Lotka-Volterra Model of Wastewater Treatment in Bioreactor System using 4th Order Runge-Kutta Method

Wastewater treatment is essential to preserve the ecosystem and to ensure water resources are uncontaminated. This paper presents the Lotka-Volterra model of nonlinear ordinary differential equations of the interaction between predator-prey and substrate. The dimensionless ordinary differential equations of the model are solved using the 4th Order Runge-Kutta method (RK4) in MATLAB®. This study discusses the behaviour parameters of predators, prey and substrate. The results are shown graphically for different values of each parameter. Hence, the biological reaction of clean water from the interaction of predator-prey and substrate in wastewater treatment is identified. The higher the concentration of prey, the faster the concentration of substrate reaches 0 with and without the natural death of prey. The clean water will be produced whenever the concentration of prey and the concentration of predator are in balance regardless of the natural death rate. Stability analysis using the Jacobian matrix at the equilibrium point is also performed to determine the stability of the system.

Raising People With Special Needs

All social communities strive to take care of the development, upbringing, and education of children deprived of parental care. The reasons for denial of parental care for children are known in theory and practice: death of parents due to war, natural death of one or both parents, loss of parents due to accident, illness, inability to care for the child, abandonment of children by parents, and other reasons. These children are included in the category of children without parental care and become a subject of social care. If they feel a lack of natural parental care, they can go on the crime route and start dealing with crime. Crime is a complex social phenomenon that, because of its dangers and the consequences it leaves for the individual and the social community, is studied from various aspects.

VITAMIN D3 IN BREAST CANCER PREVENTION: MYTH OR REALITY (literature review)

В 2018 году в Республике Казахстан было зарегистрировано 4648 новых случая рака молочной железы (РМЖ). Результаты: О взаимосвязи уровня витамина Д3 и риска развития РМЖ свидетельствуют результаты достаточного числа исследований. Женщины с высоким содержанием витамина Д в рационе питания имеют меньший риск развития РМЖ. Положительное противоопухолевое действие витамина Д3 связано с двумя основными механизмами: антипролиферативным эффектом, ингибирующим ростом клеток путем подавления сигналов, стимулирующих рост рецепторов, которые имеются в ткани молочной железы, и проапоптотическим эффектом, способствующим естественной гибели клеток молочной железы. Заключение: Накопленные к настоящему времени данные о роли витамина Д3 в организме человека, взаимосвязи его уровня с развитием и течением онкологической патологии позволяют предположить, что коррекция недостаточного уровня витамина Д3 может быть перспективным направлением в профилактике и комплексном лечении онкологических заболеваний. Introduction: In 2018, 4648 new cases of breast cancer (BC) were registered in the Republic of Kazakhstan. Results: The relationship between the level of vitamin D3 and the risk of developing breast cancer is evidenced by the results of a sufficient number of studies. Women with a high vitamin D diet have a lower risk of developing breast cancer. The positive antitumor effect of vitamin D3 is associated with two main mechanisms: the antiproliferative effect, which inhibits cell growth by suppressing signals that stimulate the growth of receptors present in the breast tissue, and the proapoptotic effect, which promotes the natural death of breast cells. Conclusion: The data accumulated to date on the role of vitamin D3 in the human body, the relationship of its level with the development and course of oncological pathology suggests that the correction of insufficient levels of vitamin D3 may be a promising direction in the prevention and complex treatment of cancer.

A forgotten past is the past that is yet to be

South Africa is one of the few countries in Africa that has a running oral history association. In some countries, especially in southern Africa, these oral history associations have arisen and then died a natural death. For example, Oral Traditions Association of Zimbabwe (OTAZI) did not last long. Therefore, it is a positive development for South Africa to have a functioning oral history association. The Oral History Association of South Africa (OHASA) is the brainchild of the government and is mainly funded by the government. It is involved in the coordination and documentation of stories that were silent during the apartheid era. Therefore, with this highly perceived task it is necessary to critically evaluate its successes and failures in meeting the objectives of the National Oral History Programme (NOHP). This paper, through document analysis and purposively selected interviews, critically evaluates the achievements and shortcomings of the OHASA from its inception to present with the aim of proposing a ‘working’ model which involves the setting up of a monitoring and evaluating system. The paper concludes that although OHASA unveiled the muted marginalised voices, it soral history programme demonstrate elitism in critical emancipatory as mostly the stories of the elites are covered. Furthermore, such recorded stories are not accessible as the recordings are stashed in the boxes in archives repositories.

