Preferences of urban dwellers on urban forest recreational services in South Korea

This paper aims to investigate the preferences of urban dwellers for various attributes of urban forests, with an emphasis on forest recreational services. A choice experiment was conducted using face-to-face interviews with 823 urban dwellers in 2010. Urban forest attributes such as trails, slope, biodiversity, environmental education programs and entrance fees were found to influence Korean citizens’ preferences regarding urban forests. Among the six urban forest attributes, biodiversity was the most influential among Korean urban dwellers in their choice of urban forest recreation. Three latent groups with relatively homogeneous preferences over various urban forest attributes were identified. Residential area, family composition and the purpose of their visit determined group membership. It was notable that the preferences of urban forest recreationists differ from the general preferences of visitors to forests located in remote areas. Urban forest planning and management should consider the attributes of urban forests and the preferences of citizens visiting urban forests to improve urban dwellers’ welfare.     

Spectroscopic Analyses on Chain Structure and Thermal Stabilization Behavior of Acrylonitrile/Methyl Acrylate/Itaconic Acid-based Copolymers Synthesized by Aqueous Suspension Polymerization

We have synthesized a series of copolymers with different compositions of acrylonitrile (AN, 80–100 wt%), methyl acrylate (MA, 4–20 wt%) and itaconic acid (IA, 0–3 wt%) by using an efficient aqueous suspension polymerization, and have investigated the molecular structure and thermal stabilization behavior of PAN homopolymer, AN/MA-based bipolymers, and AN/MA/IA-based terpolymers by adopting ¹H/¹³C-NMR and thermal FT-IR analyses. The viscosity-average molecular weight of the synthesized polymers were measured to be ~263,000 g/mol. The reactivity ratios of AN and MA for all the copolymers were evaluated to be 0.99 and 1.05, respectively. Accordingly, the output compositions of the synthesized copolymers were quite consistent with the input monomer compositions. The ¹³C NMR analysis revealed that all the synthesized polymers have an atactic chain configuration, regardless of the feed composition. The structural evolutions during the thermal stabilization process of the copolymers in air environment were characterized by monitoring the temperature-dependent changes of characteristic absorbance bands at 2240 cm^-1 (C≡N), 1595 cm^-1 (C=N) and 1660 cm^-1 (C=O) with aid of thermal FT-IR spectroscopy. It was found that the IA unit in the terpolymers accelerated the oxidation and cyclization reactions, unlike the retarding effect of MA unit, and that the onset temperatures of the oxidation reaction of the copolymers with IA unit was lower than that of the cyclization reaction.     

Inherently Flame Retardant Nylon 6 Nanocomposite Fibers

In this study, inherently flame retardant nanocomposite nylon 6 fibers infused with nanoclay and intumescent additives were compounded and melt-spun. Two approaches were adopted to mitigate the loss of mechanical properties typically observed nanocomposite fiber systems: (a) additive particle size reduction; and (b) elastomer toughening of the nanocomposite system. As a result, the ductility of the FR nanocomposite formulations was improved significantly. Structural and morphological characterization of the melt-spun fibers using TEM and XRD demonstrated good dispersion of the additives and exfoliation of the nanoclay platelets. Microscale Combustion Calorimetry analysis demonstrated effective reduction of heat release capacity and thus significant enhancement of flame retardant performance of the compounded fibers.     

Silver Carp Bone Powder as Natural Calcium for Fish Sausage

Although silver carp bones (SCB) are generated as waste, they are a natural source of calcium and have the potential to be a food ingredient. When the SCB had been soaked in hot sodium hydroxide (0.8%), autoclaved, and ground into SCB powder (SCBP), the total calcium content, analyzed by inductive coupled plasma-optical emission spectroscopy, was about 32%. X-ray absorption near-edge structure (XANES) spectroscopy specified hydroxyapatite as the major calcium component. The soluble calcium in SCBP was found to be 0.59% in de-ionized water. SCBP induced the cross-linking of proteins in minced fish after incubation at 40°C, as indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Fortification of SCBP at 0.0, 0.5, and 1.0% (w/w) in fish emulsion sausage resulted in a decrease of moisture content, while the fat and protein contents increased slightly. Total ash content in the sausage increased significantly, and total calcium content increased 15-fold in fortified SCBP. The hardness and gumminess values of sausage were improved with the addition of SCBP, while the microstructure was not altered by SCBP.     

Comparison of electrocardiographic parameters in dogs with different stages of myxomatous mitral valve disease

This study evaluated changes in electrocardiographic (ECG) parameters according to the stage of myxomatous mitral valve disease (MMVD) in dogs, as well as the utility of ECG parameters as prognostic indicators for congestive heart failure (CHF). Medical records of dogs with MMVD were retrospectively searched. Dogs with MMVD (N = 101) were classified into stages B [B1 (n = 52) and B2 (n = 23)] and C (n = 26) according to the American College of Veterinary Internal Medicine guidelines. Baseline variables were collected; these included signalment, radiographic, echocardiographic, and ECG parameters. Corrected QT intervals (QTc) were calculated using the logarithmic (QTc1) and Fridericia (QTc2) formulas. The P wave duration, QTc1, and QTc2 were significantly longer in stage C than in stage B. The P wave duration cutoff of 43.5 ms had a diagnostic accuracy of 65% for differentiating CHF, with a sensitivity of 63% and a specificity of 90%. A cutoff value of 307.8 ms for QTc1 yielded a sensitivity of 62%, a specificity of 76%, and a diagnostic accuracy of 78%, and a cutoff value of 239.2 ms for QTc2 yielded a sensitivity of 62%, a specificity of 83%, and a diagnostic accuracy of 77% for diagnosing CHF. Therefore, prolonged P wave and QTc in dogs with MMVD may facilitate the prediction of CHF. Electrocardiography could provide clinicians with a readily available and cost-effective screening tool for predicting CHF, if the usefulness of ECG parameters can be verified.     

