A New Orthorhombic Ba8Co7O21 Phase: Polymorphism in the (Ba3Co2O6)α(Ba3Co3O9)β System

2000 ◽  
Vol 151 (1) ◽  
pp. 77-84 ◽  
Author(s):  
K. Boulahya ◽  
M. Parras ◽  
J.M. González-Calbet ◽  
A. Vegas
Keyword(s):  
Phase Polymorphism

Phase polymorphism of novel [Ru(NH3)6](ClO4)3—Comparison with [Ru(NH3)6](BF4)3. Part II

2013 ◽  
Vol 204 ◽  
pp. 233-244 ◽  
Author(s):  
Diana Dołęga ◽  
Edward Mikuli ◽  
Natalia Górska ◽  
Akira Inaba ◽  
Krystyna Hołderna-Natkaniec ◽  
...  
Keyword(s):  
Phase Polymorphism

scholarly journals One hundred years of phase polymorphism research in locusts

2021 ◽  
Vol 207 (3) ◽  
pp. 321-326
Author(s):  
Hans-Joachim Pflüger ◽  
Peter Bräunig
Keyword(s):  
Basic Research ◽  
Short Review ◽  
Phase Polymorphism

AbstractOne hundred years ago in 1921, Sir Boris Uvarov recognized that two locust species are one species but appearing in two different phases, a solitarious and a gregarious phase. As locust swarms are still a big problem affecting millions of people, basic research has tried to understand the causes for the transition between phases. This phenomenon of phase polymorphism, now called polyphenism, is a very complex multifactorial process and this short review will draw attention to this important aspect of insect research.

Assessment

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Evolutionary Biology ◽  
Developmental Plasticity ◽  
Phenotypic Traits ◽  
Phase Polymorphism ◽  
Aesthetic Sense ◽  
Adaptive Assessment ◽  
Important Barrier ◽  
Symbiotic Microorganism ◽  
Adaptive Developmental Plasticity ◽  
Adaptive Switch

A book on developmental plasticity needs a chapter on assessment, if only to show that adaptive environmental assessment occurs. Skepticism regarding the ability of nonhuman organisms to assess conditions well enough to make adaptive decisions has a long history in evolutionary biology, and it has been an important barrier to understanding the evolution of adaptive developmental plasticity. It is worth briefly reviewing this history in order to understand certain preconceptions about assessment that still persist. In the nineteenth century, critics of Darwin’s theory of sexual selection (Darwin, 1871) balked at the idea of an “aesthetic sense” in lowly creatures that would enable female choice of mates (representative papers are reprinted and discussed in Bajema, 1984). Later, the barrier persisted for other reasons. Even though naturalists routinely used the condition-appropriate expression of phenotypic traits to support adaptation hypotheses—a practice that assumes adaptive assessment of conditions as it is defined here—theoretically inclined biologists paid little attention to the question of facultatively expressed traits. Part of the difficulty lay in the problem of explaining how adaptive assessment could evolve within the framework of conventional genetics. Theodosius Dobzhansky, one of the twentieth century’s leading evolutionary biologists, acknowledged this unresolved problem in remarks following a lecture by J. S. Kennedy on the phase polyphenisms of migratory locusts (Kennedy, 1961). Dobzhansky referred to the “challenge to a geneticist” of explaining the adaptive switch between the sedentary and the migratory phenotypes of the locusts, which had been shown to be largely independent of genotype. He suggested that an extrachromosomal factor may be involved, a symbiotic microorganism that acts as a “plasmagene” whose multiplication would eventually stimulate phase change. Although Dobzhansky’s proposal was no more preposterous than some of the regulatory devices that have actually been discovered, Kennedy (1961) minced no words in his reply to this suggestion: . . . [W]e need not feel obliged to invoke a second organism to explain [phase polymorphism] unless we are reluctant to concede an important part to the environment as well as to heredity in moulding development. . . .

scholarly journals Phase Polymorphism of [Co(DMSO)6](BF4)2 Studied by Differential Scanning Calorimetry

2006 ◽  
Vol 61 (3-4) ◽  
pp. 180-188 ◽  
Author(s):  
Anna Migdał-Mikuli ◽  
Łukasz Skoczylas ◽  
Elżbieta Szostak
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transitions ◽  
Melting Point ◽  
Title Compound ◽  
Metastable Phases ◽  
Scanning Calorimetry ◽  
Phase Polymorphism ◽  
Solid Phases ◽  
High Degree ◽  
Dynamical Disorder

Five solid phases of [Co(DMSO)6](BF4)2 have been detected by differential scanning calorimetry (DSC). Phase transitions were detected between the following solid phases: stable KIb↔ stable KIa at T̅C4 = (328±2) K, metastable KIII ↔ undercooled phase K0 at T̅C3 = (383±4) K, metastable KII ↔ undercooled K0 at T̅C2 = (399±2) K and stable KIa ↔ stable K0 at T̅C1 = (404±1) K. The title compound melts at Tm = 440 K. From the entropy changes at the melting point and at phase transitions it can be concluded that the phases K0 and undercooled K0 are orientationally dynamically disordered crystals. The stable phases KIa, KIb are ordered solid phases. The metastable phases KII and KIII are probably solid phases with a high degree of orientational dynamical disorder

Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH3)6](BF4)3. Part I

2013 ◽  
Vol 197 ◽  
pp. 429-439 ◽  
Author(s):  
Diana Dołęga ◽  
Edward Mikuli ◽  
Akira Inaba ◽  
Natalia Górska ◽  
Krystyna Hołderna-Natkaniec ◽  
...  
Keyword(s):  
Structural Investigations ◽  
Phase Polymorphism

Physical properties of glycosyldiacylglycerols: an infrared spectroscopic study of the gel-phase polymorphism of 1,2-di-O-acyl-3-O-(.beta.-D-glucopyranosyl)-sn-glycerols

Biochemistry ◽  
1990 ◽  
Vol 29 (38) ◽  
pp. 8933-8943 ◽  
Author(s):  
Ruthven N. A. H. Lewis ◽  
David A. Mannock ◽  
Ronald N. McElhaney ◽  
Patrick T. T. Wong ◽  
Henry H. Mantsch
Keyword(s):  
Physical Properties ◽  
Spectroscopic Study ◽  
Infrared Spectroscopic Study ◽  
Phase Polymorphism ◽  
Infrared Spectroscopic ◽  
Gel Phase

Phase polymorphism and thermal stability of new cholesterol thioesters derivatives

2015 ◽  
Vol 42 (10) ◽  
pp. 1405-1418 ◽  
Author(s):  
Magdalena Ordon ◽  
Arkadiusz Rudzki ◽  
Ewa Juszyńska-Gałązka ◽  
M.D. Ossowska-Chruściel ◽  
Wojciech Zając ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phase Polymorphism ◽  
Thermal Stability Of
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