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bayes theorem

در نشریات گروه پزشکی
تکرار جستجوی کلیدواژه bayes theorem در مقالات مجلات علمی
  • Hosseinali Asgharnia, Mahdieh Haddadi, Zeynab Gerinasab, Mehdi Vosoughi, Fatemeh Aligholizadeh, Hajar Tabarinia, Mohammad Shirmardi*
    Background

    Removing dyes from wastewater is crucial for environmental protection and public health. Dyes used in various industries can be toxic and persistent, posing threats to aquatic ecosystems and human health.

    Methods

    This study examined the efficiency of beech wood-derived activated carbon (BW-AC) in removing Acid Red 18 (AR18) and Methylene Blue (MB) dyes. A batch adsorption procedure was used to investigate the impacts of various operational variables, including pH, contact time, adsorbent dosage, and initial dye concentration.

    Results

    Changes in pH did not significantly affect removal efficiency. However, increasing contact time and adsorbent dosage notably enhanced removal rates, achieving nearly complete removal after 180 minutes. Various statistical metrics were used to identify the best-fitting model, including the corrected Akaike information criterion (AICc) and Bayesian information criterion (BIC). The general order kinetic model provided the best fit to the experimental data based on its AICc values (range: -45.42 to 12.435) and BIC values (range: -48.16 to 6.67) for AR18. For MB dye, the ranges were -5.81 to 7.057 for AICc and -9.58 to 3.282 for BIC. Regarding the adsorption isotherms, the correlation capabilities of the models, as assessed by AICc and BIC, were ranked as follows for AR18: Freundlich, Liu, and Langmuir; while for MB dye, the ranking was Langmuir, Liu, and Freundlich.

    Conclusion

    The results demonstrate that BW-AC is a highly promising adsorbent for dye removal from aqueous solutions, offering a sustainable, environmentally friendly, and cost-effective solution for water and industrial wastewater treatment.

    Keywords: Adsorption, Bayes Theorem, Charcoal, Methylene Blue, Water
  • Bahare Gholami Chaboki, Manijeh Tabrizi, Maryam Heydarpour Meymeh, Hojjat Alaei, Alireza Akbarzadeh Baghban*
    Background

    Congenital hypothyroidism (CH) is one of the most prevalent preventable causes of mental retardation. Studies show that the incidence rate of CH is very high in Iran. Disease mapping is a tool for visually expressing the frequency, incidence, or relative risk of illness. The present study aimed to model CH counts considering the effects of the neighborhood in towns and perform mapping based on the relative risk.

    Methods

    In this historical cohort study, data of all neonates diagnosed with CH with TSH level ≥5 mIU/L between March 21, 2017, and March 20, 2018, in health centers in Guilan, Iran were used. The number of neonates with CH was zero in most towns of Guilan Province. The Bayesian spatial zero-inflated Poisson (ZIP) regression model was employed to investigate the effect of the town’s neighborhood on the relative risk of CH incidence. Then, the map of the posterior mean of the relative risk for CH incidence was provided. The analysis was performed using OpenBUGS and Arc GIS software programs.

    Results

    The relative risk of CH incidence was high in the West of Guilan. Moreover, the goodness-of-fit criterion indicated that it is more appropriate to fit the Bayesian spatial ZIP model to these data than the common model.

    Conclusions

    Considering the high relative risk of CH in the Western towns of Guilan Province, it is better to check important risk factors in this region.

    Keywords: Bayes theorem, congenital hypothyroidism, neonates, Poisson distribution, spatialanalysis
  • Roghaye Zare, Hooshang Saberi, Mahboubeh Parsaeian, Abbas Rahimiforoushani *
    Background
    A pre-surgical evaluation of cognitive functions in patients with mesial temporal lobe epilepsy (mTLE) is critical. The limitations of the usual brain analysis model were resolved by the spatial Bayesian variable selection (SBVS) method. An Ising and Dirichlet Process (Ising-DP) model considers SBVS and the grouping of a large number of voxels. The present study aimed to identify brain areas involved in episodic memory in patients with right mTLE and controls via the Ising-DP model. The model was extended to include between-subject factors (BSFs), and the results were compared with other classical methods.
    Methods
    The present cross-sectional study was conducted on 15 patients with right mTLE and 20 controls in Tehran, Iran, in 2018. During functional magnetic resonance imaging, the subjects were tested with the face-encoding memory task, followed by a recognition memory test. The participants demographic factors such as age, sex, marital status, area of residence, and years of schooling were considered to comprise BSFs. The independent t test, the chi-square test, and the correlation test were conducted using the SPSS software (version 20.0). The image processing was carried out using SPM (version 12.0) and MATLAB (version R2014a).
    Results
    The Ising-DP model appropriately (R2=0.642) detected activated hippocampal areas. The model adjusted for BSFs indicated a better fit by the significant effect of age (P[γ]>0.91), sex (P[γ]>0.87), and years of schooling (P[γ]>0.89). The heat maps exhibited decreased activation in the right hippocampal region in the patients compared with the controls (p <0.0001). Right hippocampal activity had a significant positive correlation with the recognition memory test in the mTLE group (r=0.665) and the control group (r=0.593).
    Conclusion
    The Ising-DP model was sufficiently sensitive to detect activated areas in our patients with right mTLE during the face-encoding memory task. Since the model adjusted for BSFs improved sensitivity, we recommend the use of more detailed BSFs such as seizure history in future research.
    Keywords: Bayes theorem, Magnetic Resonance Imaging, Hippocampus, Epilepsy, Temporal Lobe
  • Omid Karimipour Baseri, Soleiman Kheiri *, Morteza Sedehi, Ali Ahmadi
    BACKGROUND AND AIM

