Realization of real-time DSP for C-band PAM-4 transmission in inter-datacenter network.

We designed and realized real-time pulse amplitude modulation-4 (PAM-4) digital signal processing (DSP) including forward error correction (FEC) for a C-band inter-datacenter network. The PAM-4 DSP is intended to compensate for chromatic dispersion and provide dispersion tolerance. A decision feedback equalizer (DFE) and maximum likelihood sequence equalizer (MLSE) were employed for the dispersion compensation. A low-density parity check (LDPC) code was used to increase coding gain. The soft-decision Viterbi algorithm (SOVA) was adopted to provide probabilistic information to the LDPC code. For implementation in a real-time field programmable gate arrays (FPGAs), we employed fully parallelized structures. In the design, three LDPC cores were operated in parallel, and the equalizers were also operated with 128 PAM-4 symbols. With the DSP, we empirically proved the feasibility of 25 km transmission without error-floor sign, corresponding to a dispersion compensation capacity of 425 ps/nm. We confirmed 35 km ∼ 85 km error-free transmission for inter-datacenter network.

Toxic Effects and Depuration on the Antioxidant and Neurotransmitter Responses after Dietary Lead Exposure in Starry Flounder.

Starry Flounder Platichthys stellatus were exposed to dietary lead (Pb) at concentrations of 0, 30, 60, 120, and 240 mg/kg for 4 weeks. Recover period was conducted for 2 weeks after the exposure. Exposure to Pb concentrations over 60 mg/kg induced significant changes in the antioxidant responses in the liver, kidney, and gill and continued even after the depuration period in the liver (over 120 mg/kg for superoxide dismutase [SOD] activity) and kidney (at 240 mg/kg for glutathione [GSH] levels). Glutathione S-transferase (GST) activity in liver, kidney, and gill were increased by dietary Pb exposure, and recovery was observed in all groups during the recovery period. Acetylcholinesterase (AChE) activity was significantly inhibited in the brain and muscle of flounder at Pb exposure over 120 mg/kg, and no restoration was observed after the depuration period. Lysozyme activity in the plasma was significantly increased at Pb exposures greater than 60 mg kg but was restored after the depuration period. The results of this study indicate that dietary Pb exposure induces toxic effects on antioxidant responses, neurotransmitter, and immune responses of Starry Flounder.

Toxic effects of juvenile sablefish, Anoplopoma fimbria by ammonia exposure at different water temperature.

Juvenile sablefish, Anoplopoma fimbria (mean length 17.1±2.4cm, and mean weight 75.6±5.7g) were used to evaluate toxic effects on antioxidant systems, immune responses, and stress indicators by ammonia exposure (0, 0.25, 0.75, and 1.25mg/L) at different water temperature (12 and 17°C) in 1 and 2 months. In antioxidant responses, superoxide dismutase (SOD) and catalase (CAT) were significantly increased by ammonia exposure, whereas glutathione (GSH) was decreased. In immune responses, lysozyme and phagocytosis activity were significantly increased by ammonia exposure. In stress indicators, plasma glucose, heat shock protein 70 (HSP 70), and cortisol were significantly increased. At high water temperature (17°C), alterations by ammonia exposure were more distinctly. The results of this study indicated that ammonia exposure can induce toxic effects in the sablefish, and high water temperature can affect the ammonia exposure toxicity.

Growth performance, oxidative stress, and non-specific immune responses in juvenile sablefish, Anoplopoma fimbria, by changes of water temperature and salinity.

Juvenile sablefish, Anoplopoma fimbria (mean length 15.5 ± 1.9 cm, mean weight 68.5 ± 4.8 g), were used to evaluate the effects on growth, oxidative stress, and non-specific immune responses by changes of water temperature (8, 10, 12, 14, 16, 18, and 20 °C) and salinity (100 (35.0), 90 (31.5), 80 (28.0), 70 (24.5), 60 (21.0), 50 (17.5), and 40% (14.0) (‰)) for 4 months. The growth performance was significantly increased at the temperature of 12 and 14 °C, and the feed efficiency was notably decreased at the temperature of 18 °C. The growth performance and feed efficiency were also significantly decreased at low salinity. The antioxidant responses such as superoxide dismutase and catalase were significantly increased by the high temperature and decreased by the low salinity. The immune responses such as lysozyme and phagocytosis were elevated by the temperature of 18 °C and decreased by the salinity of 50%. The results of this study indicate that the growth performance of juvenile sablefish, A. fimbria, is influenced by the temperature and salinity, and the excessive temperature and salinity levels can affect the antioxidant and immune responses.

Toxic effects and depuration after the dietary lead(II) exposure on the bioaccumulation and hematological parameters in starry flounder (Platichthys stellatus).

Platichthys stellatus (mean length 20±2cm, mean weight 160.15±15g) were exposed to the different levels of dietary lead(II) at the concentrations of 0, 30, 60, 120, 240mg/kg for 4 weeks. Depuration was conducted for 2 weeks after exposure. The lead exposure over 60mg Pb/kg induced the significant bioaccumulation in tissues of P. stellatus (5-30µg/g tissue), except for brain and muscle where the exposure to 240mg Pb/kg caused the bioaccumulation (2-4µg/g tissue). The hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht) value and hemoglobin (Hb) concentration were substantially decreased over 60mg Pb/kg, and lasted even after the depuration period. For plasma components, calcium and magnesium levels in plasma were generally decreased over 60mg Pb/kg, and glucose level was also mainly increased over 60mg Pb/kg. Total protein was significantly decreased over 120mg Pb/kg after 4 weeks exposure. Glucose and total protein showed the restoration after the depuration period in groups of fish exposed previously to over 60 and 120mg Pb/kg, respectively. However, other parameters that changed during the exposure over 60mg Pb/kg did not recovered. For enzymatic components in plasma, glutamic oxalate transminase (GOT), glutamic pyruvate transminase (GPT) and alkaline phosphatase (ALP) were significantly increased over 120mg Pb/kg, and there was only restoration observed after the depuration for ALP over 120mg Pb/kg.