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1.
Heliyon ; 10(13): e33378, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39027588

RESUMO

In developing countries, informal sector is the primary job provider for a significant portion of the workforce. This study aims to analyze how jobs in the informal sector affect the unemployment dynamics of developing nations. To achieve this goal, we formulate a nonlinear mathematical model by categorizing the considered workforce into three distinct classes: unemployed, employed, and self-employed, and include a separate dynamic variable to represent vacancies within the informal sector. The proposed model is analyzed using the qualitative theory of dynamical systems. A threshold quantity known as the reproduction number is derived and using this, one can compute the job generation rate necessary to stabilize the system. It is observed that variations in the reproduction number lead to qualitative changes, such as transcritical (forward or backward) and saddle-node bifurcations in the formulated system. Moreover, we propose an optimal control problem to determine an optimal strategy for government policy implementation in enhancing the employment rate of unemployed individuals and promoting the self-employment of informal employees inside the informal sector. Further, the analytical findings are validated numerically. The obtained results suggest that promoting the self-employment of informal employees for job generation effectively reduces unemployment.

2.
MethodsX ; 12: 102723, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38660034

RESUMO

Currently, India has become one of the largest economies of the world in which tourism and hospitality have significantly contributed; however, the growth rate of tourism industry has been greatly affected during the COVID-19 pandemic. In this study, we have used the modeling approach to analyze and understand the growth pattern of Indian tourism industry. To achieve this, we consider the data of international tourist arrivals before and after the lockdown. The Dickey-Fuller test, AIC and BIC methods are used to obtain the best fitted model and further, the accuracy of obtained model is also analyzed. Data and forecasting indicate that the weather and public holidays significantly affect the tourism industry.

3.
Math Biosci ; 368: 109133, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38145656

RESUMO

The unprecedented scale and rapidity of dissemination of re-emerging and emerging infectious diseases impose new challenges for regulators and health authorities. To curb the dispersal of such diseases, proper management of healthcare facilities and vaccines are core drivers. In the present work, we assess the unified impact of healthcare facilities and vaccination on the control of an infectious disease by formulating a mathematical model. To formulate the model for any region, we consider four classes of human population; namely, susceptible, infected, hospitalized, and vaccinated. It is assumed that the increment in number of beds in hospitals is continuously made in proportion to the number of infected individuals. To ensure the occurrence of transcritical, saddle-node and Hopf bifurcations, the conditions are derived. The normal form is obtained to show the existence of Bogdanov-Takens bifurcation. To validate the analytically obtained results, we have conducted some numerical simulations. These results will be useful to public health authorities for planning appropriate health care resources and vaccination programs to diminish prevalence of infectious diseases.


Assuntos
Doenças Transmissíveis , Modelos Biológicos , Humanos , Doenças Transmissíveis/epidemiologia , Modelos Teóricos , Vacinação , Hospitais
4.
Chaos ; 33(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38079647

RESUMO

In the past few decades, the use of fossil fuels has increased dramatically due to industrialization in developing nations. The elevation of carbon dioxide (CO2) has become a serious concern for the entire world. Therefore, most countries want to reduce the use of fossil fuels by transitioning to renewable energy sources. In this research work, we formulate a nonlinear mathematical model to study the interplay between atmospheric CO2, human population, and energy production through traditional energy sources (coal, oil, and gas) and renewable energy sources (solar, wind, and hydro). For the model formulation, we consider that the atmospheric level of CO2 increases due to human activities and energy production through traditional energy sources. Additionally, we consider that the dependency of the human population shifts from traditional to renewable sources of energy as the atmospheric level of CO2 increases. Through the model analysis, we have obtained a condition that implies a change in the equilibrium level of CO2 by increasing the deployment rate of renewable energy sources. This condition demonstrates that the atmospheric level of CO2 can be reversed from its current level through sufficient deployment of renewable energy sources. Moreover, for a certain critical value of the growth rate parameter of renewable energy, three interior equilibria may exist. This situation indicates the presence of hysteresis, which implies that the system may undergo discontinuous jumps between different stable steady states. Furthermore, we discuss an optimal control problem to minimize atmospheric CO2, simultaneously minimizing the cost of the considered strategy.

