Memoirs: Observation on the Breeding and Development of the viviparous fish, Heterandria formosa

1940 ◽  
Vol s2-81 (324) ◽  
pp. 479-520
Author(s):  
ELIZABETH A. FRASER ◽  
RACHEL M. RENTON
Keyword(s):  
Early Stage ◽  
Late Development ◽  
Head Region ◽  
Mature Ovum ◽  
Entire Area ◽  
Short Account ◽  
Viviparous Fish ◽  
Large Size ◽  
Noteworthy Feature ◽  
Heterandria Formosa

1. A short account is given of the breeding habits of Heterandria formosa in an aquarium. 2. The ovary and the mature ovum are briefly described, the noteworthy feature of the ripe ovum being the small quantity of yolk. 3. Degeneration of ova is found to be a common occurrence in unfertilized females, and to a less extent in those full of developing embryos. 4. The method for ensuring the fertilization of the egg within the follicle is portrayed. Over the area where the spermatozoa have entered the cells of the ovarian epithelium and those of the follicle form a solid plug which eventually disrupts to enable the fully developed embryo to escape into the cavity of the ovary. 5. It is characteristic of early development that the egg is encircled by a unilaminar ectoderm before there is any visible differentiation into endoderm and mesoderm. 6. Owing to the scarcity of yolk only a few periblast cells arise and no syncytial layer is formed. 7. The primitive-germ cells are visible at an early stage within the apparently undifferentiated mesendoderm cells. 8. A striking feature is the large size of the pericardium and its growth upwards as a pericardium hood which completely surrounds the head region of the embryo. Over the walls runs a network of blood-vessels from which the maternal capillaries become eventually separated by only an attenuated layer of protoplasm. Both respiration and nutrition are effected through the follicle. 9. A remarkable specialization is the development of a urinary bladder which expands into a thin-walled vesicle of enormous dimensions, finally occupying almost the entire area formerly filled by the pericardium and the yolk-granules. 10. The development of Heterandria is compared with that of other viviparous fishes. 11. The significance of the unusual features in early and late development is discussed and some comparisons are made with the conditions in higher vertebrates.

Computational Fluid Dynamic Using Parallel Loop of Multi-Cores Processor

2014 ◽  
Vol 493 ◽  
pp. 80-85 ◽  
Author(s):  
C.L Siow ◽  
Jaswar ◽  
Efi Afrizal
Keyword(s):  
Fluid Flow ◽  
Early Stage ◽  
Fluid Dynamic ◽  
Visual Basic ◽  
Computer Hardware ◽  
Navier Stokes ◽  
Computer Memory ◽  
Large Size ◽  
Computational Fluid Dynamics Cfd ◽  
Reynolds Average

Computational Fluid Dynamics (CFD) software is often used to study fluid flow and structures motion in fluids. The CFD normally requires large size of arrays and computer memory and then caused long execution time. However, Innovation of computer hardware such as multi-cores processor provides an alternative solution to improve this programming performance. This paper discussed loop parallelize multi-cores processor for optimization of sequential looping CFD code. This loop parallelize CFD was achieved by applying multi-tasking or multi-threading code into the original CFD code which was developed by one of the authors. The CFD code was developed based on Reynolds Average Navier-Stokes (RANS) method. The new CFD code program was developed using Microsoft Visual Basic (VB) programming language. In the early stage, the whole CFD code was constructed in a sequential flow before it is modified to parallel flow by using VBs multi-threading library. In the comparison, fluid flow around the hull of round-shaped FPSO was selected to compare the performance of both the programming codes. Besides, executed results of this self-developed code such as pressure distribution around the hull were also presented in this paper.

scholarly journals Giant Complex Odontoma of Mandible: A Spectacular Case Report

2017 ◽  
Vol 11 (1) ◽  
pp. 413-419 ◽  
Author(s):  
Narjiss Akerzoul ◽  
Saliha Chbicheb ◽  
Wafaa El Wady
Keyword(s):  
Case Report ◽  
Early Stage ◽  
Facial Asymmetry ◽  
Growth Potential ◽  
Benign Tumors ◽  
Large Size ◽  
General Dental Practitioner ◽  
Dental Practitioners ◽  
Complex Odontoma ◽  
Well Differentiated

Introduction: Odontomas are considered as benign tumors of odontogenic tissue origin and are more over non-aggressive. They can also be categorized as hamartomas and are a result of developmental malformation of odontogenic tissues. As the name suggests, they are composed of mature tooth substances. They possess limited and slow growth potential and are well differentiated. They can be ectodermal, mesodermal or mixed in origin. Mixed variety may be further divided into compound or complex depending upon their radio-graphical resemblance to the tooth. Compound odontomes are reported to be twice more common than complex odontomes. Among them, complex odontomes are asymptomatic unless they cause bony expansion of the jaws. Case Report: This paper aims to report and discuss a case of complex odontoma with unusually large size leading to gross facial asymmetry. Further this paper will highlight the important information the general dental practitioner must possess to diagnose such lesions at an early stage. Conclusion: Odontomas are benign odontogenic tumors with unusually large size leading to gross facial asymmetry. The general dental practitioners must possess the knowledge and important information to diagnose such lesions at an early stage.