    Recognizing the factors affecting the number of decayed and filled teethhas a major role in oral health. Dental data usually suffer from over-dispersion and excess zero frequencies. The purpose of this study was to use theConway-Maxwell-Poisson (COM-Poisson) model to determine some of the factors affecting the number of decayed and filled teeth.

    METHODS

    In this cross-sectional study, a sample of 1000 people from a cohort study in Shahrekord City, Iran, aged 35-70 years, was selected through systematic sampling. The data were analyzed using the Bayesian approach through Markov chain Monte Carlo (MCMC) simulation by OpenBUGS. Zero-inflated Poisson (ZIP), COM-Poisson model, and zero-inflated Com-Poisson (ZICMP) model were fitted on the data and compared using the deviance information criterion (DIC).

    RESULTS

    The mean numbers of decayed and filled teeth were 0.77 ± 1.63 and 4.37 ± 4.62, respectively. The Com-Poisson and ZICMP showed to be better fit for the number of decayed and filled teeth, respectively. Those people who were younger, male, smokers, diabetics, did not floss, and did not use mouthwash had significantly more number of decayed teeth (P < 0.05). Those people who were younger, female, non-diabetics, non-smokers, employed, literate, had less body mass index (BMI), flossed, and got higher score of quality of life had significantly more number of filled teeth (P < 0.05).

    CONCLUSION

    By controlling such factors as education, BMI, flossing, using mouthwash, smoking, diabetes, and quality of life, we could improve the oral health.

    Keywords: Bayes’ Theorem, Conway-Maxwell-Poisson Distribution, Decayed, Missing, and Filled Teeth, Zero-inflated
  • فرزانه سعیدی فرد، فرشته قدیری، سحر معنوی، مطهره طالبا، معین فروغی، حمیده موسی پور، پروانه انصاری، مصطفی قربانی، اکبر سلطانی
    هنگام رویکرد بالینی به بیماران، پزشکان بایستی قادر به تخمین میزان اهمیت و نیز اولویت یافته های بالینی باشند. هدف از این مطالعه بررسی میزان همبستگی وزن دهی پزشکان به یافته های بالینی، با نسبت احتمال مثبت یافته ها ((likelihood ratio (LR) در بیمار مبتلا به آسیت می باشد.
    در این مطالعه از 110 پزشک خواسته شد تا پرسشنامه ای را تکمیل نمایند که حاوی یک سناریو از یک بیمار مبتلا به آسیت و تعدادی یافته بالینی مربوط به آسیت بود. آنها بایستی به این یافته های بالینی براساس میزان اهیمت آن ها در تشخیص آسیت و اینکه وجود آن یافته ها تا چه میزان می تواند تشخیص آسیت را تحت تاثیر قرار دهد، وزنی بین 0 تا 100 اختصاص دهند. هم زمان نسبت احتمال مثبت یافته ها نیز از شواهد معتبر موجود استخراج شد و میزان همبستگی وزن هایی که پزشکان به یافته ها اختصاص داده بودند با نسبت احتمال مثبت یافته ها ارزیابی شد.
    نتایج نشان داد که اختلاف معناداری بین وزن هایی که پزشکان به یافته ها اختصاص داده بودند با نسبت احتمال مثبت یافته ها وجود دارد و اوزان اختصاص داده شده توسط پزشکان با نسبت احتمال مثبت یافته ها همبستگی ندارد.
    کلید واژگان: نسبت احتمال یافته ها، آسیت، تئوری Bayes، تصمیم گیری بالینی
    Farzane Saeidifard, Fereshteh Ghadiri, Sahar Manavi, Motahareh Taleba, Moein Foroughi, Hamideh Moosapour, Parvaneh Ansari, Mostafa Qorbani, Akbar Soltani
    Background
    It is critical to understand how accurately physicians can estimate the importance of each clinical finding in estimating the probability of a specific diagnosis in the process of clinical decision making. This study aimed to investigate whether physicians’ estimates of the importance of various clinical findings of ascites correlated with the positive likelihood ratios of these findings in diagnosis of ascites.
    Methods
    One hundred and ten physicians were asked to respond to a questionnaire. In this questionnaire they were presented with a clinical scenario about a patient suspected of having ascites followed by a list of clinical findings. Participants were asked to assign a weight (between 0 and 100%) to each clinical finding based on their perception of how much the presence of that finding changed the probability of ascites for the patient. Positive likelihood ratios of those findings were extracted from current best evidence. We investigated if the weights assigned by physicians were associated with the positive likelihood ratios of those findings.
    Results
    Significant differences were discovered between the weights assigned by the physicians and the positive likelihood ratios for each clinical finding. Significant positive correlation was observed between the weights assigned by different groups of physicians.
    Conclusion
    Physicians inaccurately estimated the importance of various clinical findings in the diagnosis of ascites. Further research is needed to determine if such inaccurate estimations would lead to any adverse clinical outcomes
    Keywords: likelihood ratio, Ascites, Bayes theorem, Clinical decision making
  • نسرین شیرمحمدی، عباس مقیم بیگی *، منوچهر کرمی، حسین محجوب، اعظم صبوری
    سابقه و هدف

