Study of Infectious Diseases by Mathematical Models: Predictions and Controls

The aim of this thesis is to understand the spread, persistence and prevention mechanisms of infectious diseases by mathematical models. Microorganisms that rapidly evolve pose a constant threat to public health. Proper understanding of the transmission machinery of these existing and new pathogens may facilitate devising prevention tools. Prevention tools against transmissions, including vaccines and drugs, are evolving at a similar pace. Efficient implementation of these new tools is a fundamental issue of public health. We primarily focus on this issue and explore some theoretical frameworks. Pre-exposure prophylaxis (PrEP) is considered one of the promising interventions against HIV infection as experiments on various groups and sites have reported its significant effectiveness. This study evaluates the effectiveness of Tenofovir gel, one of the widely used PrEPs for women, through a mathematical model. Our model has excellent agreement with the experimental data on the use of Tenofovir gel as a PrEP in South African women. Using our model, we estimate both male-to-female and female-to-male transmission rates with and without Tenofovir gel protection. Through these estimates, we demonstrate that the use of Tenofovir gel as a PrEP can significantly reduce the reproduction numbers, new infections, and HIV prevalence in South Africa. Our results further show that the effectiveness of Tenofovir gel largely depends on the level of adherence to the gel and the proportion of women under gel coverage. Even though Tenofovir gel alone may not be able to eradicate the disease, as indicated by our estimates of the reproduction numbers, together with other interventions, such as condom use, it can serve as a strong weapon to fight against HIV epidemics. Another promising drug-oriented intervention against HIV infection is antiretroviral treatment (ART). We study some crucial aspects of this intervention on the HIV epidemic. ART has the potential to reduce mortality and disease progression among HIV infected individuals. It can reduce the viral load of the infected individual to an undetectable level and help prevent new infections. Whether the treatment should begin early or be delayed is still under debate. This study considers the impact of early versus delayed ART on the HIV epidemic and demonstrates the optimum timing of ART initiation. Our results highlight the long-term consequences of early treatment. Finally, we investigate the consequences of vaccine implementation strategies for infectious diseases. Vaccines are said to be the intervention with the most potential against many infectious diseases. However, their success relies on proper and strategic management and distribution. In an infectious disease, the degree of infection may vary widely among those individuals. Reports show that individuals belonging to certain groups possess considerably higher risk for infection. Integrating this phenomenon into vaccination strategies, the host is categorized into different groups to measure the outcome of the vaccination. A mathematical model is proposed and analyzed to evaluate this measure. Our results suggest that vaccinating a group with a certain priority may lead to effective elimination of the disease

Hepatoprotective potential of glyceryl trinitrate against chemically induced oxidative stress and hepatic injury in rats

Glyceryl trinitrate (GTN) has been used widely as a potent vasodilator to treat heart conditions, such as angina pectoris and chronic heart failure. This study aims to elucidate the effect of exogenous nitric oxide (NO) administration, using GTN, on carbon tetrachloride (CCl4)-induced oxidative stress and liver injury in rats. The results obtained demonstrated that NO generated by the administration of GTN affords protection against CCl4-induced oxidative stress and liver injury. Administration of CCl4 resulted in a significant (p < 0.001) increase in lipid peroxidation and tissue damage markers (aspartate and alanine transaminase and lactate dehydrogenase) release in serum. Parallel to these changes, CCl4 also caused downregulation of antioxidant enzymes including glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST), and several fold induction in γ-glutamyl transpeptidase (GGT) activity. Subsequent administration of GTN resulted in significant (p < 0.001) recovery of GSH-metabolizing enzymes in a dose-dependent manner. Further, administration of NO inhibitor, NG-nitro-l-arginine methyl ester (l-NAME), exacerbated CCl4-induced oxidative tissue injury. Overall, the study suggests that GTN might suppress oxidant-induced tissue injury and hepatotoxicity in rats