scholarly journals The dynamics of low pay employment in Australia

2015 ◽  
Vol 36 (7) ◽  
pp. 1095-1123 ◽  
Author(s):  
Lixin Cai
Keyword(s):  
Hazard Rate ◽  
Early Stage ◽  
Descriptive Analysis ◽  
Content Type ◽  
Large Size ◽  
Information Gap ◽  
English Speaking ◽  
Low Pay ◽  
Pay Duration

Purpose – The purpose of this paper is to enhance understanding low pay dynamics of Australian employees, with a focus on the determination of low pay duration. Design/methodology/approach – The study draws on a representative longitudinal survey of Australian households to provide empirical findings from both descriptive analysis and econometric modelling. Findings – The results show that workers who have entered low pay from higher pay also have a higher hazard rate of transitioning to higher pay; and those who have entered low pay from non-employment are more likely to return to non-employment. Union members, public sector jobs and working in medium to large size firms tend to increase the hazard rate of transitioning to higher pay, while immigrants from non-English speaking countries and workers with health problems have a lower hazard rate of moving into higher pay. There is some evidence that the longer a worker is on low pay, the less likely he or she is to transition to higher pay. Originality/value – This study addresses an information gap regarding the determination of low pay duration. The findings help identify workers who are at high risk of staying on low pay or transitioning into non-employment and are therefore informative for developing targeted policy to help the low paid maintain employment and/or move up the earnings ladder. The results also suggest that policy intervention should take place at an early stage of a low pay spell.

Superfetation in the viviparous fish Heterandria formosa (Poeciliidae)

2019 ◽  
Vol 280 (5) ◽  
pp. 756-770
Author(s):  
María Guadalupe Guzmán‐Bárcenas ◽  
Mari Carmen Uribe
Keyword(s):  
Viviparous Fish ◽  
Heterandria Formosa

Art Creations of Pramila Giri

2019 ◽  
Vol 6 (1) ◽  
pp. 30-35
Author(s):  
Banshi Shrestha
Keyword(s):  
Women Artists ◽  
Early Stage ◽  
Large Size ◽  
New Concepts ◽  
Art Scene ◽  
Art Forms ◽  
Creative Art ◽  
New Ideas

During the 60s and 70s, various new concepts and trends of European modern arts were slowly and nobly emerging in Nepali Art. Traditional Paubha artists and some senior artists such as Chandraman Singh Maskey, Tej Bahadur Chitrakar were following the conventional grammar, characteristics and themes in their art creations. There were virtually no women artists in the creative art scene. Later Pramila Giri and Shilu Payri along with some other female artists appeared on the art stage with new ideas and concepts of modernity. Artist Giri in her early stage, was also following the conventional approaches, but later she began to experiment and present her new art forms with mythical figures and themes. Her analytical thoughts and search led her to use the various forms, images and symbols of religious and mythical figures of BHAIRAV in her art creations. Thus, she started in presenting the figures and forms plus sculptures on her large size canvas. It was completely a noble approach and presentation. BHAIRAV, a gigantic demonic figure but with all the divine powers is regarded as the incarnation of Lord Shiva. Red, white, blue, black colors are used to represent a chosen incarnation of the Lord. Thus, if the viewers are familiar with the mythical figures of Lord BHAIRAV, it will be easier to understand the use of colours and the presentations of the figures in her art creations.

scholarly journals Optical observations of nonthermal galactic radio sources

1959 ◽  
Vol 9 ◽  
pp. 315-322 ◽  
Author(s):  
R. Minkowski
Keyword(s):  
Early Stage ◽  
Optical Observations ◽  
Type I ◽  
Type Ii ◽  
Cassiopeia A ◽  
Cygnus Loop ◽  
Large Size ◽  
Low Surface Brightness ◽  
The Galaxy ◽  
Galactic Radio

A total of 9 nonthermal sources near the plane of the Galaxy have now been definitely identified with nebulosities. The identifications are well established; positions and sizes of the nebulosities and of the sources are in satisfactory agreement. At least three types of objects can be recognized:1. Remnants of supernovae of type I.2. The Cassiopeia A source, a remnant of a supernova of type II.3. The Cygnus loop and several other large nebulosities which are most likely of similar origin. They also may be remnants of supernovae type II.The large size and the low surface brightness of these objects render their detailed investigation a difficult and time-consuming task. The true picture may emerge slowly, and conclusions drawn at an early stage of the work may have to be discarded as the investigation progresses.