Effects of scoparone on dopamine release in PC12 cells

The effects of scoparone on dopamine release in PC12 cells were investigated. Scoparone at 50–200 µM increased dopamine release into the culture medium. However, the released levels of dopamine by scoparone were not altered in the absence of extracellular Ca²⁺ and by adenylyl cyclase inhibitor MDL-12,330A. Scoparone increased phosphorylation of PKA, CaMK II and synapsin I. Scoparone also enhanced K⁺-induced levels of dopamine release by CaMK II phosphorylation. These results suggest that scoparone increases dopamine release by synapsin I phosphorylation via activation of PKA and CaMK II, which are mediated by cyclic AMP levels and Ca²⁺ influx.     

Effect of Roscovitine‐Treated Donor Cells on Development of Porcine Cloned Embryos

Synchronization of the donor cell cycle is an important factor for successful animal cloning by nuclear transfer. To improve the efficiency of porcine cloning, in the present report, we evaluated effects of contact inhibition, serum starvation and roscovitine treatment of donor cells on in vitro and in vivo developmental potency of cloned porcine embryos. Fibroblasts derived from a porcine foetus at day 30 of gestation were isolated and cultured to 70% confluency. Then, cells were either cultured to 100% confluency for contact inhibition, or cultured in 0.5% serum for 72 h for serum starvation or with 15 μm roscovitine for 24 h. Cells were most effectively synchronized at G0/G1 in the serum starvation group (87.5%) compared with the contact inhibition and roscovitine treatment groups (76.3% and 79.9% respectively p < 0.05). However, after somatic cell nuclear transfer followed by in vitro culture, the serum starvation group showed a significantly lower blastocyst formation rate (5.6%) compared with the contact inhibition and roscovitine treatment groups (11.6% and 20.0% respectively). Differential expression of apoptosis‐related genes and the level of apoptosis in each treatment group explain the variation in developmental competence among the groups. Significantly higher level of apoptosis was observed in the serum starvation group. On the other hand, the roscovitine treatment group shows the lowest level of apoptosis and the best in vitro development among the groups. Cloned embryos derived from roscovitine‐treated donor cells were transferred to surrogate pigs. Three healthy live piglets were produced. In conclusion, we suggest that roscovitine treatment of donor cells improves development of cloned porcine embryos and can raise the efficiency of cloned piglet production.     

Effect of oat particle size on energy and nutrient utilization in growing pigs

An experiment was conducted to determine the energy content of oats and to investigate the effects of oat particle size on nutrient and energy balance in growing pigs. Eighteen barrows (23.56 ± 0.94 kg initial body weight) were randomly assigned to one of the three dietary treatments with six replicates per treatment. Whole oats were ground with a hammermill fitted with 4.8- and 3.2-mm screens to make coarse and medium particle size oats, respectively. Medium oats were further ground with a rotary steel cutting grinder fitted with a 2.0-mm screen, and the further ground oats were mixed with medium oats in a 1:3 ratio to make fine oats. Three experimental diets consisted of 96.3% of the coarse, medium, or fine oats as a sole source of energy were used. Pigs were fed diets for 16 d, including 10 d for adaptation and 6 d for total fecal and urine collection. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. All data were analyzed using the MIXED procedure of SAS with the individual pig as the experimental unit. The geometric mean particle sizes for coarse, medium, and fine oats were 765, 619, and 569 μm, respectively. Pigs fed the medium oats diet tended to have (P < 0.10) greater apparent total tract digestibility (ATTD) of starch, neutral detergent fiber, and gross energy than those fed coarse oats diet. The medium oats diet contained greater (P < 0.05) digestible energy (DE), metabolizable energy (ME), and net energy (NE) than the coarse oats diet. Pigs fed the fine oats diet had lower (P < 0.05) ATTD of Ca and P than those fed the coarse oats diet. The DE, ME, and NE contents of fine oats were comparable with those of coarse oats. The determined NE contents for coarse, medium, and fine oats were 2,335, 2,615, and 2,521 kcal/kg on a dry matter basis, respectively. The NE content in medium oats was greater (P < 0.05) than the NE values predicted using published equations. In conclusion, it was suggested to grind whole oats for 619 μm concerning energy utilization. Further grinding to 569 μm reduces Ca and P digestibility.     

Effect of Dimethyl Sulfoxide on Cell Cycle Synchronization of Goldfish Caudal Fin Derived Fibroblasts Cells

Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin‐derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.