Prosodic Constraints on Morphological Development

2001 ◽  
pp. 3-21 ◽  
Author(s):  
Katherine Demuth
Keyword(s):  
Morphological Development

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

1995 ◽  
Vol 53 ◽  
pp. 978-979
Author(s):  
G. M. Hutchins ◽  
J. S. Gardner
Keyword(s):  
Growth And Development ◽  
Furfuryl Alcohol ◽  
Apical Meristem ◽  
Plant Cells ◽  
Triticum Aestivum L ◽  
Morphological Development ◽  
Naturally Occurring ◽  
Chinese Spring Wheat ◽  
Sem Study ◽  
Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

Intestinal microbiota balance modulates host susceptibility to infection with enteric pathogenss

2007 ◽  
Vol 30 (4) ◽  
pp. 93
Author(s):  
I Sekirov ◽  
N Tam ◽  
M Robertson ◽  
C Lupp ◽  
B Finlay
Keyword(s):  
Intestinal Microbiota ◽  
Small Animal ◽  
Host Susceptibility ◽  
Morphological Development ◽  
Future Design ◽  
Susceptibility To Infection ◽  
Colonic Microbiota ◽  
Food Borne ◽  
Serovar Typhimurium ◽  
Intestinal Pathogens

Background: During our lifetimes we develop a very complex set of interactions with the multitude of microorganisms colonizing our bodies. In the gastrointestinal system, the microbiota is highly important for morphological development, nutrition, and protection against infectious diseases. The gastrointestinal pathogens, enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) and Salmonella enterica serovar Typhimurium (ST) are food-borne pathogens that cause much morbidity and mortality worldwide. Citrobacter rodentium (Cr) is a mouse pathogen that is used in small animal models to mimic EHEC and EPEC infections. Methods: We began to characterize the contribution of intestinal microbiota to the progression of these infections. Two main phyla comprise the majority of mouse intestinal microbiota: Bacteroidetes and Firmicutes. Bacteria from a number of additional phyla are also present in smaller numbers; among them γ-Proteobacteria class, belonging to Proteobacteria phylum, is note-worthy as this class harbours many intestinal pathogens, such as ST and Cr. The mouse intestinal microbiota was perturbed using tetracycline (Tet) and streptomycin (Sm) to increase the proportion of Bacteroidetes in the colonic microbiota, and using vancomycin (Vanc) to create a predominance of Firmicutes. The mice with this perturbed microbiota were infected with ST to investigate the resultant pathology and virulence characteristics, and any additional shifts in microbiota as a result of infection. Results: Treatment of mice with Sm and Vanc was found to decrease the resistance of mice to colonization with ST, while Tet-treated mice exhibited unchanged colonization resistance. Treatment of mice with gradually increasing doses of Sm, which gradually augmented the proportion of CFB bacteria in the microbiota, resulted in progressively increasing colonization of mice by ST, as well as a step-wise increase in the ST-induced typhlitis, associated with higher levels of inflammatory markers IL-6 and KC. The increasing levels of ST colonization following both Sm and Vanc treatment were associated with an increase in the proportion of γ-Proteobacteria in the cecal and colonic microbiota, as well as a decrease in the total bacterial numbers in both organs. Conclusions: It is evident that the intestinal microbiota plays a significant role in the host’s response to infection with enteric pathogens, and its composition and numbers are also affected by the offending bacteria. Elucidation of the details regarding the contribution of the microbiota to infectious disease progression will offer novel targets for the future design of superior prevention and treatment methods.

scholarly journals Effectiveness of Push–Pull Systems to Fall Armyworm (Spodoptera frugiperda) Management in Maize Crops in Morelos, Mexico

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 298
Author(s):  
Ouorou Ganni Mariel Guera ◽  
Federico Castrejón-Ayala ◽  
Norma Robledo ◽  
Alfredo Jiménez-Pérez ◽  
Georgina Sánchez-Rivera ◽  
...  
Keyword(s):  
Spodoptera Frugiperda ◽  
Insect Pest ◽  
Fall Armyworm ◽  
Maize Yield ◽  
Morphological Development ◽  
Main Method ◽  
Development Of Resistance ◽  
Pull Systems ◽  
Complex Scenario ◽  
Block Experiment

