Following the previous study, which investigated the pharmacological properties of the Technekitty injection (Tc-99m), the toxicity of a single intravenous administration of the Technekitty injection (Tc-99m) and the side effects that may occur at the diagnostic dose were confirmed. The Technekitty injection (Tc-99m) was administered intravenously once at a dose of 0, 0.67, 2.0, and 6.0 mCi/kg to 5 male and female rats per group. Mortality, general symptom observation, and weight measurement were performed for 2 weeks, followed by observation of autopsy findings. There were no deaths, and no statistically significant weight change was observed. No abnormal systemic signs related to the Technekitty injection (Tc-99m) were observed. These results confirmed that Technekitty injection (Tc-99m) can be safely administered intravenously at doses up to 6.0 mCi/kg. Additionally, technetium-99m at an average dose of 2 mCi (74 MBq) has been verified as a diagnostic dose without adverse effects, allowing the Technekitty injection (Tc-99m) to be used safely without side effects at this dosage. This study demonstrates that the Technekitty injection (Tc-99m) has a wide safety margin, supporting its potential for clinical application. Moreover, these findings align with the nonclinical safety standards for radiopharmaceuticals, reinforcing its utility in veterinary medicine. The Technekitty injection (Tc-99m) is expected to be applicable for clinical diagnosis as a veterinary drug in Korea.

Thyroid scanning using technetium-99m (99mTc) is the gold standard for diagnosing feline hyperthyroidism. In cats with an overactive thyroid, a thyroid scan is the most appropriate imaging technique to detect and localize any hyperfunctional adenomatous thyroid tissue. In this study, the pharmacological properties of the Technekitty injection (Tc-99m), developed as a diagnostic agent for feline hyperthyroidism using 99mTc as an active ingredient, were tested in FRTL-5 thyroid follicular cell line and ICR mice. The percentage of cell uptake of the Tc-99m in FRTL-5 thyroid cells was 0.182 ± 0.018%, which was about 6 times higher compared to Clone 9 hepatocytes. This uptake decreased by 38.2% due to competitive inhibition by iodine (sodium iodide). In tissue distribution tests by using ICR mice, the highest distribution was observed in the liver, kidneys, spleen, lungs, and femur at 0.083 hours after administration, and this distribution decreased as the compound was excreted through the kidneys, the primary excretory organ. Maximum distribution was confirmed at 1 hour in the small intestine, 6 hours in the large intestine, and 2 hours in the thyroid gland. Additionally, the total amount excreted through urine and feces over 48 hours (2 days) was 78.80% of the injected dose, with 37.70% (47.84% of the total excretion) excreted through urine and 41.10% (52.16% of the total excretion) through feces. In conclusion, the Tc-99m has the same mechanism of action, potency, absorption, distribution, metabolism, and excretion characteristics as 99mTc used for feline hyperthyroidism in the United States, Europe, and other countries, because the Technekitty injection (Tc-99m) contains 99mTc as its sole active ingredient. Based on these results, the Technekitty injection (Tc-99m) is expected to be safely used in the clinical diagnosis of feline hyperthyroidism.

Despite the widespread recognition of the prominent contribution of key language subskills, such as grammar and vocabulary knowledge, to reading comprehension, a research consensus on their relative significance has not been reached. Moreover, the extent of the contribution vocabulary depth makes to reading comprehension has received little research attention. The present study assessed the relative potential contribution of vocabulary depth and grammar knowledge to advanced Korean EFL college students’ reading comprehension abilities, while controlling for their language proficiency and vocabulary breadth, through hierarchical regression analyses. 56 advanced EFL Korean college students were tested on reading comprehension abilities and a range of reading-related subskills including vocabulary breadth, vocabulary depth, grammar, and listening comprehension in English. The findings revealed the unique contribution of vocabulary depth to reading comprehension abilities beyond the effects of both vocabulary breadth and grammar knowledge when English proficiency was controlled for. The findings further underscore the need for balanced approaches in developing L2 learners’ language skills to enhance their reading comprehension abilities.