Drivers to sustainable manufacturing practices and circular economy: A perspective of leather industries in Bangladesh

© 2017 Elsevier Ltd Sustainable manufacturing practices and the circular economy have recently received significant attention in academia and within industries to improve supply chain practices. Manufacturing industries have started adopting sustainable manufacturing practices and a circular economy in their supply chain to mitigate environmental concerns, as sustainable manufacturing practices and a circular economy result in the reduction of waste generation and energy and material usage. The leather industry, in spite of it contributing remarkably to a country's economic growth and stability, does not bear a good image because of its role in polluting the environment. Therefore, the leather industries of Bangladesh are trying to implement sustainable manufacturing practices as a part of undertaking green supply chain initiatives to remedy their image with the buyer and to comply with government rules and regulations. The main contribution of this study is to assess, prioritize and rank the drivers of sustainable manufacturing practices in the leather industries of Bangladesh. We have used graph theory and a matrix approach to examine the drivers. The results show that knowledge of the circular economy is paramount to implementing sustainable manufacturing practices in the leather industry of Bangladesh. This study will assist managers of leather companies to formulate strategies for the optimum utilization of available resources, as well as for the reduction of waste in the context of the circular economy

Agricultural systems in Bangladesh: the first archaeobotanical results from Early Historic Wari-Bateshwar and Early Medieval Vikrampura

The present paper reports the first systematic archaeobotanical evidence from Bangladesh together with direct AMS radiocarbon dates on crop remains. Macro-botanical remains were collected by flotation from two sites, Wari-Bateshwar (WB), an Early Historic archaeological site, dating mainly between 400 and 100 BC, with a later seventh century AD temple complex, and Raghurampura Vikrampura (RV), a Buddhist Monastery (vihara) located within the Vikrampura city site complex and dating to the eleventh and sixteenth centuries AD. Despite being a tropical country, with high rainfall and intensive soil processes, our work demonstrates that conventional archaeobotany, the collection of macro-remains through flotation, has much potential towards putting together a history of crops and agricultural systems in Bangladesh. The archaeobotanical assemblage collected from both sites indicates the predominance of rice agriculture, which would have been practiced in summer. Spikelet bases are of domesticated type rice, while grain metrics suggest the majority of rice was probably subspecies japonica. The presence of some wetland weeds suggests at least some of the rice was grown in wet (flooded) systems, but much of it may have been rainfed as inferred from the Southeast Asian weed Acmella paniculata. Other crops include winter cereals, barley and possible oat, and small numbers of summer millets (Pennisetum glaucum, Sorghum bicolor, Setaria italica), a wide diversity of summer and winter pulses (14 spp.), cotton, sesame and mustard seed. Pulse crops included many known from India. Thus, while most crops indicate diffusion of crops from India eastwards, the absence of indica rice could also indicate some diffusion from Southeast Asia. The later site RV also produced evidence of the rice bean (Vigna umbellata), a domesticate of mainland Southeast Asia. These data provide the first empirical evidence for reconstructing past agriculture in Bangladesh and for the role of connections to both India and mainland Southeast Asia in the development of crop diversity in the Ganges delta region

