scholarly journals Implication of mating on oocyte development in red cotton bug, Dysdercus koenigii (Fabricius, 1775) (Heteroptera: Pyrrhocoridae)

2019 ◽  
Vol 88 (4) ◽  
pp. 333-348
Author(s):  
Kamal Kumar Gupta ◽  
Sunil Kayesth ◽  
Mohd Shazad ◽  
Shailendra Kumar
Keyword(s):  
Adult Development ◽  
Oocyte Development ◽  
Follicular Cells ◽  
Histological Changes ◽  
Squamous Cells ◽  
Stage Of Development ◽  
Initial Stage ◽  
Dysdercus Koenigii ◽  
Further Development ◽  
Old Females

Abstract The ovaries of Dysdercus koenigii are consisted of meroistic telotrophic ovarioles. Each ovariole can be differentiated into tropharium and vitellarium. The tropharium contains stem line oogonia, newly formed oocytes, trophocytes, prefollicular cells and follicular cells. The vitellarium possesses 10-12 developing oocytes. The developing oocytes are connected to the trophocytes, present in the tropharium, by nutritive cords. During premating period, the ovarioles change, resulting in increase the number of oocytes in the vitellarium. The developing oocytes in the initial stage of development are surrounded by columnar follicular cells, which are subsequently changed to cuboidal and squamous cells in a sequence. The process of vitellogenesis was initiated after 48 h of adult development with the appearance of perioocytic space. There was deposition of yolk material at the periphery of oocytes in the ovarioles of 72 h old females. The further development of oocytes and vitellogenesis remained suspended up to 12-14 days in the virgin females. On the other hand, mating stimulates the oocyte development and process of vitellogenesis. There were distinct morphometric and histological changes in the ovarioles as a consequence of mating; dimensions of vitellarium and oocytes of the mated female increased drastically. However, the size of tropharium and number of oocytes present in the vitellarium largely remained unchanged. The process of vitellogenesis also resumed followed by mating stimulus. Therefore, the oocytes were laden with yolk material; at this stage, the surrounded follicular layer is replaced by chorion.

scholarly journals Developmental decisions in Aspergillus nidulans are modulated by Ras activity.

1994 ◽  
Vol 14 (8) ◽  
pp. 5333-5348 ◽  
Author(s):  
T Som ◽  
V S Kolaparthi
Keyword(s):  
Aspergillus Nidulans ◽  
Essential Gene ◽  
Cell Types ◽  
Tube Formation ◽  
Stage Of Development ◽  
Initial Stage ◽  
Concentration Threshold ◽  
High Level ◽  
Multicellular Organisms ◽  
Further Development

To better understand how Ras controls development of multicellular organisms, we have chosen Aspergillus nidulans as a model system. When grown on solid medium, this fungus follows a well-defined program of development, sequentially giving rise to several cell types which produce three distinct structures: vegetative hyphae, aerial hyphae, and the conidiophore structure. Here we describe a ras homolog found in this fungus (Aras) and demonstrate that it is an essential gene that regulates the ordered program of development. We created dominant alleles of this gene and expressed them to different levels in order to vary the ratio of GTP-bound (active) to GDP-bound (inactive) A-Ras protein. When the amount of active Ras is large, nuclear division proceeds, but further development is inhibited at the early step of germ tube formation. At an intermediate level of active Ras, aerial hypha formation is inhibited, while at a low level, conidiophore formation is inhibited. Maintenance of an even lower level of the active Ras is essential for initiation and progression of conidiophore formation, the final stage of development. When the level of active Ras is artificially lowered, each stage of development is initiated prematurely except germination, the initial stage of development. Therefore, the progression of the ordered developmental pathway of A. nidulans is dependent upon an initial high level of active Ras followed by its gradual decrease. We propose that several concentration threshold exist, each of which allows development to proceed to a certain point, producing the proper cell type while inhibiting further development.

