Ovarian activity and pregnancy in the Siberian tiger, Panthera tigris altaica, assessed by fecal gonadal steroid hormones analyses

Feces were collected from two female and one male Siberian tigers, Panthera tigris altaica. Steroid hormones were extracted from lyophilized feces and quantified by enzyme immunoassay. The fecal contents of estradiol-17beta (E(2)) and testosterone in the females and male, respectively, changed markedly throughout the year. The fecal E(2) contents of females Nos. 179 and 238 increased at 26.4 +/- 8.0 and 28.0 +/- 14.2 day intervals, respectively. However, the fecal contents of progesterone (P(4)) in the female kept alone did not change. In contrast, the other female, which was kept with a male, had increased fecal P(4) contents after copulation. The fecal progesterone levels of the pregnant female remained high during her 106-day pregnancy.     

Long-term growth analyses of Japanese cedar trees in a plantation: neighborhood competition and persistence of initial growth deviations

The individual growth of tree diameter at breast height (dbh) is analyzed in an even-aged plantation of Cryptomeria japonica from stand age of 45 to 94 years, to examine how the growth of individual trees has been affected by the changes in spacing resulting from thinning operations. At any age, a significant proportion (0.37–0.46) of the variation in dbh growth during a 5–11-year period was explained by dbh at the beginning of the period, probably due to greater leaf mass of larger trees. Next, either one-sided or two-sided competition was added to the model, by calculating the basal area (BA) of neighboring trees around each tree within a given radius or BA for trees having larger dbh than the focal tree within the radius. After preliminary analyses, a radius of 8 m was selected as the critical range for tree competition. Although both types of competition explained a significant proportion (0.09–0.43) of growth variation, one-sided competition was not significant at ages greater than 54 years. Based on the model at 45 years of age, the initial deviation of growth rate for each tree from the predicted rate was calculated and added to the models as a third variable. This raised the coefficient of determination up to 0.50–0.74. These findings have practical significance for forest plantation management, particularly for controlling the growth of standing trees via thinning, to produce high-quality timber in the future.     

Effect of monensin withdrawal on rumen fermentation,methanogenesis and microbial populations in cattle

This study was designed to obtain information on the residual influence of dietary monensin on ruminant fermentation, methanogenesis and bacterial population. Three ruminally cannulated crossbreed heifers (14 months old, 363 ± 11 kg) were fed Italian ryegrass straw and concentrate supplemented with monensin for 21 days before sampling. Rumen fluid samples were collected for analysis of short chain fatty acid (SCFA) profiles, monensin concentration, methanogens and rumen bacterial density. Post‐feeding rumen fluid was also collected to determine in vitro gas production. Monensin was eliminated from the rumen fluid within 3 days. The composition of SCFA varied after elimination of monensin, while total production of SCFA was 1.78 times higher than on the first day. Methane production increased 7 days after monensin administration ceased, whereas hydrogen production decreased. The methanogens and rumen bacterial copy numbers were unaffected by the withdrawal of monensin.     

Antitumor activity of compounds isolated from leaves of Eriobotrya japonica

In a search for possible antitumor agents from natural sources, megastigmane glycosides and polyphenolic constituents isolated from the leaves of Eriobotrya japonica (Rosaceae) were found to inhibit the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced activation of Epstein-Barr virus early antigen in Raji cells. Roseoside and procyanidin B-2 were among the active compounds found in an in vitro assay; these compounds were further assessed for antitumor activity in vivo in a two-stage carcinogenesis assay on mouse skin. Roseoside significantly delayed carcinogenesis induced by peroxynitrite (initiator) and TPA (promoter), and its potency was comparable to that of a green tea polyphenol, (-)-epigallocatechin 3-O-gallate, in the same assay.     

Effects of warming basal ends of Carolina poplar (Populus × canadensis Moench.) softwood cuttings at controlled low-air-temperature on their root growth and leaf damage after planting

We investigated the effects of warming the basal ends of Carolina poplar (Populus × canadensis Moench.) softwood cuttings at controlled low-air-temperature on their root growth and leaf damage after planting. The warming treatment was applied to the cuttings by soaking 10 mm beyond the cut end in warmed water maintained at 30 °C in a cold chamber maintained at an air temperature of 10 °C and a photosynthetic photon flux density (PPFD) of 10 μmol m^?2 s^?1 (near the light compensation point at 10 °C) until rooting was observed. The warmed cuttings were then grown in a growth chamber at an air temperature of 30 °C, relative humidity 85–90 %, and a PPFD of 100 μmol m^?2 s^?1. Control cuttings were grown in the growth chamber throughout the experiment. Rooting occurred simultaneously for both warmed and control cuttings, irrespective of air temperature. Root development was greater and leaf damage, evaluated on the basis of extent of necrosis, was less for warmed cuttings than for control cuttings. The reduction of leaf damage for warmed cuttings probably resulted from reduced post-planting water stress and leaf senescence, because of improved root development as a result of the pre-planting warming treatment. This technique could improve the propagation of cuttings of woody plants, because it would ensure that the cuttings are ready to develop roots with minimum loss of carbohydrates, irrespective of weather conditions.     