In this study, we conduct a multi-frequency analysis of the gamma-ray bright blazar 1308+326 from February 2013 to March 2020, using the Korean VLBI Network at 22 and 43 GHz and gamma-ray data from the Fermi Large Area Telescope (LAT). Our findings reveal spectral variations around the 2014 gamma-ray flare, aligning with the shock-in-jet model. A strong correlation is observed between gamma-ray and 43 GHz emissions, with a 27-day lag in the VLBI core light curve, indicating a 50-day delay from the beginning of a specific radio flare to the gamma-ray peak. This radio flare correlates with a new jet component, suggesting the 2014 gamma-ray flare resulted from its interaction with a stationary component. Our analysis indicates the 2014 gamma-ray flare originated 40–63 parsecs from the central engine, with seed photons for the gamma-ray emission unlikely from the broad-line region.

We present the analysis results of the simultaneous multifrequency observations of the blazar 4C +28.07. The observations were conducted by the Interferometric Monitoring of Gamma-ray Bright Active Galactic Nuclei (iMOGABA) program, which is a key science program of the Korean Very Long Baseline Interferometry (VLBI) Network (KVN). Observations of the iMOGABA program for 4C +28.07 were conducted from 16 January 2013 (MJD 56308) to 13 March 2020 (MJD 58921). We also used γ-ray data from the Fermi Large Array Telescope (Fermi-LAT) Light Curve Repository, covering the energy range from 100 MeV to 100 GeV. We divided the iMOGABA data and the Fermi-LAT data into five periods from 0 to 4, according to the prosody of the 22 GHz data and the presence or absence of the data. In order to investigate the characteristics of each period, the light curves were plotted and compared. However, a peak that formed a hill was observed earlier than the period of a strong γ-ray flare at 43–86 GHz in period 3 (MJD 57400–58100). Therefore, we assumed that the minimum total CLEANed flux density for each frequency was quiescent flux (Sq) in which the core of 4C +28.07 emitted the minimum, with the variable flux (Svar) obtained by subtracting Sq from the values of the total CLEANed flux density. We then compared the variability of the spectral indices (α) between adjacent frequencies through a spectral analysis. Most notably, α22–43 showed optically thick spectra in the absence of a strong γ-ray flare, and when the flare appeared, α22–43 became optically thinner. In order to find out the characteristics of the magnetic field in the variable region, the magnetic field strength in the synchrotron self-absorption (BSSA) and the equipartition magnetic field strength (Beq) were obtained. We found that BSSA is largely consistent with Beq within the uncertainty, implying that the SSA region in the source is not significantly deviated from the equipartition condition in the γ-ray quiescent periods.

Following the previous study, the toxicity of a single subcutaneous administration of the Thyrokitty injection (I-131) and the side effects that may occur at therapeutic doses were confirmed. The Thyrokitty injection (I-131) was administered subcutaneously once at a dose of 0, 2.0, 6.0, and 18.0 mCi/kg, 5 male and female rats per group, and mortality, general symptom observation, and weight measurement were performed for 2 weeks, followed by observation of autopsy findings. There were no deaths, and no statistically significant weight change was observed. Mild hair loss, fissures, and crusting were observed by general symptom observation, but it was not a toxic change related to the Thyrokitty injection (I-131). Gastric atrophy and a decrease in the size of the spleen were observed by the autopsy. As a results of single subcutaneous administration of the Thyrokitty Injection (I-131) to rats at a maximum dose of 18.0 mCi/kg, a decrease in the size of the spleen and gastric atrophy were observed as the dose of the Thyrokitty Injection (I-131) increased, which may be related to the test substance. No abnormal findings related to the Thyrokitty injection (I-131) were observed. Therefore, the approximate lethal dose of the Thyrokitty injection (I-131) was 18.0 mCi/kg or more. In addition, as reported for the treatment of feline hyperthyroidism with radioiodine (131I), side effects of the Thyrokitty injection (I-131) are expected to be extremely rare. Temporary dysphagia and fever may occur, but it will recover naturally. It should be administered with caution in cats with diseases such as urinary system, cardiovascular system, gastrointestinal system and endocrine system, especially with kidney disease. And it should not be used in cats who are pregnant, lactating, or likely. It is expected that the Thyrokitty injection (I-131) can be used for clinical treatment in Korea as a veterinary drug.

