Serum lactate as a prognostic factor in coronary artery bypass graft operation by on pump method

Background: Lactic acidosis in cardiac surgical patients is a manifestation of systemic inflammation and excess pro-inflammatory cytokine production. This investigation was designed to integrate basic concepts about lactate acidosis with a clinically used of serum lactate in patients under coronary artery bypass surgery (CABG) by on pump method. Methods: From August to September 2012, 15 patients scheduled for routine cardiac surgery entered to our sample and followed up two weeks. Lactate concentration in arterial blood sample was studied. Method of surgery duration of cardiopulmonary bypass, aorta cross clamp timing, hemodynamic parameters, inotrope dosage and patient outcome were documented. The data were collected and analyzed. Results: The mean age of the patients was 62±14 years. The patients with a poor outcome had significantly higher lactate levels in ABG samples (p0.05). The PH of ABG samples did not generally correlate with the ABG lactate concentration (r=0.116, p=0.68). Increased lactate concentration was reliably associated with patient hemodynamic parameters, inotrope dosage, duration of on pump time and aorta cross clamp time. Conclusion: This study demonstrates a correlation between serum lactate levels and patient prognosis after CABG surgery by on pump method

Defense Against Reward Poisoning Attacks in Reinforcement Learning

We study defense strategies against reward poisoning attacks in reinforcement learning. As a threat model, we consider attacks that minimally alter rewards to make the attacker's target policy uniquely optimal under the poisoned rewards, with the optimality gap specified by an attack parameter. Our goal is to design agents that are robust against such attacks in terms of the worst-case utility w.r.t. the true, unpoisoned, rewards while computing their policies under the poisoned rewards. We propose an optimization framework for deriving optimal defense policies, both when the attack parameter is known and unknown. Moreover, we show that defense policies that are solutions to the proposed optimization problems have provable performance guarantees. In particular, we provide the following bounds with respect to the true, unpoisoned, rewards: a) lower bounds on the expected return of the defense policies, and b) upper bounds on how suboptimal these defense policies are compared to the attacker's target policy. We conclude the paper by illustrating the intuitions behind our formal results, and showing that the derived bounds are non-trivial

Differences in the prevalence of obesity among Fars-native, Turkman, and Sisstanish ethnic groups in Iranian northern adults in 2010

Objectives: The aim of this study was to evaluate the differences of obesity rate among three ethnic groups in northern adults in IR Iran in 2010. Methods: The present cross-sectional, analytical study was conducted on 2994 cases of the same age and sex in three ethnic proportions (Fars-native=1625, Turkman=977, and Sisstani=392). The subjects aged between 15 and 65 years old and were selected by multistage cluster sampling techniques including 150 clusters each containing 20 subjects in urban and rural areas in 11 districts in Golestan province (northern IR Iran). Obesity was defined after WHO classification by BMI (Body Mass Index) equal or over 30 kg/ m2. SPSS 16.0 software was used for statistical analysis and P value<0.05 was considered as statistically significant. Results: Mean±SD of BMI in Fars-native, Turkman, and Sisstanish ethnic groups was 26.72±5.56, 26.18±5.34, and 24.59±6.72 kg/m2, respectively. Averagely, obesity was common in 22.8% of the subjects and was significantly higher among the females compared to males (32.3% vs13.3%) (P=0.001). Also, its prevalence was estimated as 25%, 22.6%, and 14% in Fars-native, Turkman, and Sisstanish ethnic groups, respectively. Statistical differences were significant among the three ethnic groups (P=0.001). The risk of obesity was 2.041 [95% CI, 1.502-2.722] in Fars-native and 1.781 [95% CI, 1.298-2.472] in Turkman groups compared to Sisstanish ethnic group. Conclusions: Over one out of five adults in northern IR Iran suffer from obesity and an alarming rate was shown among the women. Among the three ethnic groups, the highest and the lowest rates were seen in Fars-native and Sisstanish ethnic groups, respectively. Variation of obesity among the three ethnic groups should be studied in future studies

Study of symptoms of anxiety and depression and quality of life before and after radioactive iodine intake in patients with thyroid cancer

