Neural Predictive Control of Broiler Chicken Growth

Active control of the growth of broiler chickens has potential benefits for farmers in terms of improved production efficiency, as well as for animal welfare in terms of improved leg health. In this work, a differential recurrent neural network (DRNN) was identified from experimental data to represent broiler chicken growth using a recently developed nonlinear system identification algorithm. The DRNN model was then used as the internal model for nonlinear model predicative control (NMPC) to achieve a group of desired growth curves. The experimental results demonstrated that the DRNN model captured the underlying dynamics of the broiler growth process reasonably well. The DRNN based NMPC was able to specify feed intakes in real time so that the broiler weights accurately followed the desired growth curves ranging from $-12$ to +12% of the standard curve. The overall mean relative error between the desired and achieved broiler weight was 1.8% for the period from day 12 to day 51

Dynamic assembly of end-joining complexes requires interaction between Ku70/80 and XRCC4

International audienceDNA double-strand break (DSB) repair by nonhomologous end joining (NHEJ) requires the assembly of several proteins on DNA ends. Although biochemical studies have elucidated several aspects of the NHEJ reaction mechanism, much less is known about NHEJ in living cells, mainly because of the inability to visualize NHEJ repair proteins at DNA damage. Here we provide evidence that a pulsed near IR laser can produce DSBs without any visible alterations in the nucleus, and we show that NHEJ proteins accumulate in the irradiated areas. The levels of DSBs and Ku accumulation diminished in time, showing that this approach allows us to study DNA repair kinetics in vivo. Remarkably, the Ku heterodimers on DNA ends were in dynamic equilibrium with Ku70/80 in solution, showing that NHEJ complex assembly is reversible. Accumulation of XRCC4/ligase IV on DSBs depended on the presence of Ku70/80, but not DNA-PK(CS). We detected a direct interaction between Ku70 and XRCC4 that could explain these requirements. Our results suggest that this assembly constitutes the core of the NHEJ reaction and that XRCC4 may serve as a flexible tether between Ku70/80 and ligase IV

Dynamic assembly of end-joining complexes requires interaction between Ku70/80 and XRCC4

DNA double-strand break (DSB) repair by nonhomologous end joining (NHEJ) requires the assembly of several proteins on DNA ends. Although biochemical studies have elucidated several aspects of the NHEJ reaction mechanism, much less is known about NHEJ in living cells, mainly because of the inability to visualize NHEJ repair proteins at DNA damage. Here we provide evidence that a pulsed near IR laser can produce DSBs without any visible alterations in the nucleus, and we show that NHEJ proteins accumulate in the irradiated areas. The levels of DSBs and Ku accumulation diminished in time, showing that this approach allows us to study DNA repair kinetics in vivo. Remarkably, the Ku heterodimers on DNA ends w