Radioiodine (131I) has been used for the treatment of feline hyperthyroidism since the 1990s in the USA and Europe, and it is recommended as the most effective treatment for feline hyperthyroidism because it has a high therapeutic effect, small side effects, and does not require anesthesia. In this study, the pharmacological properties of the Thyrokitty injection (I-131), which is being developed as a treatment for feline hyperthyroidism, using radioiodine (131I) as an active ingredient, was tested. The %cell uptake of the Thyrokitty injection (I-131) in FRTL- 5 thyroid cells was 0.410 ± 0.016%, which was about 18 times higher compared to Clone 9 hepatocytes, and it was decreased by 30.7% due to the competitive reaction with iodine (sodium iodide). In addition, the %cell growth of the FRTL-5 thyroid cells was reduced by 25.0% by treatment with the Thyrokitty injection (I-131). As a result of the tissue distribution test, the Thyrokitty injection (I-131) was distributed at the highest concentration at 0.083 hours (5 minutes) after subcutaneous administration to animals in most organs except the stomach, small intestine, large intestine, muscle and thyroid gland, and it was excreted mainly through the kidneys. The stomach and thyroid gland showed a typical distribution pattern observed when radioiodine (131I) was administered. In addition, about 78.45% of the total amount of excretion was excreted within 48 hours, of which more than 85% was excreted in urine. In conclusion, the Thyrokitty injection (I-131) has the same mechanism of action, potency, absorption, distribution, metabolism and excretion characteristics as radioiodine (131I) reported in connection with the treatment of feline hyperthyroidism. In the future, using the results of this study, it is expected that the Thyrokitty (I-131) could be safely used in the clinical treatment of feline hyperthyroidism.

Tropical cyclone scale vortices and associated Rossby waves were investigated numerically using high-resolution barotropic models on the global domain. The equations of the barotropic model were discretized using the spectral transform method with the spherical harmonics function as orthogonal basis. The initial condition of the vortex was specified as an axisymmetric flow in the gradient wind balance, and four types of basic zonal states were employed. Vortex tracks showed similar patterns as those on the beta-plane but exhibited more eastward displacement as they moved northward. The zonal-mean flow appeared to control not only the west-east translation but also the meridional translation of the vortex. Such a meridional influence was revealed to be associated with the beta gyre and the Rossby wave, which are formed around the vortex due to the beta effect. In the case of the basic zonal state of climatological mean, the meridional translation speed reached the maximum value when the vortex underwent recurving.