Chemical control is the main method used to combat fall armyworm in maize crops. However, its indiscriminate use usually leads to a more complex scenario characterized by loss of its effectiveness due to the development of resistance of the insect pest, emergence of secondary pests, and reduction of the populations of natural enemies. For this reason, efforts to develop strategies for agroecological pest management such as Push–Pull are increasingly growing. In this context, the present study was carried out to evaluate field effectiveness of Push–Pull systems for S. frugiperda management in maize crops in Morelos, Mexico. In a randomized block experiment, the incidence and severity of S. frugiperda, the development and yield of maize were evaluated in nine Push–Pull systems and a maize monoculture. The Push–Pull systems presented incidence/severity values lower than those of the monoculture. Morphological development and maize yield in the latter were lower than those of most Push–Pull systems. Mombasa—D. ambrosioides, Mulato II—T. erecta, Mulato II—C. juncea, Tanzania—T. erecta and Tanzania—D. ambrosioides systems presented higher yields than those of monocultures.

scholarly journals Genetic Involvement of a cAMP-Dependent Protein Kinase in a G Protein Signaling Pathway Regulating Morphological and Chemical Transitions in Aspergillus nidulans

Genetics ◽  
2001 ◽  
Vol 157 (2) ◽  
pp. 591-600
Author(s):  
Kiminori Shimizu ◽  
Nancy P Keller
Keyword(s):  
Protein Kinase ◽  
Aspergillus Nidulans ◽  
Signaling Pathway ◽  
G Protein ◽  
Radial Growth ◽  
Morphological Development ◽  
Dependent Protein Kinase ◽  
Α Subunit ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein

Abstract In the filamentous fungus Aspergillus nidulans, a heterotrimeric G protein α-subunit and an RGS domain protein, encoded by fadA and flbA, respectively, regulate production of the carcinogenic metabolite sterigmatocystin (ST) and asexual spores (i.e., conidia). We investigated the genetic involvement of the cAMP-dependent protein kinase catalytic subunit (PkaA), a potential downstream target of FadA activity, in ST production and conidiation. Relative to wild type, sporulation was decreased in the pkaA overexpression strain but was not totally absent, as occurs in ΔflbA or fadAG42R (fadA-dominant active) strains. Deletion of pkaA resulted in a hyper-conidiating strain with limited radial growth. This phenotype was epistatic to mutation in flbA or fadA; the double mutants ΔpkaA; ΔflbA and ΔpkaA; fadAG42R recovered sporulation and their radial growth was severely restricted. PkaA overexpression also negatively regulated AflR, the ST biosynthesis-specific transcription factor, both transcriptionally and post-transcriptionally. Deletion of pkaA restored ST production in the ΔflbA background but not in the fadAG42R background. These data provide genetic evidence that the FlbA/FadA signaling pathway regulating ST production and morphological development is partially mediated through PkaA.

scholarly journals Overexpression of arginine decarboxylase in transgenic plants

1997 ◽  
Vol 325 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Daniel BURTIN ◽  
Anthony J. MICHAEL
Keyword(s):  
Transgenic Plants ◽  
Arginine Decarboxylase ◽  
Polyamine Metabolism ◽  
Morphological Development ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Two Generations ◽  
Key Enzyme ◽  
Polyamine Conjugate ◽  
And Control

The activity of arginine decarboxylase (ADC), a key enzyme in plant polyamine biosynthesis, was manipulated in two generations of transgenic tobacco plants. Second-generation transgenic plants overexpressing an oat ADC cDNA contained high levels of oat ADC transcript relative to tobacco ADC, possessed elevated ADC enzyme activity and accumulated 10–20-fold more agmatine, the direct product of ADC. In the presence of high levels of the precursor agmatine, no increase in the levels of the polyamines putrescine, spermidine and spermine was detected in the transgenic plants. Similarly, the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase were unchanged. No diversion of polyamine metabolism into the hydroxycinnamic acid–polyamine conjugate pool or into the tobacco alkaloid nicotine was detected. Activity of the catabolic enzyme diamine oxidase was the same in transgenic and control plants. The elevated ADC activity and agmatine production were subjected to a metabolic/physical block preventing increased, i.e. deregulated, polyamine accumulation. Overaccumulation of agmatine in the transgenic plants did not affect morphological development.