Micro-RNA (miRNA): A biomarker to identify novel compounds in drug discovery and delivery for cancer therapy

2020 ◽  
Vol 17 ◽  
Author(s):  
Gokul Paramasivam
Keyword(s):  
Cancer Therapy ◽  
Early Stage ◽  
Drug Efficacy ◽  
Micro Rna ◽  
Molecular Probe ◽  
The Novel ◽  
Cancer Disease ◽  
Large Size ◽  
Conventional Drug ◽  
Micro Rnas

: Micro-RNAs (miRNA) are short non-coding sequences involved in the biological regulatory process. The miRNA shows a unique expression in diseases resulting in the pathogenesis. Identifying the novel compounds are interesting during this process. The miRNA is a biomarker that helps to find the early stage of cancer disease through pathogenesis. Azobenzene and pyrazole are the novel compounds having a cytotoxic effect on cancer cells. These novel compounds are molecular probe used in breast cancer therapy. The viral-based systems have few limitations such as toxicity and immunogenicity. So, the non-viral based lipoplex and polyplex systems are attractive due to no size limitations for the transfection of micro RNAs. The conventional drug delivery systems are having a large size and low drug efficacy at the target site. The nanoparticles prepared by nanoprecipitation methods are attractive in cancer therapy. Thus, the miRNA acts as a powerful tool and is used to identify the drug target in cancer therapy.

Budding and the Reproductive Cycle of Distaplia

1948 ◽  
Vol s3-89 (7) ◽  
pp. 253-289
Author(s):  
N. J. BERRILL
Keyword(s):  
Early Stage ◽  
Cell Number ◽  
Brood Pouch ◽  
Developmental Cycle ◽  
Differential Growth ◽  
Large Size ◽  
Adhesive Organs ◽  
The Individual ◽  
Tail Muscle ◽  
Great Growth

The complete developmental cycle, sexual and asexual, is described for several species of the ascidian genus, Distaplia. Part I. The cycle of D. rosea is described, from the active larva to the establishment of the first blastozooid generation. Of the four or five buds produced from the larval probud, only one develops, the rest remain abortive. Some larvae are often retained in the colony after the dissolution of the parent zooid and give rise to blastozooids (Text-figs. 1-3). The general morphology of mature zooids is described for D. bermudensis, and their arrangement into typical systems in the colony. Zooids are at first functional males, while the brood-pouch develops later as the first egg in the ovary approaches maturity. The brood-pouch is essentially a loop of the oviduct and does not involve the atrial wall (Text-figs. 4-5). In the gross development of the bud up to the time it becomes functional, the originally spherical bud elongates relatively along its antero-posterior axis but otherwise does not exhibit differential growth. After the functional state is reached, differential growth of the atrial siphon commences and eventually transforms the small circular siphon into the relatively enormous atrial aperture of the mature zooid (Text-figs. 4 and 6). Gonads develop as hermaphrodite structures in buds of D. rosea, D. bermudensis, D. occidentalis, and D. clavata, but as either ovaries or testes alone in D. magnilarva (Text-fig. 7). Part 2. Tadpole larvae of Distaplia vary greatly in size according to the species, but not in organization, the cell number of purely larval structures such as adhesive organs and sensory organs being constant (Text-fig. 8). Cleavage of the egg, in spite of large size and yolk content, is typical of ascidians in general, and shows bilateral patterning comparable with that of Styela and Ciona (Text-fig. 9). There is great growth in the development from the egg to the tadpole stage, though the full number of cells of both the notochord and tail muscle is reached at an early stage, about 40 in the case of the notochord (as in all other ascidians) and over 2,000 tail-muscle cells (the largest number known). In the later development of the tadpole larva, the anterior region bearing the adhesive organ and the ampullae becomes progressively constricted off until it remains attached only by a vascular stolon. The probud is separated from the abdomen at a precise stage in the whole development and subdivides before tadpole development is complete (Text-figs. 10-12). The sensory vesicle contains a typical unicellular otolith and an ocellus consisting of optic pigment cup, layer of retinal cells, and three unicellular lens cells. In the tail the intracellular notochordal vacuoles run together to form a continuous fluid cylinder with the chordal cells forming a limiting sheath. Myofibrillae are continuous from cell to cell in the lateral interfaces of the ectoplasmic regions (Text-fig. 13). Part 3. Contrary to all previous reports, buds are produced by adult zooids and are not confined to the tadpole larva, but they are produced at a different phase of the life-cycle of the individual zooid. After sexual reproduction is complete, the zooids atrophy, their tissues autolysing and becoming phagocytosed in part. All of the zooid degenerates with the exception of the epicardium and surrounding epidermis. This structure actually undergoes extensive elongation, at the close of which the posterior end of the pericardium and enclosing epidermis constricts off as one of two probuds (Text-figs. 14-15). This is essentially the same process, apart from the stage with which it is associated, as occurs in the tadpole larva. In both cases the probud elongates and constricts into two or more definitive buds (Text-figs. 16-17), the smallest of which fail to develop. The formation of hermaphrodite or unisexual gonads depends primarily on the mass of the presumptive gonad tissue segregated at a very early critical period in bud morphogenesis (Text-fig. 18). The process of bud formation is compared with that of the allied genus Colella, and an interpretation very different from that of Brien is presented (Text-fig. 20).

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