• Journal of Multimedia Information System
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• v.7 no.2
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• pp.189-196
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• 2020

We have developed a device for recording biological data by inserting three electrodes and a needle with an angular velocity sensor into the moth for the purpose of measuring the electromyogram of the flapping and the corresponding lift force. With this measurement, it is possible to evaluate the moth-physiological function of moths, and the amount of pesticides that insects are exposed to (currently LD50-based standards), especially the amount of chronic low-concentration exposure, can be reduced the dose. We measured and recorded 2-channel electromyography (EMG) and angular velocity corresponding to pitch angle (pitch-like angle) associated with wing flapping for 100 sweet potato hawkmoths (50 females and 50 males) with the animals suspended and constrained in air. Overall, the angular velocity and amplitude of EMG signals demonstrated high correlation, with a correlation coefficient of R = 0.792. In contrast, the results of analysis performed on the peak-to-peak (PP) EMG intervals, which correspond to the RR intervals of ECG signals, indicated a correlation between ΔF fluctuation and angular velocity of R = 0.379. Thus, the accuracy of the regression curve was relatively poor. Using a DC amplification circuit without capacitive coupling as the EMG amplification circuit, we confirmed that the baseline changes at the gear change point of wing flapping. The following formula gives the lift provided by the wing: angular velocity × thoracic weight - air resistance - (eddy resistance due to turbulence). In future studies, we plan to attach a micro radio transmitter to the moths to gather data on potential energy, kinetic energy, and displacement during free flight for analysis. Such physiological functional evaluations of moths may alleviate damage to insect health due to repeated exposure to multiple agrochemicals and may lead to significant changes in the toxicity standards, which are currently based on LD50 values.

• Korean Journal of Veterinary Research
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• v.53 no.1
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• pp.29-35
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• 2013

To develop a live vaccine candidate using an attenuated strain of Salmonella Typhimurium (ST), biochemical properties, plasmid profile, PFGE patterns and pathogenic analysis of the ST isolate were carried out after sequential passage of the ST isolate in porcine neutrophils. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. Also, changes including deletion of the gene fragments were observed in PFGE analysis of the neutrophil-adapted isolates. Two plasmids, 105kb and 50kb, were cured in the strain passaged over 15 times in porcine neutrophils. The 50% of lethal dose ($LD_{50}$) of the parent strain was changed from $1{\times}10^5\;LD_{50}$ to $6{\times}10^6\;LD_{50}$ by the passage in intraperitoneal injection of the strains into mice. These results suggested that bacterial genotypic and phenotypic responses might be globally altered depending on the inside environment of neutrophils.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.163-166
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• 1975

This experiment was performed to investigate the X-ray sensitivities at the various stages of life cycle and to determine the sterillizing dose of stable fly, Stomoxys calcitrans(L). A dose of 300 rad caused about $50\%$ mortality in 2-hour-old eggs as measured by egg hatch, and $100\%$ mortality was obtained with a does of 1 Krad. Sub-lethal dose $(LD_{50})$ for the pupal mortality after irradiation of 3-5days old pupae were 11.5 Krad and the mortality was decreased with increasing pupal age at irradition. A significant reduction of egg hatch by $1.5\%$ was observed when treated males with 3 Krad at pupal stage were mated to untreated virgin femleas. On the other hand, $100\%$ sterility in females was resulted by 2 Krad irradiation and oviposition was completely inhibited with 3 Krad. Thus, both sexes of stable fly could be sterilized with a dose of 4 Krad irradiated to 3-5 days old pupae.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.310-313
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• 1996

Acute oral toxicity studies of KDRD-002 (Coriolus versicolor polysaccharide :DDB= 19.2:1) were carried out in Sprague-Dawley rats of both sexes. In this study, we daily examined number of deaths, clinical signs, body weights and pathological examinations for 7 days after single oral administration of KDRD-002 with different dose levels. KDRD-002 did not show any toxic effect in rats and oral LD$_{50}$ value was over 3.25 g/kg in rats.s.

