본 연구의 목적은 지방간 환자의 간내 18FDG 섭취율과 CT 계수값(Number)의 관련성을 연구하여, 지방간 환자의 진단 및 치료에 도움이 되는 기초 정보 제공을 위하여 시행되었다. 본 연구의 데이터는 2014년 1월부터 2015년 10월까지 서울소재 N 종합병원에 내원하여 PET-CT 검사를 시행한 환자를 대상으로 데이터를 분석하였다. 연구결과, 지방간일 확률은 남자가 여자보다 5배 높았으며(p<.05), 간의 우측, 중간, 좌측에서 18FDG 섭취율이 각각 1.000배이상 증가하고(p<.05), CT 계수값은 각각 0.93배, 0.88배, 0.92배 감소하였다(p<.05). 결론적으로 18FDG 섭취율과 CT Number값의 지방간 유무에 따른 유의미한 변화는 지방간 환자의 진단 및 치료에 신뢰할만한 정보를 제공하고, 지방간 예측성 연구를 위한 기초자료로 활용 될 수 있을 것이다.

방사선 방호의 목적 중 하나는 확률적 영향을 최소화 하는 것이다. PCXMC 2.0은 몬테카를로 시뮬레이션 기반의 프로그램으로 입사표면선량을 통해 유효선량과 암의 발병확률을 예측가능하게 해준다. 그렇기 때문에 선량계에 따른 입사표면선량 측정이 특히 중요하다. 본 연구는 반도체 선량계, 일반 선량계, 유리선량계를 통해 입사표면선량을 측정하고 그에 따른 결정 장기의 유효선량과 발병 확률을 비교분석 하는 것에 목적을 두었다. 실험방법은 두개부, 흉부, 복부의 선량계 별 입사표면선량을 측정하고 PCXMC 2.0을 통해 부위 별 결정 장기의 유효선량과 암의 발병 확률을 평가하였다. 그 결과 부위 별 입사표면선량은 동일한 조건임에도 일반 선량계, 반도체 선량계, 유리 선량계 순으로 차이가 났다. 이를 토대로 유효선량과 결정 장기의 암 발병 확률을 분석한 결과 또한 일반 선량계, 반도체 선량계, 유리 선량계 순으로 차이가 났다. 결론적으로 동일한 조건임에도 사용한 선량계에 따라 유효선량과 발병 위험도는 다르게 나타났음을 알 수 있었고, 본 연구를 통해 각각의 선량계에 따른 정확한 입사표면선량 모델을 제시하는 것이 중요하다는 것을 알 수 있었다.

양성자가속기연구센터(KOMAC)의 100-MeV 양성자 선형가속기에서 생성된 고에너지 양성자를 사용하여 천연 텅스텐과 핵반응을 일으켰다. 핵반응을 통해 생성된 다양한 핵종으로 부터의 감마선은 HPGe 검출기 감마선 분광시스템을 사용하여 측정하였다. 감마선 표준선원은 에너지 교정 및 검출기의 효율 측정에 사용되었다. 측정된 스펙트럼에서 관찰된 감마선을 분석한 결과 방사성 핵종은 167Re, 178Re, 179Re, 180Re, 181Re, 182Re, 184Re, 172Ta, 174Ta, 178Ta, 182Ta, 184Ta, 175W, 176W, 177W 및 179W 으로 총 16 종류의 핵종이 생성되었다. 이 연구의 결과는 미래의 핵융합, 천체 물리학 및 핵의학 응용 분야에 적용될 것으로 생각된다.

