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Recently, Radio over Fiber (RoF) technology has become a hot research topic in the broadband communication access network field and has attracted much attention in the industry. This is mainly because the technology makes full use of the massive bandwidth of optical fiber transmission and the application advantages of flexible coverage of wireless communication. In the evolution and development of RoF technology, multi-dimensional multi-order modulation has important scientific research significance and practical value because it can improve the system bandwidth utilization and reduce the signal transmission and receiving cost. This paper summarizes the research progress of traditional amplitude modulation, typical multi-dimensional multi-order modulation and some representative new multi-dimensional multi-order modulation technologies. We also briefly analyzes the application prospect of multi-dimensional multi-order modulation technology in RoF system.

The communication system between the islands has the problems of high cost and the transmitted signal may require relay amplification. In order to solve this issue, a novel Free Space Optical (FSO) communication system using Manchester encoded and decoded signals is designed. It can support 10 Gbit/s optical signal transmission over 100 km submarine cable (using G. 654 standard single-mode fiber) cascaded with 1 km FSO wireless link. We evaluate the performance by measuring the time-domain waveform, optical spectrum, eye diagrams and Bit Error Rate (BER) in simulation with Manchester coded signals, under sunny, rainy and foggy day. The measured results show that the receiver sensitivity can reach -18.92 dBm at the back-to-back system. Under the 100 km submarine cable and 1 km FSO wireless link, the receiver sensitivity can reach -17.72, -16.66 and -11.16 dBm in the sunny, rainy and foggy day, respectively. The simulation results prove that the FSO communication system using Manchester code may have potential application in the field of islands information transmission in the future.

The article reports on the dietary survey concerning food consumption and nutrient intake of middle school students from rural area near Shanghai, China. The survey is carried out from 392 students aged 13-19 in Qi-bao Middle School. The nutrient contents in their diet is measured from the food consumption records and its height and weight records are taken from the school clinic records. The survey reveals that the protein intake of these students are only 58.4 grams per day per capita. Accordingly, the estimated intake of nutrients and food consumption patterns suggest that the nutritional status of students in the middle school many not be adequate.

Hemopressin and related peptides have shown to function as the endogenous ligands or the regulator of cannabinoid receptors. The previous studies demonstrated that the endocannabinoid system played important roles in modulating several physiological functions such as sleep, olfaction, emotion, learning and memory, and reward behaviors. Mouse VD-hemopressin (α) [(m)VD-HPα], an 11-residue peptide derived from the α1 chain of hemoglobin, was recently presumed as a selective agonist of the CB 1 receptor. The present study was undertaken to investigate the effects of (m)VD-HPα on the sleep-wake cycle and power spectrum of cortical EEG in freely moving rats and the potential neurons in the brain activated by (m)VD-HPα. The results showed that 20.1 nmol of (m)VD-HPα i.c.v. administration increased non-rapid eye movement (NREM) sleep in the first 2 h section accompanied by an increase in EEG delta (0.5-4 Hz) activity. The (m)VD-HPα-induced NREM sleep enhancement was due to extended episode duration instead of the episode number. In addition, the effect of (m)VD-HPα (20.1 nmol) on sleep-wake states was significantly attenuated by an antagonist of the CB 1 receptor, AM251 (20 nmol, i.c.v.) but not by the CB 2 receptor antagonist, AM630 (20 nmol, i.c.v.). In comparison with vehicle, (m)VD-HPα increased Fos-immunoreactive (-ir) neurons in the ventrolateral preoptic nucleus (VLPO), but reduced Fos-ir neurons in the lateral hypothalamus (LH), tuberomammillary nucleus (TMN), and locus coeruleus (LC). These findings suggest that (m)VD-HPα promotes NREM sleep via the CB 1 cannabinoid receptor to probably activate VLPO GABAergic neurons, but inactivates the LH orexinergic, LC noradrenergic, and TMN histaminergic neurons., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Xie, Wang, Ren, Wang, Gao, Chen, Zhao, Ren, Xie, Shao and Hou.)