Effects of different soybean proteins on lipid digestion and growth of yellowtail <Emphasis Type="Italic">Seriola quinqueradiata</Emphasis>

Two experiments were conducted to determine whether the undigested high molecular fraction (HMF) of soybean protein reduces growth of yellowtail through impairment of lipid digestion and absorption. Soybean meal (SBM), soy protein isolate (SPI), digested SPI (DSPI), and digested and purified SPI (DPSPI) were used as experimental diets. In experiment 1 (exp. 1), yellowtail were fed 4 diets with aforementioned soybean products for 3 weeks. In experiment 2 (exp. 2), the fish were fed soybean protein or fish meal (FM) diets for 8 weeks. Growth performance of DPSPI-fed fish was better than that of fish fed other soybean proteins, and comparable to that of fish fed with FM. Plasma and tissue lipid levels of DPSPI-fed fish tended to be higher than those of fish fed other soybean proteins. Significantly lower intestinal lipid levels and higher bile acid levels were found in DPSPI-fed fish than in fish fed with SBM, SPI, and DSPI. These findings indicate that one of the factors contributing to growth depression in yellowtail fed with SBM-based diets is the negative effect of undigested HMF of soybean protein on bile acid levels and lipid digestion.     

Load-carrying capacity of steel-to-timber joints with a pretensioned bolt

Previous experimental studies reported that bolt pretensioning greatly increases the initial stiffness and load-carrying capacity of bolted joints. It is also a matter of great importance to structural designers to understand the effect of pretension on the load-carrying capacities of bolted joints, and this study presents an extended yield model that considers the fastener’s pretension force. In the extended yield model, the load-carrying capacity was defined as the load at a slip of 15 mm. The ultimate fastener bending angle at the yielded cross section equivalent to this joint slip, which was affected by the fastener’s axial force, was iteratively evaluated in numerical analyses. The introduction of bolt pretensioning largely increased the joint slip resistance at initial loading, but it decreased the ultimate fastener bending angle. This decrease of fastener bending angle resulted in a relatively low stiffness hardening (or secondary stiffness), which is caused by secondary axial forces associated with embedment of steel plates into the wood member. Prediction was verified by the tests of 36 steel-to-timber joints under three different pretension forces and two loading directions relative to the grain. Some of the observed load-carrying capacities of the joints, particularly in loading perpendicular to the grain, however, were not as high as those expected by the numerical analyses considering the given pretension forces.     

One-year stress relaxation of timber joints assembled with pretensioned bolts

In our previous study, great increases of hysteretic damping and initial slip resistance of timber joints were attained by applying axial pretension to the steel fasteners. To evaluate the effectiveness of this method, 1-year stress-relaxation measurement was carried out. Nine prestressed joints were prepared and three of them were restressed after 3 and then 6 months after the initial prestressing. All joints were exposed to indoor conditions, and relaxation of the pretension was regularly measured from time-dependent decreases of axial strain of the bolts. After measurement, the joints were subjected to cyclic and monotonic loading tests until failure. The average ratio of residual stress to the initial prestress after 1 year was about 0.23 and 0.66, respectively, for joints without restressing and those with restressing. A simulated stress-relaxation curve developed from the four-element relaxation model predicted 3% of the initial stress after 5 years. Without a regular restressing program, the initial prestressing effect therefore must be considered negligible. However, about 20% of the pre-stress level can be reasonably assumed if restressing is carried out annually. This small residual stress was found to introduce suffi cient frictional damping to signifi cantly increase the equivalent viscous damping ratio of the joints. Part of this study was presented at the 10th World Conference on Timber Engineering, Miyazaki, June 2008     

Identification of imported Chirimen at the genus level by a direct sequencing method using mitochondrial partial 16S rDNA region

ABSTRACT:   Quality control of imported fish products is a constant challenge for Customs officials. To help officials access the quality and integrity of imported fish products, and to enhance the effectiveness and accuracy of product screening, a method was developed to identify boiled and dried larval and juvenile sardines (Chirimen) at the genus level by direct sequencing using a partial sequence (606 bp) of mitochondrial 16S rDNA. A phylogenetic tree was constructed, based on nucleotide sequences of seven kinds of Chirimen imported from four countries with 16 standard samples belonging to the orders Clupeiformes and Salmoniformes. To identify the fish genera in imported Chirimen, bootstrap values and branch lengths of the phylogenetic tree as well as genetic distances were used. The data revealed that Chirimen imported from China and Korea contains species of the genus Engraulis . Regarding other imported Chirimen, the least that could be verified was that the sardine ingredients do not belong to regulated genera.     

