Caligus sclerotinosus (Copepoda: Caligidae), a serious pest of cultured red seabream Pagrus major (Sparidae) in Korea

Caligid copepods (Crustacea) known as sea lice are pests of cultured fish, causing serious diseases and economic losses in fish aquaculture worldwide. One species, Caligus sclerotinosus Roubal, Armitage & Rohde, 1983 (Caligidae), is considered a serious pest of the highly prized red seabream Pagrus major (Temminck and Schlegel, 1843) (Sparidae) cultured in Japan. Recently, in neighboring Korea, red seabream culture has intensified and almost replaced yellow tail culture. However, until now, there have been no reports on infection of this sea louse from red seabream in Korea. We surveyed 120 (20 fish per month) P. major from a sea ranched Tongyeong Marine Research Center aquaculture facility, Gyeongsangnamdo, Korea for six months in 2011 (June to November). We recorded severe infection by the sea louse C. sclerotinosus on the skin of P. major. Prevalence was 100%, mean intensity 7.06, maximum intensity 49, and minimum intensity 2. Adult females (624), males (219) and few chalimi (5) were observed and identified by their morphology. As an average of all our collections, less than 0.6% of individuals were chalimi. We suggest, therefore, that adults of C. sclerotinosus undergo ontogenetic host switching after their final moult. No infection of C. sclerotinosus was found on wild P. major collected from Tongyeong and Yeosu fish markets on the southern coast of Korea. Severe infection by this sea louse may cause secondary infections of the host. This copepod is already reported from Australia and Japan and hence, this is the first report from Korea. We expect this pest to have an impact on Korean red seabream fisheries equally serious to that being experienced in Japan.     

A modified method for inducing periodontitis in dogs using a silk-wire twisted ligature

This study was designed to assess the effectiveness of a modified silk ligature twisted with wire for inducing advanced periodontitis. Periodontitis was induced in five premolars and one molar of 20 healthy dogs over a 60-day period. The dogs were divided into four groups according to the ligature-inducing materials used: soft moistened food only, wire ligature (WL), silk ligature (SL) and twisted ligature with silk and wire (SWL). Periodontal indices were recorded, and dental radiographs were taken before and after 60 days of ligation. The ligatures were checked daily and the day the ligature fell out was noted. The period during which the ligatures were maintained was significantly shorter for the SL group compared to the SWL group (p < 0.05). Results of the clinical examination showed that almost all periodontal status parameters including the plaque index, gingival index, clinical attachment level, and bleeding on probing were significantly exacerbated in the SWL group compared to the other groups (p < 0.05). Radiographic evaluation demonstrated that alveolar bone levels were significantly lower in the SWL group than the other groups on day 60 (p < 0.05). These results suggested that experimental periodontitis induced by SWL could be an effective method for investigating periodontitis in canine models.     

SRY-positive 78, XY ovotesticular disorder of sex development in a wolf cloned by nuclear transfer

Recently, we reported the three wolves cloning with normal karyotype from somatic cells of endangered male gray wolves (Canis lupus), but one wolf had female external genitalia. In this study, we conducted further clinical, histological, and genetic analyses. This cloned wolf had a normal uterus but developed ovotestis. Through molecular analysis of the SRY gene, a mutation in the coding sequence of SRY gene could be excluded as a cause of intersexuality. This is the first report of a cloned wolf with a 78, XY ovotesticular disorder affecting sexual development characterized by bilateral ovotestes.     

Relating Tree Ring Chemistry of Pinus densiflora to Precipitation Acidity in an Industrial Area of South Korea

To test the possible use of tree ring chemical properties as proxies for precipitation acidity ([H⁺]), we investigated the relationships between tree ring chemistry (δ¹³C, δ¹⁵N, Ca-to-Al ratio, and N concentration) of Pinus densiflora and precipitation [H⁺] between 1992 and 2005 in an industrial area in the southwest region of South Korea. Statistical analyses showed that all tree ring chemistry parameters were significantly correlated with precipitation [H⁺]. Tree ring δ¹³C was negatively correlated with precipitation acidity (r?=??0.67, P?<?0.01), reflecting the photosynthetic fixation of ¹³C-depleted CO₂ from fossil fuel combustion that would be the primary source of precipitation acidity. A positive correlation of N concentration (r?=?0.89, P?<?0.001) and a negative correlation of δ¹⁵N (r?=??0.63, P?<?0.05) in tree rings with precipitation acidity most likely reflected the influence of ¹⁵N-depleted N compounds deposited via precipitation. The Ca-to-Al ratio was negatively (r?=??0.58, P?<?0.05) correlated with precipitation acidity, indicating that soil acidification caused the loss of Ca from the soil and solubilization of Al resulting from acid precipitation. Such relationships suggest that δ¹³C, δ¹⁵N, N concentration, and Ca-to-Al ratio in tree rings can be reliably used to evaluate the impact of acid precipitation on the studied P. densiflora stands.     

