Volvox is one of the simplest multicellular organisms with only two cell types, yet it has a surprisingly complex extracellular matrix (ECM) containing many region-specific morphological components, making Volvox suitable as a model system for ECM investigations. ECM deposition begins shortly after inversion, which is the process by which the embryo turns itself right-side-out at the end of emb...

From November 1991 to October 1993, 980 specimens of the characid Brycinus nurse were collected from Asa reservoir to examine its diet. The diet was analyzed using the frequency of occurrence, numerical and gravimetric methods. Two hundred and sixty nine (27.45%) of the stomachs examined were empty. The fish was an omnivore feeding extensively on a wide array of plant and animal food items. The...

the potato tuberworm, phthorimaea operculella (zeller) (lepidoptera: gelechiidae), is one of the most damaging pests of cultivated potato (solanum tuberosum l.) crop, in both field and stores in tropical and subtropical regions. the biological parameters of this pest were evaluated in the growth chamber at 24±1ºc, 65±5% rh and photoperiod of 14:10 h (l:d) on leaves of ten potato cultivars, agri...

Many embryonic deformations during development are the global result of local cell shape changes and other local active cell sheet deformations. Morphogenesis does not only therefore rely on the ability of the tissue to produce these active deformations, but also on the ability to regulate them in such a way as to overcome the intrinsic variability of and geometric constraints on the tissue. He...