新疆主要城市城市化水平及其发展对策

本文选取了经济城市化、产业结构城市化、人口城市化、生活质量城市化四个一级指标以及其下层的十三个二级子指标构成了新疆各主要城市城市化水平测度的指标体系。通过层次分析法(AHP)以及德尔菲法(Delphi)来确定各指标的权重,根据多指标综合评价模型得出新疆主要城市城市化水平。依据各市的城市化水平进行聚类,并根据聚类结果将新疆19个主要城市分为五个层次:第一层次:克拉玛依和乌鲁木齐,城市化水平最高;第二层次:库尔乐、哈密、奎屯、昌吉、伊宁、石河子、喀什,城市化水平较高;第三层次:阜康、米泉、城市化水平中等;第四层次:塔城、博乐、和田、阿克苏、阿勒泰、吐鲁番和乌苏,城市化水平较低;第五层次:阿图什,城市化水平最低。同时,城市化水平的空间分布不平衡。针对各城市城市化水平的层次性和区域不平衡性提出了城市今后发展相应的对策。     

Dietary lipid requirement of whiteleg shrimp Litopenaeus vannamei juveniles cultured in biofloc system

An eight‐week feeding trial was conducted to evaluate the contribution of biofloc on dietary lipid requirement in whiteleg shrimp Litopenaeus vannamei. Five diets with graded levels of dietary lipid (45, 60, 90, 120 and 150 g/kg) were fed to juvenile shrimp. Final weight, weight gain and specific growth rate of shrimp fed diets with 60, 90 and 120 g/kg lipid levels were significantly higher than those of shrimp fed diets with lipid levels 45 and 150 g/kg (p < .05). Feed efficiency and protein efficiency ratio of shrimp fed 60, 90 and 120 g/kg were higher than those fed 150 g/kg diet. Plasma total cholesterol and triglyceride levels were lower in shrimp fed 45 g/kg compared with those fed the 90 g/kg (p < .05). Also, lysozyme activity for 90 g/kg group was higher than the 15 g/kg group. Hepatopancreas lipase and amylase activities of shrimp fed 90 and 120 g/kg diets were significantly higher than those of shrimp fed 45 and 150 g/kg diets. Broken‐line regression analysis for weight gain indicated that the dietary lipid requirement of whiteleg shrimp juveniles reared in a biofloc system was estimated to be higher than 56 g/kg but <60 g/kg.     

Thyroid hormone‐induced swim bladder and eye maturation are transduced by IGF‐1 in zebrafish embryos

Maternally derived thyroid hormones (THs) deposited in yolk promote fish embryogenesis and survival, and understanding early regulatory mechanisms could lead to improved seedstock production. We have tested the hypothesis that some thyroid actions may be mediated by insulin‐like growth factor I (IGF‐1), another promoter of embryo development. Differentiation and performance were assessed in embryos treated with THs in the presence or absence of an IGF‐1 receptor blocking peptide. Treatment with the TH triiodothyronine (T₃) promoted IGF‐1 gene expression at days 1 and 5, and advanced swim bladder and eye development, but blocking the IGF‐1 receptor eliminated the swim bladder and eye effects. Growth and survival at 1 week of age were impaired by the IGF‐1 receptor blocking peptide alone, but concurrent treatment with T₃ partially restored these indices. Our results confirm interaction of T₃ and IGF‐1 regulatory signalling in zebrafish embryogenesis and transduction by IGF‐1 of thyroid‐driven swim bladder and eye maturation.     

Effect of Sucrose on Glass Transition,Gelatinization, and Retrogradation of Wheat Starch

Differential scanning calorimetry (DSC) was used to study the effect of sucrose on wheat starch glass transition, gelatinization, and retrogradation. As the ratio of sucrose to starch increased from 0.25:1 to 1:1, the glass transition temperature (T_g, T_g′) and ice melting enthalpy (ΔH_ice) of wheat starch‐sucrose mixtures (with total moistures of 40–60%) were decreased to a range of −7 to −20°C and increased to a range of 29.4 to 413.4 J/g of starch, respectively, in comparison with wheat starch with no sucrose. The T_g′ of the wheat starch‐sucrose mixtures was sensitive to the amount of added sucrose, and detection was possible only under conditions of excess total moisture of >40%. The peak temperature (T_m) and enthalpy value (ΔH_G) for gelatinization of starch‐sucrose systems within the total moisture range of 40–60% were increased with increasing sucrose and were greater at lower total moisture levels. The T_g′ of the starch‐sucrose system increased during storage. In particular, the significant shift in T_g′ ranged between 15 and 18°C for a 1:1 starch‐sucrose system (total moisture 50%) after one week of storage at various temperatures (4, 32, and 40°C). At 40% total moisture, samples with sucrose stored at 4, 32, and 40°C for four weeks had higher retrogradation enthalpy (ΔH) values than a sample with no sucrose. At 50 and 60% total moisture, there were small increases in ΔH values at storage temperature of 4°C, whereas recrystallization of samples with sucrose stored at 32 and 40°C decreased. The peak temperature (T_p), peak width (δT), and enthalpy (ΔH) for the retrogradation endotherm of wheat starch‐sucrose systems (1:0.25, 1:0.5, and 1:1) at the same total moisture and storage temperature showed notable differences with the ratio of added sucrose. In addition, T_p increased at the higher storage temperature, while δT increased at the lower storage temperature. This suggests that the recrystallization of the wheat starch‐sucrose system at various storage temperatures can be interpreted in terms of δT and T_p.     

