• Biomolecules & Therapeutics
• /
• v.29 no.5
• /
• pp.483-491
• /
• 2021

Parkinson's disease (PD) is a neurodegenerative disorder that involves the loss of dopaminergic neurons in the substantia nigra (SN). Matrix metalloproteinases-8 (MMP-8), neutrophil collagenase, is a functional player in the progressive pathology of various inflammatory disorders. In this study, we administered an MMP-8 inhibitor (MMP-8i) in Leucine-rich repeat kinase 2 (LRRK2) G2019S transgenic mice, to determine the effects of MMP-8i on PD pathology. We observed a significant increase of ionized calcium-binding adapter molecule 1 (Iba1)-positive activated microglia in the striatum of LRRK2 G2019S mice compared to normal control mice, indicating enhanced neuro-inflammatory responses. The increased number of Iba1-positive activated microglia in LRRK2 G2019S PD mice was down-regulated by systemic administration of MMP-8i. Interestingly, this LRRK2 G2019S PD mice showed significantly reduced size of cell body area of tyrosine hydroxylase (TH) positive neurons in SN region and MMP-8i significantly recovered cellular atrophy shown in PD model indicating distinct neuro-protective effects of MMP-8i. Furthermore, MMP-8i administration markedly improved behavioral abnormalities of motor balancing coordination in rota-rod test in LRRK2 G2019S mice. These data suggest that MMP-8i attenuates the pathological symptoms of PD through anti-inflammatory processes.

• Journal of Life Science
• /
• v.25 no.2
• /
• pp.151-157
• /
• 2015

Zebrafish (Danio rerio) has been more widely used to study pharmacology. Oxytectracycline (OTC) is a broad-spectrum antibiotic and works by interfering with the ability to produce essential proteins of bacteria. The aim of this study was to identify the effects of exposure to OTC on behavioral changes or endocrine response in zebrafish. The behavioral effects of exposure to OTC (50, 100 or 200 mg/l) were characterized in several novelty-based paradigms such as the novel tank or open field test in zebrafish. Moreover, to investigate effects of exposure to OTC on endocrine response, we measured whole-body cortisol level using cortisol ELISA kit. As results of novel tank test, duration in top and immobile duration were significantly increased by the exposure to OTC in a concentration-dependent manner (p<0.05). In addition, moving distance, highly mobile, velocity and zone transition were significantly decreased by the exposure to OTC in a concentration-dependent manner (p<0.05). As results of open field test, the exposure to OTC increased immobile duration significantly (p<0.05). However, moving distance, mobile duration and velocity were significantly decreased by the exposure to OTC in a concentration-dependent manner (p<0.05). Besides, the exposure to OTC elevated whole-body cortisol levels in zebrafish. These results suggest that the exposure to OTC may induce chemical stress in zebrafish.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.5A
• /
• pp.490-496
• /
• 2007

This paper describes the design and implementation of an integrated LTCC front-end module for the IEEE802.11a WLAN applications by performing the behavioral-level simulation using measurement-based behavioral model. To meet the IEEE802.11a WLAN standard, a system transmitting 1024 symbols through 64-QAM process at the rate of 54Mbps should be implemented and nonlinear properties are confirmed by simulations of ACPR and EVM in this circumstance. The right offsets of ACPR which are 30MHz, 20MHz, and 11MHz distant from the center frequency of 5.8GHz are 49.36dBc, 36.90dBc, and 24.58dBc, respectively. The left offsets are 50.14dBc, 30.04dBc, and 28.85dBc, respectively and EVM is 2.94%. The size of the module implemented with LTCC five-layer substrates is $13.4mm{\times}14.2mm$. The measured characteristics of the transmitter show P1dB of 16.2dBm and power gain of 16.73dB. Those of the receiver exhibit the small signal gain of 16.24dB and noise figure of 7.83dB.