홍콩의 비중국어권 유치원생들은 중국어 학습 과정 중에 많은 어려움을 겪게 된다. 개인적인 이유 외에도 교사와 학교 모두 자원, 교재, 경험 등의 부족으로 이들의 중국어 학습은 도전적 상황에 직면해있다. 최근 홍콩 평등기회위원회(香港平等機會委員會)는 중국어권 학습자와 비중국어권 학습자의 통합교육을 적극적으로 건의하였는데, 본래의 좋은 취지와는 다르게 여러 가지 새로운 문제점들이 제기되는 결과를 가져왔다. 이러한 어려움을 해결하기 위해 홍콩 경마자선기금(香港賽馬會慈善基金)과 관련 협력 기관에서는 큰 규모의 연구를 기획하고 실제 프로그램을 개발하여 비중국어권 유치원 교육을 지원하였다. 다양한 프 로그램 가운데, 본 연구는 언어 학습 이론과 효과적인 교육에 중점을 두고, 수업 현장 관찰, 수업 비디오 녹화, 교장과 교사 인터뷰, 학습자 언어 학습 평가와 같은 연구 방법을 사용하 여 연구를 진행하였다. 본 연구는 비중국어권 유아를 대상으로, 유아반에서 상위반까지의 언어학습 발달과정을 추적 하여 네 차례 언어학습 평가를 진행하였다. 학습자의 3년간의 언어 성적은 뚜렷한 성장을 보였는데, 이를 통해 학습이론과 실제 교육법 사이에 분명한 효과가 있음을 알 수 있었다. 또한 본 연구가 통합 정리한 10종의 언어학습이론은 홍콩의 중국어권 유아와 비중국어권 유아의 통합교육에 매우 적합했고, 본 연구에서 얻어진 여러 실제 사례들은 간단히 실행 가능할 뿐만 아니라 많은 자원이 투입되지 않는다는 사실도 도출해 내었다. 본 연구의 이론과 실제 성과가 학계 및 교육 실무자들에게 참고가 되기를 기대해 본다.

Koreans considered themselves as a critical link between the past and future and not as an autonomous individual of now, in contrast to what many westerners emphasized and modern Koreans are beginning to think. This study is to apply the "Asian Jeong Nang silver model" as a spirit of "happiness and dignity of the elderly " as the basic policy for the aging Baby Boomers. The way of life of Jeju Haenyeos was similar to the typical life style of retired Baby Boomers, who had been devoted to social contribution until the last minute, returning expert knowledge to the community. That’s why Haenyeo community was chosen as a typical archetype, as well as other example, for a new silver model development. Cross Cultural Ageing Initiative (CCAI)’s purpose is to promote international exchange and collaboration between Korea and United States for research, education and service for the aging population. To bring together the best practices of the East and West, involving all the stake holders of the wider community such as participants in “the 2021 Global Ageing Network(GAN) Biennial Conference : East meets West: Approaches to Healthy Ageing and Wellness in both Seoul and Jeju Island in S. Korea September by GAN and GAN Korea. In particular, the upcoming “Silver Tsunami” in Korean society shows the necessity of welfare models for Korean baby boomers who have retired as highly educated professionals.

장미는 소비자 기호도가 빠르게 변화하는 화종으로서 소비 트렌드 변화에 대응하고 로열티 지출 부담을 줄이고자 전북농업기술원에서 향기가 있고 수량성이 우수한 절화용 복색 스탠다드 ‘Blondie’를 육성하였다. 2013년 ‘Regato’를 모본으로, ‘Cherry Brandy’를 부본으로 인공교배를 실시한 후 74개 종자를 획득하여 53 실생 개체를 얻었다. 2014~2015년 특성 평가를 통해 개화가 균일하고 향기가 있으며 생산성이 우수한 ‘R132093-45’ 계통을 선발하였고, 2016년부터 2년 동안 특성검정, 기호도 평가 및 생산력 검정을 통하여 ‘Blondie’ 품종으로 육성하였다. ‘Blondie’는 오렌지와 살구색 복색 화색(O24C, R36D)의 겹꽃 스탠다드 계열로 향기가 있고, 신초는 안토시아닌 색소가 강하게 발현되며, 엽 형태는 중간 타원형, 엽색은 진한 녹색(N137A), 잎 표면의 광택은 강하다. 꽃 모양은 불규 칙한 원형이고 꽃 측면에서 본 윗부분과 아랫부분은 모두 평평한 고유특성을 가진다. ‘Blondie’의 소화폭은 9.4cm로 대조 품종(‘Hera’)보다 작고 꽃잎수도 36.7개로 적었으며, 가시 발생 정도, 절화장, 경경 및 엽 생육은 유사하였다. ‘Blondie’의 절화 수명과 기호도 평가는 대조품종인 ‘Hera’보다 우수하였으며, ㎡당 연평균 절화량은 150.3본으로 대조품종보다 18.4본 더 많았다. ‘Blondie’ 품종은 2019년 7월 22일 신품종보호권이 최종 등록(등록번호: 제7824호)되었다.

