Methane (CH(4)) is the second most important greenhouse gas (GHG) and that emitted from enteric fermentation in livestock is the single largest source of emissions in Japan. Many factors influence ruminant CH(4) production, including level of intake, type and quality of feeds and environmental temperature. The objectives of this review are to identify the factors affecting CH(4) production in ruminants, to examine technologies for the mitigation of CH(4) emissions from ruminants, and to identify areas requiring further research. The following equation for CH(4) prediction was formulated using only dry matter intake (DMI) and has been adopted in Japan to estimate emissions from ruminant livestock for the National GHG Inventory Report: Y = -17.766 + 42.793X - 0.849X(2), where Y is CH(4) production (L/day) and X is DMI (kg/day). Technologies for the mitigation of CH(4) emissions from ruminants include increasing productivity by improving nutritional management, the manipulation of ruminal fermentation by changing feed composition, the addition of CH(4) inhibitors, and defaunation. Considering the importance of ruminant livestock, it is essential to establish economically feasible ways of reducing ruminant CH(4) production while improving productivity; it is therefore critical to conduct a full system analysis to select the best combination of approaches or new technologies to be applied under long-term field conditions.

The relationship between dry matter intake (DMI) and methane (CH4) production was investigated using results obtained from 190 energy balance trials with dairy cattle, beef cattle, sheep and goats to predict total methane emission from livestock in Japan.The results were as follows : 1) CH4 production per unit of feed intake decreased as feeding level increased although the absolute amount of CH4 production (X, kg/day) can be expressed as a quadratic form. The equation best fitted to the data for all aminals was Y=-17.766+42.793X-0.849X2 (r=0.966).3) From the estimation equation, average dry matter intake and cattle populations, annual CH4 production was estimated to be 0.182 teragrams (Tg) from dairy cattle and 0.150Tg from beef cattle.Total CH4 emission from ruminant livestock in Japan was estimated to be 0.332 Tg/year, and total CH4 emission from all livestock including ruminants, pigs and horses was 0.345 Tg/year in Japan. This only accounts for around 0.5% of total CH4 emissions from animals all over the world.

Bacillus subtilis is an effective probiotic product for prevention of enteric infections both in humans and animals. We hypothesized that a mouth rinse containing Bacillus subtilis should adhere to and colonize part of the oral bacteria on periodontal tissue. The rinsing ability of Extraction 300E (containing Bacillus subtilis: E-300) was compared with that of a mouth wash liquid , Neosteline Green (benzethonium chloride; NG) that is commonly used in Japan. Compared with NG rinsing, E-300 rinsing resulted in a marked change in the BANA-score. The mean BANA values (score +/- SD) over the course of the study from 0 to 30 days were 1.52 +/- 0.51 (p < or = 0.1) and 0.30 +/- 0.47 (p < or = 0.01) for E-300, and 1.56 +/- 0.51 and 0.93 +/- 0.68 for NG, respectively. Gingival Index also had improvement, while probing pocket depth and bleeding on probing showed small improvements. Mouth rinsing with E-300 significantly reduced periodontal pathogens compared with NG. These results suggest that Bacillus subtilis is an appropriate mouth rinse for patients with periodontitis.

ATP hydrolyzing activity of a mutant ␣ 3 ␤ 3 ␥ subcomplex of F 0 F 1 -ATP synthase (⌬NC) from the thermophilic Bacillus PS3, which lacked noncatalytic nucleotide binding sites, was inactivated completely soon after starting the reaction (Matsui, T., Muneyuki, E., Honda, M., Allison, W. S., Dou, C., and Yoshida, M. (1997) J. Biol. Chem. 272, 8215-8221). This inactivation is caused by rapid accumulation of the "MgADP inhibited form" which, in the case of wild-type enzyme, would be relieved by ATP binding to noncatalytic sites. We reconstituted F 0 F 1 -ATP synthase into liposomes together with bacteriorhodopsin and measured illumination-driven ATP synthesis. Remarkably, ⌬NC F 0 F 1 -ATP synthase catalyzed continuous turnover of ATP synthesis while it could not promote ATP-driven proton translocation. ATP synthesis by ⌬NC F 0 F 1 -ATP synthase, as well as wild-type enzyme, proceeded even in the presence of azide, an inhibitor of ATP hydrolysis that stabilizes the MgADP inhibited form. The time course of ATP synthesis by ⌬NC F 0 F 1 -ATP synthase was linear, and gradual acceleration to the maximal rate, which was observed for the wild-type enzyme, was not seen. Thus, ATP synthesis can proceed without nucleotide binding to noncatalytic sites even though the rate is sub-maximal. These results indicate that the MgADP inhibited form is not produced in ATP synthesis reaction, and in this regard, ATP synthesis may not be a simple reversal of ATP hydrolysis.The F 0 F 1 -ATP synthase is a ubiquitous enzyme in plasma membranes of bacteria, inner membranes of mitochondria, and thylakoid membranes of chloroplasts which utilizes a transmembrane electrochemical potential difference of protons (⌬H ϩ ) 1 for ATP synthesis (1, 2). It can be reversibly separated into a hydrophilic, water-soluble F 1 part and a hydrophobic, membrane-embedded F 0 part. F 0 conducts protons across the membrane. F 1 , also called F 1 -ATPase, has a subunit composition of ␣ 3 ␤ 3 ␥␦⑀ and shows strong activity of ATP hydrolysis. According to the crystal structure of the major part of beef heart mitochondrial F 1 -ATPase (3), ␣ and ␤ subunits are alternatively arranged to form a hexagonal cylinder with a central cavity through which coiled-coil ␣ helices of the ␥ subunit penetrate. F 1 -ATPase was recently proven to be a "rotary motor enzyme", the first ever found in the biological world; the ␥ subunit rotates within an ␣ 3 ␤ 3 hexagon during ATP hydrolysis (4 -6).The F 1 -ATPase has six nucleotide binding sites. Three of them are catalytic and located mainly on the ␤ subunits. The other three, called noncatalytic sites, are mainly located on the ␣ subunits. The function of the noncatalytic site had been obscure but recent studies indicated its regulatory role as follows. During multiple turnover of ATP hydrolysis, MgADP is prone to be entrapped in a catalytic site producing the MgADP inhibited form of the enzyme, which is inactive in ATP hydrolysis. ATP binding to the noncatalytic sites causes release of this inhibitory MgADP from the affected catalytic s...

Mastication is a developmental function. It matures through learning experiences. The biting force is one of the components of masticatory function. The biting force increases with age. During the developmental stage, it is believed feasible to enhance the maturation of the masticatory function by increasing the biting force.The previous results of masticatory training for adults and school children had revealed 20% to 30% increase of the biting force.In this study, masticatory training with specially fabricated chewing gum for young ( preschool) children was performed. The subjects were 5 males and 5females from 3 years old to 5 years old. These children were instructed to bite onthe chewing gum for 5 minutes, 2 times a day, for 3 months. The results show that there was a 94% average increase of biting force after 3 months of training. It was also noted that the rate of the increase of the biting force was remarkable during the firs tmonth of training.