Influence of different feeding systems on the growth performance and muscle development of Japanese Black steers

This study investigated the growth performance and gene expression for muscle development between grass hay-fed (GH) and concentrate-fed (CT) steers. Daily gain and energy intake during the fattening period of the GH group were lower than those of the CT group. Analysis of C/EBPα, PPARγ2, myosin heavy chain (MHC), and myostatin gene expressions was performed by real-time PCR. Expressions of C/EBPα and myostatin in semitendinosus and longissimus lumborum (LL) muscles were higher in the CT group than in the GH group at the end of fattening. In LL muscle, MHC expression at the end of fattening was greater in the GH group than in the CT group. These results suggest that regulation of adipogenesis and myogenesis by the expression of genes involved in muscle development might have occurred in the skeletal muscle of the GH group by the feeding of grass hay and/or because of the low energy intakes.     

Piecewise linear elastic–plastic analysis

The purpose of this paper is to show that a mathematical programming method, due to Maier and his co-workers, of nonlinear structural analysis can be rerformulated so that greater computational efficiences are achived. The methods are designed for a class of elastic–plastic structures under ‘piecewise linear’ assumptions and solve among others the problem of determining the stresses and strains in the structure. The reformulation gives rise to a class of mathematical programming problems calles a ‘n by dn linear complementarity problem’, for which the author has developed an efficient algorithm. It will be explained why and by how much the proposed method (the reformulation and its solution by the author's algorithm) solves the structural problems more efficiently than the existing one. Results of a systematic computer experiment supporting the efficiency of the proposed method are also presented.     

Difference in postmortem degradation pattern among troponin T isoforms expressed in bovine longissimus, diaphragm, and masseter muscles

The postmortem degradation of troponin T (TnT) in bovine longissimus (LT), diaphragm (DP), and masseter (MS) was analyzed. A 28.3kDa (conventional 30kDa) fragment of fast-type TnT isoforms showed the highest content in both LT and DP, where a 35.4kDa isoform had the highest expression among the other fast isoforms. Meanwhile, a 26.0kDa fragment was found to be the most highly produced among the fast TnT fragments in MS, where the expression of 36.5 and 32.8kDa isoforms was higher than that of 35.4 and 34.8kDa isoforms. Thus, the compositions of both the intact TnT isoform proteins and the postmortem fragments differed among the muscles examined, indicating that each TnT isoform degrades into a specific fragment in each muscle. Among the muscles, the LT muscle showed a high extent of TnT degradation and the highest expression of fast TnT isoforms containing a taste-related peptide sequence.     

A non-destructive method to monitor changes in a troponin T peptide in beef drip with a monoclonal antibody

To simplify the monitoring of postmortem beef aging, we established a system to detect a troponin T (TnT) peptide fragment in bovine muscle drip (natural exudates) with an original monoclonal antibody. The antibody was raised against a synthetic peptide APPPPAEVPEVHEEVH corresponding to the N-terminal region of bovine fast-type TnT. In a competitive enzyme-linked immunosorbent assay (ELISA), our antibody detected the standard peptide dose-dependently. According to the monitoring examination with a competitive ELISA during 22 days postmortem, the concentration of the peptide in both the drip and trichloroacetic acid extracts from the longissimus muscle (n = 4) significantly increased in parallel, up to 10 nmol/ml and 16.4 nmol/g at day 14 postmortem, respectively. These events were accompanied by an increase in the conventional 30 kDa fragment in western blot analysis and a decrease in the Warner–Bratzler shear force value of the beef from 5.0 to 2.4 N/cm². The peptide detection system using drips with the antibody has advantages applicable to a non-destructive, simple, quick, and on-site monitoring method, such as immunochromatography.     

N-terminal amino acid sequences of troponin T fragments, including 30 kDa one, produced during postmortem aging of bovine longissimus muscle

We have determined the amino (N)-terminal amino acid (AA) sequences of five troponin T (TnT) fragments produced during postmortem aging of bovine longissimus muscle. Western blot analysis showed that 32.1, 28.8, 27, and 25.8 kDa anti-fast-type TnT (fTnT)-positive fragments and a 31 kDa anti-slow-type TnT (sTnT)-positive fragment were present at 14 d postmortem. The N-terminal AA sequences of the 32.1, 28.8 (conventional 30 kDa), 27, and 25.8 kDa fragments were APPPPAEV, EVHEPEEK, EKPRPRLT, and APKIPEGE, respectively, and they were mapped to the N-terminal region of bovine fTnT isoforms. The N-terminal sequences of the 31 kDa fragment, EAPEEPEP, were mapped to the sTnT isoforms. These findings indicate that the two isoform types of fTnT predominantly expressed in the longissimus muscle are cleaved specifically at Glu(21)-Ala(22) and Glu(15)-Ala(16), His(37)-Glu(38) and His(31)-Glu(32), Glu(43)-Glu(44) and Glu(37)-Glu(38), and/or Thr(51)-Ala(52) and Thr(45)-Ala(46), respectively, and that a sTnT isoform is cleaved specifically at Glu(23)-Glu(24).     

A mathematical programming method for the inelastic analysis of reinforced concrete frames

A mathematical programming method is presented for solving problems of (i) determining the moments and rotations and (ii) determining the safety factor of reinforced concrete frames. The proposed method is essentially a reformulation of those developed by De Donato and Maier. However, the reformulation results in a new mathematical programming model for which an efficient algorithm is developed. The advantage of the proposed method is mainly computational; in fact it requires roughly one half computer time and storage space as compared with those De Donato and Maier employ to solve the same problem.     

Association of ceramides in human plasma with risk factors of atherosclerosis

Atherosclerosis is a multifactorial disorder. Recent studies indicate that the plasma level of sphingomyelin, which yields ceramide, correlates with the risk of coronary heart disease. Therefore, ceramide, a well-known lipid causing apoptosis in various cell types, may contribute to atherogenesis. We examined the relationship between ceramide concentration and risk factors of atherosclerosis in normal human plasma using electrospray tandem mass spectrometry (LC-MS/MS). Major ceramides in human plasma were C24∶0 and C24∶1. The ceramide concentration showed a significant positive correlation with total cholesterol (TC) and triglycerides (TG). In addition, plasma ceramide level increased drastically at a high level of LDL cholesterol (more than 170 mg/dL). Our previous studies demonstrated that the sum of fragmented and conjugated apolipoprotein B-100 proteins (B-ox), which were products of a radical reaction of LDL as well as plasma, was a reliable index of atherosclerosis. B-ox showed a significant positive correlation with the plasma ceramide level. Based on these results, we propose that the ceramide level in human plasma is a risk factor at the early stages of atherosclerosis.     

Complete solutions for a class of elastic-plastic structures

A mathematical programming method is proposed for determining the complete history of (generalized) stresses and strains during a loading process for a class of elastic-plastic structures. This method is based on a pivoting procedure similar to the simplex method for a linear program and is suited for computer implementation. The method is illustrated by a simple truss problem. Based on the method, some results on existence and uniqueness of the solution of the structural problem are established.