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In this study, we examine multiple perspectives on soliton solutions to the (3+1)-dimensional Boussinesq model by applying the unified Riccati equation expansion (UREE) approach. The Boussinesq model examines wave propagation in shallow water, which is derived from the fluid dynamics of a dynamical system. The UREE approach allows us to derive a range of distinct solutions, such as single, periodic, dark, and rational wave solutions. Furthermore, we present the bifurcation, chaotic, and sensitivity analysis of the proposed model. We use planar dynamical system theory to analyze the structure and characteristics of the system's phase portraits. The current study depends on a dynamic structure that has novel and unexplored results for this model. In addition, we display the behaviors of associated physical models in 3-dimensional, density, and 2-dimensional graphical structures. Our findings demonstrate that the UREE technique is a valuable mathematical tool in engineering and applied mathematics for studying wave propagation in nonlinear evolution equations.
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BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic and associated mitigation policies created a global economic and health crisis of unprecedented depth and scale, raising the estimated prevalence of depression by more than a quarter in high-income countries. Low- and middle-income countries (LMICs) suffered the negative effects on living standards the most severely. However, the consequences of the pandemic for mental health in LMICs have received less attention. Therefore, this study assesses the association between the COVID-19 crisis and mental health in 8 LMICs. METHODS AND FINDINGS: We conducted a prospective cohort study to examine the correlation between the COVID-19 pandemic and mental health in 10 populations from 8 LMICs in Asia, Africa, and South America. The analysis included 21,162 individuals (mean age 38.01 years, 64% female) who were interviewed at least once pre- as well as post-pandemic. The total number of survey waves ranged from 2 to 17 (mean 7.1). Our individual-level primary outcome measure was based on validated screening tools for depression and a weighted index of depression questions, dependent on the sample. Sample-specific estimates and 95% confidence intervals (CIs) for the association between COVID-19 periods and mental health were estimated using linear regressions with individual fixed effects, controlling for independent time trends and seasonal variation in mental health where possible. In addition, a regression discontinuity design was used for the samples with multiple surveys conducted just before and after the onset of the pandemic. We aggregated sample-specific coefficients using a random-effects model, distinguishing between estimates for the short (0 to 4 months) and longer term (4+ months). The random-effects aggregation showed that depression symptoms are associated with a increase by 0.29 standard deviations (SDs) (95% CI [-.47, -.11], p-value = 0.002) in the 4 months following the onset of the pandemic. This change was equivalent to moving from the 50th to the 63rd percentile in our median sample. Although aggregate depression is correlated with a decline to 0.21 SD (95% CI [-0.07, -.34], p-value = 0.003) in the period thereafter, the average recovery of 0.07 SD (95% CI [-0.09, .22], p-value = 0.41) was not statistically significant. The observed trends were consistent across countries and robust to alternative specifications. Two limitations of our study are that not all samples are representative of the national population, and the mental health measures differ across samples. CONCLUSIONS: Controlling for seasonality, we documented a large, significant, negative association of the pandemic on mental health, especially during the early months of lockdown. The magnitude is comparable (but opposite) to the effects of cash transfers and multifaceted antipoverty programs on mental health in LMICs. Absent policy interventions, the pandemic could be associated with a lasting legacy of depression, particularly in settings with limited mental health support services, such as in many LMICs. We also demonstrated that mental health fluctuates with agricultural crop cycles, deteriorating during "lean", pre-harvest periods and recovering thereafter. Ignoring such seasonal variations in mental health may lead to unreliable inferences about the association between the pandemic and mental health.
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COVID-19 , Humanos , Feminino , Adulto , Masculino , COVID-19/epidemiologia , Países em Desenvolvimento , Saúde Mental , Pandemias , Estudos Prospectivos , Controle de Doenças TransmissíveisRESUMO
BACKGROUND: This study examines the association between food insecurity and mental health of women during the COVID-19 pandemic in a resource poor setting. MATERIALS AND METHODS: Data were collected at two time-points (wave 1 and 2) from 2402 women, one per household, participating in a larger study during extended COVID-19 lockdown in the rural areas of the southwest region of Bangladesh. The primary outcome of the analyses is the association between food insecurity, measured using the Food Insecurity Experience Scale (FIES), and stress level, measured using the Perceived Stress Scale (PSS), for women during the lockdown. General awareness about COVID-19 and attitude towards prescribed preventive measures were also measured since COVID-19 health concerns could exacerbate food insecurity. RESULTS: An individual-level evaluation of the effect of wave 2 FIES score on PSS score showed that worsening of the food security status increasing the stress level of the participants (95% CI: 1.61; 2.13; p-value: <0.001). Additionally, a significant negative association was observed between the PSS score and change in food security status between the two waves (Coefficient: -1.15, 95% CI: -1.30; -0.99, p-value: <0.001), indicating that deterioration in food security status over the pandemic period increasing the stress level. At the village level, the results showed a similar pattern. General awareness around ways coronavirus spreads was high, yet there were misperceptions at a higher level. Maintaining hand hygiene, wearing face masks outside the home, and going outside only when necessary were widely practised. Fewer respondents could maintain a 1.5-metre distance from others in the outside and maintained cough and sneeze etiquette. CONCLUSION: The results indicate a higher stress level, a potential contributor to poor mental health, as food insecurity deteriorated. Policy initiatives in ameliorating immediate food insecurity during crises, improving long-term wellbeing, and expanding the reach of mental health support are warranted.
