scholarly journals An exploratory study of Nantou Ancient Village revitalisation focusing on visual, cognitive and structural aspects

2021 ◽  
Author(s):  
Jaksa Nikodijevic ◽  
Milica Grujic
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.


2020 ◽  
Vol 5 (1) ◽  
pp. 119-130
Author(s):  
Raúl Rojas ◽  
Farzan Irani

Purpose This exploratory study examined the language skills and the type and frequency of disfluencies in the spoken narrative production of Spanish–English bilingual children who do not stutter. Method A cross-sectional sample of 29 bilingual students (16 boys and 13 girls) enrolled in grades prekindergarten through Grade 4 produced a total of 58 narrative retell language samples in English and Spanish. Key outcome measures in each language included the percentage of normal (%ND) and stuttering-like (%SLD) disfluencies, percentage of words in mazes (%MzWds), number of total words, number of different words, and mean length of utterance in words. Results Cross-linguistic, pairwise comparisons revealed significant differences with medium effect sizes for %ND and %MzWds (both lower for English) as well as for number of different words (lower for Spanish). On average, the total percentage of mazed words was higher than 10% in both languages, a pattern driven primarily by %ND; %SLDs were below 1% in both languages. Multiple linear regression models for %ND and %SLD in each language indicated that %MzWds was the primary predictor across languages beyond other language measures and demographic variables. Conclusions The findings extend the evidence base with regard to the frequency and type of disfluencies that can be expected in bilingual children who do not stutter in grades prekindergarten to Grade 4. The data indicate that %MzWds and %ND can similarly index the normal disfluencies of bilingual children during narrative production. The potential clinical implications of the findings from this study are discussed.


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