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Author (up) Alvarez, J.; Fadic, R. file  url
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  Title Assembly and disassembly of axonal microtubules of the toad Xenopus laevis under the effect of temperature Type Journal Article
  Year 1992 Publication The Journal of Experimental Zoology Abbreviated Journal J Exp Zool  
  Volume 264 Issue 3 Pages 261-266  
  Keywords Animals; Axons/*physiology; Cytoplasm/metabolism; Kinetics; Microtubules/*physiology; Seasons; *Temperature; Tubulin/metabolism; Xenopus laevis  
  Abstract In toads Xenopus laevis living at 11 degrees (winter), the microtubular density of 4-microns myelinated axons of lumbosacral nerves was assessed with the electron microscope. In controls, the density was 11.2 microtubules/microns2. In nerves incubated at 0 degrees, microtubules decreased following a simple exponential curve with a half time of 4.7 min (k = 0.149 min-1); residual microtubules were 4.5%. After rewarming, the full complement of microtubules reappeared within 60 min. In steady state, the microtubular density exhibited a linear relationship with temperature (range: 0-22 degrees; slope 0.94 microtubules/microns 2 per degree; r, 0.96). After heating the nerve by 11 degrees above the physiological temperature, microtubules increased by 83%, whereby the pool of unpolymerized tubulin was at least 2.7 mg/ml of axoplasm. A seasonal variation of the microtubular density was observed which accorded with the environmental temperature. The macroscopic kinetics of microtubule disassembly in the axoplasm is similar to that reported for purified tubulin but that of assembly is slower. Microtubules of peripheral axons of Xenopus are cold-labile and vary during the annual cycle.  
  Call Number Serial 1174  
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Author (up) Bakker, D.P.; Klijnstra, J.W.; Busscher, H.J.; van der Mei, H.C. file  url
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  Title The effect of dissolved organic carbon on bacterial adhesion to conditioning films adsorbed on glass from natural seawater collected during different seasons Type Journal Article
  Year 2003 Publication Biofouling Abbreviated Journal Biofouling  
  Volume 19 Issue 6 Pages 391-397  
  Keywords Adhesiveness/drug effects; *Bacterial Physiological Phenomena; Biofilms/*drug effects; Carbon/pharmacology; Glass; Netherlands; Seasons; Seawater/*microbiology; Spectrum Analysis; Surface Properties  
  Abstract Adhesion of three marine bacterial strains, i.e. Marinobacter hydrocarbonoclasticus, Psychrobacter sp. and Halomonas pacifica with different cell surface hydrophobicities was measured on glass in a stagnation point flow chamber. Prior to bacterial adhesion, the glass surface was conditioned for 1 h with natural seawater collected at different seasons in order to determine the effect of seawater composition on the conditioning film and bacterial adhesion to it. The presence of a conditioning film was demonstrated by an increase in water contact angle from 15 degrees on bare glass to 50 degrees on the conditioned glass, concurrent with an increase in the amount of adsorbed organic carbon and nitrogen, as measured by X-ray photoelectron spectroscopy. Multiple linear regression analysis on initial deposition rates, with as explanatory variables the temperature, salinity, pH and concentration of dissolved organic carbon (DOC) of the seawater at the time of collection, showed that the concentration of DOC was most strongly associated with the initial deposition rates of the three strains. Initial deposition rates of the two most hydrophilic strains to a conditioning film, increased with the concentration of DOC in the seawater, whereas the initial deposition rate of the most hydrophobic strain decreased with an increasing concentration of DOC.  
  Call Number Serial 437  
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Author (up) Brimblecombe, P. file  url
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  Title London air pollution, 1500-1900 Type Journal Article
  Year 1977 Publication Atmospheric Environment Abbreviated Journal Atmos Environ  
  Volume 11 Issue 12 Pages 1157-1162  