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COVID-19/psicologia , Adulto , Atitude Frente a Saúde , Bangladesh , Países em Desenvolvimento , Características da Família , Feminino , Insegurança Alimentar , Humanos , Saúde Mental , Pandemias/estatística & dados numéricos , Distanciamento FísicoRESUMO
A hidden cost of the COVID-19 pandemic is the stigma associated with the disease for those infected and groups that are considered as more likely to be infected. This paper examines whether the provision of accurate and focused information about COVID-19 from a reliable source can reduce stigmatization. We carry out a randomized field experiment in the state of Uttar Pradesh, India, in which we provide an information brief about COVID-19 by phone to a random subsample of participants to address stigma and misconceptions. We find that the information brief decreases stigmatization of COVID-19 patients and certain groups such as religious minorities, lower-caste groups, and frontline workers (healthcare, police), and reduces the belief that infection cases are more prevalent among certain marginalized social and economic groups (Muslims, low caste, rural-poor population). We provide suggestive evidence that improved knowledge about the prevention and transmission of COVID-19 and reduced stress about the disease are important channels for the reduction in stigmatization.
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COVID-19 , Informação de Saúde ao Consumidor , Pandemias , Humanos , Índia/epidemiologia , SARS-CoV-2 , Estigma SocialRESUMO
Past studies that have designed interventions to reduce the prevalence of sexually transmitted infections (STIs) have typically provided onsite treatment to sex workers who tested positive, which were expensive and difficult to implement. The purpose of this study was to examine the effect of an intervention which tested for STIs and provided information on the closest treatment facility on reducing the prevalence of STIs among female brothel-based sex workers (BSWs) in Bangladesh. The study adopted a pre-post interventional design as well as a randomized controlled study design. A baseline sample and follow-up urine sample were collected to evaluate the prevalence of STIs among participants in the treatment, but not control group. A baseline survey and interviews were also conducted for both the groups. The study found a nonsignificant reduction from baseline to follow-up in STI prevalence among intervention participants (adjusted odds ratio [aOR]: 0.74; 95% CI: 0.38, 1.45). However, the participants in the intervention group were significantly more likely to have a repeat client (aOR: 1.60; 95% CI: 1.12, 2.29) and nonsignificantly less likely to engage with a client suspected of having an STI (aOR: 0.62; 95% CI: 0.39, 1.00) than participants in the control group. The intervention testing of STIs and providing information to the positive cases about nearest treatment facilities were not effective in reducing the prevalence of STIs among BSWs. Further study of the clinical and behavioral impacts of such efforts to reduce STIs among BSWs is warranted.
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Infecções por HIV/diagnóstico , Programas de Rastreamento/normas , Profissionais do Sexo/estatística & dados numéricos , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Adulto , Bangladesh/epidemiologia , Feminino , Infecções por HIV/epidemiologia , Humanos , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Prevalência , Comportamento Sexual , Adulto JovemRESUMO
The paper shows the effect of the probe on the performance of a transonic axial speed compressor. The unobstructed flow case with the experimental data was validated and used as a guide for all subsequent study cases. The aerodynamic performance for different probe parameters were calculated numerically using ANSYS-CFX. This covered the results on compressor output from changing probe axial positions, the radial immersion depths, the size of the probe, and the total number of probes. The findings were evaluated in relation to the total pressure ratio, performance, margin of deflation and stability. The velocity part distributions further showed that the probe block and raises the flow Mach value, which is the explanation why the compressor rotor's total pressure ratio is lost. In fact, the parameters of the sample will significantly influence the calculation outcomes and affect the standard margin. The range of stability was also affected, which changes the performance trend from the choke to the stall. Consequently, the collection of correct probe parameters with fewer impact on compressor output is addressed.
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Desenho de Equipamento , Modelos TeóricosRESUMO
COVID-19 has threatened food security of the poor due to the lockdown of markets amidst poor institutions and lack of social safety nets in the developing world. To provide rapid evidence on the determinants and dynamics of food insecurity and to understand the coping strategies adopted by rural households during the pandemic, we carried out a telephone survey of roughly 10,000 rural households in Bangladesh, three weeks after the country went into lockdown. We found that roughly 90% of households reported experiencing a negative income shock after the countrywide lockdown was implemented. Households that primarily depend on daily casual labor for their income were affected the most, while households with regular jobs were affected the least in terms of food insecurity. Households adversely hit by income shock due to the pandemic were also found to rely more on past savings, food stocks, and loans from various sources to cope with the food crisis. When we followed-up 2402 households, about 3 to 4 weeks after the first survey, to understand the dynamics of food insecurity, we found that food insecurity increased significantly across households and began affecting groups that were in an advantageous position during the first survey. This poses a threat to the poor as food security has already worsened since the crisis hit and would presumably worsen further in the future unless rapid measures are taken to attenuate it at the earliest.
