44 research outputs found

    Chain-Based Anonymous Routing for Wireless Ad Hoc Networks

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    Wireless ad hoc networks are so vulnerable to passive attacks and eavesdropping adversaries due to their shared medium which makes network traffic easy to capture and analyze. Therefore, security and privacy protections are of extreme importance for protocols and applications in such networks. In this paper, we introduce a new framework for anonymous routing, named chain-based routing, to improve the privacy. In our framework, nodes on a path are virtually bound to each other like a chain. Each node is only aware of its associated links in a flow and does not require any other information about source, destination, or other parts of the chain. Based on this framework, we propose an on-demand routing protocol, called Chain-based Anonymous Routing (CAR), which uses unicast-based broadcast data transfer to fulfill anonymous communication in wireless ad hoc networks. Through hiding identifiers of nodes inside the chain, CAR realizes sender, receiver, and relationship anonymity in addition to untraceability in the network. Moreover, it is resistant to a wide range of passive attacks while adapting to implement other security mechanisms in the presence of active attacks

    Estimation and prediction of avoidable health care costs of cardiovascular diseases and type 2 diabetes through adequate dairy food consumption: a systematic review and micro simulation modeling study

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    Background: Recent evidence from prospective cohort studies show a relationship between consumption of dairy foods and cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2DM). This association highlights the importance of dairy foods consumption in prevention of these diseases and also reduction of associated healthcare costs. The aim of this study was to estimate avoidable healthcare costs of CVD and T2D through adequate dairy foods consumption in Iran. Methods: This was a multistage modelling study. We conducted a systematic literature review in PubMed and EMBASE to identify any association between incidence of CVD and T2DM and dairy foods intake, and also associated relative risks. We obtained age- and sex-specific dairy foods consumption level and healthcare expenditures from national surveys and studies. Patient level simulation Markov models were constructed to predict the disease incidence, patient population size and associated healthcare costs for current and optimal dairy foods consumption at different time horizons (1, 5, 10 and 20 years). All parameters including costs and transition probabilities were defined as statistical distributions in the models, and all analyses were conducted by accounting for first and second order uncertainty. Results: The systematic review results indicated that dairy foods consumption was inversely associated with incidence of T2DM, coronary heart disease (CHD) and stroke. We estimated that the introduction of a diet containing 3 servings of dairy foods per day may produce a 0.43savinginannualpercapitahealthcarecostsinIraninthefirstyearduetosavingincostofCVDandT2DMtreatment.Theestimatedsavingsinpercapitahealthcarecostswere0.43 saving in annual per capita healthcare costs in Iran in the first year due to saving in cost of CVD and T2DM treatment. The estimated savings in per capita healthcare costs were 8.42, 39.97and39.97 and 190.25 in 5, 10 and 20-years’ time, respectively. Corresponding total aggregated avoidable costs for the entire Iranian population within the study time horizons were 33.83,33.83, 661.31, 3,138.21and3,138.21 and 14,934.63 million, respectively. Conclusion: Our analysis demonstrated that increasing dairy foods consumption to recommended levels would be associated with reductions in healthcare costs. Further randomized trial studies are required to investigate the effect of dairy foods intake on cost of CVD and T2DM in the population

    DeepSpeed-Chat: Easy, Fast and Affordable RLHF Training of ChatGPT-like Models at All Scales

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    ChatGPT-like models have revolutionized various applications in artificial intelligence, from summarization and coding to translation, matching or even surpassing human performance. However, the current landscape lacks an accessible, efficient, and cost-effective end-to-end RLHF (Reinforcement Learning with Human Feedback) training pipeline for these powerful models, particularly when training at the scale of billions of parameters. This paper introduces DeepSpeed-Chat, a novel system that democratizes RLHF training, making it accessible to the AI community. DeepSpeed-Chat offers three key capabilities: an easy-to-use training and inference experience for ChatGPT-like models, a DeepSpeed-RLHF pipeline that replicates the training pipeline from InstructGPT, and a robust DeepSpeed-RLHF system that combines various optimizations for training and inference in a unified way. The system delivers unparalleled efficiency and scalability, enabling training of models with hundreds of billions of parameters in record time and at a fraction of the cost. With this development, DeepSpeed-Chat paves the way for broader access to advanced RLHF training, even for data scientists with limited resources, thereby fostering innovation and further development in the field of AI.Comment: 14 pages, 7 figure

