PERIODIZATION OF THE DEVELOPMENT OF A CHICKEN EMBRYO

2020 ◽  
Vol 15 (5) ◽  
pp. 684-689
Author(s):  
F.I. Suleimanov ◽  
◽  
A.S. Migachev ◽  

Embryology (from the Greek embryon – embryo, logos – doctrine) is not just a biological discipline, but a science that studies the formation, development, and also the formation of embryos of living beings from the moment of the appearance of germ cells and their fusion until the birth of the world a new organism. One of the largest embryologists who studied the development of avian embryos, Hamilton, considering it amazing how the beginning of the functioning of one organ correlates with the functioning of other organs and systems of the body, writes: "It is not surprising that there are certain sensitive periods when the embryo is susceptible to disturbances both in the internal and and in the external environment". Quite a lot of literature is devoted to the issues of periods of hypersensitivity, or, as they are usually called, critical periods in the embryogenesis of various animals (invertebrates and vertebrates). The position of critical periods of development was first put forward by the English physician-scientist K. Stockard in the 20s. XX century And later it was deepened and expanded by the Soviet scientist-embryologist PG Svetlov. Periods of increased sensitivity to damaging influences in the embryonic development of fish are named. Omitting a large number of works, let us inform that Korovina, recognizing the stages of development and formation of a new quality at each stage, denies the existence of periods of increased sensitivity to the action of all environmental factors without exception. The author acknowledges that there are periods in embryonic development when embryos are equally sensitive to several influences, but considers it necessary to emphasize the specificity of the response to various environmental factors.

2020 ◽  
Author(s):  
Nikolay Raychev ◽  

This article discusses the current state of neurointerface technologies, not limited to deep electrode approaches. There are new heuristic ideas for creating a fast and broadband channel from the brain to artificial intelligence. One of the ideas is not to decipher the natural codes of nerve cells, but to create conditions for the development of a new language for communication between the human brain and artificial intelligence tools. Theoretically, this is possible if the brain "feels" that by changing the activity of nerve cells that communicate with the computer, it is possible to "achieve" the necessary actions for the body in the external environment, for example, to take a cup of coffee or turn on your favorite music. At the same time, an artificial neural network that analyzes the flow of nerve impulses must also be directed at the brain, trying to guess the body's needs at the moment with a minimum number of movements. The most important obstacle to further progress is the problem of biocompatibility, which has not yet been resolved. This is even more important than the number of electrodes and the power of the processors on the chip. When you insert a foreign object into your brain, it tries to isolate itself from it. This is a multidisciplinary topic not only for doctors and psychophysiologists, but also for engineers, programmers, mathematicians. Of course, the problem is complex and it will be possible to overcome it only with joint efforts.


Author(s):  
Shruti Krishna Mapsekar ◽  
Ragini R. Patil

Twacha or skin is the largest organ in the human body enveloping the whole body. The thickness of skin varies according to the part of the body it covers. Since, skin is the barrier separating the internal tissues and organs from the external environment; it is more prone to various types of hazards. The skin is affected potentially due to two main reasons. First, that it is exposed to the harmful environmental factors and secondly due to the degenerative and neoplastic changes occurring within its own various cell types which is the reason for majority of skin diseases. As it is generally seen that the most common reason for manifestation of skin diseases is faulty dietary habits.


Author(s):  
O. Vodianitskyi ◽  
N. Hrynevych ◽  
O. Khomiak ◽  
N. Prysiazhniuk

During the monitoring of cytological parameters of embryos and fi sh larvae under changing environmental conditions, it was found that the body adapts to the environmental temperature conditions at the cellular level. Threshold temperature is the limit of the resistance of body cells to the action of extreme ambient temperatures. Since this ability is diff erent for diff erent species, their temperature threshold is not the same. It is proved that for each fi sh species there is a certain temperature amplitude, within which their embryonic development is possible. The rate of passage of embryogenesis depends on temperature. Deviation from the optimal temperature and its approach to the “threshold” causes disturbances in the embryogenesis of fi sh, leads to the death of embryos or to the appearance of anomalies in their development. Under the infl uence of a threshold temperature on fertilized eggs, polyploidy of cells is possible. Genetic changes in somatic cells is an integral indicator of homeostasis disturbance. They characterize the pr esence of environmental mutagens and the eff ectiveness of the body's immune response. Normally, most genetic disorders are eliminated. The presence of such disorders is an indicator of stress, which leads to the appearance of abnormal cells and a decrease in the body's immune status. Such abnormalities can be detected at the chromosomal level. It has been proved that critical periods in the embryonic development of fi sh are manifested at the stages of crushing of morula cells and gastrulation in embryos during organogenesis. However, the presence of sensitive periods is not always associated with diff erentiation processes, for example, the onset of cell crushing, the period of embryo exit from the membranes. Key words: predatory fi sh species, temperature regime, metabolism, micronuclear test, embryonic cell, nucleoli, stress factors, abiotic effect.


