The mathematical theory of epidemics: a study of the evolution of resistance in microorganisms

1971 ◽  
Vol 3 (2) ◽  
pp. 206-208 ◽  
Author(s):  
V. P. Krus ◽  
L. A. Rvachev
Keyword(s):  
Mathematical Theory ◽  
Modern Medicine ◽  
Mathematical Methods ◽  
Resistance To Antibiotics ◽  
Epidemic Theory ◽  
Evolution Of Resistance

In modern medicine it becomes more and more urgent every year to solve new epidemiological problems. One of these is the evolution of resistance to antibiotics of a large spectrum of microorganisms; this resistance is a consequence of the mass administration of antibiotics. In this problem it becomes necessary to apply the mathematical methods of epidemic theory as here the key lies in a purely epidemiological factor, namely the mass character of the use of antibiotics. A first model of the phenomenon encountered is presented.

The mathematical theory of epidemics: a study of the evolution of resistance in microorganisms

1971 ◽  
Vol 3 (02) ◽  
pp. 206-208
Author(s):  
V. P. Krus ◽  
L. A. Rvachev
Keyword(s):  
Mathematical Theory ◽  
Modern Medicine ◽  
Mathematical Methods ◽  
Resistance To Antibiotics ◽  
Epidemic Theory ◽  
Evolution Of Resistance

In modern medicine it becomes more and more urgent every year to solve new epidemiological problems. One of these is the evolution of resistance to antibiotics of a large spectrum of microorganisms; this resistance is a consequence of the mass administration of antibiotics. In this problem it becomes necessary to apply the mathematical methods of epidemic theory as here the key lies in a purely epidemiological factor, namely the mass character of the use of antibiotics. A first model of the phenomenon encountered is presented.

Resistance economics: social cost and the evolution of antibiotic resistance

1996 ◽  
Vol 1 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Gardner Brown ◽  
David F. Layton
Keyword(s):  
Antibiotic Resistance ◽  
Social Cost ◽  
Selective Pressure ◽  
Human Beings ◽  
Resistance To Antibiotics ◽  
Current State ◽  
Evolution Of Resistance

Daily and Ehrlich have described the current state of our epidemiological environment in chilling detail. While their point is that human beings interact and affect the epidemiological environment in a variety of ways, the development of antibiotic resistance in bacteria strikes us as one aspect that we can begin to analyse immediately. The evolution of resistance to antibiotics is a function of their use by humans. The more we use, the more selective pressure is placed upon bacteria to develop resistance. This is further complicated by how they are used. Both the duration and the amounts used affect the change in the level of resistance. Finally, the primary feature driving the concern over the use of these drugs is that the evolution of resistance makes these ‘miracle’ drugs exhaustible. We can try to develop new and better antibiotics, but it is uncertain how successful we will be and how expensive they will be if we are successful.

scholarly journals A Physiological Basis for Nonheritable Antibiotic Resistance

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Mauricio H. Pontes ◽  
Eduardo A. Groisman
Keyword(s):  
Bacterial Growth ◽  
Feedback Inhibition ◽  
Large Fraction ◽  
Bacterial Genome ◽  
Modern Medicine ◽  
Antibiotic Tolerance ◽  
Physiological Basis ◽  
Genetic Changes ◽  
Resistance To Antibiotics ◽  
Expression Of Genes

ABSTRACT Antibiotics constitute one of the cornerstones of modern medicine. However, individuals may succumb to a bacterial infection if a pathogen survives exposure to antibiotics. The ability of bacteria to survive bactericidal antibiotics results from genetic changes in the preexisting bacterial genome, from the acquisition of genes from other organisms, and from nonheritable phenomena that give rise to antibiotic tolerance. Nonheritable antibiotic tolerance can be exhibited by a large fraction of the bacterial population or by a small subpopulation referred to as persisters. Nonheritable resistance to antibiotics has been ascribed to the activity of toxins that are part of toxin-antitoxin modules, to the universal energy currency ATP, and to the signaling molecule guanosine (penta) tetraphosphate. However, these molecules are dispensable for nonheritable resistance to antibiotics in many organisms. By contrast, nutrient limitation, treatment with bacteriostatic antibiotics, or expression of genes that slow bacterial growth invariably promote nonheritable resistance. We posit that antibiotic persistence results from conditions promoting feedback inhibition among core cellular processes, resulting phenotypically in a slowdown or halt in bacterial growth.