    شناسایی روند میزان بروز بیماری ها و تغییر در آن، پاسخ به هنگام نظام سلامت را به دنبال خواهد داشت. نظام مراقبت سندرومیک که مبتنی بر موارد مشکوک به بیماری است، سرعت بالایی در تعیین طغیان ها دارد. در این مطالعه به بررسی عوامل موثر بر میزان بروز تب و راش و چگونگی روند آن در ایران پرداخته شد.

    مواد و روش ها

    این مطالعه یک مطالعه هم گروهی تاریخی بوده و داده های آن به صورت تمام شماری و شامل همه موارد مشکوک به سرخک ثبت شده در تمام استان های ایران طی سال های 1391-1376 بود؛ که از نظام مراقبت بیماری های قابل پیشگیری با واکسن کشور استخراج گردید. مدل رگرسیونی پواسون و دوجمله ای منفی با اثرات تصادفی برای این داده ها برازش شد. برازش مدل و استنباط ها از طریق رهیافت بیزی و با استفاده از نرم افزارهای R و Open BUGS انجام شد. مدل ها بر اساس آماره های نیکویی برازش دویانس و خی- دو پیرسون مقایسه شدند.

    یافته ها

    اثر متقابل زمان و انجام واکسیناسیون تکمیلی بر تعداد موارد مشکوک به سرخک از نظر آماری معنی دار شد (95% CrI:1.083،1.737). تعداد موارد تب وراش بعد از انجام این واکسیناسیون با گذشت زمان شیب افزایشی را نشان داد و واریانس جزء تصادفی مدل معنادار برآورد شد (95% CrI: 0.219،0.430). ویژگی های خاص استان ها، عامل موثر بر میزان موارد تب و راش یافت شد.

    نتیجه گیری

    با توجه به روند افزایشی این میزان بروز در کشور به خصوص در سال های اخیر و موثر بودن ویژگی های خاص استانی بر میزان بروز تب و راش، لزوم کنترل دقیق تر و بهبود کیفیت واکسیناسیون به ویژه در بعضی استان ها نتیجه گیری شد.

    کلید واژگان: کنترل بیماری های واگیر، سرخک، تجزیه و تحلیل رگرسیون، برآورد بیزی
    Nasrin Shirmohammadi, Abbas Moghimbeigi, Manoochehr Karami, Hossein Mahjub, Azam Sabouri
    Introduction

    The identifying incidence rate trend of disease and its changes lead to update response of surveillance system. Syndromic surveillance system is based on the suspected cases, so it has high speed in detecting outbreaks. This study aimed to evaluate trend of fever and rash incidence rates and detect affecting factors.

    Materials And Methods

    This study was a retrospective cohort study and the data included the suspected measles cases in provinces of Iran in 1977-2012, which extracted from surveillance system of vaccine preventable diseases. We fitted Poisson and Negative-Binomial regression models with random effect. Modeling and inferences were based on a Bayesian algorithm. We used R and OpenBUGS software. The fitted models were compared based on Deviance and Chi-square goodness of fit statistics.

    Results

    Interaction effect between year and immunization campaign was statistically significant (95% CrI:1.083,1.737), after immunization campaign, trend was increasing. The variance of random component in model was statistically significant (95% CrI: 0.219,0.430). On the other hand, province-specific characterizes found affecting factor on suspected incidence rate.

    Conclusion

    In attention to increasing trend of this incidence in Iran, especially in recently years, and affecting of province-specific characterizes on suspected incidence rate, We found that more accurate control and improvement of quality vaccination is essential

    Keywords: Communicable Disease control, Measles, Regression analysis, Bayes Theorem
نکته
  • نتایج بر اساس تاریخ انتشار مرتب شده‌اند.
  • کلیدواژه مورد نظر شما تنها در فیلد کلیدواژگان مقالات جستجو شده‌است. به منظور حذف نتایج غیر مرتبط، جستجو تنها در مقالات مجلاتی انجام شده که با مجله ماخذ هم موضوع هستند.
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