Two Lipoxygenases from Germinated Barley-Heat and Kilning Stability

Using ammonium sulfate precipitation followed by hydrophobic and ion exchange chromatography, two lipoxygenase isoenzymes, LOX 1 and LOX 2, were 18.3- and 44.5-fold purified from germinated barley, with 18 and 24% recovery of activity respectively. LOX 1 and LOX 2 were characterized by isoelectric points 4.9 and 6.4, and molecular weights of 90 kd and 110 kd, respectively. Apparent Km values for linoleic acid were 0.06 mM for LOX 1 and 0.18 mM for LOX 2. LOX 1 converted linoleic acid to 9 and 13 hydroperoxides at about 4:1, whereas the 13 hydroperoxide was the major product formed by LOX 2 (ratio 3:7). For both isoforms, thermal inactivation data indicated first order kinetics with activation energies influenced by ionic strength and pH. Isoenzymes composition was analyzed for three kilning schemes: the 1:3 ratio between LOX 1 and LOX 2 observed in germinated barley increased during the course of kilning.     

Effect of Antioxidants on Malonaldehyde Production and Fatty Acid Composition in Pieces of Bovine Muscle and Adipose Tissue Stored Fresh and Frozen

TBA-reactive material was produced in pieces of bovine semitendinosus muscle and adipose tissue during storage at 2° 2°C and ?10° 2°C. The process was faster in muscle than in adipose tissue and the total content, higher at 2°C than at ?10°C. The effect of sprying butylated hydroxytoluene and a citric acid-EDTA-ascorbic acid mixture on the production of malonaldehyde was studied. Declines in both saturated and unsaturated fatty acid proportions of the polar lipids without increases in the content of free fatty acids suggests that enzymes involved in lipid catabolism remain active at low temperatures. Whereas lipid breakdown was unaffected, malonaldehyde production was inhibited by sprying antioxidants in early stages of the slaughtering process.     

Inhibition of Horse Bean and Germinated Barley Lipoxygenases by Some Phenolic Compounds

Phenolic compounds have been repeatedly implicated as potent antioxidants. Efficiency has been frequently estimated by radical scavenging activity and few reports have considered lipoxygenase (LOX) inhibition. Horse bean LOX was inhibited by a range of phenolic acids, gallates and flavonoids. All compounds tested were uncompetitive inhibitors with the exception of flavonol aglycons which were non competitive type. In each class of compounds, inhibition constants were strongly affected by structures. Inhibition patterns of (-)-epicatechin on germinated barley LOXs were detailed: (-)-epicatechin acted as an uncompetitive inhibitor while (-)-epicatechin reduced hydroperoxide formation by its radical scavenging activity and thus limited enzyme activation.     

Socialization in an Open Source Software Community: A Socio-Technical Analysis

Open Source Software (OSS) development is often characterized as a fundamentally new way to develop software. Past analyses and discussions, however, have treated OSS projects and their organization mostly as a static phenomenon. Consequently, we do not know how these communities of software developers are sustained and reproduced over time through the progressive integration of new members. To shed light on this issue I report on my analyses of socialization in a particular OSS community. In particular, I document the relationships OSS newcomers develop over time with both the social and material aspects of a project. To do so, I combine two mutually informing activities: ethnography and the use of software specially designed to visualize and explore the interacting networks of human and material resources incorporated in the email and code databases of OSS. Socialization in this community is analyzed from two perspectives: as an individual learning process and as a political process. From these analyses it appears that successful participants progressively construct identities as software craftsmen, and that this process is punctuated by specific rites of passage. Successful participants also understand the political nature of software development and progressively enroll a network of human and material allies to support their efforts. I conclude by discussing how these results could inform the design of software to support socialization in OSS projects, as well as practical implications for the future of these projects.     

影像磨坊 城市历史的多媒体表达

影像磨坊,世界上最大的室外多媒体工程,旨在庆祝魁北克市400周年纪念而设计。这座影像磨坊有个40分钟的视听工程设计以魁北克港口的谷粮仓为背景。这座庞大的混凝土建筑成为了叙述魁北克市400年历史故事的讲说员。     

SOLUBILITY AND EMULSIFYING PROPERTIES OF BETACASEIN MODIFIED ENZYMATICALLY BY TRYPSIN

Beta A1-casein was treated with TPCK-trypsin to give 3.2, 5.0, 5.8 and 7.4% hydrolysis of the peptide bonds. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis the resulting peptides had apparent molecular weights in the range 8,000–4,000. Size-exclusion chromatography of hydrolyzed samples showed four major peaks near 15,000, 5,500, 3,500 and 2,500 molecular weights, representing 17, 15, 7 and 14% of the material, respectively, after 3.2% hydrolysis and 9, 6, 14 and 52% of the material, respectively, after 7.4% hydrolysis. Between the extremes 3.2% and 7.4% hydrolysis, a peak near 8,500 molecular weight was present until 5.8% hydrolysis then disappeared after 7.4% hydrolysis to be replaced by a peak near 12,000 molecular weight. Peptides recovered from reversed-phase high performance liquid chromatography were analyzed by determination of their amino acid composition and identified in the sequence of β-casein. After trypsin treatment, the solubility of β-casein hydrolysates was largely increased at pH 4.0–7.5. The emulsifying activity of the hydrolysates was higher than that of β-casein in the range of pH 1.5–3.5 and 6.5–10.0, but all the emulsions obtained with trypsin-treated β-casein were less stable than those obtained with original β-casein.     

Propriétés antiélastasiques des propionylaminoacides

Antielastase activity of derivatives like 'propionylaminoacid'(C₃ prolin, C₃ hydroxyprolin, C₃ collagen) was examined for pancreatic elastase, and fibroblastic elastase production. Essential metabolic variations of normal dermal fibroblasts were evaluated: adhesion, proliferation capacity, total protein biosynthesis and collagen type I and type III production. Possible other factors such as cellular nutrients were examined by oxygen consumption evaluation.
Propionylaminoacid derivatives have antielastase activities. Pancreatic elastase showed dose related inhibition (20% to 50% inhibition for concentration from 5 to 80 mg ml⁻¹.
Moreover, fibroblastic elastase production was inhibited, cellular respiration was enhanced. A very good tolerance in vitro was observed for concentration 0–1 mg ml⁻¹ range: adhesion, proliferation capacity and collagen (type I and type III) production were not altered, and oxygen consumption was enhanced.     

Playtime

Three installation projects take tropes such as the labyrinth, the lumberjack culture and the neighbor's fence, and turn them into spaces of gathering and play.     

杭州市市民中心景观设计

杭州市市民中心是杭州未来具有中央商务区功能的城市中心--钱江新城的核心建筑.钱江新城是杭州市从"西湖时代"迈向"钱塘江时代"的标志性工程,其核心区主轴线自西向东,由中央公园、市民中心、杭州大剧院和科技图书馆等文化娱乐类建筑构成,并向钱塘江边延伸以高架城市阳台为结束.