Initiation, Development and Anatomy of Lignotubers in Some Species of Eucalyptus

1984 ◽  
Vol 32 (4) ◽  
pp. 415 ◽  
Author(s):  
DJ Carr ◽  
R Jahnke ◽  
SGM Carr
Keyword(s):  
Analytical Study ◽  
Growth Habit ◽  
Stem Growth ◽  
Morphological Development ◽  
Alternative Pathways ◽  
Stem Wood ◽  
Initial Survey ◽  
And Performance ◽  
Lateral Fusion ◽  
Taxonomic Groups

An initial survey of the diversity of early lignotuber development in Eucalyptus and an analytical study of the anatomy of young lignotubers and the seedling stem are presented. Studies of the early stages of the morphological development of the lignotuber in 13 species, representative of five taxonomic groups, resulted in the recognition of four modes of lignotuber initiation. The importance to lignotuber formation of the presence of a suite of accessory buds, adaxial to the axillary bud, is emphasized but lignotuber initiation is not in all cases associated with these buds. Lignotuber buds are derived by branching from existing buds, ultimately from the accessory buds of the node. Following its initiation, the possibilities of later morphological development of the lignotuber are discussed. Lignotuber growth may dominate over stem growth and the lignotubers at a node may then fuse laterally to encircle the stem. Stem growth, on the other hand, may dominate over lignotuber growth and the lignotuber then appears to regress. The consequences for the growth habit of the plant of these alternative pathways of development are outlined. The wood of young lignotubers (and that of the swollen hypocotyl) is shown to be different in composition and in the sizes of its elements from that of seedling stem wood; these differences owe their origin to differences in the nature and performance of the cambia of the lignotuber and stem. In lateral fusion of the lignotubers at a node, and their upward and downwards extension over the stem, e.g. over the hypocotyl, stem cambial initials are either progressively lost or, more likely, converted to lignotuber-type initials. The possibility of the reverse process occumng in stem dominance is discussed.

Effects of maternal and post-weaned rumen-protected folic acid supplementation on slaughter performance and meat quality in the offspring lambs

2020 ◽  
pp. 1-28
Author(s):  
H.Q. Li ◽  
B. Wang ◽  
Z. Li ◽  
H.L. Luo ◽  
C. Zhang ◽  
...  
Keyword(s):  
Folic Acid ◽  
Gastrointestinal Tract ◽  
Meat Quality ◽  
Maternal Diet ◽  
Folic Acid Supplementation ◽  
The Body ◽  
Morphological Development ◽  
Muscle Area ◽  
Eye Muscle ◽  
Slaughter Performance

Abstract This study was undertaken to evaluate the influence of rumen-protected folic acid (RPFA) on slaughter performance, visceral organ and gastrointestinal tract coefficients, and meat quality in lambs. Sixty-six lambs from 120 Hu ewes were selected based on body weight and maternal diets, and then assigned to six groups using a randomized block experimental design in a 3 × 2 factorial arrangement. The first factor was folic acid (FA) as RPFA in the maternal diet (0 mg/kg [M0F], 16 mg/kg [M16F] or 32 mg/kg [M32F] on dry matter basis). The second factor was FA in the lambs’ diet from weaning until slaughter (0 mg/kg [OC] or 4.0 mg/kg [OF]). The results indicated that the addition of 16 mg/kg FA to the maternal diet increased pre-slaughter weight (PSW), dressing and meat percentage, the reticulum and omasum coefficients, length of the jejunum and ileum, tail fat and perirenal fat coefficient and a* value of the meat color. The addition of RPFA to the lambs’ diet increased PSW, dressing and meat percentage, eye muscle area, abomasum weight, weight and length of the small intestine, but reduced the coefficients of tail fat. A M×O interaction was observed for the weights of heart, lungs, rumen and total stomach, weight and coefficient of omental fat and the GR value. Collectively, RPFA in the maternal and lambs’ diet improved slaughter performance and meat quality by stimulating the morphological development of the gastrointestinal tract and the distribution of fat in the body.

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