5.
Chaos ; 33(4)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37097933

RESUMO

This paper is concerned to a mathematical model for the management of hospital beds when a new infection emerges in the population with the existing infections. The study of this joint dynamics presents formidable mathematical challenges due to a limited number of hospital beds. We have derived the invasion reproduction number, which investigates the potential of a newly emerged infectious disease to persist when some infectious diseases are already invaded the host population. We have shown that the proposed system exhibits transcritical, saddle-node, Hopf, and Bogdanov-Takens bifurcations under certain conditions. We have also shown that the total number of infected individuals may increase if the fraction of the total number of hospital beds is not properly allotted to the existing and a newly emerged infectious disease. The analytically obtained results are verified with the help of numerical simulations.


Assuntos
Doenças Transmissíveis , Modelos Biológicos , Humanos , Modelos Teóricos , Doenças Transmissíveis/epidemiologia , Hospitais
6.
Model Earth Syst Environ ; 9(1): 397-412, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36059593

RESUMO

The media has a significant contribution in spreading awareness by broadcasting various programs about prevalent diseases in the society along with the role of providing information, feeding news and educating a large mass. In this paper, the effect of media programs promoting precautionary measures and sanitation practices to control the bacterial infection in the community is modeled and analyzed considering the number of media programs as a dynamical variable. In the modeling phenomena, human population is partitioned into three classes; susceptible, infected and recovered. The disease is supposed to spread by direct contact of susceptible with infected individuals and indirectly by the ingestion of bacteria present in the environment. The growth in the media programs is considered proportional to the size of infected population and the impact of these programs on the indirect disease transmission rate and bacteria shedding rate by infected individuals is also considered. The feasibility of equilibria and their stability conditions are obtained. Model analysis reveals that broadcasting media programs and increasing its effectiveness shrink the size of infected class and control the spread of disease to a large extent.

7.
MethodsX ; 9: 101932, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36467328

RESUMO

Marketers and entrepreneurs need to keep up with the fast-paced changes that are happening in the business environment, or they might face the risk of becoming obsolete in the rapidly changing business environment. It is long gone the days when a conventional business model used to help grow fast and get success. With the emergence of social media, the role of consumer-to-consumer communication about the new products and the firms that produce them has been highly magnified in the marketplace. Social media advertisements are promising tools that affect the adoption of a new product. In this paper, a non-linear mathematical model is introduced for this study. To perceive the impact of social media advertisements on the adoption of a new product, we have considered three dynamic variables; namely, (i) non-adopting population, (ii) adopting population, and (iii) social media advertisements. The stability theory of differential equations has been used to study the model analytically. The computer generated figures are drawn in support of derived analytical results for a particular set of parameter values.•We have proposed and analyzed an nonlinear mathematical model to study the impact of social media advertisements on adoption of new product.•We have considered three dynamical variables; namely, non-adopting population, adopting population, and social media advertisements.•The stability theory of differential equations has been used to study the model analytically.

8.
Trop Anim Health Prod ; 55(1): 4, 2022 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-36502455

RESUMO

Supplementation is an integral part of modern dairy-feeding practices which mainly emphasise on higher production. Different supplements have been utilized by the farmers according to the need and action of supplements. Tinospora cordifolia (TC) is one such herbal supplement which can be utilized to feed dairy animals either alone or in combination with other supplements. TC is a herb found in tropical countries and having number of medicinal properties. Beneficial health effects of TC include immunostimulation, protection against inflammation and bacterial action, hepatoprotection, antioxidant and antineoplastic effects. Available studies on TC supplementation in dairy animals have shown a positive effect on health, body parameters and production performance. Supplementing TC is economically feasible, and it can be adopted by farmers as it helps in improving their net income. However, more research is needed in the field of dairy animals to explore the full potential of this herb. This review is written with the objective of highlighting the possibilities of using TC in dairy animal rations and promoting research in the concerned field to fill the gaps in knowledge. Thorough knowledge about TC and its effect in dairy animals can add a new concept to the supplementation process and developments of dairy rations.


Assuntos
Tinospora , Animais , Extratos Vegetais/farmacologia , Suplementos Nutricionais , Antioxidantes
9.
Math Biosci Eng ; 19(11): 11628-11656, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-36124606

RESUMO

One of the key factors to control the spread of any infectious disease is the health care facilities, especially the number of hospital beds. To assess the impact of number of hospital beds and control of an emerged infectious disease, we have formulated a mathematical model by considering population (susceptible, infected, hospitalized) and newly created hospital beds as dynamic variables. In formulating the model, we have assumed that the number of hospital beds increases proportionally to the number of infected individuals. It is shown that on a slight change in parameter values, the model enters to different kinds of bifurcations, e.g., saddle-node, transcritical (backward and forward), and Hopf bifurcation. Also, the explicit conditions for these bifurcations are obtained. We have also shown the occurrence of Bogdanov-Takens (BT) bifurcation using the Normal form. To set up a new hospital bed takes time, and so we have also analyzed our proposed model by incorporating time delay in the increment of newly created hospital beds. It is observed that the incorporation of time delay destabilizes the system, and multiple stability switches arise through Hopf-bifurcation. To validate the results of the analytical analysis, we have carried out some numerical simulations.