• Korean Journal of Biological Psychiatry
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• v.24 no.3
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• pp.149-154
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• 2017

Objectives This study investigated associations between symptom severity and neurocognitive functions in patients with major depressive disorder using comprehensive neuropsychological tests. Methods Ten patients with low depression (LD) and 22 patients with high depression (HD) participated. Symptom severity was determined by both the Beck Depression Inventory and the Hamilton Depression Rating Scale. Additionally, anxiety was measured by the Korean version of the State-Trait Anxiety Inventory (STAI-KYZ). Ten subtests of the Korean-Wechsler Adult Intelligence scale (K-WAIS), Stroop test, the word/design fluency tests were administered to assess cognition. Results The LD and HD groups did not differ in any of cognitive measures but anxiety level. Namely, the HD group obtained significantly higher scores on the state (U = 29.50, p < 0.01) and trait (U = 28.50, p < 0.001) anxiety scales than the LD group. A significant interaction effect between trait anxiety and depression severity was observed on the picture arrangement subtest of the K-WAIS [F (1, 27) = 5.09, p < 0.05]. Conclusions Cognitive deficits observed in patients with major depressive disorder may be related to other factors rather than current symptom severity. Trait anxiety possibly moderates the effect of current symptom severity on social judgment in these patients.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.2
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• pp.12-17
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• 1998

Weight loss of pear packed with corrugated paperboard box after 50 days storage at $20^{\circ}C$ was 4.4%, and those of 20LD, 40LD film and EPS box were 0.8-0.7%. Ascorbic acid content of EPS was 20% higher than that of control. Hardness of EPS was also similar trend. Titratable acid and total soluble solid content of pear were not different among the packages. Decay of control was 1-2 pieces per box, but the others was not found. Overall appearences of LD, CE and EPS were better than that of control.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.489-492
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• 2006

We demonstrate a beat frequency-Switchable dual-mode external cavity laser hybrid integrated on planar lightwave circuit with an FP-LD and a sampled grating as external reflector. The dual-mode external avity laser was able to switch its beat frequency from 132GHz to 406GHz by changing LD current from 50mA to 55mA.

• ETRI Journal
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• v.45 no.1
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• pp.163-170
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• 2023

We report an electroabsorption modulator (EAM)-integrated distributed Bragg reflector laser diode (DBR-LD) capable of supporting a high data rate and a wide wavelength tuning. The DBR-LD contains two tuning elements, plasma and heater tunings, both of which are implemented in the DBR section, which have blue-shift and red-shift in the Bragg wavelength through a current injection, respectively. The light created from the DBR-LD is intensity-modulated through the EAM voltage, which is integrated monolithically with the DBRLD using a butt-joint coupling method. The fabricated chip shows a threshold current of approximately 8 mA, tuning range of greater than 30 nm, and static extinction ratio of higher than 20 dB while maintaining a side mode suppression ratio of greater than 40 dB under a window of 1550 nm. To evaluate its modulation properties, the chip was bonded onto a mount including a radiofrequency line and a load resistor showing clear eye openings at data rates of 25 Gb/s nonreturn-to-zero and 50 Gb/s pulse amplitude modulation 4-level, respectively.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.324-330
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• 1986

The responses of brain acetylcholinesterase(Ach-E) and plasma cholinesterase (Ch-E) activities were studied in chicknes given oral doses of Terbufos(S-tert-butyl thiomethyl 0,0-diethyl phosphorodithioate), an organophosphorus insecticide. The acute oral $LD_{50}$ of terbufos was 1.82mg/kg. The activity of plasma Ch-E was inhibited more rapidly than that of brain Ach-E, whereas recovery of plasma Ch-E activity was more rapid than that of brain Ach-E. Recovery of brain Ach-E and plasma Ch-E was followed the model $Y=a+b(log_{10}X)$. Brain Ach-E activity and plasma Ch-E were inhibited 83% and 94%, respectively, at 60min after administered oral $LD_{50}$. Brain Ach-E and plasma Ch-E was inhibited in vitro by Terbufos

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.139-143
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• 1991

GRIN-SCH quantum well structured Laser Diode were fabricated using MOCVD and operated as CW at room temperature. The threshold current density of the LD with 670${\mu}{\textrm}{m}$ cavity length was 530 A/$\textrm{cm}^2$. For the ridge waveguide type index guiding structured LD with 6${\mu}{\textrm}{m}$ stripe width and 240${\mu}{\textrm}{m}$ cavity length, the threshold current was 50㎃. The maximum differential quantum efficiency was 0.95W/A when the optical output was 60mW. The lasing wavelength of QW LD was 865nm. In the L-I measurement. TE mode was superior to TM mode. From the near field pattern, single lateral mode operation was observed.