Descriptive Image Analysis. Foundations and Descriptive Image Algebras

2019 ◽  
Vol 33 (11) ◽  
pp. 1940018 ◽  
Author(s):  
Igor Gurevich ◽  
Vera Yashina
Keyword(s):  
Image Analysis ◽  
Mathematical Theory ◽  
State Of The Art ◽  
Mathematical Methods ◽  
Mathematical Objects ◽  
Intelligent Decision Making ◽  
Current State ◽  
Intelligent Decision ◽  
Methodological Principles ◽  
Basic Ideas

The paper is devoted to Descriptive Image Analysis (DA) — a leading line of the modern mathematical theory of image analysis. DA is a logically organized set of descriptive methods, mathematical objects, and models and representations aimed at analyzing and evaluating the information represented in the form of images, as well as for automating the extraction from images of knowledge and data needed for intelligent decision-making. The basic idea of DA consists of embedding all processes of analysis (processing, recognition, understanding) of images into an image formalization space and reducing it to (1) construction of models/representations/formalized descriptions of images; (2) construction of models/representations/formalized descriptions of transformations over models and representations of images. We briefly discuss the basic ideas, methodological principles, mathematical methods, objects, and components of DA and the basic results determining the current state of the art in the field. Image algebras (IA) are considered in the context of a unified language for describing mathematical objects and operations used in image analysis (the standard IA by Ritter and the descriptive IA by Gurevich).

scholarly journals ANALYSIS OF MICROFLORA IN MODERN OUTPATIENT CLINIC

2020 ◽  
Vol 10 (1) ◽  
pp. 92-93
Author(s):  
Mikhail Pahomov ◽  
Artyom Morozov ◽  
Alexey Sergeev ◽  
Evgeny Mokhov, ◽  
Nikolay Sergeev ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Streptococcus Pyogenes ◽  
Resistance Genes ◽  
Bacterial Resistance ◽  
Antibiotic Sensitivity ◽  
Modern Medicine ◽  
Resistance To Antibiotics ◽  
The Right

Antibiotic resistance is a global problem of modern medicine. In the research a microflora of out-patient department visitors in 2018–2019 was examined. It was revealed that the most often microbes were Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli. The dynamics of bacterial resistance to antibiotics was also analyzed. The multiple bacterial resistance to antibiotics were detected. The data show a rapid resistance genes spread among non-hospital strains, which necessitates constant monitoring of antibiotic sensitivity in order to develop the right tactics to combat antibiotic resistance.

scholarly journals Evolution of Resistance to Continuously Increasing Streptomycin Concentrations in Populations of Escherichia coli

2015 ◽  
Vol 60 (3) ◽  
pp. 1336-1342 ◽  
Author(s):  
Fabrizio Spagnolo ◽  
Conrad Rinaldi ◽  
Dannah Rae Sajorda ◽  
Daniel E. Dykhuizen
Keyword(s):  
Escherichia Coli ◽  
High Frequency ◽  
Bacterial Resistance ◽  
Low Frequency ◽  
Antibiotic Sensitivity ◽  
Modern Medicine ◽  
Bacterial Cells ◽  
Modern Biology ◽  
Content Type ◽  
Evolution Of Resistance

The evolution of antibiotic resistance in bacteria has become one of the defining problems in modern biology. Bacterial resistance to antimicrobial therapy threatens to eliminate one of the pillars of the practice of modern medicine. Yet, in spite of the importance of this problem, only recently have the dynamics of the shift from antibiotic sensitivity to resistance in a bacterial population been studied. In this study, a novel chemostat method was used to observe the evolution of resistance to streptomycin in a sensitive population ofEscherichia coli, which grew while the concentration of antibiotic was constantly increasing. The results indicate that resistant mutants remain at a low frequency for longer than expected and do not begin to rise to a high frequency until the antibiotic concentrations are above the measured MIC, creating a “lull period” in which there were few bacterial cells growing in the chemostats. Overall, mutants resistant to streptomycin were found in >60% of the experimental trial replicates. All of the mutants detected were found to have MICs far above the maximum levels of streptomycin to which they were exposed and reached a high frequency within 96 h.

