adequacy and further studies are needed to establish this.

Optical parametric oscillator-based photoacoustic detection of hydrogen cyanide for biomedical applications.

A versatile, continuous wave, optical parametric oscillator is used in combination with photoacoustic spectroscopy for long-term trace gas experiments of volatile compounds emitted by biological samples. The optical parametric oscillator-based spectrometer (wavelength near 3 µm, 8-MHz linewidth, output power ∼1 W) is successfully tested for the detection of hydrogen cyanide (HCN) emission from clover leaves, and Pseudomonas bacteria; in addition, the presence of HCN in exhaled human breath is measured. For specific experiments, the spectrometer is operated continuously up to 10 days and has a detection limit of 0.4 parts-per-billion volume of HCN in air over 10 s, using the P8 rotational line in the ν3 vibrational band of HCN at 3287.25 cm⁻¹. This results in an overall sensitivity of the system of 2.5 × 10⁻9 cm-1 Hz⁻¹/².