2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.


2020 ◽  
Vol 99 (5) ◽  
pp. 478-482
Author(s):  
N. P. Setko ◽  
A. G. Setko ◽  
Ekaterina V. Bulycheva ◽  
A. V. Tyurin ◽  
E. Yu. Kalinina

Introduction. Changes in the body of children and adolescents aimed at adapting to environmental factors are determined by genetic polymorphism in xenobiotic biotransformation genes, determining the degree of susceptibility of the child’s body to pollutants, which is the basis of modern personalized preventive medicine when managing risks to the health of the child population under the influence of environmental factors. Material and methods. Trace elements, including heavy metals, lead and cadmium, were determined in the hair of 256 practically healthy teenagers by atomic absorption spectrophotometry. Depending on the level of content of the latter, two groups of adolescents were formed to determine six genes of the cytochrome P-450 family. Group 1 consisted of adolescents whose cadmium lead content exceeded the average Russian indices. The second group included adolescents whose heavy metals were above the level of average Russian standards. Results. Studies have shown that in adolescents of the 1st group, compared with the data of adolescents of the 2nd group, an increase in the number of carriers of two mutant alleles at the locus rs 1048943 (gene CYP1A1) is 3.08 times, rs 464621 (gene CYP1A1) is 1. 8 times; locus rs 2069522 (CYP1A2 gene) 3.63 times; locus rs 1799853 (CYP2C9 * 2 gene) 4.5 times; locus rs 1057910 (gene CYP2C9 * 3) 3.8 times and locus rs 2279343 (gene CYP2B6) 4.25 times. Moreover, carriers of two normal alleles in adolescents of the first group at the locus rs 1048943 (gene CYP1A1) were 5.14 times; locus rs 2279343 (CYP2B6 gene) was 6.5 fold less than among adolescents of the 2nd group; and at the locus rs 464621 (gene CYP1A1), rs 2069522 (gene CYP1A2), rs 1799853 (gene CYP2C9 * 2), rs 1057910 (gene CYP2C9 * 3) there were no carriers of normal homozygotes. Conclusion. Group 1 adolescents with heavy metal contamination of the body are carriers significantly in a greater number of pathological mutations in the genes of the cytochrome P-450 detoxification system in comparison with data from group 2 adolescents.


2020 ◽  
pp. 14-17
Author(s):  
Irina A. Shkuratova ◽  
◽  
Lyudmila I. Drozdova ◽  
Aleksander I. Belousov ◽  

Mycotoxicological monitoring of forages shows that the problem of mycotoxicosis has been relevant for several decades. Minimal doses of mycotoxins in feed lead to a decrease in milk productivity, increased sensitivity to infectious and non-infectious diseases. When several mycotoxins enter the body simultaneously, a synergistic effect develops, causing a significant increase in toxicity. Feed contaminated with several types of fungi and their toxins is dangerous for dairy cattle. It was found that the feed mixture contained the types of associations of Aspergillus spp. fungi + Fusarium; Aspergillus spp. + Penicillium spp. + Mucor spp; Fusarium + Penicillium; Mucor spp. + Fusarium + Ustilaginales. Pathogenetic features of metabolic and morphological changes in highly productive cows with polymycotoxicosis were studied. Feeding food contaminated with various metabolites of mold fungi leads to the development of signs of chronic toxemia in animals. Clinical manifestations are the development of diarrhea and dehydration, with a decrease in milk productivity. Metabolic disorders feature the development of an inflammatory process, metabolic acidosis, hyperfermentonemia, with an increase in the amount of creatinine and urea in the blood serum. Metabolic signs indicate the development of hepatorenal syndrome due to structural disorders of the liver and kidneys. Histological signs of polymicotoxicosis are intracapillary and hemorrhagic glomerulonephritis, hepatocyte micronecrosis, and proliferation of connective tissue stroma cells, which leads to the development of atrophic cirrhosis in the interstitial and circular phases.


