Cost-effectiveness of a potential Zika vaccine candidate: a case study for Colombia

Background: A number of Zika vaccine platforms are currently being investigated, some of which have entered clinical trials. We sought to evaluate the cost-effectiveness of a potential Zika vaccine candidate under the WHO Vaccine Target Product Profile for outbreak response, prioritizing women of reproductive age to prevent microcephaly and other neurological disorders. Methods: Using an agent-based simulation model of ZIKV transmission dynamics in a Colombian population setting, we conducted cost-effectiveness analysis with and without pre-existing herd immunity. The model was parameterized with estimates associated with ZIKV infection, risks of microcephaly in different trimesters, direct medical costs, and vaccination costs. We assumed that a single dose of vaccine provides a protection efficacy in the range 60% to 90% against infection. Cost-effectiveness analysis was conducted from a government perspective. Results: Under a favorable scenario when the reproduction number is relatively low (R0 = 2.2) and the relative transmissibility of asymptomatic infection is 10% compared with symptomatic infection, a vaccine is cost-saving (with negative incremental cost-effective ratio; ICER) for vaccination costs up to US$6 per individual without herd immunity, and up to US$4 per individual with 8% herd immunity. For positive ICER values, vaccination is highly cost-effective for vaccination costs up to US$10 (US$7) in the respective scenarios with the willingness-to-pay of US$6610 per disability-adjusted life-year, corresponding to the average per capita GDP of Colombia between 2013 and 2017. Our results indicate that the effect of other control measures targeted to reduce ZIKV transmission decreases the range of vaccination costs for cost-effectiveness due to reduced returns of vaccine-induced herd immunity. In all scenarios investigated, the median reduction of microcephaly exceeded 64% with vaccination. Conclusions: Our study suggests that a Zika vaccine with protection efficacy as low as 60% could significantly reduce the incidence of microcephaly. From a government perspective, Zika vaccination is highly cost-effective, and even cost-saving in Colombia if vaccination costs per individual is sufficiently low. Efficacy data from clinical trials and number of vaccine doses will be important requirements in future studies to refine our estimates, and conduct similar studies in other at-risk populations. Keywords: Zika, Microcephaly, Vaccination, Agent-based modeling, Cost-effectivenessYork University Librarie

Friction in metal-on-metal total disc arthroplasty: effect of ball radius

Total Disc Arthroplasty (TDA) can be used to replace a degenerated intervertebral disc in the spine. There are different designs of prosthetic discs, but one of the most common is a ball-and-socket combination. Contact between the bearing surfaces can result in high frictional torque, which can then result in wear and implant loosening. This study was designed to determine the effects of ball radius on friction. Generic models of metal-on-metal TDA were manufactured with ball radii of 10, 12, 14 and 16 mm, with a radial clearance of 0.015 mm. A simulator was used to test each sample in flexion-extension, lateral bending and axial rotation at frequencies of 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2 Hz under loads of 50, 600, 1200 and 2000 N, in new born calf serum. Frictional torque was measured and Stribeck curves were plotted to illustrate the lubrication regime in each case. It was observed that implants with a smaller ball radius showed lower friction and showed boundary and mixed lubrication regimes, whereas implants with larger ball radius showed boundary lubrication only. This study suggests designing metal-on-metal TDAs with ball radius of 10 or 12 mm, in order to reduce wear and implant loosening

Long-term Water Balance of an Inland River Basin in an Arid Area, North-Western China

China, like many other countries in the region suffers from the water scarcity and problems of desertification and land degradation. One of the most useful approaches to deal with such a problem in the region is water balance study and analysis of different components involved to get an overview of the water supply and demand of the region so that engineers and policy makers can use that in their decision. Different hydrologic models have been developed for different conditions e.g. catchment size and data availability. Hydrologic Modeling System (HEC-HMS) among them is capable to simulate different catchment sizes with well detailed information as well as limited data availability. Geographic Information System (GIS) is also used as a useful tool to delineate sub-basins and extract terrain and physical characteristics of the region and associate them to the hydrologic model. Long term water balance for years between 1963 and 2001 was studied at Shiyang River basin, an inland catchment in Gansu province in western part of China. Calibration for the model could not be applied because of immense data limitation, though the model computes a fairly good estimation of water volume of the region which was applied in water balance equation. The hydrologic components e.g. water supply and demand of the region was determined and the trend of changes of the components were also presented for the study period. The study shows a good cooperation between GIS and HEC-HMS to apply for water balance study and gives a good estimation of component values despite limited data