Introduction: Thyroid cancer can affect the quality of life of patients and no validated study has beenconducted to evaluate the quality of life in patients with thyroid cancer in Iran. The purpose of thisstudy was to evaluate the changes of quality of life in patients with thyroid cancer treated withradioactive iodine.Materials and Methods: According to a prospective longitudinal study, quality of life and mood inthese patients were studied by two questionnaires: Short Form Health Survey (SF36) and HospitalAnxiety and Depression Scale (HADS) provided to the patients by the researcher. The questionnaireswere completed one month before iodine injection, on the day of injection, at the end of the secondweek, and sixth month after radioactive iodine injection. The patients were treated in two groups of100 and 150 μ Curie. After completing the questionnaires, the resulting scores at four different timepoints were evaluated and compared.Results: The mean SF36 scores were lower than one month before iodine intake and after 6 months,the mean scores were lower than one month before iodine intake. The mean HADS scores one monthafter iodine intake were not significantly different from the time of iodine intake, but after two weeks,anxiety and depression were reduced, and the result continued till the sixth months. No difference wasfound in the levels of anxiety and depression between the doses of 100 and 150 μ Curie.Conclusion: The highest level of anxiety and depression and quality of life during the first two weeksof iodine intake reduced with time and iodine intake dose did not affect it

Explicit Tradeoffs between Adversarial and Natural Distributional Robustness

Several existing works study either adversarial or natural distributional robustness of deep neural networks separately. In practice, however, models need to enjoy both types of robustness to ensure reliability. In this work, we bridge this gap and show that in fact, explicit tradeoffs exist between adversarial and natural distributional robustness. We first consider a simple linear regression setting on Gaussian data with disjoint sets of core and spurious features. In this setting, through theoretical and empirical analysis, we show that (i) adversarial training with $\ell_1$ and $\ell_2$ norms increases the model reliance on spurious features; (ii) For $\ell_\infty$ adversarial training, spurious reliance only occurs when the scale of the spurious features is larger than that of the core features; (iii) adversarial training can have an unintended consequence in reducing distributional robustness, specifically when spurious correlations are changed in the new test domain. Next, we present extensive empirical evidence, using a test suite of twenty adversarially trained models evaluated on five benchmark datasets (ObjectNet, RIVAL10, Salient ImageNet-1M, ImageNet-9, Waterbirds), that adversarially trained classifiers rely on backgrounds more than their standardly trained counterparts, validating our theoretical results. We also show that spurious correlations in training data (when preserved in the test domain) can improve adversarial robustness, revealing that previous claims that adversarial vulnerability is rooted in spurious correlations are incomplete.Comment: Accepted to NeurIPS 202

Influence of education in the prevalence of obesity in Iranian northern adults

Background: The main aim of this study was to evaluate whether prevalence of obesity in educational levels is different and some related factors in Iranian northern adults. Materials and methods: This was a cross-sectional descriptive study based on population and 2452 cases (1224 men and 1228 women) aged 15e65 years were chosen by cluster and stratify sampling. Subjects were randomly chosen from 125 clusters and each cluster included 20 cases. Interviewers recorded the data using a multidimensional questionnaire including socio-demographic indexes. Results: As a whole, the prevalence of obesity was seen in 24% of subjects (15.5% in male and 32.5% in female) and significantly was seen in 3.1% and 14.1% of uneducated people more than in 1e9 year schooling and in high school or college-educated people, respectively (P = 0.001). The risk of obesity was 2.294 (P = 0.001) in uneducated compared to high school or college-educated people, 1.668 (P = 0.001) in urban area compared to rural area, 2.619 (P = 0.001) in 40e65 year people compared to 15e40 year people, and 1.534 (P = 0.003) in good economic compared to poor economic groups. After adjusted for location area, gender, age, and economic stats, the risk of obesity was 2.044 (P = 0.001) in uneducated people compared to high school or college-educated subjects. Conclusion: The obesity as a health problem in Iranian northern adults supported in this study and it was negatively associated with educational levels. Public health programs that aim to reduce obesity should primarily focus on the illiterate and low-educated people. Copyright © 2013, SciBioIMed.Org, Published by Reed Elsevier India Pvt. Ltd. All rights reserved

Five-year trend in hydrogenated vegetable oil consumption among Northern Iranian families

