Modulation of sheep lymphocyte responses by Fasciola hepatica excretory-secretory products

The effect of Fasciola hepatica excretory-secretory products (FhESPs) on mitogen-induced proliferation of sheep peripheral blood mononuclear cells (PBMCs) and PBMC subsets (CD2(+), CD4(+), CD8(+), gammadeltaTCR(+) or CD21(+) cells) were studied. PBMCs were incubated with Concanavalin A (ConA) or phytohemagglutinin (PHA) at optimal (1 microg per well) or suboptimal (0.25 microg per well) doses and with FhESPs at several doses (1.25-20 microg per well). PBMC subsets were incubated with ConA at a suboptimal dose and with FhESPs at 5 microg per well. These cells were incubated with or without monocytes (CD14(+) cell). FhESPs slightly increased the proliferation of PBMCs stimulated with optimal doses of PHA. FhESPs (10 and 20 microg per well) inhibited the PBMCs stimulated with optimal doses of ConA. FhESP dose-dependent inhibition was observed on PBMCs stimulated with suboptimal doses of ConA. CD21(+) lymphocytes (B lymphocytes), CD14(+) cells (monocytes) and gammadeltaTCR(+) cells were not stimulated by ConA. T lymphocyte subsets (CD2(+), CD4(+) or CD8(+) cells) proliferation was decreased by FhESPs at 5 microg per well. FhESPs inhibits the ConA-induced stimulation of sheep PBMCs and sheep T lymphocyte subsets. Further studies should be done to investigate the mechanism of this FhESP immunomodulatory effect.     

转型中的亚洲林业(续一)

在过去的20年里,亚洲林业经历了引人注目的转型,包括从计划经济到市场经济的转变,从天然林供给木材到人工林供给木材的转变,木材替代品与非木质林产品的增加,地方分权与当地群众的参与,生态时代的发展与生态系统管理。在促进亚洲可持续森林资源管理中,市场工具、社区参与和环境服务都得到了应用。亚洲林业的转型表现出多样化,其森林、社会与环境之间的联系是丰富多彩的。     

Effect of Various Acids and Sulfites in Steep Solution on Yields and Composition of Corn Fiber and Corn Fiber Oil

The addition of six acids (organic and inorganic) and four sulfite compounds (including gaseous SO₂) during the conventional corn wet‐milling steeping process of two yellow dent corn hybrids were evaluated for the effect on corn fiber yield, corn fiber oil yield, and the composition of three phytosterol compounds (ferulate phytosterol esters [FPE], free phytosterols [St], and phytosterol fatty acyl esters [St:E]) in the corn fiber oil. No significant effect of different sulfite compounds and acids were observed on corn fiber yields. However, a significant effect was observed on corn fiber oil yield and the composition of corn fiber oil for phytosterol compounds. Three of the sulfite compounds (including gaseous SO₂) caused very little effect on the levels of phytosterol compounds compared with the control sample (corn steeped with sodium metabisulfite and lactic acid). However, for one hybrid, ammonium sulfite gave a significantly higher yield of FPE and St:E and had no effect on the yield of St. For the other hybrid, it gave a significantly higher yield of FPE and had no effect on the yield of St and St:E compared with the control sample. This indicates that the effect of these sulfite compounds on yields of these phytosterol compounds in corn fiber oil is probably hybrid‐dependent. No significant effect of acids was observed on corn fiber yields, but significant effects were observed on corn fiber oil yields and yields of phytosterol compounds in the corn fiber oil. The effect also seems to be hybrid‐dependent because different acids affected the two hybrids differently. Overall, it seems that weak acids have a positive effect on increasing the individual phytosterol compounds in the corn fiber. When comparing the effect of experimental acids and sulfites on the two hybrids, acids have a more positive effect than sulfites in increasing the yield of phytosterol compounds in corn fiber oil.     

Structure of the Cell-Wall-Associated Polysaccharides from the Deep-Sea Marine Bacterium Devosia submarina KMM 9415T

Two cell-wall-associated polysaccharides were isolated and purified from the deep-sea marine bacterium Devosia submarina KMM 9415^T, purified by ultracentrifugation and enzymatic treatment, separated by chromatographic techniques, and studied by sugar analyses and NMR spectroscopy. The first polysaccharide with a molecular weight of about 20.7 kDa was found to contain d-arabinose, and the following structure of its disaccharide repeating unit was established: →2)-α-d-Araf-(1→5)-α-d-Araf-(1→. The second polysaccharide was shown to consist of d-galactose and a rare component of bacterial glycans-d-xylulose: →3)-α-d-Galp-(1→3)-β-d-Xluf-(1→.     

Renal -gulono-1,4-lactone oxidase activity as affected by dietary ascorbic acid in lake sturgeon (Acipenser fulvescens)

Sturgeon can synthesize -ascorbic acid (vitamin C) as they possess in their kidney -gulono-1,4-lactone oxidase, the enzyme catalyzing the last step of AA biosynthesis. The effect of increasing dietary ascorbic acid on gulonolactone oxidase activity was studied in lake sturgeon. Two-year-old lake sturgeon (body weight 253±89 g) were fed in triplicate groups with casein-based semipurified diets supplemented with either 0, 50, 250 or 1250 mg ascorbic acid/kg in the form of ascorbyl-2-monophosphate Mg for 38 days at 19.8°C. At the end of the trial, there were no significant differences in growth rate and survival among groups. Tissue total ascorbic acid concentrations increased significantly with dietary ascorbic acid. Renal gulonolactone oxidase activity was inconsistently affected by dietary treatment. These results suggested that, in sturgeon kidney unlike in the livers of ascorbic acid-synthesizing mammals, dietary ascorbic acid did not exert a negative feedback control on gulonolactone oxidase activity and thus on ascorbic acid synthesized. Using in vitro kinetics data we estimated a theoretical biosynthetic rate of ascorbic acid of 17 μmol (or 3 mg) per kilogram body weight per day at 15°C in juvenile lake sturgeon.     