    Rapamycin protects testes against germ cell apoptosis and oxidative stress induced by testicular ischemia-reperfusion

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    Objective(s):Rapamycin is an immunosuppressant compound with a broad spectrum of pharmaco-logical activities. In recent years, it has been used successfully to decrease ischemia-reperfusion injury in several organ systems. The purpose of the present study was to examine the effect of rapamycin on testicular ischemia-reperfusion injury. Materials and Methods: Seventy-two adult male Wistar rats were divided into six groups: control (group1), sham-operated (Group2), T/D + DMSO as vehicle group (group3), and groups 4–6; respectively received 0.5, 1, and 1.5 mgkg-1 of rapamycin , IP 30 min before detorsion. Ischemia was achieved by twisting the right testis 720o clockwise for 1 hr. The right testis of 6 animals from each group were excised 4 hr after detorsion for the measurement of lipid peroxidation, caspase-3, and antioxidant enzyme activities. Histopathological changes and germ cell apoptosis were determined by measuring mean of seminiferous tubules diameters (MSTD) and TUNEL test in right testis of 6 animals per group, 24 hr after detorsion. Results: Testicular T/D caused increases in the apoptosis, malondialdehyde (MDA), and caspase-3 levels and decreases in the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in ipsilateral testis (

    Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021

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    Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions

    Oral Health Literacy and its Determinants in Young Couples

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    Objectives: Oral health literacy (OHL) is an interplay of cultural, social and individual factors and plays an effective role in public health promotion. This study aimed to assess OHL and its socioeconomic and demographic determinants among young couples. Materials and Methods: This analytical cross-sectional study was conducted on 828 adults between 15 to 35 years in 2018 in Zanjan city. Data regarding their OHL were collected by using a 17-item Oral Health Literacy-Adult Questionnaire (OHL-AQ) that was filled out by a combination of self-report and interview. OHL was categorized as adequate, marginal, and inadequate. The effects of age and gender as demographic variables, and floor area per person as a proxy of financial status on OHL were also assessed. Data were analyzed using the linear and multinomial logistic regression models. Results: The mean OHL score was 7.86±3.83 out of 17 in equal number of males and females. Only 21% of the couples had adequate OHL. The socioeconomic, but not demographic variables had significant correlations with the qualitative and quantitative variables of OHL even after controlling for the effect of confounders. A correlation was particularly found between inadequate OHL and years of education [odds ratio:6.00; 95% CI: 3.86-9.28); P<0.001]. Conclusion: Socioeconomic factors had independent correlations with inadequate OHL. Participants with higher levels of education, those living in urban areas, and individuals with better financial status had higher levels of OHL and lower odds of inadequate OHL

    Presenting the Course of Community Dentistry as Problem Based Learning Workshop and Comparing It to Learning through Lecture

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    Introduction: Nowadays, the attitudinal aspect of community dentistry course and the way in which this course is taught is critically important. The aim of this study is to compare the presentation of theoretical community dentistry course through workshops using PBL method with that of contemporary method of lecture. Methods: In this quasi experimental study, 64 dental students of Tehran University of Medical Sciences who took the course of community dentistry in second semester of academic year of 2006-2007 were entered into the survey through census. They were randomly allocated into two groups of experiment and control each including thirty two. The course of community dentistry was taught to control group through traditional method in 17 lecturing sessions meanwhile this course was instructed to experiment group through problem based learning method. A questionnaire was used for gathering data. Data was analyzed by SPSS software using descriptive statistics and Chi². Results: The improvement in attitude of PBL group was significant in contrast with that of traditional method group. In post-test, the mean score of knowledge and attitude of the group attending in workshop was higher than that of traditional group but the difference was not statistically significant. The mean score of satisfaction and transferring educational concepts was significantly higher in the group attending in workshop. Eighty one percent of the workshop attendees were satisfied with the method employed in the course. Conclusion: The new method of education has been successful in its achievements as forming a positive atti-tude in students and making them eager for community dentistry issues
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