  Keywords Air Pollution--history; Coal; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; Humans; London; Models, Theoretical; Seasons; Sulfur Dioxide--analysis; Vitamin D Deficiency--etiology  
  Abstract Documentary evidence for the changes in the air pollutant levels and climate of London are compared with the results obtained from a simple single box model for the annual mean SO2 and particulate levels in the London air. Sulphur dioxide reaches a maximum of nearly 200 μg m−3 in a plateau that stretches from 16901880. Particulate concentrations show a peak at the end of the 19th century.  
  Call Number Serial 982  
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Author (up) Cefola, M.; Amodio, M.L.; Cornacchia, R.; Rinaldi, R.; Vanadia, S.; Colelli, G. url  doi
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  Title Effect of atmosphere composition on the quality of ready-to-use broccoli raab (Brassica rapa L.) Type Journal Article
  Year 2010 Publication Journal of the Science of Food and Agriculture Abbreviated Journal J Sci Food Agric  
  Volume 90 Issue 5 Pages 789-797  
  Keywords Antioxidants--analysis; Ascorbic Acid--analysis; Brassica rapa--anatomy, histology, chemistry; Carbon Dioxide--chemistry; Cell Respiration; Chlorophyll--analysis; Fast Foods; Food Handling--methods; Nutritive Value; Odors; Oxygen--chemistry; Phenols--analysis; Pigmentation; Plant Shoots--anatomy, histology, chemistry; Quality Control; Refrigeration; Seasons; Spectrophotometry; Time Factors  
  Abstract BACKGROUND: Many leafy brassicas are widely used for ready-to-use salads. Broccoli raab (Brassica rapa L.), also called turnip top, or rapini, is extensively cultivated in southern Italy. The edible portion is made up of the green, immature inflorescences and the stem with its most tender leaves. Recently, interest in this crop has increased among European consumers; moreover, a substantial increase in consumption could come from the ready-to-use product. RESULTS: The effects of four different atmosphere compositions (air, 3% O(2) in nitrogen, 3% O(2) + 10% CO(2) in air, and 10% CO(2) in air) on quality attributes of ready-to-use broccoli raab were studied. Controlled atmosphere affected appearance, composition, respiration rate, weight loss, and presence of off-odours. Storage of broccoli raab florets under low oxygen conditions delayed post-cutting deterioration during storage at 5 degrees C and preserved appearance and typical odour, up to 17 days. Moreover, respiration rate as well as loss of green colour, chlorophyll and vitamin C were also slowed down in this condition. Finally, in this study no effect of controlled atmosphere storage was found on total phenols content and antioxidant activity. CONCLUSION: Results showed that cold storage in 3% O(2) can be beneficial in order to maintain quality of ready-to-use, broccoli raab for up to 17 days.  
  Call Number Serial 41  
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Author (up) Hadley, E.B.; Kieckhefer, B.J. file  url
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  Title Productivity of Two Prairie Grasses in Relation to Fire Frequency Type Journal Article
  Year 1963 Publication Ecology Abbreviated Journal  
  Volume 44 Issue 2 Pages 389-395  
  Keywords Prairies, Growing seasons, Biomass burning, Root biomass, Plant roots, Grasses, Biomass production, Productivity, Plant ecology, Phenology  
  Abstract The nature of the relationship between grassland

vegetation and frequent natural fires has been dis-

cussed by Sauer (1950), Stewart (1951, 1956),

and Curtis (1959). A number of studies have

shown that frequent fires affect herbage produc-

tion, litter accumulation, and flowering stalk pro-

duction of the burned prairie sites (Curtis and

Partch 1950, Weaver and Rowland 1952, Dix and

Butler 1954, Aikman 1955, Robacker and Miller

1955, Ehrenreich 1957, Kucera and Ehrenreich

1961, and Tester and Marshall 1961). Most in-

vestigations have not considered total energy pro-

duction (biomass and caloric values) but have been

concerned primarily with the effect of fire on bio-

mass. This study examined the effects of burning

and burning frequency on the biomass and caloric

content of shoots, roots, and litter on a recon-

structed prairie site in east-central Illinois.
 
  Call Number Serial 1870  
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