• Journal of Life Science
• /
• v.30 no.4
• /
• pp.321-330
• /
• 2020

The aim of this study was to investigate the effect of copper (II) chloride (CuCl₂) on zebrafish. Zebrafish were exposed to various CuCl₂ concentrations and subjected to different exposure times to determine the median lethal concentration (LC₅₀) values. To evaluate stress responses, we measured whole-body cortisol levels and behavioral parameters using the open field test (OFT) or the novel tank test (NTT). The zebrafish were exposed to CuCl₂ solution at concentrations of 1.5-150 ㎍/l or a vehicle for 1 hr before behavioral tests or sample collection for whole-body cortisol. The LC₅₀ values were 30.3, 25.3, and 14.8 ㎍/l at 24, 48, and 96 hr, respectively. The NTT showed that mobility, velocity, and distance covered were significantly lower in zebrafish exposed to CuCl₂ than in the control group (p<0.05), while the turn angle was significantly higher in zebrafish exposed to a CuCl₂ concentration of 150 ㎍/l than in the control group (p<0.05). The OFT also showed that mobility, velocity, and distance covered were significantly lower and the turn angle and meandering were significantly higher in zebrafish exposed to all concentrations of CuCl₂ than in the control group (p<0.05). The whole-body cortisol levels were significantly higher in zebrafish exposed to CuCl₂ than in the control group (p<0.05). These results suggest that exposure to lethal CuCl₂ concentrations induces an intense toxic and stress response in zebrafish, causing behavioral changes and increasing whole-body cortisol levels.

• The Korean Journal of Pesticide Science
• /
• v.17 no.1
• /
• pp.33-40
• /
• 2013

Pyrifluquinazon is known to act as a feeding inhibitor in several insect species. In this study, we investigated the effect of pyrifluquinazon on the whiteflies, Trialeurodes vaporariorum and Bemisia tabaci. Pyrifluquinazon showed high insecticidal activity (> 90%) against adult T. vaporariorum and B. tabaci at 12.5 ppm to 50 ppm. However, there was no effect on eggs and nymphs of both species. Pyrifluquinazon showed low insecticidal activity in root and foliar uptake. Control efficacy of pyrifluquinazon was above 90% at 5 days after treatment. In order to investigate the behavioral response of the whiteflies initiated by application of pyrifluquinazon, we tested the contact toxicity and ingestion toxicity. After 1 h of contact, whitefly drop, wing convulsion, and paralysis were observed. Similar phenomenon of whitefly population was observed in test of ingestion toxicity after 3 h. In the choice test, pyrifluquinazon showed repellent activity against both species. These results suggest that pyrifluquinazon cause behavioral disorder rather than direct inhibition of feeding.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.20 no.5
• /
• pp.1149-1154
• /
• 2006

Repeated administration of all addictive drugs, including nicotine, can produce sensitization of extracellular dopamine levels in the nucleus accumbens and behavioral sensitization in rat, as evidenced by an enhanced locomotor response and increased dopamine release in brain to a subsequent injection of the drug. In order to investigate the effect of Zizyphus jujuba extract on repeated nicotin-induced sensitization, rats were given repeated injection of saline or nicotine (0.4 mg/kg s.c., twice a day for 7 d), followed by one challenge injection on the 4th day after the last daily injection. Systemic challenge with nicotine (0.4 mg/kg s.c.) and a direct local challenge of 3 mM a larger increase in locomotor activity and extracellular dopamine release in the nucleus accumbens in nicotine-pretreated rats than in saline-pretreated rats, respectively. Zizyphus jujuba extract significantly decreases locomotor activitiy and dopamine release in the nucleus accumbens induced by a nicotine challenge. These results suggest that Zizyphus jujuba extract may attenuate nicotine-induced neurochemical and behavioral sensitization and may be effective in suppressing compulsive nicotine-seeking behavior.

