Search Results - (Author, Cooperation:J. Hackney)

2012-09-18

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Basic-Leucine Zipper Transcription Factors/metabolism ; Cell Differentiation/genetics ; Chromatin Immunoprecipitation ; Humans ; Immunomodulation/*genetics ; Interferon Regulatory Factors/*metabolism ; Mice ; Mice, Inbred C57BL ; *Regulatory Elements, Transcriptional ; Th17 Cells/*immunology ; Transcription Factor AP-1/*metabolism ; *Transcriptional Activation

2014-04-18

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Autoimmunity/genetics ; Bone Marrow Cells/cytology ; Central Nervous System/metabolism/pathology ; Encephalomyelitis, Autoimmune, Experimental/*immunology/*metabolism/pathology ; Endoplasmic Reticulum/enzymology/metabolism ; Escherichia coli/*immunology ; Female ; Inflammation/immunology/metabolism/pathology ; Listeria monocytogenes/*immunology ; Macrophages/cytology/enzymology/immunology/metabolism ; Male ; Mice ; NADPH Oxidase/metabolism ; Oxidation-Reduction ; Oxidative Stress ; Phagocytes/cytology/immunology/metabolism ; Proteins/genetics/*metabolism ; Reactive Oxygen Species/*antagonists & inhibitors/metabolism

0003-9861

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

1432-2048

Alginate ; Cellulose ; Cell wall ; Crystalline allomorphs ; Hydrodynamics ; Phaeophyta

Springer Online Journal Archives 1860-2000

Biology

Abstract To test whether secondary and tertiary structures of marine-algal structural polysaccharides may be altered during adaptive responses to hydrodynamic stresses, juvenile Egregia menziesii (Turn.) Aresch. sporophytes were cultured under three different regimes: (i) low-energy (LE) specimens were subjected to water motion produced by standard bubbling and circulation of tank water; (ii) high-energy (HE) specimens received additional movement in pumped streams of water; and (iii) stretched (STR) specimens were grown under low-energy conditions but also were subjected to constant, longitudinal tension (0.7 N). After 6–10 weeks growth, cell-wall structural polysaccharides from specimen blades were isolated by solubilizing less-ordered matrix polysaccharides. Neutral-sugar and uronic acid contents of these isolates were measured, and samples were analyzed by x-ray diffraction and by Raman and 13C-nuclear magnetic resonance (NMR) spectroscopy. On average, structural polysaccharides formed about 7.2% of dry-weight biomass. The portion of isolated mass accountable to neutral sugars ranged from an average of 85% for STR sporophytes to 94% for both LE and HE specimens. For all specimens, glucose composed an average of 99% of this fraction. Uronic acids could not be detected in isolates from any treatment group. Cellulose dominance in each isolate was indicated clearly in x-ray diffraction patterns and in Raman and 13C-NMR spectra. These data further demonstrated that both the cellulose I allomorph and the disordered form of the polymer were present in each isolate and that the STR isolate contained small quantities of the cellulose II allomorph. In general, the LE and HE samples had very similar crystallinity; lateral order was slightly more developed in LE samples. However, the STR treatment produced cellulose with lowest crystallinity and least lateral order. Results suggest that mechanical stress modified cellulose crystallinity in these kelps by altering levels of disordered cellulose and lateral dimensions of cellulose crystallites and, in one instance, changed the crystallinity qualitatively. Physical disturbances to cell plasma membranes may have instigated these trends. In the STR specimens in particular, such disturbances might have been supplemented by fundamental changes to kelp physiology, affecting both substantial decreases in crystallinity and production of the cellulose II allomorph. Changes in the nature of the cellulose cannot, however, account for changes in the elastic moduli.

Electronic Resource

1432-1793

Springer Online Journal Archives 1860-2000

Biology

Abstract In studies conducted from 1982 to 1983, productivity (14C uptake) of a coral reef algal-turf assemblage was unaffected by oxygen concentration but decreased when pH rose, probably in response to declining CO2 and HCO 3 - supplies. Release of prefixed 14C was substantially lower in the light than in the dark and was unaffected by oxygen concentration. Release of organic prefixed 14C was greater in the light than in darkness. Total CO2 compensation-points were low, showing no consistent response to oxygen or the photorespiratory inhibitor alpha-hydroxy-2-pyridine-methanesulfonic acid (HPMS). Oxygen has little if any influence upon turf productivity, which was high in comparison to other benthic algae. Decreases in net carbon-fixation rates of this turf more likely result from decreased photosynthesis than increased photorespiration, which is either not significant in turf metabolism under natural conditions or is compensated by efficient refixation of respired carbon.

Electronic Resource

0006-3592

biopdegradation ; cellulose ; crystallinity ; x-ray diffraction ; Chemistry ; Biochemistry and Biotechnology

Wiley InterScience Backfile Collection 1832-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

Chemical treatments similar to those routinely used to extract cellulose from plant biomass caused significant increases in the relative crystallinity index (RCI) of Sig-macell 100 (a commercial cellulose of moderate crystallinity), as measured by x-ray powder diffraction in both the reflectance and transmittance modes. In general, the largest increases in RCI were observed following higher (rather than lower) temperature treatments. Substantial increases in crystalliity were also observed upon resuspension in water prior to drying, with higher temperatures again resulting in the greatest increases in RCI. Measurement of the RCIs of wetted Sigmacell 100 samples by acid hydrolysis kinetics revealed that most of the increased crystallinity occurred rapidly upon contact with water. In contrast to Sigmacell 100, a cellulose of higher initial crystallinity (the microcrystalline cellulose Sigmacell 50) showed little change in crystallinity following the above treatments. The results provide a partial explanation for the inconsistent relationships reported between cellulose crystallinity and cellulose biodegradation. © 1995 John Wiley & Sons, Inc.

2 Ill.

Electronic Resource