Ayush Srivastava

The physical properties of in vitro iron-reconstituted and genetically engineered human heteropolymer ferritins were investigated.

In this paper, a review of execution of Long Short-Term Memory Accelerator on FPGA is presented. The paper starts with a brief overview on the significance of LSTM accelerators, historical background and general structure of LSTM accelerators. Then recent works in this area are highlighted. The research in this domain is focused on modifying the architecture of LSTM to overlap the computation of different stages in the network. This yields less power and higher performance as compared to the corresponding software implementation. The implementation on FPGA provides user with the ability to tradeoff resource utilization and speed of operation by adjusting the amount of parallelization for different operation such as vector multiplication and addition. This offers flexibility to adjust the computational load for different FPGA boards.

Exact computation techniques require a high amount of resources and time. But the need of today’s Electronics world is a system that is faster and requires less area. Approximate Computing has emerged as a technique that plays with the trade-off between the requirement of exact computing to improve area requirement, speed, and power performance. In this paper, a speed-efficient model for approximate matrix multiplier is proposed with the use of the Dadda compression technique followed by the Carry-Save Ahead (CSA) adder. Hardware design is modeled in Verilog. Artix-7 xc7a100t-3csg324 is used as a target device in Xilinx ISE Design Suite 14.7. ISIM simulation results and device utilization summary have been presented. Synthesis results show that the proposed design is faster, requires less area, consumes less power than published designs.

The excessively high and inconsistent literature values for K_m,Fe and K m,O₂ prompted us to examine the iron oxidation kinetics in ferritin, the major iron storage protein in mammals, and to determine whether a traditional Michaelis–Menten enzymatic behavior is obeyed. The kinetics of Fe(II) oxidation and mineralization catalyzed by three different types of ferritins (recombinant human homopolymer 24H, HuHF, human heteropolymer ∼21H:3L, HL, and horse spleen heteropolymer ∼3.3H:20.7L, HosF) were therefore studied under physiologically relevant O₂ concentrations, but also in the presence of excess Fe(II) and O₂ concentrations. The observed iron oxidation kinetics exhibited two distinct phases (phase I and phase II), neither of which obeyed Michaelis–Menten kinetics. While phase I was very rapid and corresponded to the oxidation of approximately 2 Fe(II) ions per H-subunit, phase II was much slower and varied linearly with the concentration of iron(II) cations in solution, independent of the size of the iron core. Under low oxygen concentration close to physiological, the iron uptake kinetics revealed a Michaelis–Menten behavior with K m,O₂ values in the low μM range (i.e. ∼1–2 μM range). Our experimental K m,O₂ values are significantly lower than typical cellular oxygen concentration, indicating that iron oxidation and mineralization in ferritin should not be affected by the oxygenation level of cells, and should proceed even under hypoxic events. A kinetic model is proposed in which the inhibition of the protein's activity is caused by bound iron(III) cations at the ferroxidase center, with the rate limiting step corresponding to an exchange or a displacement reaction between incoming Fe(II) cations and bound Fe(III) cations.