scholarly journals Insight into the relationship of chlorophyll a fluorescence yield to the concentration of its natural quenchers in oxygenic photosynthesis.

1993 ◽  
Vol 90 (16) ◽  
pp. 7466-7469 ◽  
Author(s):  
V. P. Shinkarev ◽  
Govindjee
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


2019 ◽  
Vol 58 (2) ◽  
pp. 249-259
Author(s):  
Joseph Acquisto

This essay examines a polemic between two Baudelaire critics of the 1930s, Jean Cassou and Benjamin Fondane, which centered on the relationship of poetry to progressive politics and metaphysics. I argue that a return to Baudelaire's poetry can yield insight into what seems like an impasse in Cassou and Fondane. Baudelaire provides the possibility of realigning metaphysics and politics so that poetry has the potential to become the space in which we can begin to think the two of them together, as opposed to seeing them in unresolvable tension. Or rather, the tension that Baudelaire animates between the two allows us a new way of thinking about the role of esthetics in moments of political crisis. We can in some ways see Baudelaire as responding, avant la lettre, to two of his early twentieth-century readers who correctly perceived his work as the space that breathes a new urgency into the questions of how modern poetry relates to the world from which it springs and in which it intervenes.


2015 ◽  
Vol 130 (1) ◽  
pp. 25-31 ◽  
Author(s):  
S Degeest ◽  
P Corthals ◽  
I Dhooge ◽  
H Keppler

AbstractObjective:This study aimed to determine the characteristics of tinnitus and tinnitus-related variables and explore their possible relationship with tinnitus-related handicap.Methods:Eighty-one patients with chronic tinnitus were included. The study protocol measured hearing status, tinnitus pitch, loudness, maskability and loudness discomfort levels. All patients filled in the Tinnitus Sample Case History Questionnaire, the Hyperacusis Questionnaire and the Tinnitus Handicap Inventory. The relationship of each variable with the Tinnitus Handicap Inventory score was evaluated by univariate and multivariate analyses.Results:Five univariables were associated with the Tinnitus Handicap Inventory score: loudness discomfort level, subjective tinnitus loudness, tinnitus awareness, noise intolerance and Hyperacusis Questionnaire score. Multiple regression analysis showed that the Hyperacusis Questionnaire score and tinnitus awareness were independently associated with the Tinnitus Handicap Inventory score.Conclusion:Hyperacusis and tinnitus awareness were independently associated with the Tinnitus Handicap Inventory score. Questionnaires on tinnitus and hyperacusis are especially suited to providing additional insight into tinnitus-related handicap and are therefore useful for evaluating tinnitus patients.


2017 ◽  
Vol 49 (3) ◽  
pp. 382-399 ◽  
Author(s):  
JOSHUA BERNING ◽  
ADAM N. RABINOWITZ

AbstractWe examine the relationship of product characteristics of ready-to-eat breakfast cereal and targeted television advertising to specific consumer segments. We compile a unique data set that includes brand-packaging characteristics, including on-box games, nutrition information, and cobranding. We find that the relationship of television advertising and a cereal's brand-packaging characteristics varies by target audience. Our results provide insight into understanding how manufacturers strategically utilize branding, packaging, and television advertising. This can help industry and policy makers develop food product advertising policy. This analysis extends to other product markets where extensive product differentiation and promotion are present as well.


Micron ◽  
2017 ◽  
Vol 102 ◽  
pp. 88-96 ◽  
Author(s):  
Daniele Borin ◽  
Luca Puzzi ◽  
Valentina Martinelli ◽  
Matteo Cibinel ◽  
Romano Lapasin ◽  
...  

1985 ◽  
Vol 73 (1) ◽  
pp. 299-310
Author(s):  
J.S. Hyams

Axonemes from the heterosporous water fern Marsilea vestita were fixed in the presence of tannic acid and examined by thin-section electron microscopy. Transverse sections revealed the normal 9+2 configuration except for the absence of the outer of the two dynein arms. Both arms were normally preserved in parallel preparations of Chlamydomonas axonemes. Isolated dynein from the ciliated protozoon Tetrahymena bound to Marsilea axonemes at the site normally occupied by the outer arm. Dynein binding was partially reversed by ATP as judged by both electron microscopy and polyacrylamide gel electrophoresis. This system should provide a valuable insight into the biochemistry and function of the inner dynein arm and the relationship of the two arms to motility in more conventionally equipped axonemes.


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