Comparative dynamics of monovalent and bivalent vaccination for immunologically unrelated pathogens

Multivalent vaccines are designed to immunize against two or more pathogens in a single dose vaccination. A challenge for wide spread use of these vaccines is their lower protection efficacy compared to monovalent vaccines that immunize individuals against a single pathogen. We sought, for the first time, to evaluate the outcomes of bivalent and monovalent vaccines in terms of the reduction in the number of infections over time. For this evaluation, we developed epidemiological models governing the transmission dynamics of two immunologically unrelated pathogens, where immunity conferred by vaccination or natural infection of one pathogen does not provide any cross-protection against the other pathogen. We assumed that a monovalent vaccine provides full, but temporary, protection against a particular pathogen. While protecting against both pathogens requires two pathogen-specific monovalent vaccines, a single dose of the bivalent vaccine provides partial protection against both pathogens. We analyzed the two models to investigate the impact of vaccination. In addition to examining global behaviors and disease persistence of the models, we performed simulations to show the existence of a biologically feasible region for the bivalent vaccine to outperform monovalent vaccines for prevention of disease transmission using a lower number of vaccines

La comparación del dolor de cabeza en la medicina iraní moderna y tradicional

Headache is one of the most common pains in during life all of the human, which even children sometimes suffer from it. In modern medicine, headaches are broadly classified into two primary and secondary. Primary headaches usually are headaches in which the illness or other factor has not caused headache, and include cluster headaches - migraines and tension-type headaches and chronic daily headaches. Secondary headaches have many causes and pathologies (disease or pathology) that affected by disease or problems in other parts of the body, or intracranial disease, such as meningitis, which has been shown as a headache. Fortunately, about 98% of the headaches are benign and improvable and 1to 2 percent of the headaches occur due to brain tumors or brain damage. According to the World Health Organization, 64% to 77% of the world’s population experienced headaches at least once in their life, and  50% of the people once a year had headaches. In traditional Iranian medicine, as many as sixty types of headaches in various temperaments: Bilious, Sanguine, phlegmatic and melancholic, by Iranian great scientists such as Avicenna and Hakim Momen, have been investigated and various strategies for prevention and treatment many of them have been recommended. In this research, several studies to search in the authoritative traditional medicine resources and PubMed databases investigated and various mechanisms for the treatment of headache in Iranian traditional medicine have been interpreted.El dolor de cabeza es uno de los dolores más comunes en la vida de todo el ser humano, que incluso los niños a veces sufren. En la medicina moderna, los dolores de cabeza se clasifican ampliamente en dos primarios y secundarios. Los dolores de cabeza primarios generalmente son dolores de cabeza en los que la enfermedad u otro factor no ha causado dolor de cabeza e incluyen dolores de cabeza en racimo: migrañas y dolores de cabeza de tipo tensional y dolores de cabeza crónicos diarios. Los dolores de cabeza secundarios tienen muchas causas y patologías (enfermedades o patologías) que se ven afectadas por enfermedades o problemas en otras partes del cuerpo o enfermedades intracraneales, como la meningitis, que se ha demostrado como un dolor de cabeza. Afortunadamente, alrededor del 98% de los dolores de cabeza son benignos y mejorables y del 1 al 2 por ciento de los dolores de cabeza ocurren debido a tumores cerebrales o daño cerebral. Según la Organización Mundial de la Salud, del 64% al 77% de la población mundial experimentó dolores de cabeza al menos una vez en su vida, y el 50% de las personas una vez al año tenían dolores de cabeza. En la medicina tradicional iraní, se han investigado hasta sesenta tipos de dolores de cabeza en varios temperamentos: biliosos, sangrientos, flemáticos y melancólicos, por grandes científicos iraníes como Avicena y Hakim Momen, y se han investigado varias estrategias para la prevención y el tratamiento, muchos de ellos. recomendado. En esta investigación, se investigaron varios estudios para buscar en los recursos autorizados de la medicina tradicional y las bases de datos PubMed y se han interpretado varios mecanismos para el tratamiento del dolor de cabeza en la medicina tradicional iraní