본 연구는 점 선원인 60Co, 137Cs 및 혼합부피선원을 이용하여 피크 대 컴프턴 비율, 연속체 배경 스펙트럼을 감소시키기 위해 저 에너지 peak부터 고 에너지 peak에서 측정된 측정치와 PENELOPE와 비교하였다. 또한, 저에너지 부근에서의 변화를 통해 후방산란, 컴프턴 단(compton edge)의 효율 변화를 PENELOPE와 비교하였다. 혼합부피 선원에서 나온 결과를 토양시료에 적용하여 억제와 비 억제(unsuppressed)모드에서 토양시료의 최소검출한계치가 얼마큼 감소하였는지 확인하고자 한다. 60CO(1,173 keV)의 저에너지 영역의 컴프턴 억제가 상당히 되었으며, 137Cs(661 keV) 피크에 대한 Compton edge의 RF는 2.8이다. 특히, 60Co 선원은 1,173.2keV와 1,332.5 keV의 coincidence 감마선을 방출하므로 컴프턴 억제는 대략 21% 감소하였다. 60Co 선원에서 방출되는 1,173keV와 1,332keV의 compton edge의 RF는 3.2, 3.4였으며 피크대 컴프턴 edge 비율은 8:1로 향상되었다. 그리고, PENELOPE와 비교했을 때 불확도는 2% 이내로 잘 일치하였다. Compton unsuppressed 모드에서 661 keV, 1,173 keV 및 1,332 keV의 MDA 값은 각각 0.535, 0.173 및 0.136Bq/kg이었으나, Compton suppressed 모드에서는 0.121, 0.00826 및 0.00728B/kg로 감소하였다. 따라서, Compton suppres sed는 배후방사능과 검출기 자체에 함유된 방사능을 줄일 수 있었다.

Purpose – Before the economic reforms, the Chinese communication industry was poorly developed. After China’s entering to WTO, the Chinese market were gradually opened, domestic companies will be faced with more and more pressures of competition from the world rival countries. As time goes on, the overseas telecommunications companies will occupy the Chinese market with the opening of China Telecommunications market to outside. So this paper focuses on problems and development methods based on the research about the present situation and development methods of communication industry(communication manufacturing industry and communication manufacturing industry) in China. Research design, data, and methodology – This study analyzed the policies of China’s entering to WTO. This paper observed previous researches and made an empirical research on Chinese communication industry based on the governmental policies, strategies, books and previous papers with several kinds of clear data announced formally by China authorities. Results – Most recently, reorganization of the communication industry has brought good opportunities for the development of the communication manufacturing enterprises. This paper analyze policy changes of Chinese communication industry, the status of communication manufacturing industry and communication service industry. Finally, this study for further research analyzes the existing problems and puts forward some practicable measures to solve them. Conclusions - Looking ahead, with China’s rapid economic development and steady deepening of reform and opening-up, the Chinese communication industry is faced with an even broader prospect of development. Chinese communication industry will be become the pillar one in national economy after 10 years development. Foreign communication companies accelerated investment and progresses to Chinese information and communication markets. Positive ones are more foreign investment, export increase, domestic innovation, communication industry made steep growth. But negative ones are obstacles of domestic companies' development and jobless rate increase etc. Second communication manufacturing industry made good development, but computer and TV related industry made decline in growth. Third, market sizes of internet and mobile services are growing but the size of wired communication services is downsizing gradually. To overcome them, the studies of components or parts of communication manufacturing industry are needed individually. Second China Unicom, China Telecom, China Mobile etc. are Chinese representatives. The sales volumes are very similar at the beginning, but now they are different and make big differences. So the analysis about, their differences and its impact, are needed.

Purpose - The purpose of this article is to examine the effects of perceived value, satisfaction, and continued use intention of e-service Quality of taxi-booking apps. Research design, data, and methodology - The questionnaire was created to examine every relevant variables to practical and theoretical implications. The pilot survey was conducted for 15 days from April 7th to April 21st in 2016. Their total numbers were 354 surveys. But 330 copies were used for the analysis except 24 of them. To make a more effective analysis, several analysis tools and analysis programmes were used, such as IBM SPSS and AMOS. Results - The results are as follows. First, all variables of e-service quality except safety make influences on perceived value. Second, e-service quality except safety makes influences on satisfaction. Third, perceived value makes influence on satisfaction and on intention of continued use. Fourth, satisfaction makes influence on intention of continued use. Conclusions - First, 5 variables are very limited. more valuable variables are need to test with this model. Second, this study was conducted only in China. So there may be possible to the representatives. To use this model for better analysis and application abroad, more characteristics and strategic factors should be considered like the local culture of a particular country, attributes for different environment etc.

