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Pollution
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Global Resources and Universal Processes, 2020
Vera Lucia S.S. de Castro, Paola Poli
RT-PCR uses fluorescent probes to measure the exact amount of a nucleic acid. In genotoxicology, it can be used to quantify gene expression to detect genetic polymorphisms and to quantify chromosome deletions. These probes are used to verify the expressed gene or to selectively analyze its expression over time or dose parameters. It will also become more important to analyze expression in specific cell populations in order to profile the global alterations in gene expression involved in chronic chemical exposure that may lead to tumor development.[122]
Toxic Responses of the Female Reproductive System
Published in Stephen K. Hall, Joana Chakraborty, Randall J. Ruch, Chemical Exposure and Toxic Responses, 2020
Joana Chakraborty, Maureen McCorquodale
When the blood sample arrives in the laboratory, the white cells are grown in culture and after three days are treated with a chemical which arrests cell division in a stage called metaphase where the chromosomes are most easily studied since the individual features are clearly observable with a microscope at this state. The cells are then burst open, the chromosomes are released on a microscope slide, stained, photographed, enlarged, cut out and then arranged into a specific pattern on a sheet of paper. The arrangement of the chromosomes is called a karyotype and is based on the size and shape of the chromosomes as well as on the specific pattern of bands found on each chromosome. A normal karyotype consists of 46 chromosomes in 23 pairs. The autosomes (nonsex chromosomes) are numbered 1 to 22, and the sex chromosomes consist of two X chromosomes for a female and an X and Y chromosome for a male (Figures 12.3 and 12.4).
Radiation Sources, Exposure, and Health Effects
Published in James H. Saling, Audeen W. Fentiman, Radioactive Waste Management, 2018
James H. Saling, Audeen W. Fentiman
Cells are injured by the molecular changes caused by radiation-induced ions and free radicals. Among the many types of molecules that are affected by ionizing radiation, the most critical is DNA because of the limited redundancy of the genetic information encoded in it. The total amount of energy deposited by an acutely lethal dose of x rays affecting the whole body (about 3–5 Sv) can cause hundreds of breaks in DNA molecules in every cell of the body. Figure 2.3 illustrates the low-level radiation damage to DNA by an electron from an ionized hydrogen atom, which can have direct or indirect effects.19 The schematic representation of DNA at the right shows the types of damage that can occur. Since the simple types of lesion can to a considerable extent be repaired by enzymes in the cells, the damage to DNA may be amplified many times as the DNA is transcribed and translated, ultimately to countless daughter cells. Damage to chromosomes and genes appears to figure more prominently than any other type of damage in the injuries. Chromosomal abnormalities include changes in the number and structure of chromosomes. The frequency of such chromosomal aberrations increases as a linear, nonthreshold function of the radiation dose in the low to intermediate range, with the slope of the line being steeper for high-LET than for low-LET radiation.19
A Comprehensive Literature of Genetics Cryptographic Algorithms for Data Security in Cloud Computing
Published in Cybernetics and Systems, 2023
Ozgu Can, Fursan Thabit, Asia Othman Aljahdali, Sharaf Al-Homdy, Hoda A. Alkhzaimi
A chromosome is a DNA and protein strand in the nucleus of living organisms that carry genetic information in the form of genes. As a natural transporter of information, DNA may be employed in a variety of ways to ensure information security. The order of bases along a DNA strand forms a code or information for making proteins. As shown in Figure 4, the components of genetics in DNA and RNA are used to create the Genetic Algorithm as follows: Encoding schemes, Creation, Fitness Evaluation, Selection, Reproduction, Crossover, Inversion, Mutation, Elitism, and Stopping Criteria. Each DNA molecule contains these elements in a random order, and the distribution of these nucleotides determines DNA's genetic code. The power of any genetic scheme is directly correlated with the randomization it provides. According to researchers, the nucleotide sequence’s randomization can be effectively used to design a strong and dependable coding scheme. Using fundamental DNA to enhance coding systems is not feasible due to complicated laboratory requirements (Maniyath and Kaiselvan 2016).
The Problem of Spontaneous Abortion: Is the Pro-Life Position Morally Monstrous?
Published in The New Bioethics, 2019
Bruce P. Blackshaw, Daniel Rodger
There is already significant ongoing research into spontaneous abortion, which as we have noted is commonly referred to as miscarriage. This research is aimed at treating recurrent miscarriage — two or more miscarriages — and improving IVF success rates. According to Jeve and Davies (2014, p. 166), ‘recurrent miscarriage is one of most widely researched areas in medicine’. Although establishing causation can be difficult, particularly for pre-implantation spontaneous abortions, a number of probable causes have been identified. The most common cause of spontaneous abortion is chromosomal abnormalities, accounting for perhaps 70% of all spontaneous abortions (Salim 2011), whether anembryonic or not (Lathi et al. 2007). These abnormalities are mostly aneuploidies, an abnormal number of chromosomes in cells (O’Connor 2008). The most frequent of these are trisomies, where cells have one extra chromosome, and are rarely compatible with life with the exception of Down’s syndrome and Klinefelter’s syndrome (O’Connor 2008). This is a broad category of causes — there are a variety of aneuploidies, which in turn are caused by chromosomal defects in oocytes or spermatozoa, or errors in the fertilisation process.
Toward Human Chromosome Knowledge Engine
Published in Cybernetics and Systems, 2022
Maiqi Wang, Yi Lai, Minghui Li, Haoxi Zhang, Edward Szczerbicki
Chromosome classification plays a critical role in karyotype analysis. Human chromosomes are the carriers of human genetic materials and genes, and karyotype analysis is an important technique to identify genetic abnormalities through chromosome metaphase images. Karyotype analysis is carried out by preparing karyotype images through segmenting metaphase images and then classifying and organizing chromosome instances into 23 pairs, including 22 pairs of autosomes and a pair of sex chromosomes (XY for males and XX for females) and sending the prepared karyotype images to experts for final analysis (Piper and Granum 1989).