Isolation and Characteristics of Anti-Inflammatory Peptides from Enzymatic Hydrolysates of Sandfish (Arctoscopus japonicus) Protein

In the present study, a peptide showing anti-inflammatory activity was isolated from Arctoscopus (A.) japonicus sandfish protein hydrolysate by hydrolysis and analyzed using ultrafiltration (UF), prep-high-performance liquid chromatography (HPLC), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Effects of heat, pH, salt, and intestinal proteases on stability of the isolated anti-inflammatory peptide were determined. The nitric oxide (NO) scavenging activities of the peptide from meat and roe hydrolysates were 18.43 ± 3.21% and 52.35 ± 8.85%, respectively, at a concentration of 0.1 mg/mL. The anti-inflammatory peptide maintained a similar level of NO scavenging activity to the control in the presence of salt, whereas it showed no resistance to heat, pH, and intestinal proteases. These results suggest that the anti-inflammatory peptide derived from A. japonicus could be used for producing functional foods, protein supplements, and pharmaceutical agents. However, it is necessary to find methods for protection against heat, pH, and proteolysis.     

Synergistic UV-curable flame-retardant finish of cotton using comonomers of vinylphosphonic acid and acrylamide

While ‘Pyrovatex’ and’ Proban’ processes have been widely used for durable flame-retardant finishing of cotton, the flame retardants could release formaldehyde inevitably during or even after the finishing process, which is not environmentally compatible. As a new formaldehyde-free flame retardant and finishing process, the comonomers of vinylphosphonic acid (VPA) and acrylamide (AAm) can be in situ copolymerized upon LED-UV irradiation and impart excellent flame retardancy to the cotton. The increasing AAm addition enhanced fixation, flame retardancy effectivity and synergistic effectiveness by reducing the steric hindrance between the VPA monomers during the copolymerization. Also the multifunctional crosslinkers of either methylene bisacrylamide or triacryloylhexahydro triazine significantly improved the laundering durability of the finished fabrics. The increased char formation and residue number after pyrolysis indicated the solid-phase retarding mechanism of the synergistic VPA and AAm combination.     

Status of freshwater fish around the Korean Demilitarized Zone and its implications for conservation

• 1. The Korean Demilitarized Zone (DMZ), which divides the Korean peninsula, currently serves as a sanctuary for diverse biological resources, owing to limited development and human activities. The fish fauna of the DMZ areas, including the Civilian Control Zone (CCZ) and Military Facility Protection Area (MFPA), was investigated by quarterly sampling at 53 sites from August 2001 to May 2004.
• 2. In total, 10 946 fish were collected and classified into 99 species and 26 families. Zacco platypus (relative abundance, RA 18.6%) was the dominant species, while other key species were Rhynchocypris steindachneri (16.0%), Pungitius sinensis (12.5%) and Zacco temmincki (8.5%).
• 3. Thirty species were found to be Korean endemics, representing seven families. Eight Korean vulnerable species and two Korean natural monument species were recorded. Three exotic fish species (Carassius cuvieri, Micropterus salmoides and Lepomis macrochirus) were collected at 13 study sites, all but one of which are outside the CCZ. There were significant relationships between altitude and fish species richness (r²=0.448, P<0.001) and the number of endemic fish species (r²=0.487, P<0.001).
• 4. Owing to very limited human interference, the DMZ could provide good benchmark sites to enable ecological restoration on other rivers and streams for maintenance of natural freshwater fish biodiversity. It is suggested that a natural park is instituted around the DMZ areas for ecological protection and as a symbol of peaceful coexistence between South and North Korea.

Copyright © 2007 John Wiley & Sons, Ltd.