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Ichthyophthirius multifiliisis a major pathogen that causes a high mortality rate in trout farms. However, systemic responses to the pathogen and its interactions with multiple organs during the course of infection have not been well described. In this study, dual-organ transcriptomic responses in the liver and head kidney and hemato-serological indexes were profiled underI. multifiliisinfection and recovery to investigate systemic immuno-physiological characteristics. Several strategies for massive transcriptomic interpretation, such as differentially expressed genes (DEGs), Poisson linear discriminant (PLDA), and weighted gene co-expression network analysis (WGCNA) models were used to investigate the featured genes/pathways while minimizing the disadvantages of individual methods. During the course of infection, 6,097 and 2,931 DEGs were identified in the head kidney and liver, respectively. Markers of protein processing in the endoplasmic reticulum, oxidative phosphorylation, and the proteasome were highly expressed. Likewise, simultaneous ferroptosis and cellular reconstruction was observed, which is strongly linked to multiple organ dysfunction. In contrast, pathways relevant to cellular replication were up-regulated in only the head kidney, while endocytosis- and phagosome-related pathways were notably expressed in the liver. Moreover, interestingly, most immune-relevant pathways (e.g., leukocyte trans-endothelial migration, Fc gamma R-mediated phagocytosis) were highly activated in the liver, but the same pathways in the head kidney were down-regulated. These conflicting results from different organs suggest that interpretation of co-expression among organs is crucial for profiling of systemic responses during infection. The dual-organ transcriptomics approaches presented in this study will greatly contribute to our understanding of multi-organ interactions underI. multifiliisinfection from a broader perspective.

Although over-nutrition from overfeeding-induced obesity is known to be highly associated with metabolic and immunological disorders in humans, little is known about overfeeding-induced obesity in fish farming. The purpose of this study was to investigate changes in immuno-physiological parameters, to better understand the potential risk of overfeeding&ndash, induced obesity in fish. Commercial feed was provided to fish in the overfed group until they refuse to eat, but fish in the control group was fed with the feed at 1% bodyweight per day. The hemato-serological, histological, and immunological changes were observed at weeks 2 and 8. Rainbow trout leukocytes were co-incubated with oxidized low-density lipoprotein (OxLDL), and the phagocytes engulfing the OxLDL and the presence of apoptotic cells were evaluated. The body weight, body mass index (BMI), and hepatosomatic index (HSI) index were significantly higher in the overfed group, and high lipid accumulation and fatty changes were also observed in their livers, indicating that the feeding regime used in this study led to overfeeding-induced obesity. Likewise, much higher numbers of and larger vacuoles were observed in overfed fish macrophages, showing unclear boundaries between the cytoplasm and extracellular space. In the overfed group, the expression of IL-10, HSP70, TLR2, and CD36 was significantly higher, and lymphocyte apoptosis was more evident, indicating that overfeeding-induced obese fish might have immunologic disorders. This was the first study to demonstrate that overfeeding-induced obesity could cause an immune-physiological imbalance in rainbow trout, making them more vulnerable to infectious diseases and various stressful conditions. This study will contribute to improvements in fish nutrition, feeding practices, fish nutrition, and disease prevention in the aquaculture industry.

Although Carnobacterium maltaromaticum has been used as a probiotic in fish, it was reported to cause disease for the first time in Korea. The objective of this study was to understand the differences between pathogenic and non-pathogenic strains. Pathogenicity was tested by challenging rainbow trout with C. maltaromaticum ATCC35586 and 18ISCm isolated from diseased fish, and DSM20342 isolated from a dairy product. We also compared 24 genomes of C. maltaromaticum strains plus the genome of our isolate 18ISCm sequenced in this study. Only the strains from diseased fish caused high mortality with severe histopathological changes. Although all strains shared more than 90% of Ko_id, wecC and xtmA were found only in strains from diseased fish. Interestingly, only strains from diseased fish harboured two wecC paralogs involved in the production of D-mannosaminuronic acid which is a major component of a well-known virulence factor, teichuronic acid. Two wecC paralogs of 18ISCm were increased when they were co-cultured with trout blood cells, suggesting that wecC genes might play a role in virulence. The results of this study show that strains isolated from diseased fish are different from strains derived from food in terms of pathogenicity to fish and the presence of virulence-related genes.