It is known that the growth and development of the mosquito are greatly affected by the change of the meteorological factors. In particular, temperature and precipitation are closely related to the life cycle of the mosquito, and their effects have different characteristics for each species of mosquito. Therefore, to develop a mosquito activity index based on mosquito density, it is essential to develop a prediction model based on weather data. In this study, we developed a functional formula that can estimate the change of mosquito density according to the change of meteorological factors using the mosquito classification data of Incheon region collected from 2011 to 2017. Also, using the data of the digital mosquito monitoring system (DMS) from April to October 2018, mosquito activity index according to characteristics of space in city was developed. In order to reflect the temporal characteristics of the mosquito life-cycle, we used data of temperature and precipitation prior to 1-2 weeks, and used land cover data to reflect the spatial characteristics of mosquito density. Density of Culex pipiens collected in the Incheon area were gradually increased when the average temperature increased two weeks ago after adjusting the precipitation. However, when the average temperature reached 22°C, the density of Culex pipiens marked a peak, and above the 22°C, the density was decreased. The predicted mosquito activity index calculated by applying the machine learning method to the DMS data of the Incheon area is designed to calculate from 1 to 10 grades. The accuracy of the mosquito activity index was 87% when the one grade error was allowed.

The purpose of this study is to confirm whether spontaneous adipocyte generation during chondrogenic induction culture affects the chondrogenic differentiation of porcine skin-derived stem cells (pSSCs). For this purpose, chondrogenic differentiation characteristics and specific marker gene expression were analyzed using cell lines showing different characteristics of spontaneous adipocyte formation. Of the four different lines of pSSCs, the pSSCs-IV line showed higher Oil red O (ORO) and glycosaminoglycan (GAG) extraction levels. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that the levels of adipogenic markers peroxisome proliferator-activated receptor gamma 2 (PPARγ2) and adipocyte Protein 2 (aP2) mRNAs were significantly higher in pSSCs-IV than those of the other pSSC lines (P<0.05). Among three chondrogenic markers, collagen type II (Col II) and sex determining region Y-box (Sox9) mRNAs were strongly expressed in pSSCs-IV (P<0.05), but not in aggrecan (Agg), which was significantly higher in pSSCs-II (P<0.05). These results demonstrate that the spontaneous adipocyte generation during chondrogenic differentiation has a positive effect on the chondrogenesis of pSSCs. More research is needed on the correlation between adipocyte generation and cartilage formation.

