Ecological Physiology - Science topic

The ribosomally synthesized and posttranslationally modified peptides (RiPPs), also called ribosomal peptide natural products (RPNPs), form a growing superfamily of natural products that are produced by many different organisms and particularly by bacteria. They are derived from precursor polypeptides whose modification by various dedicated enzymes helps to establish a vast array of chemical motifs. RiPPs have attracted much interest as a source of potential therapeutic agents, and in particular as alternatives to conventional antibiotics to address the bacterial resistance crisis. However, their ecological roles in nature are poorly understood and explored. The present review describes major RiPP actors in competition within microbial communities, the main ecological and physiological functions currently evidenced for RiPPs, and the microbial ecosystems that are the sites for these functions. We envision that the study of RiPPs may lead to discoveries of new biological functions and highlight that a better knowledge of how bacterial RiPPs mediate inter-/intraspecies and interkingdom interactions will hold promise for devising alternative strategies in antibiotic development

you most welcome

Houda

Dear sir, not yet. started reading the basic knowledge of cell biology details.  

I agree,

DNA contamination in your negative control is the most reasonable justification. The reagents must be contaminated with DNA template (in such a case you must discard them) or maybe it was just a pippeting error. Think about what you did and fix it for next runs

See E. Don Stevens (1992) "Use of plastic materials in oxygen-measuring systems" in Journal of Applied Physiology

Dear all,

I would like to mention toxicity of pollen which plays a major role for oligolectic bees; see for example: Praz C.J., Müller A., Dorn S. (2008) Specialized bees fail to develop on non-host pollen: Do plants chemically protect their pollen? Ecology 89, 795–

804.

Klaus

See attached.  Hurlbert 1971,  This is a good starting point for ecologists.  Many papers since!

Hi Leon,

Thanks for your answer!

Those experiments are actually ongoing right now. We bred them by randomizing at most, and we got plently of pups. It seems so far that there are no differences in the number of pups between early and late-born females. We have to look more precisely at the pup quality and so on.

I am using the garden dormouse (Eliomys quercinus), because it reproduces quite good, have early and late reproductive events and hibernate very well in winter (including under lab conditions too!).

Regards,

Sylvain

This is actually a pretty old question in thermal biology. Another version of the problem is "why are beetles in the Namib desert black?" Most of the animal physiology textbooks should give substantial insight as a starting point. Withers (1992) "Comparative Animal Physiology" is my usual starting point.

Anyway, the crux of the thing is that black is a pretty good colour in both cold and hot environments, depending on the aim of the game. In the cold it's a very good colour for absorbing heat (hence basking in ectotherms is often facilitated by physiological darkening). The thing is, through, in hot conditions it's a very good colour to dump excess heat. Since black surfaces become so much warmer than the environment heat can easily transfer from the surface by convection or conduction. So the real question you're asking here is what's the evolutionary driver for the vultures in these hot environments? Are they aiming to absorb and retain heat, or are they aiming to dump it? And of course this depends on their altitude, because during high altitude soaring they probably want to retain heat, but at low altitude they probably want to dump it. Hence, for a vulture, black is probably the best colour they could be because they can play both ends off against the middle.

This is, of course, all my general speculation. If you read some general textbooks you should be able to see whether my broad understanding is correct. Also, if you read the paper attached by Dr Blount (and references therein) you'll get a more detailed understanding specific to birds, and of course the whole thing is flexible to the stressors of ecology and evolution, as suggested by Dr. Veroustraete. My caution here is that even a simple question like this often indicates complicated patterns, and that if you get trapped in to narrow a set of assumptions, such as "black is a good colour for cold environments" you can often miss powerful insights.

Anyway, I hope that helps. I've suddenly realised that this reads like a lecture, and I'm probably not qualified to give one. Cheers

Sean

Thank you very much. I'll try it tomorrow