Developmental decisions in Aspergillus nidulans are modulated by Ras activity

1994 ◽  
Vol 14 (8) ◽  
pp. 5333-5348
Author(s):  
T Som ◽  
V S Kolaparthi
Keyword(s):  
Aspergillus Nidulans ◽  
Essential Gene ◽  
Cell Types ◽  
Tube Formation ◽  
Stage Of Development ◽  
Initial Stage ◽  
Concentration Threshold ◽  
High Level ◽  
Multicellular Organisms ◽  
Further Development

To better understand how Ras controls development of multicellular organisms, we have chosen Aspergillus nidulans as a model system. When grown on solid medium, this fungus follows a well-defined program of development, sequentially giving rise to several cell types which produce three distinct structures: vegetative hyphae, aerial hyphae, and the conidiophore structure. Here we describe a ras homolog found in this fungus (Aras) and demonstrate that it is an essential gene that regulates the ordered program of development. We created dominant alleles of this gene and expressed them to different levels in order to vary the ratio of GTP-bound (active) to GDP-bound (inactive) A-Ras protein. When the amount of active Ras is large, nuclear division proceeds, but further development is inhibited at the early step of germ tube formation. At an intermediate level of active Ras, aerial hypha formation is inhibited, while at a low level, conidiophore formation is inhibited. Maintenance of an even lower level of the active Ras is essential for initiation and progression of conidiophore formation, the final stage of development. When the level of active Ras is artificially lowered, each stage of development is initiated prematurely except germination, the initial stage of development. Therefore, the progression of the ordered developmental pathway of A. nidulans is dependent upon an initial high level of active Ras followed by its gradual decrease. We propose that several concentration threshold exist, each of which allows development to proceed to a certain point, producing the proper cell type while inhibiting further development.

scholarly journals THE INITIAL STAGE OF DEVELOPMENT OF ACADEMIC ROWING IN THE KATERINOSLAV REGION IN THE LATE XIX – EARLY XX CENTURY: HISTORICAL EXPERIENCE AND TRADITIONS

2021 ◽  
Vol 6 (2) ◽  
pp. 71-86
Author(s):  
Baldzhy Ilona ◽  
Dolbysheva Nina ◽  
Salenko Galina
Keyword(s):  
Physical Culture ◽  
Theoretical Knowledge ◽  
Historical Experience ◽  
Stage Of Development ◽  
Initial Stage ◽  
Archival Documents ◽  
History Of ◽  
Main Factors ◽  
Further Development

At present, in the conditions of decentralization, considerable attention is paid to the study of historical experience and traditions of development of physical culture and sports movement in the regions of Ukraine. Analysis of scientific and methodological literature shows that such studies allow not only to expand theoretical knowledge of the history of physical culture and sports in Ukraine, but also to identify priority sports in the development of programs for the development of physical culture and sports. The aim is to study the historical experience of the development of academic rowing as a sport in the Katerinoslav region in the late XIX – early XX centuries and identifying the main factors that contributed to its further development. Material and methods. During the analysis the analysis and generalization of scientific and methodical literature, historical-logical, chronological, descriptive methods on the basis of studying of periodical, local lore literature, archival documents, photographic materials and other sources were used.

Cytological and Histological Study of Adult and Neonate Epidermis in Thick and Thin Skin of Various Anatomical Sites

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Hydar Muhsin Khalfa ◽  
Adnan Albideri ◽  
Haider Salih Jaffat
Keyword(s):  
Histological Study ◽  
Single Layer ◽  
Sweat Glands ◽  
Anatomical Site ◽  
Basal Cells ◽  
Histological Changes ◽  
Mature Adult ◽  
Skin Development ◽  
Stage Of Development ◽  
Thin Skin

The integumentary system covers the surface of the embryo (skin) and its specialized skin structures including hair, nails, sweat glands, mammary glands and teeth. During fetal skin development, the epidermis changes from a single layer of ectodermal cells at 7–8 days of gestation into a more apparent stratified, keratinized epithelium at 22–24 weeks. The aim of the study is to identify the histological and cytological changes that take place during neonatal and adult epidermis development. Human neonatal and adult samples were obtained from fully informed, consenting parent or releatives from Al-hilla mortary / Iraq. Neonatal samples were obtained from neonates after sudden deaths from maternity wards. Anatomical Sites included abdomen, forehead, back, shoulder and feet sole. A totoal of 15 neonates and 10 mature adults were used for this study. Fresh tissues were sectioned using a freezing cryostat. Tissues were sectioned at 5µm in -24°C and collected on microscopic slides. Slides were allowed to air dry for 30 min prior to hematoxyline and eosin staining. Tissues were also photographed using scanning electron microscopy SEM. Cytological measurements were taken using image j software and data was analysed using graph prism. Various cytological and histological changes takes place during neonatal and adult and epidermis development. Our study shows the stages of fair follicule formation as well as number of nucleated layers present at each stage of development and at different anatomical sites. Major histological changes takes places during the transition frm a neonate to a mature adult including the number of basal cells and epidermal thickness depending on the anatomical site.