Assuntos
Doenças Transmissíveis , Doenças Transmissíveis/epidemiologia , Suscetibilidade a Doenças , Hospitais , Humanos , Modelos Teóricos
10.
Chaos ; 31(10): 103125, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34717345

RESUMO

To explore the impact of available and temporarily arranged hospital beds on the prevention and control of an infectious disease, an epidemic model is proposed and investigated. The stability analysis of the associated equilibria is carried out, and a threshold quantity basic reproduction number ( R0) that governs the disease dynamics is derived and observed whether it depends both on available and temporarily arranged hospital beds. We have used the center manifold theory to derive the normal form and have shown that the proposed model undergoes different types of bifurcations including transcritical (backward and forward), Bogdanov-Takens, and Hopf-bifurcation. Bautin bifurcation is obtained at which the first Lyapunov coefficient vanishes. We have taken advantage of Sotomayor's theorem to establish the saddle-node bifurcation. Numerical simulations are performed to support the theoretical findings.


Assuntos
Doenças Transmissíveis , Epidemias , Número Básico de Reprodução , Doenças Transmissíveis/epidemiologia , Simulação por Computador , Hospitais , Humanos , Modelos Biológicos
11.
Trop Anim Health Prod ; 53(3): 383, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34195883

RESUMO

Buffaloes contribute about 49% of total milk production and are considered as major milk-producing animals in India. During the early stage of lactation, mostly high producing animals suffer from negative energy balance (NEB) due to imbalance between the needs and availability of energy, and this NEB has a negative impact on production and health of buffaloes. Taking this into consideration, a study was conducted at National Dairy Research Institute, Karnal on 20 freshly calved healthy Murrah buffaloes (Bubalus bubalis). Buffaloes were grouped depending on their previous milk yield, body weight, and parity as T0 (control), T1 (fatty acids), T2 (Tinospora), and T3 (mix) groups having five animals each. Supplementation of 150 g of bypass fatty acids in T1 group, 150 g of Tinospora powder in T2 group, and combination of 150 of bypass fatty acid and 150 g of Tinospora powder in T3 group over and above the standard feeding schedule was done for a duration of 90 days whereas standard feeding schedule was followed in T0 group. A significant (P < 0.05) increase in average daily milk yield was observed in T1 (10.06 ± 0.56 kg/d/h), T2 (10.30 ± 0.53 kg/d/h), and T3 (10.11 ± 0.48 kg/d/h) in comparison to control group (8.05 ± 0.38 kg/d/h). Significantly (P < 0.05) higher milk fat percent and total solids were also recorded in treatment groups over the control group. Other milk constituents (SNF, protein, lactose, ash) and milk properties (pH, conductivity, freezing point, density) remained unaffected by the supplementations. The somatic cell count values were significantly (P < 0.05) decreased in T2 and T3 with the advancement in the lactation in comparison to T0 and T1. Supplementation also leads to significantly (P < 0.05) higher MUFA and PUFA contents in milk of treatment group buffaloes in comparison to control group. The study outcomes state that combination of bypass fatty acids and Tinospora cordifolia supplementation improves milk production and its composition in lactating Murrah buffaloes.


Assuntos
Búfalos , Tinospora , Animais , Suplementos Nutricionais , Ácidos Graxos , Feminino , Índia , Lactação , Leite , Gravidez
12.
Nat Commun ; 11(1): 6021, 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33244001

RESUMO

Semiconducting ferromagnet-nonmagnet interfaces in van der Waals heterostructures present a unique opportunity to investigate magnetic proximity interactions dependent upon a multitude of phenomena including valley and layer pseudospins, moiré periodicity, or exceptionally strong Coulomb binding. Here, we report a charge-state dependency of the magnetic proximity effects between MoSe2 and CrBr3 in photoluminescence, whereby the valley polarization of the MoSe2 trion state conforms closely to the local CrBr3 magnetization, while the neutral exciton state remains insensitive to the ferromagnet. We attribute this to spin-dependent interlayer charge transfer occurring on timescales between the exciton and trion radiative lifetimes. Going further, we uncover by both the magneto-optical Kerr effect and photoluminescence a domain-like spatial topography of contrasting valley polarization, which we infer to be labyrinthine or otherwise highly intricate, with features smaller than 400 nm corresponding to our optical resolution. Our findings offer a unique insight into the interplay between short-lived valley excitons and spin-dependent interlayer tunneling, while also highlighting MoSe2 as a promising candidate to optically interface with exotic spin textures in van der Waals structures.

