Almost airborne

Article Abstract:

Modern stoneflies offer possible evidence of the evolution of insect wings from the articulated gills of water-dwelling ancestors. Stoneflies of the genus Leuctra are observed to use a form of locomotion that is mechanically halfway between skimming and flying. They are sometimes found to be able to ascend above the water surface and actually fly at an air temperature of 12 degrees centigrade. The stoneflies' different forms of surface locomotion suggest the occurrence of gradual improvements in aerodynamic locomotion while aquatic organisms evolved into flying insects.

Insects, Evolution (Biology), Evolution, Flies, Flight

---

Programmed to stay together

Article Abstract:

Sciara coprophila undergoes programmed chromosome losses that are the basis of its sex determination. The sperm contributes two X chromosomes because of nondisjunction while the oocyte contributes another. This also results in the removal of L chromosomes. Maternal factors control the elimination of the X chromosomes. Sister chromatids fail to separate because the eliminated chromosomes may modulate ubiquitin-mediated proteolysis, topoisomerase II activity or phosphatase activity required during the process of chromatid-separation.

Chromosomes

---

Chironomid egg masses in Vibrio cholerae

Article Abstract:

Research describing the relationship between cholera and the non-biting midge, Chironomus sp., is presented. In particular it is shown that the egg masses of the midge harbour the bacterium vibrio cholerae.

Vibrio cholerae, Cholera

Similar abstracts:

• Abstracts: Nanometre assembly lines. Probing the transition state. Knot tied around an octahedral metal centre
• Abstracts: Oviposition site selection: unresponsiveness of Drosophila to cues of potential thermal stress. Sexual differences in coloration of Coenagrinonid damselflies (Odonata): A case of intraspecific aposematism?
• Abstracts: Isaac Asimov (1920-1992). Peter Mitchell (1920-1992). Wang Ying-lai (1907-2001)
• Abstracts: Differential abortion in the yucca. Coming up for air and sporulation. Surrogate mother for endangered Cupressus

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.