Impact of viral drift on vaccination dynamics and patterns of seasonal influenza

BACKGROUND: Much research has been devoted to the determination of optimal vaccination strategies for seasonal influenza epidemics. However, less attention has been paid to whether this optimization can be achieved within the context of viral drift. METHODS: We developed a mathematical model that links different intra-seasonal dynamics of vaccination and infection to investigate the effect of viral drift on optimal vaccination for minimizing the total number of infections. The model was computationally implemented using a seasonal force of infection, with estimated parameters from the published literature. RESULTS: Simulation results show that the pattern of large seasonal epidemics is strongly correlated with the duration of specific cross-protection immunity induced by natural infection. Considering a random vaccination, our simulations suggest that the effect of vaccination on epidemic patterns is largely influenced by the duration of protection induced by strain-specific vaccination. We found that the protection efficacy (i.e., reduction of susceptibility to infection) of vaccine is a parameter that could influence these patterns, particularly when the duration of vaccine-induced cross-protection is lengthened. CONCLUSIONS: Given the uncertainty in the timing and nature of antigenically drifted variants, the findings highlight the difficulty in determining optimal vaccination dynamics for seasonal epidemics. Our study suggests that the short- and long-term impacts of vaccination on seasonal epidemics should be evaluated within the context of population-pathogen landscape for influenza evolution

Diagnostic Accuracy of Chest Ultrasonography versus Chest Radiography for Identification of Pneumothorax: A Systematic Review and Meta-Analysis

Background: Early detection of pneumothorax is critically important. Several studies have shown that chest ultrasonography (CUS) is a highly sensitive and specific tool. The present systematic review and meta-analysis was designed to evaluate the diagnostic accuracy of CUS and chest radiography (CXR) for detection of pneumothorax. Materials and Methods: The literature search was conducted using PubMed, EMBASE, Cochrane, CINAHL, SUMSearch, Trip databases, and review article references. Eligible articles were defined as diagnostic studies on patients suspected for pneumothorax who underwent chest computed tomography (CT) scan and those assessing the screening role of CUS and CXR. Results: The analysis showed the pooled sensitivity and specificity of CUS were 0.87 (95% CI: 0.81-0.92; I2= 88.89, P<0.001) and 0.99 (95% CI: 0.98-0.99; I2= 86.46, P<0.001), respectively. The pooled sensitivity and specificity of CXR were 0.46 (95% CI: 0.36-0.56; I2= 85.34, P<0.001) and 1.0 (95% CI: 0.99-1.0; I2= 79.67, P<0.001), respectively. The Meta regression showed that the sensitivity (0.88; 95% CI: 0.82 - 0.94) and specificity (0.99; 95% CI: 0.98 - 1.00) of ultrasound performed by the emergency physician was higher than by non-emergency physician. Non-trauma setting was associated with higher pooled sensitivity (0.90; 95% CI: 0.83 – 0.98) and lower specificity (0.97; 95% CI: 0.95 – 0.99). Conclusion: The present meta-analysis showed that the diagnostic accuracy of CUS was higher than supine CXR for detection of pneumothorax. It seems that CUS is superior to CXR in detection of pneumothorax, even after adjusting for possible sources of heterogeneity. Key words: Pneumothorax; Ultrasonography; Radiography; Diagnostic tests, Routin

Empowering Learning: Standalone, Browser-Only Courses for Seamless Education

Massive Open Online Courses (MOOCs) have transformed the educational landscape, offering scalable and flexible learning opportunities, particularly in data-centric fields like data science and artificial intelligence. Incorporating AI and data science into MOOCs is a potential means of enhancing the learning experience through adaptive learning approaches. In this context, we introduce PyGlide, a proof-of-concept open-source MOOC delivery system that underscores autonomy, transparency, and collaboration in maintaining course content. We provide a user-friendly, step-by-step guide for PyGlide, emphasizing its distinct advantage of not requiring any local software installation for students. Highlighting its potential to enhance accessibility, inclusivity, and the manageability of course materials, we showcase PyGlide's practical application in a continuous integration pipeline on GitHub. We believe that PyGlide charts a promising course for the future of open-source MOOCs, effectively addressing crucial challenges in online education

Hydrochemical Effect of Different Quality of Water on the Behaviour of an Expansive Soil During Wetting and Drying Cycles

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The effect of quality of water on deformation, pH, EC (electrical conductivity) and osmotic suction was studied for an expansive soil during wetting and drying tests. The cyclic wetting and drying tests were conducted on samples of an expansive soil in a modified oedometer flooded with distilled, acidic and saline water. During the tests axial deformation of the samples was recorded continuously. pH and EC of pore water and reservoir water were measured through duplicated samples in a conventional oedometer. Osmotic suction was calculated based on the values of EC. The results show that the magnitude of deformation depends on the quality of the water and the deformation attained an equilibrium condition after almost four cycles. pH, EC and osmotic suction decreased with increasing suction. Copyright © 2016 John Wiley & Sons, Ltd