The number of companies investing substantial marketing resources in sport sponsorship has been growing rapidly. This trend has resulted in more competition among the candidate companies to acquire official sponsorship rights. Not surprisingly, the recent increase in the popularity of sport sponsorship has been accompanied by increased attempts in ambush marketing – a marketing strategy wherein the companies associate themselves with, and therefore capitalize on, a particular sporting event without paying any sponsorship fee (Hoek & Gendall, 2002). The purpose of this study is to examine how such ambush-marketing activities can damage the evaluation of the company when they are noticed by consumers. This study further examines whether the prior reputation of the company influences the relationships between ambush marketing and company evaluations. Sponsorship and Ambush Marketing Prior research in sport marketing (Meenaghan, 1983; Sullivan & Mulphy, 1998) suggests that the sponsorship of sporting events offers sponsors opportunities to develop favorable brand images by creating goodwill perceptions (Hoek, Gendall, and West, 1990; Marshall, 1992). As noted above, companies unable to fund sponsorship rights have attempted to achieve the same benefits by engaging in promotional efforts associated with the event as if they were true sponsors (McKelvey, 1994). It is, however, only when consumers are unaware of the fact that the companies are, in fact, ambush marketers that these companies can expect positive goodwill perceptions from their ambush marketing practices. This is because ambush marketing has been perceived to be an unethical business practice. Payne (1998) indicated that ambush marketing not only harms the integrity and viability of global sport events, but also infringes on official sponsors’ rights; similarly, O’Sullivan and Murphy (1998) claim that ambush marketing is just as bad as stealing. Thus, once consumers become aware of the fact that a company is implementing an ambush marketing practice, rather than being a true sponsor, those consumers will be disappointed, and negative evaluations of the company are most likely to result. Based on the discussion above, the following hypotheses are proposed: H1: When an ambush-marketing attempt is not noticed, subjects exposed to an ambush- marketing practice will have more favorable evaluations of the company than the evaluations of the subjects not exposed to an ambush- marketing practice. H2: When an ambush-marketing attempt is noticed, subjects exposed to an ambushmarketing practice will have more unfavorable evaluations of the company than the evaluations of the subjects not exposed to an ambush- marketing attempt. Expectation and Evidences We further predict that the risks associated with ambush marketing are more profound for companies with high levels of a good reputation, rather than low. Such reasoning is based on theories of the interaction between expectations and evidences. In this study, expectation refers to the belief probabilities of attribute occurrence (Olson and Dover, 1976); prior research suggests that consumers may form expectations about a company based on the corporate reputation—the sum of the values that stakeholders attribute to a company, based on their perceptions of the company’s image and behavior over time (Dalton & Croft, 2003). Corporate reputation comprises three dimensions (Graham and Helen 2005) including public responsibility (e.g., ―Are they socially responsible?‖), consumer fairness (e.g., ―Do they treat the consumers with some respect?‖), and leadership and success (e.g., ―Are they successful at what they do?‖). Thus, having established a high degree of good reputation indicates that consumers can expect more positive perceptions on each of the three dimensions of corporate reputation described above. According to research in consumer satisfaction, it is the direction and the degree of disconfirmation resulting from the incongruity between the prior expectation and the evidences that determine the product evaluation and satisfaction (Oliver 1980). In particular, Oliver (1980), and Tse and Wilton (1988) proposed that expectations are thought to create a frame of reference about which one makes a comparative judgment, whereby evidences higher (or lower) than the expectations are thought to be a positive (or negative) disconfirmation. Mandler (1982) further suggests that increasing the degree of discrepancy between a schema-triggered expectation and new information results in heightened arousal and cognitive processing, which leads to a more polarized evaluation of products and services. Therefore, in a sponsorship context, a seemingly true sponsorship activity (i.e., an unnoticed ambush attempt) is likely to lead to a positive disconfirmation of the consumers’ expectations about a company, and the degree of disconfirmation will be greater when the company’s prior degree of good reputation is low, rather than high. On the other hand, when noticed by consumers, an ambush-marketing attempt is likely to lead to negative disconfirmation of prior expectations about a company, and the degree of disconfirmation will be greater when the company’s prior degree of good reputation is high, rather than low. Based on the discussion, the following hypotheses are posed: H3: When an ambush-marketing attempt is not noticed, subjects exposed to the ambush-marketing practice will perceive a positive disconfirmation of expectations, and the degree of disconfirmation will be greater when the company is disreputable than when it is reputable. H4: When an ambush-marketing attempt is noticed, subjects exposed to the ambush-marketing practice will perceive a negative disconfirmation of expectations, and the degree of disconfirmation will be greater when the company is reputable than when it is disreputable. Disconfirmation and Evaluation Satisfaction literature (Oliver 1980) also suggests a high degree of consistency between the degree of disconfirmation and satisfaction, as well as the traditional criteria of attitudes. Oliver (1980), for example, showed positive relationships between the degree of disconfirmation and the amount of attitude change. Also, given the earlier discussion that the degree of disconfirmation is proportional to the extremity of the attitude, the following hypotheses are posed: H5: When an ambush-marketing attempt is not noticed, subjects exposed to the ambush-marketing practice will have a more favorable attitude toward the company, and the degree of enhancement in company evaluation will be greater when the company is disreputable than when it is reputable. H6: When an ambush-marketing attempt is noticed, subjects exposed to the ambush-marketing practice will have a more negative attitude toward the company, and the degree of reduction in company evaluation will be greater when the company is reputable than when it is disreputable. Method In order to examine the proposed hypotheses, a 2-by-2 by-2 full-factorial experiment will be conducted. A convenient sample of college students will be used for theory-testing purposes. There are three independent variables. Prior reputation (high vs. low reputation), and whether the ambush-marketing attempt is noticed or not (noticed vs. unnoticed) are the between-subject factors, whereas the measurement sequence (before vs. after stimulus exposures) is the within-subject factor. Corporate reputation will be manipulated by exposing subjects to either high- or low-reputation company profiles. Subjects will then be asked to rate the dependent variables the first time. Then, subjects from each company reputation condition will be exposed to hypothetical newspaper articles describing the company as either a true sponsor or an ambush marketer. After being exposed to the stimulus newspaper articles, the subjects will be asked to rate the key dependent variables the second time. The primary dependent variables include perceived corporate reputation, and attitude toward the company. Data collected from the experiment will be analyzed by three-way ANOVA.

