Assessment of A Simple Compound-Saving Method To Study Insecticidal Activity of Natural Extracts and Pure Compounds Against Mosquito Larvae.

Research on natural insecticides has intensified with the spread of resistance to chemicals among insects, particularly disease vectors. To evaluate compounds, the World Health Organization (WHO) has published standardized procedures. However, those may be excessively compound-consuming when it comes to assessing the activity of natural extracts and pure compounds isolated in limited amount.

The whole is more than the sum of its parts: Modeling community-level effects of UVR in marine ecosystems.

The effect of UVB radiation (UVBR, 290-320 nm) on the dynamics of the lower levels of the marine plankton community was modeled. The model was built using differential equations and shows a good fit to experimental data collected in mesocosms (defined as large enclosures of 1500 L filled with natural marine waters). Some unexpected results appear to be possible by indirect effects in prey (bacteria, phytoplankton and heterotrophic flagellates).

Vertical mixing and ecological effects of ultraviolet radiation in planktonic communities.

We present a mathematical model for a phytoplankton-zooplankton system, based on a predator-prey scheme. The model considers the effects of sinking in the phytoplankton, vertical mixing and attenuation of photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) in the water column. In a first approach, the model was studied under conditions of average PAR irradiance and shows fluctuations and stable equilibrium points.