Interorgan amino acid interchange in propionic acidemia: the missing key to understanding its physiopathology

Amino Acids - Propionic acidemia is an inborn error of metabolism caused by a deficiency in the mitochondrial enzyme propionyl-CoA carboxylase that converts the propionyl CoA to methyl malonyl CoA....     

Exogenous DNA transcription in cells with their native DNA inhibited. 1. DNA incorporation into homologous and heterologous cells.

The incorporation of mouse S-EAC DNA into homologous normal cells (mouse embryo secondary cultures), and into heterologous cancer cells (TC-SV40 line), with both systems having their native DNA blocked by BrUdR incorporation, was studied. 3H-TdR-DNA was inoculated with DEAE-D to protect it and to potentiate its incorporation, the process being autoradiograohically controlled. The amount of incorporated DNA was radioisotopically determined, and the incorporation process was studied by analysing the fractions obtained after density gradient centrifugation separation of the inoculated cells DNA. Receptivity was greater in those cells inoculated with DEAE-D-protected DNA. The incorporation was slightly greater for cells whose DNA had been blocked by BrUdR incorporation, and for homologous with respect to heterologous cells. In those cells inoculated while the DNA blockade was incomplete, part of the inoculated DNA became incorporated into the cell genome (L-H chains). However, in the completely blocked cells it could not be determined if the incorporation occurred in a lysogenic-like or in an episomic-like form.     

altFGF-2, A Novel ER-Associated FGF-2 Protein Isoform: Its Embryonic Distribution and Functional Analysis during Neural Tube Development

A novel fibroblast growth factor-2 (FGF-2) protein isoform, calledaltFGF-2, is expressed abundantly during chicken embryogenesis. The amino-terminal domain of the 21.5-kDaaltFGF-2 protein diverges completely from the other three FGF-2 proteins due to alternative splicing of their first coding exons. Furthermore, thealtFGF-2 protein, in contrast to FGF-2 proteins, is targeted predominantly to the endoplasmic reticulum. In chicken embryos,altFGF-2 and FGF-2 proteins are differentially distributed in several mesodermal structures including developing limbs and kidneys. All four FGF-2 protein isoforms are also expressed in the developing neural tube from early neural plate stages onward. In contrast to FGF-2 proteins, thealtFGF-2 isoform is distributed in a dynamic, spatially restricted pattern in notochord and ventral neural tube (floor plate and motor neurons) during specification of neuronal populations. To study the possible shared or differential signaling functions of chickenaltFGF-2 and FGF-2 gene products, they were ectopically expressed in the dorsal neural tube aspect of transgenic mouse embryos. Dorsal expression ofaltFGF-2, but not FGF-2 gene products, induced alteration of neural tube morphology in a significant fraction of mouse embryos (25%). However, no alterations of dorsoventral (d/v) neural tube polarity were detected, indicating thataltFGF-2 and FGF-2 gene products either function as permissive cofactors or regulate neural tube growth without affecting establishment of its primary d/v polarity.     

Comparative effect of different aerobic pretreatments on the kinetics and macroenergetic parameters of anaerobic digestion of olive mill wastewater in continuous mode

A comparative kinetic study was carried out on the anaerobic digestion of olive mill wastewater (OMW) and OMW that was previously fermented with Geotrichum candidum, Azotobacter chroococcum and Aspergillus terreus. The reactors used were continuously fed and contained sepiolite as support for the mediating bacteria. A kinetic model for multicomponent substrate removal by anaerobic digestion has been used. The model is based on the linear removal concept which is a special case of the broader Monod equation. The second-order kinetic constant, k _{2( s )}, was found to be influenced by the pretreatment carried out, and was 4.2, 4.0 and 2.5 times higher for Aspergillus, Azotobacter and Geotrichum-pretreated OMWs than that obtained in the anaerobic digestion of untreated OMW. This was significant at 95% confidence level. This behaviour is believed to be due to the lower levels of phenolic compounds and biotoxicity present in the pretreated OMWs. In fact, the kinetic constant increased when the phenolic compound content and biotoxicity of the pretreated OMWs decreased. In addition, the macroenergetic parameters of the anaerobic digestion of OMW, i.e. the specific rate of substrate uptake for cell maintenance, m, and the yield coefficient for the biomass, Y, decreased by a factor of 2.4, 3.6 and 5.1 and increased by a factor of 1.9, 2.2 and 2.4 respectively, for the OMWs previously treated with Geotrichum candidum, Azotobacter chroococcum and Aspergillus terreus in relation to the observed values for the untreated OMW.     

Information sharing in decentralised supply chains with partial collaboration

Flexible Services and Manufacturing Journal - We explore the value of information sharing for smoothing the dynamics of supply chains when some echelons do not collaborate. To this end, we study...     

Cumulative frequency-dependent selective episodes allow for rapid morph cycles and rock-paper-scissors dynamics in species with overlapping generations

Rock-paper-scissors (RPS) dynamics, which maintain genetic polymorphisms over time through negative frequency-dependent (FD) selection, can evolve in short-lived species with no generational overlap, where they produce rapid morph frequency cycles. However, most species have overlapping generations and thus, rapid RPS dynamics are thought to require stronger FD selection, the existence of which yet needs to be proved. Here, we experimentally demonstrate that two cumulative selective episodes, FD sexual selection reinforced by FD selection on offspring survival, generate sufficiently strong selection to generate rapid morph frequency cycles in the European common lizard Zootoca vivipara, a multi-annual species with major generational overlap. These findings show that the conditions required for the evolution of RPS games are fulfilled by almost all species exhibiting genetic polymorphisms and suggest that RPS games may be responsible for the maintenance of genetic diversity in a wide range of species.