Epicatechin-3-O-(3″-O-methyl)-gallate content in various tea cultivars (Camellia sinensis L.) and its in vitro inhibitory effect on histamine release

It has been reported that epigallocatechin-3-O-(3″-O-methyl)-gallate (EGCG3″Me) and the EGCG3″Me-rich green tea ( Camellia sinensis L.) cultivar 'Benifuuki' exhibit antiallergic effects. The objective of this study was to investigate the effect of various tea leaf catechins on histamine release from murine bone marrow mast cells (BMMC). At a dose of 50 μg/mL, the rank order of histamine release inhibition was observed to be epicatechin-3-O-(3″-O-methyl)-gallate (ECG3″Me) > gallocatechin-3-O-(3″-O-methyl)-gallate (GCG3″Me) > EGCG3″Me > gallocatechin-gallate (GCG) > catechin-gallate (CG) > EGCG > epicatechin-gallate (ECG) > epigallocatechin (EGC) > gallocatechin (GC). Of the various tea cultivars analyzed by HPLC, the greatest content of ECG3″Me was found in the third crop of 'Benifuuki' (1.05% dry weight). Moreover, ECG3″Me content was positively correlated with EGCG3″Me content in 'Benifuuki' tea leaves. In an assay of mixtures of ECG3″Me and EGCG3″Me, inhibitory activity (50 μg/mL in total) was increased as the content of ECG3″Me increased. This suggests that ECG3″Me might link to the antiallergic effect of 'Benifuuki' tea, as has been reported for EGCG3″Me.     

Nitrocapsanthin and nitrofucoxanthin, respective products of capsanthin and fucoxanthin reaction with peroxynitrite

The in vitro reactivity of capsanthin (1) and fucoxanthin (2) with peroxynitrite was investigated, and the reaction products produced by scavenging with peroxynitrite were analyzed. (14'Z)-Nitrocapsanthin (3) and 12-nitrocapsanthin (4) were isolated from the products of the reaction of capsanthin with peroxynitrite. Similarly, (14Z)-15-nitrofucoxanthin (5), (11Z)-11-nitrofucoxanthin (6), and (14Z,9'Z)-15-nitrofucoxanthin (7) were obtained from the reaction of peroxynitrite reaction with fucoxanthin. Capsanthin and fucoxanthin inhibited the nitration of tyrosine by peroxynitrite. Furthermore, nitrocapsanthins (3 and 4) and nitrofucoxanthins (5 and 6) exhibited an inhibitory effect on Epstein-Barr virus early antigen activation in Raji cells and an antiproliferative effect on human pancreatic carcinoma. Moreover, nitrocapsanthins (3 and 4) inhibited carcinogensis of mouse skin tumors initiated by 7,12-dimethylbenz[a]anthracene (DMBN).     

Soil physicochemical properties in a high-quality tea production area of Thai Nguyen province in northern region,Vietnam

This study investigated general physicochemical properties of tea garden soils at the alluvial plain of Cong River in Tan Cuong commune, Vietnam. Four gardens were selected as study sites on three transect lines established perpendicularly to the river. Soil samples were collected from the surface (0–10 cm) and subsurface (20–30 cm). Soil texture classes varied from sandy loam to light clay, which was affected by different terrains along the transect lines as well as severe disturbance such as terracing and earth excavation. The levels of total C and total N were correlated with increasing garden age, suggesting the replenishment of soil organic matter pool by the addition of plant residue and manure. Meanwhile, the soils showed strongly acidic nature with the average pH(H₂O) of 3.7 at the surface and 3.9 at the subsurface. The effective cation exchange capacity (ECEC) was low at 4.7 and 4.9 cmol_c kg^?1, respectively, and dominated by exchangeable Al³⁺. Soil acidification was exacerbated with increasing garden age. However, a relatively large saturation of exchangeable calcium (Ca²⁺), potassium (K⁺), and magnesium (Mg²⁺) on the ECEC was found in the surface soils. The levels of available P were high, occasionally exceeding 1000 and 500 mg kg^?1 at the surface and subsurface, respectively. In spite of strongly acidic condition, ammonium (NH₄-N) applied as fertilizer was converted to nitrate (NO₃-N) to move down to deeper layers. The levels of the bases, P, and mineral N seem to be principally determined by management practices. Significant portion of these nutrients was likely to exist in water soluble forms without adsorption onto soils. It should be required to develop proper schemes and to educate the owners for adequate fertilizer managements.     

Effects of live rock on the reef-building coral Acropora digitifera cultured with high levels of nitrogenous compounds

Reef-building corals are sensitive to excessive nitrogenous (N) compounds. To maintain levels of inorganic nitrogenous compounds low in coral aquaria, various technologies, mechanical, chemical and biological, have been applied. As one of the biological techniques, “live rock,” which can be defined as a dead coral skeleton covered with crustose coralline algae (CCA), has long been applied for coral aquaria. Until recently, however, there has been little evidence for the effectiveness of live rock in removal of N compounds from coral aquaria. Demonstrating comparative experiments with live rocks, here we report that the live rock is capable of removing N compounds and reduces the mortality of reef-building coral. We cultured the reef-building coral Acropora digitifera with the sea cucumber Holothuria atra as a natural nitrogen producer. H. atra increased the concentration of the inorganic N compounds (NH₄⁺, NO₃⁻ and NO₂⁻) that resulted in high coral mortality. The presence of the live rock remarkably reduced the concentrations and sustained a high coral photosynthetic activity. We detected the functional genes amoA and nirS within the live rock, suggesting the occurrence of both nitrifying and denitrifying bacteria. These results support the idea that “live rock” is an effective biofilter that can maintain water quality suitable for reef-building corals.