High transition temperature superconductors in cuprates exhibit the charge-density-wave fluctuations and the ferromagnetic time-reversal-symmetry-breaking fluctuation in the polar Kerr rotation experiments. We demonstrate that they share the same root of origin, and the underlying mechanism also leads to the pseudogap formation. The pseudogap formation, the charge-density-wave fluctuation, and the time-reversal-symmetry-breaking fluctuation are the consequent phenomena of the correlation. They are the basic notions in strongly correlated electron systems., 4 pages, 6 figures

The monitoring was performed to survey the mortalities and medications occurred in the inland aquaculture farms of olive flounder in South Korea from May to October, 2012. Both of the indirect inquiry for entire inland farms and the sample survey for selected farms were carried out. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic organism diseases and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. The cumulative mortalities rate by the indirect inquiry on 565 farms, was calculated to 27.18%, and the mortalities rate by infectious diseases was 22.64%. Otherwise, the mortalities rate by sample survey on 60 farms was 25.50%, 19.33% of them were caused by infectious diseases. The high mortality rates were recorded by scuticociliatosis, non-infectious loss, streptococcosis, VHS, artificial eliminations, vibriosis and gliding bacterial disease. Streptococcosis and non-infectious mortality caused to serious loss in productivity and economy of the farms, because of their outbreaks in the flounder groups over 600 g. The monitoring of medications in the selected farms revealed that formalin for the treatment of external parasites, such as scuticociliates, was the most commonly used drugs in the farms. As the antibiotic medications, amoxicillin and florfenicol for streptococcosis, and oxytetracycline and neomycin expecting wide antibacterial spectrum, were frequently prescribed.

In this study, 6-10 clinically healthy farmed abalone, Haliotis discus hannai were obtained from Jeollanam-Do Wando Soan-myeon, Bogil-myeon, and Nohwa-eup monthly for 1 year 7 months and were examined histopathologically. As a result, the adductor muscle had severe cellular swelling and myonecrosis. These lesions were stained with hematoxylin and eosin and Giemsa. The lesions were not caused by infection of bacteria or parasites. We investigated the relationship between lesion frequency and water temperature and discovered that increased water temperature was associated with increasing lesion frequency. As water temperature is related to growth rate, increased growth rate was closely related to increased lesion frequency. We considered that these lesions could be a useful factor in measuring shellfish health.

The effective lattice models in strongly correlated electron systems are \emph{derived} in particular for the cuprate superconductors, that incorporate the quantum fluctuations of the spin Berry's phase and the antiferromagnetic fluctuation. Consistent with the field-theoretical approach, the density modulation, the weak ferromagnetism, and the superconductivity are reproduced. We discussed the pros and cons of the effective-model approach and demonstrate that both positive and negative Hubbard model are the effective models subject to the occurrence of the quantum fluctuations of the correlation degrees of freedom., 10 pages, 2 figures

The practical monitoring was performed to survey the mortalities in aquaculture farms of olive flounder, rockfish, rainbow trout, Japanese eel, white shrimp and abalone in South Korea from May to November, 2011. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic disease and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. In 70 flounder farms, the cumulative mortalities rate was 27.9%, and the mortalities were caused by scuticociliatosis, streptococcosis, VHS, non-infectious loss, vibriosis and gliding bacterial disease. The moralities rate of 30 rockfish farms was 13.6%, and those were mainly contributed by gill flukes and streptococcosis. Most of mortalities of rainbow trout were caused by non-infectious loss and protozoan white spot disease. The mortalities rate of Japanese eel was 0.6% by edwardsiellosis, protozoan white spot disease and gill flukes. The loss rate of white shrimp was 71.2%, and most of them was related with non-infectious ones, such as carnivalization, transportation loss, and the rest was caused by viral white spot disease. The mortalities rate in the abalone farms was 10.7% and all of them were related with non-infectious loss.