Apoptosis within bovine follicular cells and its effect on oocyte development during in vitro maturation

2003 ◽  
Vol 59 (5-6) ◽  
pp. 1421-1433 ◽  
Author(s):  
Annemarie Zeuner ◽  
Karin Müller ◽  
Karen Reguszynski ◽  
Katarina Jewgenow
Keyword(s):  
In Vitro Maturation ◽  
Oocyte Development ◽  
Follicular Cells

scholarly journals Artificial Intelligence to Improve the Business Efficiency and Effectiveness for Enterprises in Kazakhstan

2021 ◽  
pp. 34-41
Author(s):  
Mohamed Hamada ◽  
Daniya Temirkhanova ◽  
Diana Serikbay ◽  
Sanzhar Salybekov ◽  
Saltanat Omarbek
Keyword(s):  
Artificial Intelligence ◽  
Legal Framework ◽  
Legal Aspects ◽  
Stage Of Development ◽  
Initial Stage ◽  
Efficiency And Effectiveness ◽  
Business Efficiency ◽  
Big Picture ◽  
Data Extracting ◽  
Goals And Objectives

The main objective of the research is identifying the effectiveness of artificial intelligence in the business sphere of Kazakhstan. The urgency of this problem is due to the fact that the Kazakhstani market for artificial intelligence is at the initial stage of development. The main obstacle to the introduction of artificial intelligence is the unpreparedness of managers of small and medium-sized businesses for the application of artificial intelligence technologies and, of course, the high cost of their implementation. In the study, we proceeded from the key thesis that business in Kazakhstan is striving for digital transformation. We set a goal to determine the attitude and degree of readiness of Kazakhstani business to the implementation and practical application of artificial intelligence, to describe the cases of using artificial intelligence by Kazakhstani business, to identify the main questions that arise in business at this stage, to study the legal aspects of using artificial intelligence in business and to present the big picture compliance / inconsistency of the existing legal framework with the goals and objectives of the development of artificial intelligence, provide recommendations for eliminatinge xisting barriers and stimulating businesses to implement the technology. Within the framework of this study, the concept of artificial intelligence is defined in its broadest sense - as a set of technologies for processing various types of data and information, in particular those capable of interpreting such data, extracting knowledge and using it to achieve certain goals.

scholarly journals Initial stage of development and migratory behavior of Toxocara canis larvae in BALB/c mouse experimental model

2008 ◽  
Vol 7 (2) ◽  
pp. 444-450 ◽  
Author(s):  
M.L. Camparoto ◽  
B. Fulan ◽  
C.M. Colli ◽  
M.L. Paludo ◽  
A.L. Falavigna-Guilherme ◽  
...  
Keyword(s):  
Experimental Model ◽  
Toxocara Canis ◽  
Migratory Behavior ◽  
Stage Of Development ◽  
Initial Stage

scholarly journals Study on the development of nanotechnology in advanced countries and in Brazil

2009 ◽  
Vol 45 (2) ◽  
pp. 189-200 ◽  
Author(s):  
Carolina Fracalossi Rediguieri
Keyword(s):  
Reference Lists ◽  
Scientific Literature ◽  
Developed Countries ◽  
Public And Private ◽  
Stage Of Development ◽  
Research Institutes ◽  
Initial Stage ◽  
Private Investments ◽  
The World ◽  
The Developed Countries

The study shows how nanotechnology evolves in developed countries and Brazil, raising aspects of private and governmental initiatives. The investigation was based in scientific literature, electronic articles and conference reports. Several sources of literature were used, including electronic databases and reference lists. By this study, it was observed that, although nanotechnology is in initial stage of development all over the world, the developed countries have had growing public and private investments in the area each year. In those countries, there is a concern toward both, the formation of specialists in nanotechnology and the transference of technology developed in universities and research institutes to industry. In Brazil, the study showed that despite the growing concern of investigators, national research centers and financial centers toward the development of the nanotechnology, there is still a need for more investment and formation of area specialists.

Sign in / Sign up

Export Citation Format

Share Document