Terahertz radiation by ultrafast spontaneous polarization modulation in multiferroic BiFeO3_3 thin films

Terahertz (THz) radiation has been observed from multiferroic BiFeO$_3$ thin films via ultrafast modulation of spontaneous polarization upon carrier excitation with illumination of femtosecond laser pulses. The radiated THz pulses from BiFeO$_3$ thin films were clarified to directly reflect the spontaneous polarization state, giving rise to a memory effect in a unique style and enabling THz radiation even at zero-bias electric field. On the basis of our findings, we demonstrate potential approaches to ferroelectric nonvolatile random access memory with nondestructive readability and ferroelectric domain imaging microscopy using THz radiation as a sensitive probe.Comment: 4 pages, 4 figures, submitted to Physical Review Letter

JMASM44: Implementing Multiple Ratio Imputation by the EMB Algorithm (R)

Although single ratio imputation is often used to deal with missing values in practice, there is a paucity of discussion regarding multiple ratio imputation. Code in the R statistical environment is presented to execute multiple ratio imputation by the Expectation-Maximization with Bootstrapping (EMB) algorithm

Multiple Ratio Imputation by the EMB Algorithm: Theory and Simulation

Although multiple imputation is the gold standard of treating missing data, single ratio imputation is often used in practice. Based on Monte Carlo simulation, the Expectation-Maximization with Bootstrapping (EMB) algorithm to create multiple ratio imputation is used to fill in the gap between theory and practice

Inferior displacement of the lower eyelid during intraoperative quantification in blepharoptosis surgery

Hirohiko Kakizaki, Yasuhiro Takahashi, Masahiro Zako, Masayoshi IwakiDepartment of Ophthalmology, Aichi Medical University, Nagakute, Aichi, JapanPurpose: To examine inferior displacement of the lower eyelid during eye closing in intraoperative quantification of blepharoptosis surgery.Methods: A series of lower eyelid movements during eye closing in intraoperative quantification of blepharoptosis surgery were examined in 30 eyelids of 15 patients (6 males and 9 females; mean age 70.0 years; range 43–81 years) with bilateral aponeurotic blepharoptosis.Results: Inferior displacement of the lower eyelid was observed in all eyelids examined, although the extent varied in each patient (range 2.0–4.5 mm; mean 3.2 mm). Inferior displacement occurred with upward eye movement caused by Bell's phenomenon. Many wrinkles were simultaneously observed as a result of contraction of the orbicularis oculi muscle. After maintaining the inferiorly displaced state for several seconds, 20 lower eyelids in 10 patients naturally moved superiorly to a resting position. On the other hand, 10 lower eyelids in 5 patients remained in the same inferior position for more than 5 seconds, after which we had to manually elevate them to a resting position. The eyes then moved inferiorly to their resting position with a decrease in the number of lower eyelid wrinkles. Once the patients opened their eyes, inferior displacement of the lower eyelid completely disappeared.Conclusions: Inferior displacement of the lower eyelid during eye closing increases the amount of lagophthalmos. This phenomenon needs to be considered for quantifying the intraoperative lagophthalmos level during blepharoptosis surgery.Keywords: blepharoptosis surgery, eye closing, inferior displacement, intraoperative quantification, lower eyelid&nbsp