13.
J Diabetes Complications ; 34(9): 107671, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32651031

RESUMO

The COVID-19 pandemic has added an enormous toll to the existing challenge of diabetes care world-wide. A large proportion of patients with COVID-19 requiring hospitalization and/or succumbing to the disease have had diabetes and other chronic conditions as underlying risk factors. In particular, individuals belonging to racial/ethnic minorities in the U.S. and other countries have been significantly and disproportionately impacted. Multiple and complex socioeconomic factors have long played a role in increasing the risk for diabetes and now for COVID-19. Since the pandemic began, the global healthcare community has accumulated invaluable clinical experience on providing diabetes care in the setting of COVID-19. In addition, understanding of the pathophysiological mechanisms that link these two diseases is being developed. The current clinical management of diabetes is a work in progress, requiring a shift in patient-provider interaction beyond the walls of clinics and hospitals: the use of tele-medicine when feasible, innovative patient education programs, strategies to ensure medication and glucose testing availability and affordability, as well as numerous ideas on how to improve meal plans and physical activity. Notably, this worldwide experience offers us the possibility to not only prepare better for future disasters but also transform diabetes care beyond the COVID-19 era.


Assuntos
Betacoronavirus , Infecções por Coronavirus/complicações , Infecções por Coronavirus/epidemiologia , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/terapia , Pneumonia Viral/complicações , Pneumonia Viral/epidemiologia , COVID-19 , Infecções por Coronavirus/terapia , Diabetes Mellitus/virologia , Humanos , Pandemias , Pneumonia Viral/terapia , SARS-CoV-2
14.
Biosystems ; 187: 104039, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31605719

RESUMO

In developing countries, several diseases spread in human population due to the abundance of houseflies (a kind of carrier). The main reason behind the spread of these diseases is the lack of awareness among peoples regarding the sanitation practices and economic constraints. To understand the dynamics of the spread and control of these diseases, in this paper, we propose a mathematical model by considering logistic growth of houseflies. In the model formulation, it is assumed that houseflies transport the bacteria responsible for the disease transmission from the environment to the edibles of human population. To reduce the density of houseflies and number of infected individuals, an optimization problem is also formulated and analyzed. Numerical simulations are performed to support analytically obtained results.


Assuntos
Doenças Transmitidas por Alimentos/prevenção & controle , Moscas Domésticas , Controle de Insetos/métodos , Insetos Vetores , Modelos Teóricos , Doenças Transmitidas pela Água/prevenção & controle , Animais , Cólera/etiologia , Cólera/prevenção & controle , Cólera/transmissão , Simulação por Computador , Disenteria/etiologia , Disenteria/prevenção & controle , Doenças Transmitidas por Alimentos/etiologia , Moscas Domésticas/microbiologia , Humanos , Insetos Vetores/microbiologia , Inseticidas , Biologia de Sistemas , Doenças Transmitidas pela Água/etiologia , Doenças Transmitidas pela Água/transmissão
16.
J Diabetes Complications ; 32(11): 1068-1075, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30115487

RESUMO

The prevalence of overweight and obesity is escalating in South Asian countries. South Asians display higher total and abdominal obesity at a lower BMI when compared to Whites. Consequently, metabolic dysfunction leading to metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM) will account for a majority of the health burden of these countries. In this review, we discuss those factors that contribute to MetS and T2DM in South Asians when compared to whites, focusing on adiposity. Abdominal obesity is the single-most important risk factor for MetS and its predisposition to T2DM. Excessive ectopic fat deposition in the liver (non-alcoholic fatty liver disease) has been linked to insulin resistance in Asian Indians, while the effects of ectopic fat accumulation in pancreas and skeletal muscle need more investigation. South Asians also have lower skeletal muscle mass than Whites, and this may contribute to their higher risk T2DM. Lifestyle factors contributing to MetS and T2DM in South Asians include inadequate physical activity and high intakes of refined carbohydrates and saturated fats. These are reflective of the recent but rapid economic transition and urbanization of the South Asian region. There is need to further the research into genetic determinants of dysmetabolism as well as gene x environment interactions. Collectively, MetS and T2DM have multi-factorial antecedents in South Asians and efforts to combat it through low-cost and socio-culturally appropriate lifestyle interventions need to be supported.


