Causal Imitability Under Context-Specific Independence Relations

Drawbacks of ignoring the causal mechanisms when performing imitation learning have recently been acknowledged. Several approaches both to assess the feasibility of imitation and to circumvent causal confounding and causal misspecifications have been proposed in the literature. However, the potential benefits of the incorporation of additional information about the underlying causal structure are left unexplored. An example of such overlooked information is context-specific independence (CSI), i.e., independence that holds only in certain contexts. We consider the problem of causal imitation learning when CSI relations are known. We prove that the decision problem pertaining to the feasibility of imitation in this setting is NP-hard. Further, we provide a necessary graphical criterion for imitation learning under CSI and show that under a structural assumption, this criterion is also sufficient. Finally, we propose a sound algorithmic approach for causal imitation learning which takes both CSI relations and data into account.Comment: 19 pages, 4 figures, under revie

A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac

The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a phantom and a tumor loaded with nanoparticles. Electron dose enhancement by Au, Ag, I and Fe2O3 nanoparticles of 7, 18 and 30 mg/ml concentrations for 8, 12 and 14 MeV electrons was calculated. The increase in photon contamination due to the presence of the nanoparticles was evaluated as well. The above effects were evaluated for 500 keV and 10 keV energy cut-offs defined for electrons and photons. For 500 keV energy cut-off, there was no significant electron dose enhancement. However, for 10 keV energy cut-off, a maximum electron dose enhancement factor of 1.08 was observed for 30 mg/ml of gold nanoparticles with 8 MeV electrons. An increase in photon contamination due to nanoparticles was also observed which existed mainly inside the tumor. A maximum photon dose increase factor of 1.07 was observed inside the tumor with Au nanoparticles. Nanoparticles can be used for the enhancement of electron dose in the electron mode of a linac. Lower energy electron beams, and nanoparticles with higher atomic number, can be of greater benefi t in this field. Photons originating from nanoparticles will increase the photon dose inside the tumor, and will be an additional advantage of the use of nanoparticles in radiotherapy with electron beams

A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac

The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a phantom and a tumor loaded with nanoparticles. Electron dose enhancement by Au, Ag, I and Fe2O3 nanoparticles of 7, 18 and 30 mg/ml concentrations for 8, 12 and 14 MeV electrons was calculated. The increase in photon contamination due to the presence of the nanoparticles was evaluated as well. The above effects were evaluated for 500 keV and 10 keV energy cut-offs defined for electrons and photons. For 500 keV energy cut-off, there was no significant electron dose enhancement. However, for 10 keV energy cut-off, a maximum electron dose enhancement factor of 1.08 was observed for 30 mg/ml of gold nanoparticles with 8 MeV electrons. An increase in photon contamination due to nanoparticles was also observed which existed mainly inside the tumor. A maximum photon dose increase factor of 1.07 was observed inside the tumor with Au nanoparticles. Nanoparticles can be used for the enhancement of electron dose in the electron mode of a linac. Lower energy electron beams, and nanoparticles with higher atomic number, can be of greater benefit in this field. Photons originating from nanoparticles will increase the photon dose inside the tumor, and will be an additional advantage of the use of nanoparticles in radiotherapy with electron beams

Causal Effect Identification in Uncertain Causal Networks

Causal identification is at the core of the causal inference literature, where complete algorithms have been proposed to identify causal queries of interest. The validity of these algorithms hinges on the restrictive assumption of having access to a correctly specified causal structure. In this work, we study the setting where a probabilistic model of the causal structure is available. Specifically, the edges in a causal graph exist with uncertainties which may, for example, represent degree of belief from domain experts. Alternatively, the uncertainty about an edge may reflect the confidence of a particular statistical test. The question that naturally arises in this setting is: Given such a probabilistic graph and a specific causal effect of interest, what is the subgraph which has the highest plausibility and for which the causal effect is identifiable? We show that answering this question reduces to solving an NP-complete combinatorial optimization problem which we call the edge ID problem. We propose efficient algorithms to approximate this problem and evaluate them against both real-world networks and randomly generated graphs.Comment: 27 pages, 9 figures, NeurIPS 2023 conference, causal identification, causal discovery, probabilistic model