The stability of the steady Rossby-Haurwitz wave (R-H wave) in the nondivergent barotropic model (NBM) on the sphere was investigated with the normal mode method. The linearized NBM equation with respect to the R-H wave was formulated into the eigenvalue-eigenvector problem consisting of the huge sparse matrix by expanding the variables with the spherical harmonic functions. It was shown that the definite threshold R-H wave amplitude for instability could be obtained by the normal mode method. It was revealed that some unstable modes were stationary, which tend to amplify without the time change of the spatial structure. The maximum growth rate of the most unstable mode turned out to be in almost linear proportion to the R-H wave amplitude. As a whole, the growth rate of the unstable mode was found to increase with the zonal- and total-wavenumber. The most unstable mode turned out to consist of more-than-one zonal wavenumber, and in some cases, the mode exhibited a discontinuity over the local domain of weak or vanishing flow. The normal mode method developed here could be readily extended to the basic state comprised of multiple zonalwavenumber components as far as the same total wavenumber is given.

This study was conducted to investigate the effect of activation method on the endoplasmic reticulum (ER) stress induction, apoptosis and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by four activation methods; 1) electric stimulus (ES) (E), 2) ES+10 μM Ca-ionophore (A23187) treatment (EC), 3) ES+2 mM 6-dimethylaminopurine (6-DMAP) treatment (ED), or 4) ES+A23187 and 6-DMAP treatments (ECD). Parthenogenetic embryos were sampled to analyze x-box binding protein 1 (Xbp1) mRNA, ER stress-associated genes and apoptosis genes at 3 h after ES and the 1-cell and blastocyst stages. In the EC group, the band intensity of spliced Xbp1 (Xbp1s) mRNA was higher than those of the other groups at the 3 h and 1-cell stage, and higher than that of the E group at the blastocyst stage. Four ER stress-associated genes were expressed at the highest level in the EC group and weakly expressed in the ED group at 3 h after activation. However, most of the genes were highly expressed at the 1-cell and blastocyst stages with some variation in the EC and ECD groups. Expression of Bcl-2-associated X protein (Bax) and caspase-3 mRNA was significantly higher in the EC group than in the other groups at all development stages. The developmental rates to the blastocyst stage were higher in the ED and ECD groups than in the E and EC groups. These results suggest that the intracellular ER stress of parthenogenetic porcine embryos is affected by the activation method and subsequently lead to the apoptosis of embryos.