Structural Aspects of Indoline-2,3-dione-3-oxime: An Approach towards Experimental and Theoretical Perspectives

2021 ◽  
pp. 99-109
Author(s):  
K. Laxmi
Author(s):  
C. Wiencke ◽  
A. Lauchli

Osmoregulatory mechanisms in algae were investigated mainly from a physiological point of view (KAUSS 1977, HELLEBUST 1976). In Porphyra two osmotic agents, i. e. floridoside/isofloridoside (KAUSS 1968) and certain ions, such as K+ and Na+(EPPLEY et al. 1960) are considered for osmotic balance. Accumulations of ions (particularly Na+) in the cytoplasm during osmotic adaptation is improbable, because the activity of enzymes is generally inhibited by high ionic concentrations (FLOWERS et al. 1977).The cellular organization of Porphyra was studied with special emphasis on the development of the vacuolar system under different hyperosmotic conditions. Porphyra was cultivated at various strengths of the culture medium ASP 12 (PROVASOLI 1961) ranging from normal to 6 times concentrated (6x) culture medium. Por electron microscopy freeze fracturing was used (specimens fixed in 2% glutaraldehyde and incubated in 30% glycerol, preparation in a BALZERS BA 360 M apparatus), because chemical fixation gave poor results.


Author(s):  
Wah Chiu ◽  
David Grano

The periodic structure external to the outer membrane of Spirillum serpens VHA has been isolated by similar procedures to those used by Buckmire and Murray (1). From SDS gel electrophoresis, we have found that the isolated fragments contain several protein components, and that the crystalline structure is composed of a glycoprotein component with a molecular weight of ∽ 140,000 daltons (2). Under an electron microscopic examination, we have visualized the hexagonally-packed glycoprotein subunits, as well as the bilayer profile of the outer membrane. In this paper, we will discuss some structural aspects of the crystalline glycoproteins, based on computer-reconstructed images of the external cell wall fragments.The specimens were prepared for electron microscopy in two ways: negatively stained with 1% PTA, and maintained in a frozen-hydrated state (3). The micrographs were taken with a JEM-100B electron microscope with a field emission gun. The minimum exposure technique was essential for imaging the frozen- hydrated specimens.


Author(s):  
J.R. Parsons ◽  
C.W. Hoelke

The direct imaging of a crystal lattice has intrigued electron microscopists for many years. What is of interest, of course, is the way in which defects perturb their atomic regularity. There are problems, however, when one wishes to relate aperiodic image features to structural aspects of crystalline defects. If the defect is inclined to the foil plane and if, as is the case with present 100 kV transmission electron microscopes, the objective lens is not perfect, then terminating fringes and fringe bending seen in the image cannot be related in a simple way to lattice plane geometry in the specimen (1).The purpose of the present work was to devise an experimental test which could be used to confirm, or not, the existence of a one-to-one correspondence between lattice image and specimen structure over the desired range of specimen spacings. Through a study of computed images the following test emerged.


Author(s):  
C. H. Haigler ◽  
A. W. Roberts

Tracheary elements, the water-conducting cells in plants, are characterized by their reinforced walls that became thickened in localized patterns during differentiation (Fig. 1). The synthesis of this localized wall involves abundant secretion of Golgi vesicles that export preformed matrix polysaccharides and putative proteins involved in cellulose synthesis. Since the cells are not growing, some kind of endocytotic process must also occur. Many researchers have commented on where exocytosis occurs in relation to the thickenings (for example, see), but they based their interpretations on chemical fixation techniques that are not likely to provide reliable information about rapid processes such as vesicle fusion. We have used rapid freezing to more accurately assess patterns of vesicle fusion in tracheary elements. We have also determined the localization of calcium, which is known to regulate vesicle fusion in plant and animal cells.Mesophyll cells were obtained from immature first leaves of Zinnia elegans var. Envy (Park Seed Co., Greenwood, S.C.) and cultured as described previously with the following exceptions: (a) concentration of benzylaminopurine in the culture medium was reduced to 0.2 mg/l and myoinositol was eliminated; and (b) 1.75ml cultures were incubated in 22 x 90mm shell vials with 112rpm rotary shaking. Cells that were actively involved in differentiation were harvested and frozen in solidifying Freon as described previously. Fractures occurred preferentially at the cell/planchet interface, which allowed us to find some excellently-preserved cells in the replicas. Other differentiating cells were incubated for 20-30 min in 10(μM CTC (Sigma), an antibiotic that fluoresces in the presence of membrane-sequestered calcium. They were observed in an Olympus BH-2 microscope equipped for epi-fluorescence (violet filter package and additional Zeiss KP560 barrier filter to block chlorophyll autofluorescence).


1988 ◽  
Vol 19 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Karen E. Pollock ◽  
Richard G. Schwartz

The relationship between syllabic structure and segmental development was examined longitudinally in a child with a severe phonological disorder. Six speech samples were collected over a 4-year period (3:5 to 7:3). Analyses revealed gradual increases in the complexity and diversity of the syllable structures produced, and positional preferences for sounds within these forms. With a strong preference for [d] and [n] at the beginning of syllables, other consonants appeared first at the end of syllables. Implications for clinical management of phonological disorders include the need to consider both structural position and structural complexity in assessing segmental skills and in choosing target words for intervention.


2001 ◽  
Vol 268 (6) ◽  
pp. 1518-1527 ◽  
Author(s):  
Ricardo B. Maccioni ◽  
Carola Otth ◽  
Ilona I. Concha ◽  
Juan P. Munoz

2015 ◽  
Vol 26 (4) ◽  
pp. 207-221
Author(s):  
Wolfgang Mastnak

Abstract. Five overlapping eras or stages can be distinguished in the evolution of music therapy. The first one refers to the historical roots and ethnological sources that have influenced modern meta-theoretical perspectives and practices. The next stage marks the heterogeneous origins of modern music therapy in the 20th century that mirror psychological positions and novel clinical ideas about the healing power of music. The subsequent heyday of music therapeutic models and schools of thought yielded an enormous variety of concepts and methods such as Nordoff–Robbins music therapy, Orff music therapy, analytic music therapy, regulatory music therapy, guided imagery and music, sound work, etc. As music therapy gained in international importance, clinical applications required research on its therapeutic efficacy. According to standards of evidence-based medicine and with regard to clearly defined diagnoses, research on music therapeutic practice was the core of the fourth stage of evolution. The current stage is characterized by the emerging epistemological dissatisfaction with the paradigmatic reductionism of evidence-based medicine and by the strong will to discover the true healing nature of music. This trend has given birth to a wide spectrum of interdisciplinary hermeneutics for novel foundations of music therapy. Epigenetics, neuroplasticity, regulatory and chronobiological sciences, quantum physical philosophies, universal harmonies, spiritual and religious views, and the cultural anthropological phenomenon of esthetics and creativity have become guiding principles. This article should not be regarded as a historical treatise but rather as an attempt to identify theoretical landmarks in the evolution of modern music therapy and to elucidate the evolution of its spirit.


Author(s):  
Christoph Klimmt

This comment briefly examines the history of entertainment research in media psychology and welcomes the conceptual innovations in the contribution by Oliver and Bartsch (this issue). Theoretical perspectives for improving and expanding the “appreciation” concept in entertainment psychology are outlined. These refer to more systematic links of appreciation to the psychology of mixed emotions, to positive psychology, and to the psychology of death and dying – in particular, to terror management theory. In addition, methodological challenges are discussed that entertainment research faces when appreciation and the experience of “meaning for life” need to be addressed in empirical studies of media enjoyment.


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