Health outcomes of Fitbit, Garmin or Apple Watch-based interventions

Introduction: A rising number of systematic reviews of smartwatch clinical effectiveness have been published; however, the findings are conflicting and need further investigation. Our purpose was to assess the methodological and evidence synthesis quality of meta-analyses of the therapeutic efficacy of Fitbit, Garmin, or Apple Watch-based interventions. Material and Methods: Systematic searches were carried out with three electronic databases from inception to October 2021. Full text systematic reviews originally published in English in peer-reviewed journals describing meta-analyses of all clinical outcomes of Fitbit-, Garmin-, or Apple Watch -based interventions were eligible for this study. The Amstar-2 scale and GRADE were used to assess the methodological and evidence synthesis quality, respectively. Results: One study with low methodological quality (overall score of 13.5) was identified, which contained five outcomes. None of the outcomes met the GRADE criteria for high-quality evidence (0%). Two outcomes (40%) had moderate-quality evidence synthesis, while three outcomes (60%) had low-quality evidence synthesis. The most prevalent downgrading GRADE factor was a risk of bias (100%), followed by imprecision (80%), and publication bias (60%). Conclusion: Despite the widespread adoption of smartwatches, there is a large gap in the literature as there is limited evidence. This review suggests that further clinical trials and meta- analyses are needed and it formulates research recommendations

Effect of Post-space Preparation with Rotary Devices and Heated Instruments on Microbial Leakage of Gutta-percha and Resilon-Epiphany Obturated Canals

Introduction: After endodontic procedures, root canal reinfection is a main concern for dentists. However, application of a proper apical seal can prevent such contamination. Therefore, it seems necessary to study the factors affecting the development of a suitable apical seal. Materials and Methods: In this study, 64 extracted human single-canal premolars were used. An equal length of roots was obtained by cutting the crown. The teeth were randomly divided into four experimental groups of 15 premolars, as well as 2 positive and negative controls. The root canal was manually prepared using K-file and step back method through canal filling by lateral compaction technique. In GP and GH groups, gutta-percha and AH 26 sealer were used to fill the canals, while Resilon and Epiphany sealer were used in RP and RH groups, respectively. Then, to prepare the post space, Peeso Reamer drill was used in GP and RP groups while heat carrier was applied in GH and RH groups to prepare the post space, respectively.  The coronal part of each root was contacted with enterococcus faecalis leachate in BHI medium and the root end was placed in the same culture medium. The samples were daily checked for turbidity in the lower culture medium for 90 days. The average duration of bacterial leakage between the groups wascompared using independent Student t-test. Results: All the positive control samples showed bacterial infiltration within 24 to 48 hours, while the negative control teeth remained uninfected during the test. Comparison of bacterial leakage rates between GP and GH groups showed no significant difference, which was similar to comparison results between RP and RH groups (P=0.549 and P=0.097, respectively). Comparison of bacterial leakage between GP and RP groups, as well as between GH and RH groups, showed a significant difference (P=0.018 and

Numerical analysis of side hull configuration in Trimaran

A trimaran is a multihull vessel designed to reduce wave-making resistances at high speeds. Optimization of the hull shape increases hull efficiency and speed of a vessel. The behavior of a ship is generally analyzed through numerical methods to save time and reduce high expenditures as compared to experimental methods. Although wide ranges of studies have investigated the hydrodynamic behavior of a vessel, the effect of trim angle, yaw angle, and heel angle of side hulls on hydrodynamic behavior of a trimaran has not been addressed properly. In the present study, a trimaran was modeled using computer-aided design software. Dimensions of the computational domain and boundary conditions were applied. Furthermore, mesh convergence was carried out. The accuracy of the method was validated. Analyses are based on the finite volume method. The analysis is carried out to obtain the resistance of side hulls and its effect on total trimaran resistance, effect of speed on hulls vessel resistance, wave patterns generated by the vessel at different trim and yaw angles, effect of trim, heel and yaw angles on side hull and total resistance of trimaran, the wetted surface at different trim, yaw, and heel angles, shape of free surface between the hulls, and the optimal position and trim angle of side hulls relative to the main hull. This computational analysis represents a step in quantifying the role of the trim, heel and yaw angles of side hulls on hydrodynamic characteristics of trimaran in calm water. The worth of information from the present study may express the importance of the factors that could reduce the total resistance of a trimaran.Peer Reviewe