A grey approach to predicting healthcare performance

© 2018 Elsevier Ltd The success of an organization or a particular activity is evaluated through the measurement of key performance indicators (KPIs). The aim of this paper is to analyze and predict the indicators of healthcare performance using grey systems theory. Recent advancements in science and technology have made the healthcare industry extremely efficient at collecting data using electronic claims systems such as electronic health records. Therefore, collecting field level primary data becomes easier and accumulate them to generate secondary data for research purpose and to get an insight of the organization performance is absolutely necessary. Our research analyzes the KPIs of a hospital based on a secondary data source. Since, secondary data contains uncertainty and sometimes poor information, grey prediction model suits best to make a prediction model in this regard. Conventional grey model has considerable drawbacks while making a rigorous prediction model. For this, we apply an improved grey prediction model to predict the KPIs of the healthcare performance indicators. Several error measures in our model give a best fit of the data and allow prediction of the KPIs. The prediction model gives good estimates of the quantitative indicators and produced error rate within an acceptable range. We observe that the KPIs of bed turnover rate (BTR) and bed occupancy rate (BOR) have an increasing trend, whereas the KPIs of average length of stay (ALOS), hospital death rate (HDR) and hospital infection rate (HIR) show a decreasing trend over time. The main contribution of this research is a grey-based prediction model that can provide managers with the information they need to evaluate and predict the performance of a hospital. The research indicates that managers should give greater priority to the indicators which will result in better patients’ satisfaction and improved profit margin. Healthcare managers striving towards better performance will now have an empirical basis upon which to formulate and adjust their strategies, after analyzing the predicted value

Association of sickle cell disease with anthropometric indices among under-five children: evidence from 2018 Nigeria Demographic and Health Survey

BACKGROUND: Malnutrition continues to affect under-five children in Africa to an overwhelming proportion. The situation is further compounded by the burden of sickle cell disease (SCD). However, association of SCD with stunting, wasting, and underweight in a nationally representative sample of under-five children remains unexplored. We aimed to describe prevalence of undernutrition by sickle cell status, to evaluate its association with growth faltering ascertained by anthropometric indices, and to explore mediating role of hemoglobin. METHODS: We availed data from the 2018 Nigeria Demographic and Health Survey (DHS) and the sample comprised 11,233 children aged 6-59 months who were successfully genotyped for SCD. The DHS employed a two-stage, stratified sampling strategy. SickleSCAN rapid diagnostic test was used for SCD genotyping. Z-scores of length/height-for-age (HAZ), weight-for-height (WHZ), and weight-for-age (WAZ) were computed against the 2006 World Health Organization Child Growth Standards. We fitted logistic regression models to evaluate association of SCD with stunting, wasting, and underweight. Mediation analysis was performed to capture the indirect effect of and proportion of total effect mediated through hemoglobin level in SCD-anthropometric indices association. RESULTS: Prevalences of stunting, wasting, and underweight among children with SCD were 55.4% (54.5-56.4), 9.1% (8.6-9.7), and 38.9% (38.0-39.8), respectively. The odds of stunting were 2.39 times higher (adjusted odds ratio (aOR) 2.39, 95% CI: 1.26-4.54) among sickle children than those with normal hemoglobin. SCD was also significantly associated with underweight (aOR 2.64, 95% CI: 1.25-5.98), but not with wasting (aOR: 1.60, 95% CI 0.85-3.02). Association of SCD with all three anthropometric indices was significantly mediated through hemoglobin level: for SCD-HAZ, the adjusted indirect effect (aIE) was - 0.328 (95% CI: - 0.387, - 0.270); for SCD-WHZ, the aIE was - 0.080 (95% CI: - 0.114, - 0.050); and for SCD-WAZ, the aIE was - 0.245 (95% CI: - 0.291, - 0.200). CONCLUSION: We presented compelling evidence of the negative impact of SCD on anthropometric indices of nutritional status of under-five children. Integration of a nutrition-oriented approach into a definitive SCD care package and its nationwide implementation could bring promising results by mitigating the nutritional vulnerability of children with SCD

Implementation of Q Learning and Deep Q Network For Controlling a Self Balancing Robot Model

In this paper, the implementation of two Reinforcement learnings namely, Q Learning and Deep Q Network(DQN) on a Self Balancing Robot Gazebo model has been discussed. The goal of the experiments is to make the robot model learn the best actions for staying balanced in an environment. The more time it can stay within a specified limit , the more reward it accumulates and hence more balanced it is. Different experiments with different learning parameters on Q Learning and DQN are conducted and the plots of the experiments are shown.Comment: It is under review process of a journa

