# Research Progress and Effects of Light on Poultry Circadian Rhythm Regulation Based on CiteSpace
## 2 Visual Analysis Based on CiteSpace
### CiteSpace Maps
#### 2.3.4 Research Frontiers  
The cited documents are the intellectual base of the research domain, and the label obtained by intellectual base clustering is the research frontiers of the field. Given the knowledge update cycle, we drew the timeline view of research frontiers, as shown in Figure 5, so that we can explore the development status of the domain and the current research frontiers. The relevant information on the map is shown in the top right corner.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Keywords** & **Frequency** & **Centrality** \\ \hline Rhythm & 150 & 0.02 \\ Circadian Rhythm & 142 & 0.04 \\ Melatonin & 96 & 0.04 \\ Sleep & 94 & 0.02 \\ Clock & 81 & 0.06 \\ Exposure & 77 & 0.03 \\ Expression & 67 & 0.03 \\ Gene Expression & 65 & 0.02 \\ Bright Light & 65 & 0.04 \\ Behavior & 50 & 0.06 \\ Melanopsin & 49 & 0.05 \\ Entrainment & 46 & 0.05 \\ Response & 46 & 0.03 \\ Growth & 45 & 0.05 \\ Circadian Clock & 44 & 0.01 \\ Suprachiasmatic Nucleus & 42 & 0.06 \\ Time & 41 & 0.06 \\ Ganglion Cell & 40 & 0.09 \\ Night & 37 & 0.05 \\ Sensitivity & 34 & 0.02 \\ \hline \hline \end{tabular} Top 25 keywords with the strongest citation bursts  
\begin{tabular}{c c c} \hline \hline
**Keywords** & **Year Strength Begin End** & **2018** & **2022** \\ risk & 2018 & 4.19 **2018** & **2019** \\ antioxidant & 2018 & 2.95 **2018** & **2018** \\ population & 2018 & 2.61 **2018** & **2019** \\ jet lag & 2018 & 2.45 **2018** & **2019** \\ breast cancer & 2018 & 2.42 **2018** & **2018** \\ transcription & 2018 & 2.35 **2018** & **2019** \\ intensity & 2018 & 2.35 **2018** & **2019** \\ oscillator & 2018 & 2.09 **2018** & **2019** \\ response curve & 2018 & 1.96 **2018** & **2018** \\ short wavelength light & 2018 & 1.96 **2018** & **2018** \\ drosophila melanogaster & 2018 & 1.96 **2018** & **2018** \\ syrian hamster & 2018 & 1.96 **2018** & **2018** \\ architecture & 2018 & 1.96 **2018** & **2018** \\ melatonin secretion & 2018 & 1.96 **2018** & **2018** \\ plasma melatonin & 2018 & 1.96 **2018** & **2018** \\ cycle & 2018 & 2.59 **2019** & **2019** \\ increase & 2018 & 2.32 **2019** & **2019** \\ night shift work & 2018 & 2.32 **2019** & **2019** \\ temperature & 2018 & 2.13 **2019** & **2019** \\ photoperiod & 2018 & 2.12 **2019** & **2019** \\ messenger ma & 2018 & 2.36 **2020** & **2022** \\ plant & 2018 & 2.33 **2020** & **2020** \\ rat & 2018 & 2.12 **2020** & **2020** \\ white light & 2018 & 2.57 **2021** & **2022** \\ constant light & 2018 & 2.13 **2021** & **2022** \\ \hline \hline \end{tabular}
\end{table}
Table 1: Top 20 bodies by the frequency of appearance.  
Figure 4: Top 25 keywords with strongest citation bursts (red line represents the year of the citation bursts).  
Q is 0.6436, and S is 0.8859, indicating that this clustering is reasonable and effective. The node (Figure 5) is the cited literature, and the size of the node is proportional to the number of citations of corresponding documents. The nodes with purple (high centrality) and red (high citation) in the outer circle are important documents in the field and deserve attention.  
Using the LLR algorithm, we obtained 11 clustering labels: #0 lighting, #1 light pollution, #2 light at night, #3 hepatocyte, #4 SCN, #5 stroke, #6 refractive error, #7 blue light, #8 immune function, #9 chick, and #10 insect conservation. The timeline shows that different clusters have different duration, and some clusters have lasted for 8 years and remain active (e.g., #0 lighting). The current research frontiers are #0 lighting, #hepatocyte, #4 SCN, #7 blue light, and #8 immune function, and they are not only limited to the influence of light on circadian rhythm but also extended to the influence of other functions of human or animals (e.g., hepatocyte and immune function).