• Korean Journal of Health Education and Promotion
• /
• v.35 no.5
• /
• pp.25-33
• /
• 2018

Objectives: The purpose of this study was to investigate safety consciousness (SC), cognitive-behavioral strategy (CBS), and safety behavior (SB) among university students living in dormitories on campus. Methods: The data was analyzed to compare the safety behavior by sex, safety related factors, and safety consciousness index in the SPSS 23 program using Chi-square test, t-test, Pearson correlation coefficients, and multiple regression. Results: The participants in the health and safety behaviors survey were 2,721 students who have been in dormitories on campus. On the mean of items, the Public Safety Consciousness Index (PSCI) was 93.1, SC was 26.9, CBS was 15.7, and SB was 50.4. It were significant correlations between SC, CBS, and SB among university students (r=0.74-0.78), and CBS was identified as the mediator. Finally, it was significant increase the SC, CBS, and SB by sex and participation on safety education, but decrease by age and experience of accident and disaster. Conclusions: It is necessary to develop safety education program enhancing safety consciousness and safety behavior in order to prevent accidents on campus. And it suggests that safety education should be included in regular curriculum of university to improve health status and achieve academic goals.

• The Korean Journal of Physiology and Pharmacology
• /
• v.23 no.6
• /
• pp.467-474
• /
• 2019

Exposure to lead during pregnancy is a risk factor for the development of psychiatric disorders in the offspring. In this study, we investigated whether exposure to low levels of lead acetate (0.2%) in drinking water during pregnancy and lactation causes behavioral impairment and affects the expression of proteins associated with neurodevelopment. Lead exposure altered several parameters in rat offspring compared with those unexposed in open-field, social interaction, and pre-pulse inhibition tests. These parameters were restored to normal levels after clozapine treatment. Western blot and immunohistochemical analyses of the hippocampus revealed that several neurodevelopmental proteins were downregulated in lead-exposed rats. The expression was normalized after clozapine treatment (5 mg/kg/day, postnatal day 35-56). These findings demonstrate that downregulation of several proteins in lead-exposed rats affected subsequent behavioral changes. Our results suggest that lead exposure in early life may induce psychiatric disorders and treatment with antipsychotics such as clozapine may reduce their incidence.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.2
• /
• pp.1079-1089
• /
• 2021

The development of information technology has promoted organizational transformation through the utilization of an electronic information system. This research aimed to identify factors that influence continuous intention to use E-HRM. This empirical research applies the Technology Acceptance Model and Cognitive Model for identifying significantly impacted areas of continuous intention to use E-HRM in a highly dynamic environment. The data were collected using questionnaires delivered directly to respondents. The sample was 100 employees of ESQ Group selected through random sampling. The variables used were subjective norms (X1), perceived behavioral control (X2), perceived innovativeness (Y1), cognitive absorption (Y2), satisfaction (Y3), and continuous intention to use E-HRM (Y4). Statistical analysis using Structural Equation Modelling (SEM) with Smart PLS was applied. The results revealed that behavioral control (X2) did not influence the continuous intention to use E-HRM (Y4) and that cognitive absorption (Y2) and satisfaction (Y3) did not significantly influence continuous intention to use E-HRM (Y4). Subjective norms (X1) significantly influenced both perceived innovativeness (Y1) and continuous intention to use E-HRM (Y4), perceived behavioral control (X2) significantly influenced both perceived innovativeness (Y1) and cognitive absorption (Y2), and perceived innovativeness (Y1) significantly influenced both satisfaction (Y3) and continuous intention to use E-HRM (Y4).

• Animal Systematics, Evolution and Diversity
• /
• v.37 no.1
• /
• pp.9-14
• /
• 2021

Invasive species threaten global biodiversity as well as human livelihood and much of the global lands are vulnerable to these threats. Numerous freshwater turtles from the northern hemisphere have been introduced in East Asian countries, including the Republic of Korea. Knowing turtle's behavioral ecology is valuable to manage introduced populations and a distinctive behavior is basking for behavioral thermoregulation. To understand the possibility of using basking to enhance trapping, we tested thermotaxis in the river cooter (Pseudemys concinna). Turtles were placed in an aquarium containing heated and non-heated mats under controlled water and air temperature, air humidity and light. We found that P. concinna stayed significantly longer on heated mats than on unheated control mats in 11 out of 18 trials, demonstrating that heat source is a potential attractant for P. concinna. We recommend the use of heat source to bait traps used for population control of invasive freshwater turtles.