Growth factor gene expression profiles of bone morphogenetic protein-2-treated human adipose stem cells seeded on calcium phosphate scaffolds in vitro

The secretome of stem cells strongly determines the outcome of tissue engineering strategies. We investigated how the secretome of human adipose stem cells (hASCs) can be affected by substrate, BMP-2 treatment, and degree of differentiation. We hypothesized that as differentiation progresses, hASCs produce increasingly more gene products associated with processes such as angiogenesis and bone remodeling.     

Feeding and locomotor rhythm of the ornamental cichlid fish Amatitlania sp. in different social groups

The aim of this study was to evaluate the feeding activity and the rhythm of daily locomotor activity of the convict cichlid (Amatitlania sp.) kept in different social groups under a self-feeding system. A total of 120 animals was distributed among six repetitions of four social groups, as follows: group 1 with one male and one female per tank; group 2 with three males and three females per tank; group 3 with six males per tank; and group 4 with six females per tank. Feeding activity (FA) and locomotor activity (LA) were evaluated using photoelectric presence-sensors connected to automatic feeders. The fish were fed a commercial extruded diet (46% crude protein and 3600 kcal kg⁻¹ of digestible energy). Animal growth was evaluated for all groups. After 30 days of experimentation, the fish stabilized their demands by adjusting their consumption. Amatitlania sp. showed predominantly diurnal FA and LA. All groups showed a peak of activity when the light was turned on and when it was turned off. In summary, FA and LA of Amatitlania sp. are predominantly diurnal and independent of social group. Pairs and groups of males and females together consume less food in relation to groups of one sex or the other due to reproductive behaviour. On the other hand, groups of only males or females consume more food because they lack reproductive stimuli and thus prioritize growth. These results may support good feeding management practices for this ornamental cichlid. Studies relating feeding behaviour with different social groups are of great importance for determining effective feeding strategies for this species in captivity. Thus, such a study assists in a more efficient production of Amatitlania sp.     

A spectrophotometric determination of the binding constants of cyanide by hemin in aqueous ethanol solutions

Binding constants for the coordination of cyanide by monomeric hemin in aqueous ethanol solution were determined in the pH range 8–12 by fitting spectrophotometric data to a binding isotherm using a non-linear least-squares method. Two cyanide ligands are coordinated by Fe(III) without evidence for the intermediate mono-ligated species. The binding constants are strongly pH-dependent because of protonation of the ligand and competition for the metal ion by hydroxide. From the pH dependence of the observed binding constants, a pH-independent value of log K = 17.62±0.03 for the binding of two CN⁻ ligands by monomeric hemin in alkaline solution at 25 °C, μ=0.100 M, is obtained.