In the present study, we employed Hershberger assay to determine possible androgenic or antiandrogenic activities of three di-2-ethylhexyl phthalate (DEHP) substitute candidates. The assay was carried out using immature castrated Sprague–Dawley male rats. After 7 days of the surgery, testosterone propionate (TP, 0.4 mg/kg/day) and test materials (low dose, 40 mg/kg/day; high dose, 400 mg/kg/day) were administered for 10 consecutive days by subcutaneous (s.c.) injection and oral gavage, respectively. Test materials were DEHP, 2-ethylhexyl oleate (IOO), 2-ethylhexyl stearate (IOS) and triethyl 2-acetylcitrate (ATEC). The rats were necropsied, and then the weights of five androgen-dependent tissues [ventral prostate, seminal vesicle, coagulating glands, levator ani-bulbocavernosus (LABC) muscle, paired Cowper’s glands, and glans penis] and four androgen-insensitive tissues (kidney, adrenal glands, spleen and liver) were measured. All test materials including DEHP did not exhibit any androgenic activity in the assay. On the contrary, antiandrogen-like activities were found in all test groups, and the order of the intensity was ATEC < DEHP < ISO < IOO in the five androgen-sensitive tissues. There was no statistical difference between low dose treatment and high dose treatment of all replacement candidate groups. In DEHP groups, high dose treatment exhibited significant weight gains in LABC and Glan Penis. There was no statistical difference in androgen-insensitive tissue measurements. Since the effects of ATEC treatment on the accessory sex organs were much less or not present at all when compared to those of DEHP, ATEC could be a strong candidate to replace DEHP. IOO treatment brought most severe weight reduction in all of androgen-sensitive tissues, so this material should be excluded for further screening of DEHP substitute selection.

Purpose – This study empirically analyses the changes in unemployment rates to understand push factors of generating wage pressure and how it affects the aggregate demand in Korea and the United States. We use a structural macroeconomic model which is centered on the labor market and simultaneously explains the natural rate of unemployment and deviations. Research design, data and methodology – We attempt to empirically analyse the unemployment rates through two countries to analyse the economic effects of real wages and aggregate demand between 2000 and 2016. We introduce having estimated the whole model that the growth of unemployment into the part caused by each of these factors. Results – The results of this study show that in the long run, there is not only a natural level of employment but also a natural level of real demand are positively related. in the short run, demand can vary from bring about changes in employment by means of price or wage surprises. Conclusions – The pressure of demand in the labor market shows up strongly in both countries. The estimated labor-demand equation are consistent with this framework and generally have well defined real wage and demand effects.

The annual reproductive cycle of the Korean endemic slender catfish, Silurus microdorsalis, was examined histologically regarding water temperature and day length of habitat, gonadosomatic index (GSI), and development characteristics of female and male gonads. The maximum GSI value was found in May, 1.23±0.33 and 11.77±3.23 for male and female respectively (habitat water temperature 21.5℃/13.59hr day length). On the other hand, the minimal level was 0.63±0.10 in July (26.5℃/14.17) for male and 1.36±0.08 in October (20℃/11.2hr) for female. We compared and calculated the stages of testis and ovary development process in order to determine the germ cell development characteristics and the reproductive cycle. According to results, we classified the annual reproductive cycle of the slender catfish into five stages: Growing phase (December- February), Mature phase (March-April), Ripe and spawning phase / Releasing phase in male (May-June), Degenerative phase (July-August), and Resting phase (September-November).

본 연구에서는 CT영상기반 3차원 고관절모델을 이용한 컴퓨터시뮬레이션을 통해서 고관절의 운동범위 (Range of Motion)를 측정하는 방법을 제시하였다. 본 연구에서는 그 측정방법에 대한 기술적인 사항을 제시하고, 그 기술이 재현성 있게 실현할 수 있도록 대퇴골두 중심점의 결절, 대퇴골 외전(Abduction)/내전(adduction)회전축, 굽힙(flexion)/신전(extension) 회전축을 정의하고 측정하는 명확한 방법을 제시하였다. 외전각은 해부학적인 시상면(Sagittal plane)상의 Anterior-Posterior축에 대해 아래쪽(Inferior)면으로부터 Lateral 쪽으로의 회전각으로 정의된다. 최대외전각은 대퇴골두가 엉덩이뼈(Pelvis)의 절구(Acetabulum)의 테두리와 겹치지 않고 Anterior-Posterior축을 중심으로 회전할 수 있는 최대 외전각으로 결정된다. 굴곡각은 해부학적인 관상면(Coronal plane)상의 Medial-Lateral축에 대해 아래쪽(Inferior)면으로부터 회전각으로 정의된다. 최대굴곡각은 대퇴골이 Medial-Lateral축을 중심으로 엉덩이뼈(Pelvis)의 절구(Acetabulum)의 테두리와 겹치지 않고 회전할 수 있는 최대 굴곡각으로 결정된다. 정상고관절에 비해 인공고관절술을 받은 해당 환자의 경우, 외전에서는 60도 정도, 굽힘에서는 4도 정도 운동범위가 줄어들 수 있다는 예측이 나왔다. 본 연구에서 행한 시뮬레이션을 해보고 외전의 경우 운동범위의 감소가 예측되므로, 대퇴골두를 조금 큰 것을 고르거나 대퇴골목부의 길이 (femoral neck offset)를 길게 시술해야 할 필요가 있음을 의미한다.