Effect of pH and Temperature on Halogenated DBPs

Water scarcity is one of the most challenging issues in the world in the 21st century. It is estimated that there are more than one billion of people without adequate access to freshwater and facing water shortages and water deficits. People are forced to drink polluted water despite the risk of consuming pathogenic microorganisms in the water that transmit waterborne diseases such as bacterial infections, protozoal infections and viral infections. The water disinfection process is one of the most important environmental technological advances in the 20th century which inactivates microbial contaminants in drinking water. Disinfection byproducts (DBPs) are a group of chemical compounds formed from the reaction between natural organic matter and chemical disinfectants. The formation of DBPs in drinking water has caused serious health concerns since the discovery of trihalomethanes in chlorinated drinking waters in the 1970s. Many studies have evaluated factors affecting the formation of DBPs within water treatment plants. Relatively less is known about the fate of DBPs in the distribution system. The objective of this study was to evaluate the impacts of pH and temperature on the degradation of total organic chlorine (TOC1), bromine (TOBr) and iodine (TOI). In this study, we produced TOC1 (Cl2), TOBr, TOI, and TOC1 (NC2Cl) from reactions between Suwannee River fulvic acid and chlorine, bromine, iodine and chloramine, respectively. The impact of different pH values (7.0, 8.3 and 9.5) and temperatures (10°C, 20°C, 30°C, and 55°C) on the degradation of these DBPs was investigated after oxidant residuals were exhausted. The results show that halogenated DBPs degrade through based-catalyzed dehalogenation processes. The degradation of TOC1, TOBr, and TOI increased with increasing pH values. Increasing temperatures also increased the degradation kinetics of these DBPs. Iodinated DBPs were less stable than brominated DBPs, which again were less stable than chlorinated DBPs. Relatively high degradation kinetics were also found for chloraminated DBPS. In general, the relative stability of different DBPs are in the order of TOC! (Cl2)\u3eTOBr\u3eTOI≈TOC1 (NH2CL)

Effects of organophosphate insecticide, sumithion on histopathology of common carp (Cyprinus carpio) in the natural pond condition

Sumithion is an organophosphorus insecticide, which is widely used in aquaculture ponds for eradication of aquatic insect (mainly tiger bug) prior to release of larvae. This study was conducted to evaluate the effects of an organophosphorus pesticide, sumithion on histoarchitecture of liver and kidney in common carp (Cyprinus carpio) during the period from July to December 2016. It was carried out with four treatments, each with two replications. i.e., ponds with no sumithion (T0), with 0.025ppm sumithion (T1), 0.050 ppm sumithion (T2) and 0.100 ppm sumithion (T3). The water quality parameters, such as pH, dissolved oxygen, total alkalinity, free CO2, nitrate-nitrogen (NO3-N), phosphate-phosphorus (PO4-P) were not affected by sub lethal doses of sumithion but the values were fluctuated significantly in most of the cases between the ponds throughout the study period. In case of histoarchitecture of liver and kidney, normal structure of liver and kidney cells were observed in the controlled and treated fish. Through the histological analysis of liver, small vacuole, enlarge lumen space of hepatopancreas and disrupted hepatopancreas were found in T1. Disrupted hepatopancreas, increasement intracellular space, regeneration of hepatic cell and hemorrhage were observed in T2. Moreover, enlarge lumen space of hepatopancreas, degenerated hepatic cell, disrupted hepatopancreas were observed in T3. After the histological analysis of kidney, degenerated renal corpuscle, enlargement of blood vessel, disrupted hematopoetic cell were observed in T1. Ruptured collecting duct, large vacuole, enlarge intracellular space were observed in T2. Furthermore, enlarge bowman’s space, degenerated hematopoetic cell hemorrhage and ruptured distal tubule disrupted, enlarge intracellular space and necrosis were observed in T3. The present investigation sufficiently emphasizes that sumithion has adverse effects on the major organs like liver and kidney. Int. J. Agril. Res. Innov. Tech. 10(2): 66-75, December 202