Exploitation and Application of the Middle Thickness Model in Cold Tandem Mill

2013 ◽  
Vol 650 ◽  
pp. 623-628
Author(s):  
Lian Lian Zhou ◽  
Xu Chuang Ma ◽  
Kai Wang ◽  
Hong Xin Si
Keyword(s):  
Field Test ◽  
Production Technology ◽  
Mathematical Theory ◽  
Taylor Series Expansion ◽  
Newton Iteration ◽  
Matrix Analysis ◽  
Theoretical Research ◽  
Mathematical Methods ◽  
Newton Iteration Method ◽  
Calculated Model

In the foundation of generous field test and theoretical research, we presented a calculated model of middle thickness in cold tandem mill by combining applied mathematical theory and production technology and taking advantage of Taylor series expansion, matrix analysis, Newton iteration method and other mathematical methods. This model was used for setting original middle thickness on 1220 cold tandem mill in some plant. After field usage, the result was fine and correlative precision was over 90%. It completely satisfies required precision in project and has the value to be further popularized and applied.

Theory of inductive shielding

1968 ◽  
Vol 46 (16) ◽  
pp. 1745-1752 ◽  
Author(s):  
R. W. Latham ◽  
K. S. H. Lee
Keyword(s):  
Boundary Conditions ◽  
Mathematical Theory ◽  
Arbitrary Shape ◽  
Low Frequency ◽  
Electromagnetic Shielding ◽  
Thin Shells ◽  
Shielding Effectiveness ◽  
Mathematical Methods ◽  
Electrical Thickness

A mathematical theory of low-frequency electromagnetic shielding is constructed on the basis that an appropriate set of boundary conditions can be derived to duplicate the effect of the shield's wall on the fields within the shield. Shields with electrically thin shells are considered in detail; mathematical methods that are best suited for computational purposes are presented for calculating the shielding effectiveness of such a shield of arbitrary shape. Shells with arbitrary electrical thickness are also treated, but in less detail, since the shielding problem involving this kind of shell is shown to be different from but no more general than the shielding problem involving electrically thin shells. Explicit results are given for shields of particular shape.

scholarly journals Clinical background of cognitive disorders associated with epileptic syndrome of various genesis

2020 ◽  
Vol 24 (2) ◽  
pp. 266-273
Author(s):  
H. Symonenko
Keyword(s):  
Structural Changes ◽  
Clinical Laboratory ◽  
Cognitive Impairments ◽  
Cognitive Disorders ◽  
Epileptic Seizures ◽  
Modern Medicine ◽  
Mathematical Methods ◽  
Time And Space ◽  
Retrospective Assessment ◽  
Interdisciplinary Problems

Annotation. The prevalence of cognitive impairments that have not reached the degree of dementia is 15-20%. It is known that 20% of people with intellectual disabilities, due to structural changes in the brain, can be diagnosed with epilepsy. The aim of the study was to evaluate the clinical, laboratory, and functional parameters of patients diagnosed with varying degrees of cognitive disorders in the setting of an epileptic seizure in a neurological department. A retrospective assessment was made of 211 patients with cognitive decline who had a history of epileptic seizures (with consequences of traumatic brain injury, perinatal trauma with hypoxic encephalopathy, stroke, discirculatory encephalopathy, brain tumors, arteriovenous malformations, cryptogenic and due to exogenous intoxication). To assess the patient's cognitive function, rapid tests were used: a shortened test of mental abilities - 4 (AMT-4) and a simplified MMSE test. A preliminary comparison of retrospective patients quality indicators was assessed using simple mathematical methods. It was shown a significant effect on the level of cognitive impairment of exogenous intoxication, as well as atherosclerotic changes in the vessels. Brain damage due to trauma or tumor, as the cause of a convulsive attack, showed more pronounced asthenization, lethargy, decreased criticism and intelligence in the case of right hemispheric localization. More pronounced cognitive impairments occurred with lesions in the frontal and temporal localization. So, with damage to the temporal lobe, amnestic disturbances, disorientation in time and space were characteristic. With damage to the frontal lobe - decreased attention, the occurrence of asthenic-depressive syndrome, lethargy. More pronounced speech and writing disorders, disorientation in time and space, astheno-neurotic syndrome with emotional lability were revealed in the case of damage to the left carotid system in stroke. Thus, the study of cognitive impairments in a neurological clinic is one of the important interdisciplinary problems of modern medicine.

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