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Stem Cell Biology: An Overview
Published in Jyoti Ranjan Rout, Rout George Kerry, Abinash Dutta, Biotechnological Advances for Microbiology, Molecular Biology, and Nanotechnology, 2022
A sperm fuses with an ovum to form a single-celled zygote that later forms an embryo. This division goes on till an entire organism is formed consisting of billions of specific cells arranged in an orderly fashion to perform specific tasks. All these specific cells arose from a single-celled zygote, a totipotent stem cell with the potential to form any kind of cells. The importance of stem cells lies in the fact that these are the only cells in the body with the ability to generate all other cells. Historical timeline of stem cell research can be dated back to 1962 when Sir John Gurdon successfully generated tadpoles from an enucleated frog egg cell transplanted with intestinal epithelial somatic cell nucleus without fertilization. This method was termed as somatic cell nuclear transfer (SCNT) (Gurdon, 1962). Using the same SCNT method, Sir Ian Wilmut cloned Dolly in 1997 (Wilmut et al., 1997). These two scientific endeavors proved the notion that a somatic cell nucleus contains all the essential information needed to generate the whole organism and the egg cell possesses enough factors necessary for the reprogramming of the somatic cell. Table 12.1 shows the historical timeline of stem cell research.
Introduction to Anatomy and Physiology
Published in Reginald L. Campbell, Roland E. Langford, Terry L. McArthur, Fundamentals of Hazardous Materials Incidents, 2020
Reginald L. Campbell, Roland E. Langford, Terry L. McArthur
Female sex cells are called eggs or ova (singular: ovum) and are formed in the female gonads, the ovaries. The eggs are formed by a process initially quite similar to that producing sperm. The immature cell divides by mitosis but, unlike the sperm, into two unequal-sized cells, with one receiving almost all the cellular material. A second division of the larger cells produces another unequal division, with the larger body becoming the egg and the other, like the first smaller cell, not involved in reproduction.
Radiation and man
Published in R.J. Pentreath, Nuclear Power, Man and the Environment, 2019
In this case there is first of all a cell division in which two daughter cells are formed, each of which has only half the original number of chromosomes – although each chromosome consists of a rearrangement of two chromatids. The two daughter cells immediately divide again, normally, thus ultimately producing four gamete cells each of which has, in the case of man, 23 single chromosomes. Fertilization of one ovum by one sperm produces a cell, the zygote, which therefore has a full complement of 46 chromosomes.
Thermal analysis on electromagnetic regulated peristaltic blood-based graphane/diamond nanofluid flow with entropy optimization
Published in Numerical Heat Transfer, Part B: Fundamentals, 2023
Sridhar Vemulawada, Prakash Jayavel, Anjali Verma, Kaouther Ghachem, Lioua Kolsi, Katta Ramesh
In view of the above mentioned literature, the nanofluid flows through peristalsis have significant role in drug delivery systems, and the situations can be found in movement of sperm, ovum transport and blood circulation. As per the authors knowledge, no study has been made on heat transfer and entropy production for electroosmotic flow via a non-symmetric channel by considering couple stress nanofluid and convective boundary conditions. In particular, there is a paucity of literature that deals with entropy generation and electromagnetic-hydrodynamics (EMHD) on peristaltic motion in an asymmetric channel. In view of this, the current research focusses on the effect of radiation, electromagnetohydrodynamics, entropy generation, and slip and convective boundary conditions on the peristaltic flow of nanofluid in an asymmetric channel. The governing nonlinear equations are simplified by approximating with large wavelength and small Reynolds number. In addition, the standard perturbation method is used to solve these equations. The effects of a variety of physical characteristics, including velocity, energy, and entropy generation, are investigated, and a graphical representation of the findings is provided for clarity.
Theoretical investigation of double diffusion convection of six constant Jeffreys nanofluid on waves of peristaltic with induced magnetic field: a bio-nano-engineering model
Published in Waves in Random and Complex Media, 2022
Safia Akram, Maria Athar, Khalid Saeed, Alia Razia, Taseer Muhammad
Now the significant rise in the research interest of the peristaltic flows of Newtonian and non-Newtonian fluids can be attributed to its practical implications in industry and medicine. Human physiological mechanism is one of the examples of the said phenomena. Spontaneous compression and expansion of any tube or channel’s wall is called peristalsis. In human tubular structures or organs such as the gastrointestinal tract, small & large intestine, etc. fluid movement is due to peristalsis. In the movement of food emulsion along the gastrointestinal tract, waste excretion through excretory system, blood circulation in arteries, lymph transportation of lymphatic system, ovum & sperm transmission in fallopian tube & sperm ducts respectively, are all peristaltic movements. This phenomenon is used in designing medical instruments such as dialysis machines, pumping devices for medical procedures, lung heart pumps, etc. Propelling movements of worms are also involving peristalsis. Moreover, in industries pumping devices are designed on the same principle, for instance pumps to drain toxic fluids. Due to its extensive application, researchers are involved in examining the problems of peristaltic transport with non-Newtonian fluids [6–12].
Canada’s forced birth travel: towards feminist indigenous reproductive mobilities
Published in Mobilities, 2020
Jaime Cidro, Rachel Bach, Susan Frohlick
Second, reproductive mobilities scholarship has emphasized the movements of patients, intended parents, donors, surrogates, technologies, and bio-genetic materials (sperm, ovum, oocyte) across national boundaries to ever-changing sites of supply and services within a globalizing healthcare and therapeutic industry and economy. The cross-border travel undertaken by intended parents has been critiqued for the north-south pathways, but the normativity of relatively unfettered international travel as a practice ‘of largely white urban modernity’ (Norman et al. 2015) has remained under-examined (although see Speier, this issue): certain actors’ mobilities have been foregrounded while others’ have been obfuscated. Rural racialized movement remains to be studied within an Indigenous mobilities framework, argue Norman et al. (2015). International borders and transnational networks that have been examined within reproductive cross-care and medical mobilities literatures are not the only geographical movement through which reproductive health and fertility services are mobilized. National birth evacuation attends to the tensions and power relations that inhere in borders within nation-states, for which Indigenous women’s reproductive bodies have become mired in issues of sovereignty. Questions of birth travel in Canada are thus questions of citizenship and sovereignty in a settler colonial context of displacement and dispossession