PSYCHOMETRICS AND VALIDATION OF THE IRANIAN VERSION OF THE DIABETES HEALTH LITERACY ASSESSMENT QUESTIONNAIRE

Background: Assessing the health literacy of diabetic patients requires the availability of a tool specific to this group. The Diabetes Health Literacy Assessment Questionnaire (LAD) is one of the tools used to measure the health literacy of diabetic patients. The present study was conducted with the aim of translating and validating the Persian version of the LAD questionnaire. Methods: The present study aimed to determine the validity and reliability of the Persian version of the Health Literacy Assessment Questionnaire for diabetic patients on 300 patients with diabetes in 1398, by sampling. Stages of study: First: Translation and preparation of the Persian version of the health literacy questionnaire in order to design and select items and their qualitative evaluation by the second group: Quantitative evaluation of narrative features using the opinions of the third group of experts: Formal narrative evaluation (comprehensibility) and The reliability of the questionnaire was assessed by a small group of the target population in a fourth experimental study: analysis of items, validity assessment and reliability of the final questionnaire. Results: In the analysis of organizational structure items, the effects of roof and floor were not observed. The highest averages were for items 8 and 12 and the lowest averages were for items 6. According to the Skewness Index, no deviation was observed in the items. Based on the results, the instrument had acceptable internal stability. Detective factor analysis identified two factors for the Diabetes Health Literacy Questionnaire: one was individual understanding and the second was social support. Conclusion: The results of exploratory factor analysis, Diabetes Health Literacy Questionnaire (LAD) have good validity and reliability and can be used to measure the health literacy of diabetic patients. Keywords: Validity, Reliability, Initial Validation, Health Literacy Assessment Questionnaire For Diabetic Patient

Estimation of Burden of Cystic Echinococcosis in Iran Using Disability Adjusted Life Years (DALYs) in 2018

Background: Human hydatidosis as a public concern has increased in a number of countries that have reduced control programs for the disease due to lack of resources or policies. We aimed to estimate Disability-Adjusted Life Years (DALYs) for human hydatidosis in Iran in 2018. Methods: Data were collected from the Center of Communicable Diseases Control, Ministry of Health &Medical Education, Tehran, Iran in 2018. To calculate DALYs, years of life lost due to premature death (YLL) with years of life with disability (YLD) were calculated according to the formula as DALY = YLL + YLD. The standard life expectancy lost method (SEYLL) was used to calculate the years lost due to premature death. Results: DALYs for human hydatidosis was calculated as 1210.12 years (YLD equals to 177.12 and YLL equals to 1033) in Iran for the year 2018. It was estimated to be 700.2 years for men and 509.8 years for women. DALYs in men were significantly different from women (P= 0.001) so DALYs were more in men than women were. YLD was calculated at 78.228 years in men and 98.892 years in women and in both men and women at 177.12 years. YLD was significantly different in women compared to men (P=0.001), so YLD in women was more than in men. Conclusion: We reached considerable indices for hydatidosis in our study. Therefore, disease prevention and control programs in Iran seem necessary by the policy makers. Keywords: Hydatidosis; Burden; Disability-adjusted life years; Human; Ira

Spatial-time analysis of cardiovascular emergency medical requests: enlightening policy and practice

Background: Response time to cardiovascular emergency medical requests is an important indicator in reducing cardiovascular disease (CVD) -related mortality. This study aimed to visualize the spatial-time distribution of response time, scene time, and call-to-hospital time of these emergency requests. We also identified patterns of clusters of CVD-related calls. Methods: This cross-sectional study was conducted in Mashhad, north-eastern Iran, between August 2017 and December 2019. The response time to every CVD-related emergency medical request call was computed using spatial and classical statistical analyses. The Anselin Local Moran's I was performed to identify potential clusters in the patterns of CVD-related calls, response time, call-to-hospital arrival time, and scene-to-hospital arrival time at small area level (neighborhood level) in Mashhad, Iran. Results: There were 84,239 CVD-related emergency request calls, 61.64% of which resulted in the transport of patients to clinical centers by EMS, while 2.62% of callers (a total of 2218 persons) died before EMS arrival. The number of CVD-related emergency calls increased by almost 7% between 2017 and 2018, and by 19% between 2017 and 2019. The peak time for calls was between 9 p.m. and 1 a.m., and the lowest number of calls were recorded between 3 a.m. and 9 a.m. Saturday was the busiest day of the week in terms of call volume. There were statistically significant clusters in the pattern of CVD-related calls in the south-eastern region of Mashhad. Further, we found a large spatial variation in scene-to-hospital arrival time and call-to-hospital arrival time in the area under study. Conclusion: The use of geographical information systems and spatial analyses in modelling and quantifying EMS response time provides a new vein of knowledge for decision makers in emergency services management. Spatial as well as temporal clustering of EMS calls were present in the study area. The reasons for clustering of unfavorable time indices for EMS response requires further exploration. This approach enables policymakers to design tailored interventions to improve response time and reduce CVD-related mortality.This study was financially sponsored by Mashhad University of Medical Sciences (Project grant: 980861)