Influence of growth temperature on the amounts of tocopherols, tocotrienols, and gamma-oryzanol in brown rice

Brown rice is a valuable source of lipid-soluble antioxidants including ferulated phytosterols (i.e., gamma-oryzanol), tocopherols, and tocotrienols. To evaluate the impact of temperature on the accumulation of these compounds, seeds from six different rice lines grown to maturity in replicate greenhouses in Gainesville, FL, were analyzed. The lines represented Oryza sativa indica, O. sativa japonica, and Oryza glaberrima of different origins. Temperatures were maintained near ambient at one end of each greenhouse and at approximately 4.5 degrees C above ambient at the other end. gamma-Oryzanols, tocopherols, and tocotrienols were extracted from whole seed (i.e., brown rice) and analyzed by HPLC. Tocotrienols and tocopherols varied widely between lines but changed only slightly with respect to temperature. In general, the proportions of alpha-tocotrienol and/or alpha-tocopherol increased at elevated temperature, whereas gamma-tocopherol and gamma-tocotrienol decreased. Six gamma-oryzanol peaks, identified on the basis of absorbance maxima at 330 nm and HPLC-mass spectrometry, were quantified. The most abundant component was 24-methylenecycloartanyl ferulate, present at 40-62% of total. Its levels increased 35-57% at elevated temperature in five of six lines, accounting for most of the change in total gamma-oryzanol. The results suggest that the physiological action of individual ferulated phytosterols should be investigated because their relative proportions in gamma-oryzanol can change.     

Experimental evaluation of several cycles of marker-assisted selection in maize

A program was initiated in 1994 to compare the efficiency of marker-assisted selection (MAS) and conventional phenotypic selection. A population of 300 F_3:4 families was generated from the cross between two maize inbred lines F2 and F252 and selected on an index combining grain yield and grain moisture at harvest. This population was characterised for 93 RFLP markers and evaluated as testcrosses in a large range of environments. Three methods of selection were applied (i) two cycles of conventional phenotypic selection; (ii) two cycles of MAS based on an index combining phenotypic values and QTL genetic values and (iii) one cycle of combined MAS followed by two cycles of selection based only on the QTL effects estimated in the first generation. The different populations were characterised for RFLP markers. The evolution of allele frequencies showed that selection on only-markers was very efficient for fixing QTL alleles found favourable in the initial population. This evolution was quite different from that observed for phenotypic selection or combined MAS. Genetic gain was evaluated and found significant for each method of selection. Nevertheless, the difference between phenotypic selection and combined MAS was not significant. The two additional cycles of MAS on only-markers did not improve significantly the genetic value of the population. Moreover, the genetic variance of this population remained high, despite most of the QTL initially detected were almost fixed. The results suggest that the QTL effects estimated in the initial population were not stable due to epistasis and/or QTL by environment interactions. This revised version was published online in July 2006 with corrections to the Cover Date.     

消费情景和文化习惯对国人购买红酒的影响研究

在红酒行业,国际红酒供应源源不断,而几个主要红酒消费国的红酒需求却在逐年稳步下降,这驱使国外红酒制造商进军中国市场。红酒营销主管们普遍认为制胜中国酒市的关键是创建一个强大的品牌。在中国市场发展红酒品牌的战略重要性得到了广泛的关注和探究,并衍生出一系列更为挑战的问题：如何发展适合中国市场的红酒品牌,对于品牌哪个属性的营销投资使得产品更适合在中国市场的定位,在以往对西方国家市场所作研究的基础上,笔者重点研究了在不同的消费情景下消费者主要依赖何种品牌属性对红酒做出评价,发现产品无关的品牌属性反而成为中国消费者最主要的评价因素,而不同消费情景的确影响着消费者对品牌属性的重视程度。     

RAP80 targets BRCA1 to specific ubiquitin structures at DNA damage sites

Mutations affecting the BRCT domains of the breast cancer-associated tumor suppressor BRCA1 disrupt the recruitment of this protein to DNA double-strand breaks (DSBs). The molecular structures at DSBs recognized by BRCA1 are presently unknown. We report the interaction of the BRCA1 BRCT domain with RAP80, a ubiquitin-binding protein. RAP80 targets a complex containing the BRCA1-BARD1 (BRCA1-associated ring domain protein 1) E3 ligase and the deubiquitinating enzyme (DUB) BRCC36 to MDC1-gammaH2AX-dependent lysine(6)- and lysine(63)-linked ubiquitin polymers at DSBs. These events are required for cell cycle checkpoint and repair responses to ionizing radiation, implicating ubiquitin chain recognition and turnover in the BRCA1-mediated repair of DSBs.