2017 ◽  
Vol 2017 (1) ◽  
pp. 39-54
Author(s):  
Jörg Zimmer

In classical philosophy of time, present time mainly has been considered in its fleetingness: it is transition, in the Platonic meaning of the sudden or in the Aristotelian sense of discreet moment and isolated intensity that escapes possible perception. Through the idea of subjective constitution of time, Husserl’s phenomenology tries to spread the moment. He transcends the idea of linear and empty time in modern philosophy. Phenomenological description of time experience analyses the filled character of the moment that can be detained in the performance of consciousness. As a consequence of the temporality of consciousness, he nevertheless remains in the temporal conception of presence. The phenomenology of Merleau-Ponty, however, is able to grasp the spacial meaning of presence. In his perspective of a phenomenology of perception, presence can be understood as a space surrounding the body, as a field of present things given in perception. Merleau-Ponty recovers the ancient sense of ‘praesentia’ as a fundamental concept of being in the world.


Author(s):  
Julian Bibermair ◽  
Andrew N. Ostrovsky ◽  
Andreas Wanninger ◽  
Thomas Schwaha

AbstractBryozoa is a phylum of aquatic, colonial suspension-feeders within the Lophotrochozoa. In the Phylactolaemata embryonic development occurs in an internal brood sac on the body wall accompanied by extraembryonic nutrition. Owing to previous contradictive descriptions, many aspects of their sexual reproduction require restudy. Consequently, this study analyses embryogenesis of the freshwater bryozoan Plumatella casmiana by serial sections, 3D reconstruction and transmission electron microscopy. Early embryos cleave and soon develop into blastulae with a small central cavity. The mesoderm forms by delamination starting from the distal side towards the proximal end. In later embryos two polypides form on the posterior side that ultimately will be covered by a ciliated mantle in the larva. Embryos increase in size during development and form temporary cell contacts to the embryo sac. Mesodermal cells of the embryo sac show signs of transcellular transport indicating that embryos are nourished by transferring nutrients from the maternal coelom towards the brood cavity. This study clarifies several details such as mesoderm formation and the onset of bud development. Embryos are connected to their respective embryo sacs by a variety of temporary cytoplasmic processes formed by both tissues during embryogenesis, including a ‘placental’ ring zone. Although ultrastructural data of these cell contacts are not entirely conclusive about their function, we suggest that embryos absorb nutrients via the entire surface. The close opposition of embryos to the embryo sac implies placentation as matrotrophic mode in phylactolaemate bryozoans, with embryo sacs acting as placental analogues.


1995 ◽  
Vol 7 (2) ◽  
pp. 21-23 ◽  
Author(s):  
S. Daan

The analysis of motivational systems underlying temporal organisation in animal behaviour has relied primarily on two conceptual functional frameworks: Homeostasis and biological clocks. Homeostasis is one of the most general and influential concepts in physiology. Walter Cannon introduced homeostasis as a universal regulatory principle which animals employ to maintain constancy of their ‘internal milieu’ in the face of challenges and perturbations from the external environment. Cannon spoke of “The Wisdom of the Body”, the collective of responses designed to defend the ideal internal state against those perturbations.


1972 ◽  
Vol 21 (3) ◽  
pp. 204-210 ◽  
Author(s):  
Ch. Susanne

SummaryThe results are presented of a method of generalized distances calculated by a noncentral χ2 test and applied to compare 63 twin pairs and 196 sib pairs. The advantage of this method in biometrical analysis lies in the fact that several measurements can be utilised simultaneously. Besides, it takes into account the distance of each relative to the centre of the population and also has the advantage of permitting the comparison of distances between pairs of relatives whatever their age or sex.Generalized distances were calculated for four measurements of the head, five of the body and eleven of the face. For all three sets of measurements the influence of genetical factors was demonstrated. The body seems less influenced by environmental factors and more conditioned by genetic ones.


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