A forgotten past is the past that is yet to be

South Africa is one of the few countries in Africa that has a running oral history association. In some countries, especially in southern Africa, these oral history associations have arisen and then died a natural death. For example, Oral Traditions Association of Zimbabwe (OTAZI) did not last long. Therefore, it is a positive development for South Africa to have a functioning oral history association. The Oral History Association of South Africa (OHASA) is the brainchild of the government and is mainly funded by the government. It is involved in the coordination and documentation of stories that were silent during the apartheid era. Therefore, with this highly perceived task it is necessary to critically evaluate its successes and failures in meeting the objectives of the National Oral History Programme (NOHP). This paper, through document analysis and purposively selected interviews, critically evaluates the achievements and shortcomings of the OHASA from its inception to present with the aim of proposing a ‘working’ model which involves the setting up of a monitoring and evaluating system. The paper concludes that although OHASA unveiled the muted marginalised voices, it soral history programme demonstrate elitism in critical emancipatory as mostly the stories of the elites are covered. Furthermore, such recorded stories are not accessible as the recordings are stashed in the boxes in archives repositories.

Application of a New Generalized Fractional Derivative and Rank of Control Measures on Cholera Transmission Dynamics

In this study, the mathematical model of the cholera epidemic is formulated and analyzed to show the impact of Vibrio cholerae in reserved freshwater. Moreover, the results obtained from applying the new fractional derivative method show that, as the order of the fractional derivative increases, cholera-preventing behaviors also increase. Also, the finding of our study shows that the dynamics of Vibrio cholerae can be controlled if continuous treatment is applied in reserved freshwater used for drinking purposes so that the intrinsic growth rate of Vibrio cholerae in water is less than the natural death of Vibrio cholerae. We have applied the stability theory of differential equations and proved that the disease-free equilibrium is asymptotically stable if R 0 < 1 , and the intrinsic growth rate of the Vibrio cholerae bacterium population is less than its natural death rate. The center manifold theory is applied to show the existence of forward bifurcation at the point R 0 = 1 and the local stability of endemic equilibrium if R 0 > 1 . Furthermore, the performed numerical simulation results show that, as the rank of control measures applied increases from no control, weak control, and strong control measures, the recovered individuals are 55.02, 67.47, and 674.7, respectively. Numerical simulations are plotted using MATLAB software package.

Natural death of the employees at workplace in Ukraine in the dynamics of 2015-2020

Introduction: In recent years, there has been a gradual decline in occupational traumatism in Ukraine, but an in-depth analysis of the data shows that statistics does not fully reveal the complexity of the current situation on occupational traumatism and the quality of its registration and record-keeping, especially in case of sudden death at a workplace. According to the Resolution of the Cabinet of Ministers of April 17, 2019 № 337 on «Procedure for investigation and record-keeping of the incidents, occupational diseases, and accidents at the production» (with changes made in accordance with the Resolution of the Cabinet of Ministers № 1, 05.01.2021) the amendments were made where the circumstances of an accident and / or acute occupational disease (poisoning), cases of sudden death were recognized as related to production (according to the Article 52, paragraphs 6-8). Objective: We identified the regularities of the formation of the indicators of natural death at workplace of the employees over 2015-2020 in Ukraine. Materials and methods: According to the data of the State Statistics Committee of Ukraine and the State Labour Service of Ukraine, we performed the analysis of natural deaths of the employees at workplace in the dynamics of monitoring by the types of economic activity, occupations and causes over 2015-2020 and established the ways for the improvement of their record-keeping. Statistical data were evaluated with the help of rankings, methods of generally accepted statistical analysis. Results and discussion: From 2015 to 2019, the number of the accidents at production, registered and recognized as insured events, decreased from 4,260 to 3,876 (by 9.0%), and the number of the fatal traumatized increased from 375 to 422 (by 11.1%). In 2020, the number of the accidents (A) increased up to 6121 (by 30.4%), and the accidents with fatal consequences increased up to 653 (by 42.5%), mainly due to the diseases of circulatory system and COVID-19. In recent years, there has been an increase in sudden deaths (SD) and «rejuvenation» of the contingent of working people.The problem of natural death is actual worldwide and according to the WHO, makes up 5-7%. Among those who died of natural causes, young people aged 20-39 years make up a significant proportion, mainly due to circulatory diseases and COVID-19. It was established that in the dynamics of 2015-2020, there were 4861 cases of natural death (ND) at workplace in Ukraine, which are 8.0-16.2 per 100 thousand working population and 27.2-55.0 per 100 thousand population working under harmful working conditions against 5.3 and 14.1 in 2012. The analysis of cases of ND in terms of gender, age and length of service shows that more than 77.0% are men aged 20-60 years old. The distribution of cases of ND at the workplace in Ukraine by the branches of industry shows that the socio-cultural sphere (30.0-55.2%), transport (16%), engineering and metallurgy (10.5-6.6%), coal and mining industry (4.2-2.4%) are the main ones. The cases of ND at workplaces from diseases of the circulatory system in the employees of social sphere and transport, miners of coal mines have been analyzed in details. The methods of prevention of ND at workplace are proposed. Conclusions: 1. The problem of natural death at the workplace requires an additional legislation to determine the circumstances of death connected with the working conditions or the feautures of the production process. 2. The most frequent cases of ND at the workplace in Ukraine are registered among employees of the socio-cultural sphere (30.0-55.2%), transport (16%), mechanical engineering and metallurgical industry (10.5-6.6%), construction and road construction, agro-industrial complex , coal and mining industry (4.2-2.4%). 3. Diseases of the circulatory system (acute cardiovascular failure (heart attack, stroke), coronary heart disease, heart and lung failure on the background of nervous and emotional stress, lack of sleep, the presence of a complex work schedule (daily, 12 hours, night shifts, which requires a separate study of causation) and impact of the adverse factors of the working environment were the main causes of ND in the employees. 4. Prevention of ND is in the field of the restoration of the system of providing medical care to employees, improvement of the quality of preventive medical examinations, pre-shift control, occupational selection.