Correction to: Effects of complete replacement of fish oil with plant oil mixtures and algal meal on growth performance and fatty acid composition in juvenile yellowtail Seriola quinqueradiata

Fisheries Science - A correction to this paper has been published: https://doi.org/10.1007/s12562-021-01503-y     

高温高压蒸汽干燥过程中木材的收缩应力特征

该研究利用新开发的耐热、耐压应力传感器，采用夹具束缚试件在干燥过程中的收缩变形，考察了高温高压蒸汽条件下，伴随试件干燥过程的收缩应力发生、发展特征及粘弹性特性，旨在为探索减少木材干燥缺陷和内部残留应力的高温快速干燥工艺条件提供理论基础和科学依据.该文着重探讨了100℃以上的高温高压过热蒸汽条件下，试件从饱水到全干状态或明显开裂为止，收缩应力的连续测定方法，并对其径向和弦向收缩应力的发生发展特征进行了初步探讨.研究结果表明，在高温热处理(相对湿度为0)过程中，径向的收缩应力相当大，约为弦向的2倍；而在其他相对湿度条件下，情况却相反，相对湿度60%、80%条件下，弦向的收缩应力反而变得比径向大.试件在180℃的高温高压过热蒸汽干燥过程中，随着相对湿度的增加，收缩应力明显下降，应力得到有效抑制.即使在相对湿度100%的高温条件下干燥，木材仍然存在收缩应力.      

Polyphenol composition of a functional fermented tea obtained by tea-rolling processing of green tea and loquat leaves

Phenolic constituents of a new functional fermented tea produced by tea-rolling processing of a mixture (9:1) of tea leaves and loquat leaves were examined in detail. The similarity of the phenolic composition to that of black tea was indicated by high-performance liquid chromatography comparison with other tea products. Twenty-five compounds, including three new catechin oxidation products, were isolated, and the structures of the new compounds were determined to be (2R)-2-hydroxy-3-(2,4,6-trihydroxyphenyl)-1-(3,4,5-trihydroxyphenyl)-1-propanone 2-O-gallate, dehydrotheasinensin H, and acetonyl theacitrin A by spectroscopic methods. In addition, theacitrinin A and theasinensin H were obtained for the first time from commercial tea products. Isolation of these new and known compounds confirms that reactions previously demonstrated by in vitro model experiments actually occur when fresh tea leaves are mechanically distorted and bruised during the production process.     

Potential use of cholesterol lipoprotein profile to confirm obesity status in dogs

A common sign of obesity, in dogs, is hyperlipidemia, which is characterized by hypercholesterolemia and/or hypertriglycemia. Hyperlipidemia can be caused by a quantitative increase in circulating lipoproteins (LP) or by a higher lipid concentration in the various LP classes. In this study, we sought to determine whether aberrations occur with cholesterol lipoprotein profile, especially with sub HDL-cholesterol fraction % in obese dogs. Using clinically healthy and disease free (no overt signs) body condition score classified obese dogs, of all ages, we attempted to determine the influence of age, gender and obesity status on cholesterol lipoprotein profiling. Overall, no aberration in pattern was observed in obese dogs <8 years of age. However, in older obese animals (≥8 years of age), the general aberration pattern to cholesterol lipoprotein observed was that a significant decrease in HDL2 and 3 fraction % occurs with a concomitant increase in either HDL1-Cho or VLDL and LDL -Cho fraction % depending on gender. Linear regression analysis indicated that obesity status appears to significantly affect total cholesterol, HDL2 and 3-Cho, VLDL and LDL-Cho levels (P = 0.02, 0.046, and 0.045, respectively), whereas it is borderline with HDL1-Cho (P = 0.062). On the other hand, age significantly influenced TG, Total cholesterol, and HDL1-Cho levels (P = 0.009, 0.006, and 0.002, respectively), while gender influenced VLDL and LDL-Cho (P = 0.024) level. Therefore, aberrations in cholesterol lipoprotein profile pattern might be of potential use to assess and diagnose obesity status, in conjunction with BCS, especially of older overweight animals which might be considered borderline obese.