Background: The main aim of this study was to assess the trends in hydrogenated vegetable oil (HVO) consumption and some related factors among northern Iranian families from 2006 to 2010. Methods: A cross-sectional, population-based study was conducted with 6497 subjects, 15 to 65 years old, who were chosen by multistage cluster random sampling. The subjects were randomly chosen by 325 clusters with an equal size (n = 20 subjects). A multidimensional questionnaire including so-ciodemographic questions and type of cooking oil used were administered by interviewers. Results: The percentages of the sample reporting HVO consumption across the 5 years are as follows: 2006,85.2%; 2007, 79.7%; 2008, 75.9%; 2009, 59.3%; and 2010, 55.7%. Consumption decreased 29.5% during the 5 years of study and an average of 5.9% per year (P < .05). The estimated odds ratio of HVO consumption in rural areas verus urban areas was 2.59 (95% confidence interval [CI], 2.31-2.90); for poor compared with good economic level the odds ratio was 3.99 (95% CI, 3.13-5.10 for; for the uneducated versus college-educated sample it was 5.75 (95% CI, 4.10-8.17); and the odds ratio was 3.34(95% CI, 2.51-4.45) for Sisstani compared with Fars-native ethnic group. Conclusion: HVO consumption decreased during the 5-year study (2006 to 2010), but HVO is still used extensively in northern Iran. Preventive early intervention strategies are needed to target uneducated and poor families, with an emphasis on the Sisstanish ethnic group, to increase awareness about the negative consequences of HVO consumption

The trend of seat belt use among drivers in the north of Iran, 2007-2010: An epidemiologic study

Backgrounds and Objectives: Using seat belt has a considerable role in reducing human damage. The aim of this study was to compare trend of seat belt use rate during 4 years, from 2007 to 2010, in Golestan province (northern Iran). Materials and Methods: This was a population-based cross-sectional study that enrolled 3999 subjects aged 15-65 years during four years (2007 = 1000 cases, 2008 = 1000 cases, 2009 = 999 cases and 2010= 1000 cases) using stratified cluster sampling. Interviewers recorded the data using a multidimensional questionnaire including anthropometric indexes. Using seat belt in the case of sitting in the front seat of car (as a driver or passenger) of all samples was asked. SPSS 16.0 software was used for statistical data analysis. Results: The rate of seat belt use in the years 2007, 2008, 2009 and 2010 were 71%, 69.8%, 74.5 and 86.4%, respectively. Seat belt use during the four years increased up to 15.4%. Statistical differences among four years was significant (P<0.01). The increasing seat belt use rate was 19% and 14.9% in urban and rural areas, respectively. The seat belt use rate was higher in subjects with =35 years old people in proportion to 35= years old people (17.85% versus 14.3%). During the latest year of study, using seat belt was about 14.8% higher in men comparing with women (P<0.05). Conclusion: Using seat belt increased up to 3.9% per year and the trend in the rural areas was lower than in the urban areas. Seat belt used in men more than women. Using seat belt and its growing trend, will help in reducing mortality caused by accidents in Iran. © IDOSI Publications, 2012

Admissible Policy Teaching through Reward Design

We study reward design strategies for incentivizing a reinforcement learning agent to adopt a policy from a set of admissible policies. The goal of the reward designer is to modify the underlying reward function cost-efficiently while ensuring that any approximately optimal deterministic policy under the new reward function is admissible and performs well under the original reward function. This problem can be viewed as a dual to the problem of optimal reward poisoning attacks: instead of forcing an agent to adopt a specific policy, the reward designer incentivizes an agent to avoid taking actions that are inadmissible in certain states. Perhaps surprisingly, and in contrast to the problem of optimal reward poisoning attacks, we first show that the reward design problem for admissible policy teaching is computationally challenging, and it is NP-hard to find an approximately optimal reward modification. We then proceed by formulating a surrogate problem whose optimal solution approximates the optimal solution to the reward design problem in our setting, but is more amenable to optimization techniques and analysis. For this surrogate problem, we present characterization results that provide bounds on the value of the optimal solution. Finally, we design a local search algorithm to solve the surrogate problem and showcase its utility using simulation-based experiments