고관절 시행에서 식립각도는 추후 환자의 운동범위나 힘의 분배조건에 따라 폴리에틸렌 라이너의 마모에도 영향을 미친다. 인공관절요소로부터 마모입자는 골괴사나 다른 생화학적으로 많은 합병증을 일으킨다. 이런 점에서 인공고관절에서 마모와 정렬각도를 수술 후 추시를 통해 측정하는 것은 중요하다. 특히 관절면의 마모를 측정하는 것은 그 량이 크지 않아 상당한 정밀도를 요구한다. 현재 널리 쓰이는 상용 소프트웨어는 재현성과 측정방법의 표준화가 되어 있지 않아 사용에 많은 어려움이 있다. 본 논문에서는 일반 병원의 방사선촬영 환경에서 CAD만 추가로 구비하면 행할 수 있는 인공관절면 마모와 식립각 측정법을 제시한다. 인공관절만의 X-ray영상을 이용한 본 방법의 정확도와 정밀도 평가를 수행하였다. 또한 실제 인공고관절환자의 X-ray영상을 가지고 2년추시에 따른 마모와 식립각을 측정하였다. 본 연구에서 제시한 CAD를 이용한 방법은 마모측정에서 정확도 0.06 mm, 정밀도 0.05 mm, 식립각은 0.27°의 정밀도를 갖는다.

Purpose - With the worldwide aging problem and the development of globalization, customers prefer to seek affordable medical services with the higher quality overseas. This new trend has urged some destination countries to improve their services for the more competitive advantages over other countries. Literature research indicate that medical quality and cost may be the key factors influencing global patients’ decisions. In the international environment, however, medical tourism destinations are selected due to cultural similarity between the hosting country and the customers’ own country. The more similarity perceived between the two countries leads foreign patients to choose the considering country as the destination for medical tourism. However, little research has been conducted on this topic. Thus, we empirically investigate how cultural similarity influences Chinese medical customers’ choice of the destinations. We also consider the factors related to medical competency and travel attribute which might affect customers’ decisions along with some moderating roles of disease types. Research design, data, and methodology – We proposed a research model in order to confirm the relations among different variables of cultural similarity, medical competency, travel attractiveness, disease types, and destination choice. The questionnaire survey is processed in the more economically developed regions of China such as Beijing, Shanghai, and Jiangsu. Conditional logit regression is applied to analyze the data of 881. Results - Results indicate that cultural similarity is the important predictor of Chinese customers’ decision to select a medical country. However, the effects of cultural similarity vary according to the disease types. We also find that medical competency and travel attractiveness influence their decisions with the moderating role of disease types. Conclusions – Cultural similarity is the important factor that influences Chinese potential medical tourists’ decisions to select a destination. Marketing managers should consider the effects of cultural similarity when developing strategies for attracting Chinese medical tourists. Since medical competency and travel attractiveness are still the critical key elements for them to evaluate the destination countries, it is necessary to continuously improve medical service quality and facilities. The results also recommend that medical managers should sharpen their marketing strategies by segmenting Chinese potential customers in terms of disease types.