Changes of major chemical components in larch wood through combined treatment of drying and heat treatment using superheated steam

The effects of the combined treatment of drying and heat treatment using superheated steam (SHS) were studied relative to the changes of the major chemical components in larch wood. The green lumber was dried and heat-treated in SHS conditions of 250 °C and 0.5 MPa for 18 h, and the relative percentage contents of sugars, lignin, and extractives were investigated and compared with the relative percentage contents in the lumber heat-treated in hot air conditions of 250 °C and atmospheric pressure for 18 h. After both heat treatment methods, the relative percentage contents of xylan, mannan, galactan, and arabinan were greatly decreased, whereas that of the Klason lignin was increased, additionally that of glucan and extractives remained almost unchanged. Lignin may bind with furan compounds decomposed from hemicellulose following heat treatment, thus contributing to the increase in the apparent relative percentage contents of the Klason lignin. In addition, the condensate collected in the condenser after combined drying and heat treatment using SHS was investigated qualitatively and quantitatively by high-performance liquid chromatography (HPLC). A large amount of furfural and acetic acid decomposed from hemicellulose was detected and some sugar components composed of cellulose and hemicellulose were detected in the liquid condensate.     

Occurrence of leaf spot caused by Cristulariella depraedans on Acer ginnala

The occurrence of previously unknown leaf spots on Amur maples (Acer ginnala) has consistently been noticed during disease surveys in Korea since 2004. The symptoms included circular or irregular leaf spots that were greyish‐green to brownish‐grey in colour, which led to leaf senescence and premature defoliation. The morphological and cultural characteristics confirmed the identity of the causal agent as Cristulariella depraedans. This identification was supported by sequence comparisons based on ITS and LSU regions. The monospore isolate proved to be pathogenic when inoculated to the host plant under artificial conditions. This is the first report of C. depraedans infecting Amur maples in the world.     

Influence of Poly(lactic acid) Layer on the Physical and Antibacterial Properties of Dry Bacterial Cellulose Sheet for Potential Acute Wound Healing Materials

Dry bacterial cellulose nanofiber (BC) sheet coated with poly(lactic acid) (PLA) was developed and characterized towards acute wound healing applications. This new approach of PLA coating on BC revealed enhanced physical and antibacterial properties. Commercial BC sheets originated from the manufacturing of nata de coco jelly were dried and coated with the PLA at various concentrations of 2, 4, 6, 8, 10 and 12 % w/v for the purpose of improving the mechanical properties and followed by loading of antiseptic such as benzalkonium chloride (BAC). PLA has been proposed for the use of coating materials at a concentration of 8 %, the biocomposite sheet started exhibiting a low moisture uptake, prolonged swelling in simulated wound fluid solution and high tear (9.17 Nm²/kg) and burst indices (32.5 kPa·m²/g). The 8 % PLA coating revealed porous fiber-like morphology as observed under scanning electron microscope. Therapeutic loading capacity of the BC/8 PLA was substantially higher than the pristine BC. Furthermore strong antimicrobial activities against Staphylococcus aureaus and Escherichia coli were observed for the BC/8PLA biocomposite film. These reports were clearly suggestive of the fact that synthetic biodegradable polymers, such as PLA, may be exploited for the synergistic combination with BC for antimicrobial and acute wound management. This new and modified fiber source material could reduce the dependency on plant based cellulose for more demanding biomedical applications such as wound healing materials, vascular graft, cartilage replacement, drug delivery and tissue engineering.     

Tensile,Thermal, and Electrical Conductivity Properties of Carbon Fiber Reinforced Composites Using Itaconic Acid Based Dispersants

We prepared itaconic acid based dispersants (IBDs) by the copolymerization of itaconic acid with acrylic acid, acrylamide, or vinyl sulfonic acid, and compared the efficacy of the IBDs on carbon fiber (CF) dispersion in a water-based system, against that of sodium dodecyl sulphate (SDS) which is widely used as a dispersing agent. The procedure to fabricate nonwoven CF (NCF)/PP composites using IBDs includes the following steps: the synthesis of IBDs, the dispersion of CFs in water by the IBDs, the formation of a NCF, and hot pressing of NCF with polypropylene (PP) layer. We determined the tensile, thermal properties, and the electrical conductivity of non-woven CF/PP composites. It was found that using IBDs as a CF dispersing agent led to the CF/PP composites having better tensile, thermal, and electrical properties, as compared to when SDS was used as a dispersing agent.     

Changes in the physicochemical and microbiological properties of dried anchovy <Emphasis Type="Italic">Engraulis japonicus</Emphasis> during storage

This study investigated the changes in the pH, thiobarbituric acid (TBA) value, volatile basic nitrogen (VBN), color L*, a*, b*, shear force, and microbial content (total plate count; TPC) of dried anchovy Engraulis japonicus in a home refrigerator and freezer at 2, ??1, ??5, and ??20 °C. The TBA value and shear force significantly decreased with increasing storage duration at all of the tested temperatures (p?<?0.05), whereas the VBN and TPC values increased (VBN significantly so) with increasing storage duration (p?<?0.05). The anchovy L* values decreased, whereas the a* (redness) and b* (yellowness) values increased as the storage period was lengthened. The pH decreased after 9 months. The results suggest that the optimum storage period of the dried anchovy is within 6 months. It can be stored below 2 °C for 3 months, but for storage exceeding 3 months, it should be frozen at ??5 °C.