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Survey measures of risk attitudes are primarily used in the health literature, although incentivized measures of risk preferences are being increasingly used in other fields. We exploit the unique setting of commercial female sex workers in Bangladesh to investigate whether incentivized measures of risk preferences, or non-incentivized survey measures of risk preferences, best identify the risky commercial sex decisions that they make. The study uses survey data collected during February-April 2016, and October-November 2016 from eight brothels in Bangladesh. Wave 1 includes 1,332 female sex workers, Wave 2 includes 1,185 female sex workers. Our findings suggest that researchers can reliably use survey measures to elicit risk preferences on health.
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Comportamento do Consumidor/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Assunção de Riscos , Profissionais do Sexo/psicologia , Adulto , Bangladesh , Feminino , Humanos , Profissionais do Sexo/estatística & dados numéricos , Inquéritos e QuestionáriosRESUMO
We use randomized roommate assignment in dormitories in a college in Kolkata in India to examine peer effects in weight gains among roommates. We use administrative data on weight, height, and test scores of students at the time of college admission and then survey these students at the end of their first and second years in college. We do not find any significant roommate specific peer effect in weight gain. Our results rather suggest that an obese roommate reduces the probability that the other roommates become obese in subsequent years. We examine potential mechanism using survey data on students' eating habits, smoking, exercise, and sleeping patterns. We find that obese roommates sleep longer, which in turn improves the sleep pattern of others, which might explain the weak negative effect of obese roommates on the weight of others in the same room.
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Habitação , Estudantes/estatística & dados numéricos , Universidades , Aumento de Peso , Humanos , Índia , Masculino , Probabilidade , Adulto JovemRESUMO
With recent advancements in techniques and technologies in the field of interventional cardiology, Percutaneous Coronary Intervention (PCI) is preferred over Coronary Artery Bypass Grafting (CABG), provided patient selection is kept in mind, and all the technical facilities are available to ensure successful end results without any immediate or late cardiac complications. However, dealing with Left Main Coronary Artery (LMCA) osteal disease can be challenging. We report a case of T and Protrusion (TAP) technique performed at Hearts International Hospital, Rawalpindi, Pakistan. The patient was old and had compromised Left Ventricular Ejection Fraction (LVEF).The results were excellent with no complications.
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Doença da Artéria Coronariana/cirurgia , Intervenção Coronária Percutânea/métodos , Stents , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda/fisiologia , Idoso , Angioplastia Coronária com Balão , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/fisiopatologia , Humanos , Masculino , Fatores de Risco , Volume Sistólico , Resultado do Tratamento , Disfunção Ventricular Esquerda/etiologiaRESUMO
The Epi Info Viral Hemorrhagic Fever application (Epi Info VHF) was developed in response to challenges managing outbreak data during four 2012 filovirus outbreaks. Development goals included combining case and contact data in a relational database, facilitating data-driven contact tracing, and improving outbreak data consistency and use. The application was first deployed in Guinea, when the West Africa Ebola epidemic was detected, in March 2014, and has been used in 7 African countries and 2 US states. Epi Info VHF enabled reporting of compatible data from multiple countries, contributing to international Ebola knowledge. However, challenges were encountered in accommodating the epidemic's unexpectedly large magnitude, addressing country-specific needs within 1 software product, and using the application in settings with limited Internet access and information technology support. Use of Epi Info VHF in the West Africa Ebola epidemic highlighted the fundamental importance of good data management for effective outbreak response, regardless of the software used.
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Busca de Comunicante , Surtos de Doenças/prevenção & controle , Epidemias/prevenção & controle , Sistemas de Informação em Saúde , Doença pelo Vírus Ebola/epidemiologia , Febres Hemorrágicas Virais/epidemiologia , África Ocidental/epidemiologia , Feminino , Recursos em Saúde , Doença pelo Vírus Ebola/virologia , Febres Hemorrágicas Virais/virologia , Humanos , Masculino , SoftwareRESUMO
INTRODUCTION: Cervical necrotizing fasciitis is an aggressive infection with high morbidity and mortality. We present a case of cervical necrotizing fasciitis and descending mediastinitis in a healthy young man, caused by unilateral tonsillitis with a successful outcome without aggressive debridement. CASE PRESENTATION: A 41-year-old man was admitted to our unit with a diagnosis of severe acute unilateral tonsillitis. On admission, he had painful neck movements and the skin over his neck was red, hot and tender. Computed tomography scan of his neck and chest showed evidence of cervical necrotizing fasciitis and descending mediastinitis secondary to underlying pharyngeal disease. He was treated with broad-spectrum intravenous antibiotics. His condition improved over the next 3 days but a tender and fluctuant swelling appeared in the suprasternal region. A repeat scan showed the appearance of an abscess extending from the pretracheal region to the upper mediastinum which was drained through a small transverse anterior neck incision. After surgery, the patient's condition quickly improved and he was discharged on the 18th day of admission. CONCLUSION: Less invasive surgical techniques may replace conventional aggressive debridement as the treatment of choice for cervical necrotizing fasciitis and descending necrotizing mediastinitis.