A histo-pathogical examination was carried out to evaluate the effect of commercial extruded pellet (EP) and a raw fish moist pellet (MP) diet on the health of juvenile rockfish cultured in marine net-cage for 7 months. Fish were distributed randomly to each net cage as a group of 76,000 fish (initial mean body weight 5.9 g). After 2 months, the hypertrophy or swelling of liver parenchymal cells was identified in most individuals and lasted until 7 months. Livers in EP fed group frequently showed hypertrophic parenchyma and fatty change with occasional atrophic cells. However, after 4 months, lymphocytic infiltration in splenic parenchyma was seen in a number of individuals. In addition, the gastric glandular epithelium was atrophied and in the lumen of renal tubules protozoan parasites were frequently identified but there was no correlation with the type of feed. Moreover, juvenile rockfish on EP diet showed gross and microscopic hypertrophy of the liver which would be due to oversupply of feed. Severe hepatic cellular hypertrophy or swelling could lead to the damage of microcirculation. Especially fatty change and atrophic change of liver could be the result from the damage, which could be responsible for immunological problem. Lymphocytic infiltration of spleen on the MP diet suggests that juvenile rockfish could be frequently exposed to infectious antigens.

This study was aimed to determine the fish physical status according to the gross and histopathological findings of liver in cultured black rock fish, Sebastes schlegeli. All 47 fish submitted had no marked abnormalities in the external findings. 42.55% of fish showed normal liver, 25.53% yellow liver, 25.53% atrophic brown liver, 4.26% yellowish-green liver and 2.13% fatty liver in gross examination. Grossly normal liver showed no remarkable change in lobular structure but many vacuoles were found in hepatic cell. Hepatic cells took normal roundish, polygonal shapes containing spherical nuclei. In group of yellow-brown liver, many brown pigments were seen in hepatic cells, MMCs and brown-colored hyaline droplets within cytoplasm of hepatocytes. Yellowish green pigments were seen in hepatic cells and MMCs of yellow green liver and green colored hyaline droplets within hepatocytes. The dilated central veins are highlighted with atrophy of hepatic cells. Outline of atrophic hepatocyte became ambiguous and nucleus frequently become small and pyknotic. Fatty liver showed prominent vacuolar structures in cells as clear spaces or foamy cytoplasm with degenerative nuclei. From these results, it was strongly suggested that hepatic gross and histological findings could be used as important and critical health parameters of fish prior to progression to substantial manifestation as clinical disease.

This study was aimed to investigate the pathophysiological changes of olive flounder, Paralichthys olivaceus suffering from emaciation. A plasma osmolality was higher in the emaciated and control flounders than that of normal teleost, suggesting osmoregulatory failure in both of them. Also, the control in the same stock with emaciated flounder seem to be classified into a primary degree of emaciation. According to microscopic observations, the inflammatory responses were observed in the submucosal layer of anterior intestine, although the some of mucosal intestinal epithelium still remained. It was suggested that the pathological changes of the anterior part give rise to malabsorption of nutrients through the mucosa. In the posterior intestine and rectum, the mucosal epithelium were almostly sloughed off and severe inflammatory responses were observed in the submucosa. Immunoreaction for NKCC was not detected in the mucosal epithelial cells in intestine because of sloughing of epithelium. These changes would lead to functional disorder in the intestine, such as malabsorption of nutrients and osmoregulatory failure. Also important is to investigate the recovery phase.

In order to determine a causal relation between infections and death of Manila clam, Tapes philippinarum, a routine histopathological survey was carried out along the southern coast of Korea from March 1996 to April 1997. Three kinds of parasites (Perkinsus sp., Marteilioides-like organism and Cercaria tapidis) were encountered frequently. The latter two parasites infected the gonad but did not evoke any significant host reaction. However, Perkinsus sp. infestation was characterized by a variable degree of hemocytic encapsulation. Digestive epithelia including those in the digestive diverticula showed various degrees of atrophic changes. Hemocytic infiltration occurred in various tissues and organs also to a variable degree. From the point of view of frequency as well as pathological impact, it was strongly suggested that the atrophy of digestive epithelium, hemocytic encapsulation associated with Perkinsus sp., hemocytic infiltration in various tissues and organs are lesions that should be carefully monitored for association with bivalve mortality.