Chemical Composition and Preliminary Toxicity Evaluation of the Essential Oil from Peperomia circinnata Link var. circinnata. (Piperaceae) in Artemia salina Leach

Peperomia Ruiz and Pav, the second largest genus of the Piperaceae, has over the years shown potential biological activities. In this sense, the present work aimed to carry out a seasonal and circadian study on the chemical composition of Peperomia circinata essential oils and aromas, as well as to evaluate the preliminary toxicity in Artemia salina Leach and carry out an in silico study on the interaction mechanism. The chemical composition was characterized by gas chromatography (GC/MS and GC-FID). In the seasonal study the essential oil yields had a variation of 1.2–7.9%, and in the circadian study the variation was 1.5–5.6%. The major compounds in the seasonal study were β-phellandrene and elemicin, in the circadian they were β-phellandrene and myrcene, and the aroma was characterized by the presence of β-phellandrene. The multivariate analysis showed that the period and time of collection influenced the essential oil and aroma chemical composition. The highest toxicity value was observed for the essential oil obtained from the dry material, collected in July with a value of 14.45 ± 0.25 μg·mL−1, the in silico study showed that the major compounds may be related to potential biological activity demonstrated by the present study.

MONTHLY/SEASONAL STATISTICAL STUDY ON THE CONVERGENCE OF FOE AT THE OUAGADOUGOU STATION DURING THE SOLAR CYCLE 22

In this paper we studied the variability of the peak of the critical frequency of the ionospheric E layer (foE) during the minimum and maximum phase of solar cycle 22 (SC22) at Ouagadougou station whose geographical coordinates are: 12.4°N and 358.5°E. We made a statistical study with the aim of highlighting the month which would have the value of foE which best converges towards the average of its corresponding season. We prove that the median months of each season have their critical frequencies (foE) that best converge to the average foE values of each season. Thus, for the winter, spring, summer and autumn seasons, the months best suited for a seasonal study of foE are January, April, July and October respectively at solar minimum and maximum. This study also revealed that foE varies according to the time of day, the season and the phase of the solar cycle at Ouagadougou station.

Determination of substrate composition, light, and temperature for interior plant growth

This article presents the experimental results for determining the composition of the substrate, light and temperature for growing houseplants. Substrates were prepared in 8 different variants. The properties of the substrates were evaluated on the basis of 3 types: high, medium, and low. The amount of light required for the growth of houseplants is the result of a seasonal study. The effects of daily light fall and outdoor ambient temperature in the interior environment was studied for one year, and the results obtained were tabulated. According to the attitude of plants to light, they were divided into light-loving, semi-shade, shade-loving species.