Rubia cordifolia has been used to treat diseases for many years in China and India. Although the biological properties and major compounds of R. cordifolia have been extensively studied, the underlying mechanisms of its biological effects remain elusive. In terms of immunological effects, anti-inflammation effect of macrophage (Raw 264.7) simply has been reported. In this study, R. cordifolia was extracted in 70% ethanol and the extract did not affect to macrophage (Raw 264.7) pro-inflammation and T cell (Molt-4). However, in mast cell (RBL-2H3), it showed inhibition of degranulation. The inducing inhibitory effect on degranulation was related to concentration dependent variation in phosphorylation of ERK-1/2 and upregulating the JNK phosphorylation in RBL-2H3 cells. Based on these data, we concluded that R. cordifolia newly have anti-allergenic effects in RBL-2H3 and might be used as a therapeutic agent to treat or prevent allergic diseases such as asthma and atopic dermatitis.

Various bioactive substances are found in Loranthus tanakae, including quercetin 3-rhamnoside (1), kaempferol 3-rhamnoside (2), rhamnetin 3-rhamnoside (3), and rhamnocitrin 3-rhamnoside (4), which inhibit tyrosinase. These compounds are mainly found in the EtOAc fraction of L. tanakae extract and demonstrate higher rates of tyrosinase inhibition than ascorbic acid, which was used as a control. Our results suggest that L. tanakae extracts can be utilized in skin whitening cosmetics.

원자로 내 사고발생 시 냉각수의 비등으로 기포가 발생하고, 기포율을 측정하기 위하여 열수력 안전 분 야에서는 주로 Optical Fiber Probe(OFP)나 광학 카메라를 이용하여 측정하지만 기하학적 구조의 한계로 인 해 17 × 17 배열의 봉 다발 내에 장비를 설치하는 것에는 어려움이 있다. 본 연구는 예비 연구로서 봉 다발 에 적용하기 전 X선 시스템과 다양한 모사 팬텀을 이용하여 연구 가능성 평가를 수행하였다. 라디오그라피 및 토모그라피 실험을 통해 X선 발생 장치의 관전압 130 kVp, 관전류 1 mA가 적합하였다. 또한, 기포 해상 도 팬텀을 통해 가시적으로 1 mm 크기의 구멍에 대해 측정이 가능하였으며 막대 팬텀을 이용한 대조도 평 가의 경우 프레온 내부에서 대조도가 상대적으로 떨어짐을 확인할 수 있었다. 그러나 영상 재구성 시 일그 러짐이 없는 좋은 영상을 획득할 수 있었다. 기포 발생 팬텀 실험을 통해 기포의 유동 방향 확인 및 단층 영상을 획득할 수 있었고, Image J 툴을 이용하여 하나의 단층영상에 대해 18 %의 기포율을 측정할 수 있 었다. 본 연구는 핵연료 주변 기포율 측정을 위한 선행 연구를 수행하였고 지속적인 연구를 위한 기초 연 구로서 활용할 수 있을 것이다.

In the published article “Bitter melon extract does not alter photoperiodic effects on reproduction of male golden hamsters. Dev. Reprod. 2017; 21(2):215-221. https://doi.org/10.12717/DR.2017.21.2.215,” the corresponding author’s name is given incorrectly. The Editorial Office of Korean Society of Developmental Biology would like to correct the corresponding author’s name. The Editorial Office apologizes for any inconvenience that it may have caused.

Bisphenol-A(BPA) is a member of alkylphenol family, and shows adverse effects including reduced fertility, reproductive tract abnormalities, metabolic disorder, cancer induction, neurotoxicity and immunotoxicity. In the present study, we conducted Hershberger assay to evaluate whether the two candidates to replace BPA have androgenic or antiandrogenic activity. The assay was carried out using immature castrated Sprague–Dawley male rats. After 7 days of the surgery, testosterone propionate (TP, 0.4 mg/kg/day) and test materials (low dose, 40 mg/kg/day; high dose, 400 mg/kg/day) were administered for 10 consecutive days by subcutaneous (s.c.) injection and oral gavage, respectively. Test materials were BPA, isosorbide (ISO) and cyclohexanedimethanol (CHDM). The rats were necropsied, and then the weights of five androgen-dependent tissues [ventral prostate, seminal vesicle, levator ani-bulbocavernosus (LABC) muscle, paired Cowper’s glands, and glans penis] and three androgen-insensitive tissues (kidney, spleen and liver) were measured. All test materials including BPA did not exhibit any androgenic activity in the assay. On the contrary, antiandrogen-like activities were found in all test groups, and the order of the intensity was CHDM > BPA > ISO in the five androgen-sensitive tissues. There was no statistical difference between low dose treatment and high dose treatment of BPA group as well as ISO group. In CHDM group, high dose treatment exhibited most severe weight reduction in all measured tissues. There was no statistical difference in androgen-insensitive tissue measurements, except BPA groups. Since the effects of ISO treatment on the accessory sex organs were much less or not present at all when compared to those of BPA, ISO could be a strong candidate to replace BPA. CHDM treatment brought most severe weight reduction in all of androgen-sensitive tissues, so this material should be excluded for further screening of BPA substitute selection.

Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues. Two tetraploid hESC lines were artificially acquired by reintroduction of remained 1st polar body during the establishment of SCNT-hESC using MII oocytes obtained from female donors and dermal fibroblasts (DFB) from a 35-year-old adult male. These tetraploid SCNT-hESC lines (CHA-NT1 and CHA-NT3) were identified by the cytogenetic genotyping (91, XXXY,-6, t[2:6] / 92,XXXY,-12,+20) and have shown of indefinite proliferation, but slow speed when compared to euploid SCNT-hESCs. Using the eight Short Tendem Repeat (STR) markers, it was confirmed that both CHA-NT1 and CHA-NT3 lines contain both nuclear and oocyte donor genotypes. These hESCs expressed pluripotency markers and their embryoid bodies (EB) also expressed markers of the three embryonic germ layers and formed teratoma after transplantation into immune deficient mice. This study showed that tetraploidy does not affect the activities of proliferation and differentiation in SCNT-hESC. Therefore, tetraploid hESC lines established after SCNT procedure could be differentiated into various types of cells and could be an useful model for the study of the polyploidy cells in the tissues.

Connexin (Cx) involves in the regulation of various physiological functions of tissue by forming a channel, a gap junction which allows direct cell-cell communication, between adjacent cells. The effect of a single subcutaneous treatment of estradiol benzoate (EB) or flutamide (Flu) at the weaning age on the expression of Cx isoforms in the adult caput epididymis was evaluated in this research. Using quantitative real-time PCR analysis, a low-dose of EB [0.015 μg/kg body weight (BW)] caused significant decreases of Cx30.3, Cx32, Cx40, Cx43, and Cx45 mRNA levels and no change of Cx26, Cx31, Cx31.1, Cx37 transcript levels. The treatment of a high-dose EB (1.5 μg/kg BW) resulted in reduced expression of Cx30.3, Cx31, Cx43, and Cx45 but increased expression of Cx37 and Cx40. Expression of all Cx isoforms examined, except Cx31, was significantly increased by the treatment of a low-dose Flu (500 μg/kg BW). However, the treatment of a high-dose Flu (5 mg/kg BW) led significant expressional suppression of Cx30.3, Cx31, Cx31.1, Cx32, Cx40, Cx43, and Cx45 but an increase of Cx37 transcript level. With the comparison of previous findings, the expression of Cx isoforms in the adult epididymis after the exposure to EB or Flu is likely differentially regulated in regional-specific and/or exposed postnatal age-specific manner.

Koi herpesvirus (KHV), also known as Cyprinid herpes virus 3 (Cyprinid 3) is lethal disease in common carp and koi (Cyprinus carpio). Two different groups (KK and RK) were infected KHV by intraperitoneal injection. Fish for gene expression analysis were sampled at 0 h, 12 h, 24 h, 48 h and 72 h post infection (p.i). The results showed that two immune related gene, Interferons (INFs) ɑβ and Interleukin (IL)-12 p35 induced a high response in RK. The IL-12 p35 cytokine and Toll-like receptor (TLR) 9 were significantly high expressed on 48 h post infection (p.i) in RK as compared to the KK. The histopatological examination reveals focal necrosis in liver and infiltrate of lymphocytes in spleen of KK as compared to the RK. In immunohistochemistry analysis, the KHV protein high expressed in the infected kidney cell and slenocyte of KK. Therefore, the expression of IL-12 p35, IFN ɑβ and TLR 9 may provide a potentially genes related with KHV resistance in Koi and red common carp × koi.