Assuntos
Tecido Adiposo/metabolismo , Povo Asiático/estatística & dados numéricos , Hiperglicemia/epidemiologia , Síndrome Metabólica/epidemiologia , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo/patologia , Sudeste Asiático/epidemiologia , Ásia Ocidental/epidemiologia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etnologia , Humanos , Hiperglicemia/complicações , Hiperglicemia/diagnóstico , Hiperglicemia/etnologia , Índia/epidemiologia , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/etnologia , Síndrome Metabólica/patologia , Obesidade/diagnóstico , Obesidade/epidemiologia , Obesidade/etnologia
17.
J Biol Med Sci ; 2(1)2018.
Artigo em Inglês | MEDLINE | ID: mdl-29962510

RESUMO

OBJECTIVE: Raman spectroscopy is a non-invasive laser-based technique that identifies molecular chemical composition of tissues and cells. The objective of the work was to demonstrate that unique Raman spectroscopic fingerprints of B-cell non-Hodgkin lymphoma cells could be distinguished from normal B-cells. METHODS: Normal B-cells and B-cell non-Hodgkin lymphoma cells were mounted on aluminum slides and analyzed by Raman spectroscopy using Asymmetric Least Squares and Principal Component Analysis. RESULTS: Clustering by Principal Component Analysis differentiated normal B-cells from B-cell non-Hodgkin lymphoma cells as well as between the different B-cell non-Hodgkin lymphoma cell types. CONCLUSIONS: Raman spectroscopy technology provided a different paradigm in analyzing tumor cells which could be used for diagnosis as well as contribute new information on unique characteristics of cancer cells to understand pathogenesis and potential novel treatments.

19.
Bull Math Biol ; 80(3): 626-656, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29368079

RESUMO

The extinction of species is a major threat to the biodiversity. The species exhibiting a strong Allee effect are vulnerable to extinction due to predation. The refuge used by species having a strong Allee effect may affect their predation and hence extinction risk. A mathematical study of such behavioral phenomenon may aid in management of many endangered species. However, a little attention has been paid in this direction. In this paper, we have studied the impact of a constant prey refuge on the dynamics of a ratio-dependent predator-prey system with strong Allee effect in prey growth. The stability analysis of the model has been carried out, and a comprehensive bifurcation analysis is presented. It is found that if prey refuge is less than the Allee threshold, the incorporation of prey refuge increases the threshold values of the predation rate and conversion efficiency at which unconditional extinction occurs. Moreover, if the prey refuge is greater than the Allee threshold, situation of unconditional extinction may not occur. It is found that at a critical value of prey refuge, which is greater than the Allee threshold but less than the carrying capacity of prey population, system undergoes cusp bifurcation and the rich spectrum of dynamics exhibited by the system disappears if the prey refuge is increased further.


Assuntos
Cadeia Alimentar , Modelos Biológicos , Comportamento Predatório , Animais , Biodiversidade , Extinção Biológica , Conceitos Matemáticos , Dinâmica Populacional
20.
Indian Heart J ; 69(4): 539-544, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28822528

RESUMO

The prevalence of obesity in India is increasing and ranges from 8% to 38% in rural and 13% to 50% in urban areas. Obesity is a risk factor for development of type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia, coronary heart disease and many cancers. In Asian Indians excess abdominal and hepatic fat is associated with increased risk for T2DM and cardiovascular disease. There is higher risk for development of obesity related non-communicable diseases at lower body mass index levels, compared to white Caucasians. Despite being a commonly encountered medical problem, obesity poses challenges in treatment. Many Indian physicians find themselves to be lacking time and expertise to prepare an appropriate obesity management plan and patients experience continuous weight gain over time despite being under regular medical supervision. In this article, we outline approaches to obesity management in 'real life mode' and in context to Asian Indian patients.


Assuntos
Antropometria/métodos , Gerenciamento Clínico , Obesidade , Adulto , Humanos , Índia/epidemiologia , Obesidade/diagnóstico , Obesidade/epidemiologia , Obesidade/terapia , Prevalência
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