Age, growth and reproductive characteristics of round scad Decapterus maruadsi in the waters off west Kyushu, the east China Sea

ABSTRACT:   The purpose of this study was to determine the growth and reproductive characteristics of round scad Decapterus maruadsi in the East China Sea. The characteristics regarding growth and reproduction of round scad based on otolith reading and gonad histology, respectively, were estimated. The von Bertalanffy's growth model for round scad was estimated as follows:
FL _t  = 342[1 − exp{−0.55( t  + 0.58)}], (1 <  t  < 7)
where FL _t is fork length (mm) at age in years t . The maturation stage of the ovary was observed by histological techniques. June was the main spawning period; the maturation and migratory nucleus stage of the oocyte was observed when the gonad somatic index value was approximately greater than 4.     

Epimerization of tea catechins and O-methylated derivatives of (-)-epigallocatechin-3-O-gallate: relationship between epimerization and chemical structure

Epimerization at C-2 of O-methylated catechin derivatives and four major tea catechins were investigated. The epimeric isomers of (-)-epicatechin (I), (-)-epicatechin-3-O-gallate (II), (-)-epigallocatechin (III), (-)-epigallocatechin-3-O-gallate (IV), and (-)-epigallocatechin-3-O-(3-O-methyl)gallate (V) in green tea extracts increased time-dependently at 90 degrees C. The epimerization rates of authentic tea catechins in distilled water are much lower than those in tea infusion or in pH 6.0 buffer solution. The addition of tea infusion to the authentic catechin solution accelerated the epimerization, and the addition of ethylenediaminetetraacetic acid, disodium salt (Na(2)EDTA) decreased the epimerization in the pH 6.0 buffer solution. Therefore, the metal ions in tea infusion may affect the rate of epimerization. The proportions of the epimers to authentic tea catechins [III, IV, V, and (-)-epigallocatechin-3-O-(4-O-methyl)gallate (VI)] in pH 6.0 buffer solution after heating at 90 degrees C for 30 min were 42.4%, 37.0%, 41.7%, and 30.4%, respectively. These values were higher than those of I and II (23.5% and 23.6%, respectively). The O-methylated derivatives at the 4'-position on the B ring of IV and VI were hardly epimerized. These results suggest that the hydroxyl moiety on the B ring of catechins plays an important role in the epimerization in the order 3',4',5'-triol type > 3',4'-diol type > 3',5'-diol type.     

A mixed green vegetable and fruit beverage decreased the serum level of low-density lipoprotein cholesterol in hypercholesterolemic patients

The effects of a canned mixed green vegetable and fruit beverage, containing broccoli (Brassica oleracea L. var. botrytis L.) and cabbage (Brassica oleracea L. var. capitata L.) as main materials, on serum lipid levels in hypercholesterolemic patients were investigated. Thirty-one adult subjects were administered two cans of the beverage (160 g/can) per day for 3 weeks. Their serum total cholesterol (TC) levels significantly decreased from 6.7 +/- 0.8 to 6.1 +/- 0.6 mmol/L, and, more strikingly, the level of low-density lipoprotein cholesterol (LDL-C) significantly decreased from 4.4 +/- 0.8 to 3.8 +/- 0.7 mmol/L. At 9 weeks after the cessation of the administration, these levels had returned to the preadministration levels. Furthermore, 14 other subjects who were administered one can of the sample for 12 weeks also showed a significant reduction in the levels of serum TC and LDL-C. Thus, daily consumption of this mixed green vegetable and fruit beverage may be useful in lowering serum TC and LDL-C levels in hypercholesterolemic patients.     

Activity of (-)-epigallocatechin 3-O-gallate against oxidative stress in rats with adenine-induced renal failure

Methylguanidine (MG) is widely recognized as a strong uremic toxin. The hydroxyl radical (*OH) specifically plays an important role in the pathway of MG production from creatinine (Cr). In this study, we investigated whether oral administration of (-)-epigallocatechin 3-O-gallate (EGCg) suppresses MG production in rats with chronic renal failure after intraperitoneal Cr injection. MG production from Cr was significantly increased in rats with adenine-induced renal failure, which was more vulnerable to oxidative stress, compared with that in normal rats. However, oral administration of EGCg 30 min before and after Cr injection effectively inhibited MG production. Our findings suggest that EGCg, an excellent antioxidant from green tea, exerts protective activity in rats with chronic renal failure, resulting in suppression of Cr oxidation influenced by *OH.     

Phytoestrogen-low diet for endocrine disruptor studies

Hormonally active chemicals (HACs) that are capable of inducing adverse effects on wildlife as well as human beings are featured as "endocrine disruptors". Various animal studies conducted to clarify the characteristics of HACs, including the uterotrophic assay, are sufficiently sensitive to detect the effect of 17-beta-estradiol in micrograms per kilogram of body weight or lower. In such systems, a trace amount of HACs in the dietary pellets may interfere with the test results and thus can be a serious problem for the low-dose issue, which is now a major topic in the field of endocrine disruptor research. Here, the significance of the hormonal effects of phytoestrogen components in the NIH-07 diet is confirmed and a NIH-07-based open formula "phytoestrogen-low diet" (PLD) is proposed, which effectively reduces uterine weight as well as the uterine luminal epithelial labeling index in ovariectomized rats.     

Changes in forest resource utilization and forest landscapes in the southern Abukuma Mountains,Japan during the twentieth century

Land use and landscape changes, which have much effect on local biodiversity, are driven primarily by socioeconomic forces. Understanding these forces is important for preservation of current biodiversity. In this study, we clarified the socioeconomic forces that have brought about changes in the forest landscape around the Ogawa Forest Reserve in the southern Abukuma Mountains, Japan, by interviewing local residents and reviewing local historical documents. Furthermore, we reconstructed past forest landscapes and quantified the changes that have occurred from the beginning of the twentieth century until the present by use of old land-use maps and past aerial photographs. The use of forest resources has dramatically changed during the past hundred years, and it can be divided into three periods corresponding to the level of economic development. The main landscape has changed significantly from one mainly composed of expansive grasslands and broad-leaved forests into a mosaic of fragmented secondary forests and coniferous plantations. These landscape changes reflect shifts in both the use of forest resources by local residents and the management of the national forests. Clarifying temporal–spatial landscape changes by understanding the historical relationship between humans and the landscape provides useful information for optimizing conservation and management planning.     

A low-operating-temperature solid oxide fuel cell in hydrocarbon-Air mixtures

The performance of a single-chamber solid oxide fuel cell was studied using a ceria-based solid electrolyte at temperatures below 773 kelvin. Electromotive forces of approximately 900 millivolts were generated from the cell in a flowing mixture of ethane or propane and air, where the solid electrolyte functioned as a purely ionic conductor. The electrode-reaction resistance was negligibly small in the total internal resistances of the cell. The resulting peak power density reached 403 and 101 milliwatts per square centimeter at 773 and 623 kelvin, respectively.