How safe is BDSM? A literature review on fatal outcome in BDSM play

A noteworthy number of people are interested in BDSM (bondage and discipline, dominance and submission, sadism, and masochism). Fatal outcomes while participating in BDSM activities occur. The aim of this literature review is to give a better insight into potential dangerous BDSM play by summarizing published data on BDSM fatalities. A literature search was conducted. It was searched for non-natural death related to BDSM activity. Seventeen cases were found. The age of the deceased ranged between 23 and 49 years (mean age 34.9 years). Strangulation in the course of erotic asphyxiation was the most common cause of death (88.2%). In 13 cases, a toxicology report for the deceased was mentioned, of which in eight cases (61.5%) toxicology analysis was positive. In four of these cases, the BDSM partner was also tested positive with the same substance. Drugs or alcohol was involved in 64.3% of fatal BDSM play. In nine cases, the level of experience in BDMS activity of the deceased and the partner was described, and in all of them, the deceased and the partner were not new to BDSM play. Fatal outcomes of BDSM plays are rarer than autoerotic fatalities and natural deaths related to sexual activities. Safeguards and education on medical aspects exist in the BDSM communities. If they are followed by the practitioners, the risks of BDMS play can be reduced. Cases of non-natural death connected to BDSM are rare incidents and can be prevented.

Slavery and Constitutionalism

One of the major problems faced by Americans in the Revolutionary era was slavery, and they had made it a problem. Slavery had existed in the colonies for generations without substantial criticism until the Revolution. Abolishing slavery became one of the major reforms undertaken by the Revolutionaries. In the northern states they were reasonably successful, putting an end to slavery by 1804. Virginia was crucial, and there the effort failed. Virginians and others consoled themselves with the illusion that slavery was dying a natural death. But the desire of South Carolina and Georgia for twenty more years of slave importation should have exposed the illusions. The Deep South’s commitment to slavery required protective clauses in the new Constitution that eventually became sources of sectional division.

Effects of drivers and their variations on the number of stems and aboveground carbon removals in miombo woodlands of mainland Tanzania

Background Removals caused by both natural and anthropogenic drivers such as logging and fire in miombo woodlands causes substantial carbon emissions. Here we present drivers and their effects on the variations on the number of stems and aboveground carbon (AGC) removals based on an analysis of Tanzania’s national forest inventory (NFI) data extracted from the National Forest Resources Assessment and Monitoring (NAFORMA) database using allometric models that utilize stump diameter as the sole predictor. Results Drivers of AGC removals in miombo woodlands of mainland Tanzania in order of importance were timber, fire, shifting cultivation, charcoal, natural death, firewood collection, poles, grazing by wildlife animals, carvings, grazing by domestic animals, and mining. The average number of stems and AGC removals by driver ranged from 0.006 to 16.587 stems ha−1 year−1 and 0.0–1.273 tCha−1 year−1 respectively. Furthermore, charcoal, shifting cultivation and fuelwood caused higher tree removals as opposed to timber, natural death and fire that accounted for higher AGC removals. Conclusions Drivers caused substantial effects on the number of stems and carbon removals. Increased mitigation efforts in addressing removals by timber, fires, shifting cultivation, charcoal and natural death would be effective in mitigating degradation in miombo woodlands of Tanzania. Additionally, site-specific studies need to be conducted to bring information that would be used for managing woodlands at local levels. This kind of study need to be conducted in other vegetation types like montane and Mangrove forest at national scale in Tanzania.