Uptake and respiration of organic compounds and heterotrophic growth in Pediastrum duplex (Meyen)*

SUMMARY. Axenic cultures of Pediastrum duplex, a green alga prominent in Lake Kinneret, Israel, assimilated and respired amino acids, acetate, glucose, glycollate and glycerol under conditions of light or darkness. Increased rates of uptake and respiration were observed in nutrient (P and N) depleted medium. Although ineffective in moderate light (30–100 μ Einstein m^?2 s^?1) glycerol, glucose and leucine, but not glycollate, stimulated growth and yields under faint light (～ 2 μ Einstein m^?2 s^?1). In the dark, glycerol (and sometimes leucine) permitted growth. Kinetic studies with leucine indicated an active uptake mechanism effective at substrate concentrations from 0.5 to 47 μg 1^?1.     

Adrenomedullin has a role in angiogenic effects of resveratrol in adipose tissues of obese female rats

Molecular Biology Reports - Obesity is a complex, chronic disease that arises according to the interaction between genetic and environmental factors. The expansion and growth of white adipose...     

Predation and avoidance behaviour in aphid‐ladybird interactions of native and invasive ladybirds in Europe

1. While detrimental effects of invasive predators on native species are well documented, we often lack a mechanistic understanding of the invasion success. Lack of prey avoidance behaviour can lead to higher consumption rates by invasive predators compared to native predators. This competitive advantage is expected to contribute to the invasion success of non‐native predators.
2. We compared aphid consumption and cue avoidance behaviour of aphids between four native ladybird species (Coccinella septempunctata, Adalia bipunctata, Propylea quatuordecimpunctata, and Hippodamia variegata) and the invasive Asian ladybird Harmonia axyridis.
3. The invasive H. axyridis and the native C. septempunctata consumed more aphids than the three smaller native ladybird species. In line with our expectations, aphids avoided leaves bearing cues of most native ladybird species but not of the invasive H. axyridis.
4. Our results indicate that body size rather than ladybird origin determined aphid predation rates. The lack of aphid avoidance behaviour towards cues of H. axyridis indicates that they were not able to recognise the chemical cues of the invasive predator.
5. Relatively large body size and the absence of cue avoidance in aphids might benefit the invasive H. axyridis, particularly in comparison to smaller native ladybird species. The absence of avoidance behaviour in aphids might lead to even higher predation rates of H. axyridis under more natural conditions.