| 1. |
- Murray, Christopher J. L., et al.
(författare)
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Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1995-2051
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Tidskriftsartikel (refereegranskat)abstract
- Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation.
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| 2. |
- Rahimi, Fariba, et al.
(författare)
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Concurrent and Optimal Structure, Control and Implementation Design
- 2020
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Ingår i: Proceedings of 2020 IEEE 11th International Conference on Mechanical and Intelligent Manufacturing Technologies, ICMIMT 2020. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Mechatronic system design includes a combination of different engineering disciplines. A common approach in design of mechatronic systems is based on a sequential method, where different disciplines are treated and designed separately. This paper extends earlier work on integrated physical and control design optimization with integrating an additional aspect of the corresponding embedded control system implementation. Our previous publications describe integrated design optimization through a few specific use cases but the impact of embedded control implementation on the structural design of the systems is neglected. In this paper, the approach is extended to cover discussions on control implementation and its effect on the physical dimensioning and vice versa. A multi-objective optimization approach is implemented and tested on a mechatronic system case study consisting of a DC-motor, a planetary gear, a flexible shaft, an embedded controller and a load. The couplings between the properties of different engineering domains are studied and highlighted. The presented approach which is aimed for early phases of design, considers the integration of three engineering disciplines in one design framework which so far has been missing.
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| 3. |
- Rahimi, Fariba, et al.
(författare)
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Early phase design-optimization of mechatronic systems
- 2017
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Ingår i: ICCMA 2017 Proceedings of the 2017 The 5th International Conference on Control, Mechatronics and Automation. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450353397 ; , s. 42-49
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Konferensbidrag (refereegranskat)abstract
- Methodologies on design optimization of mechatronic systems are usually based on consecutive methods, i.e., the procedure of physical design, control and optimization of a system is performed step by step to achieve the final goal. This paper is built upon previous works on developing a toolbox to integrate several engineering backgrounds in early design phase to avoid time and cost consuming iterations in later deign steps. The previous methodology was mainly applicable for linear one-degree of freedom systems without time-variant dynamics. In this paper, the method is upgraded towards covering concepts on nonlinear systems where extra degrees of freedom are added to the system. Additionally, the library of the mentioned toolbox is extended to include ball-screw drive and rotational rigid beam components in terms of physical design, dynamic and static models to examine the feasibility of the design. A conceptual nonlinear multi-degree design case is presented and linearized at specified operational points in the supported software framework and the implemented models are verified in both SimMechanics and Simulink.
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| 4. |
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| 5. |
- Rahimi, Fariba
(författare)
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Multi-Criteria Co-Design optimization of Mechatronic Systems
- 2020
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Ingår i: 2020 IEEE International Conference on Mechatronics and Automation, ICMA 2020. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 756-766
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Konferensbidrag (refereegranskat)abstract
- Integrated design optimization of mechatronic systems necessitates a concrete definition of requirements, design parameters and variables, optimization objectives and constraints. A multidisciplinary mechatronic design requires engineers from different domains to work together on the design approach. Different engineering disciplines impose different constraints on the system. To consider the impact of these disciplines and the interactions and coupling between different parameters, there is a need for integrated design method. In this paper, an integrated design optimization approach is presented that takes into account three engineering domains, physical dimensioning, control design and embedded control implementation impact, simultaneously. The optimization problem is a multi-objective method that considers the size of system, sampling frequency and sensor resolution as main objectives. Regarding each objective, there are a few constraints to be satisfied by the final optimum system. The approach is applied to a non-linear mechatronic case including a DC-motor, a timing belt drive and a load. Non-linear dynamics of a timing belt are considered as a new physical component in the method and the system is linearized, controlled and optimized at defined operational points. Sensor resolution and location impact on the optimal system are analysed using a quantization model. It is shown that the approach allows engineering designers to integrate multidisciplinary optimization method to achieve a logical optimal system without degrading the system performance in each domain.
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| 6. |
- Rahimi, Fariba, 1986-
(författare)
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Towards a Concurrent Multidisciplinary Design Optimization of Mechatronic Systems
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multidisciplinary design optimization of mechatronic systems is a cumbersome task that considers integration of several engineering domains simultaneously. Hence, a holistic method should treat these engineering domains concurrently in the development phase and result in a solution for the system that is optimum considering several disciplines. Conventional design approaches for multi-disciplinary systems often consider each domain separately and integrate them at the end stage of the design. In these methods, the interactions and couplings between parameters from different disciplines can get lost and if any error arises at later design phase, it might lead to back-tracking and debugging, and hence, be time and cost consuming.Therefore, a method that includes concurrent design of mechanics, electronics, control, considering the impact of embedded control implementation (on physical design and performance) which results in an integrated system is of noteworthy importance. This dissertation summarizes research by the author regarding ideas and suggestions for an integrated multi-criteria design method. The purpose of this research is to enable an early-phase design that takes into account three domains (physical design, control design, and embedded control implementation) simultaneously. Therefore objectives, specifications and constraints from each domain are taken into account. The efficiency feature is enhanced by the use of an early-phase design method which reduces time and cost consuming debugging, and removes the necessity to have iterative design loops in later design phases.The method develops two types of components: physical and control. Physical components are basic mechanical/electrical elements which include three types of models: physical dimension, static properties, and dynamic behaviour models. Control components include control methods and dynamic performance constraints. The concept of a mechatronic system under design in the supporting software toolbox is configured using the components library. A multi-criteria optimization method is employed in a system level which yields an optimal solution for the system in terms of size, implementation cost, hardware cost and control performance. Using this system level optimization, there is no need to partition the problem or to integrate several optimization loops in the method.Four design cases are used to enable some features of the software toolbox and investigate capability of the method to handle multi-DOF nonlinear systems; and to highlight correlation between engineering domains and broaden the coverage of disciplines. The feasibility of the method is evaluated by variations of design tests for the design cases. Accordingly, mechanical and control components are studied, developed and integrated into the IDIOM (Integrated Design Optimization of Mechatronic Systems) software toolbox. Since the model of each component is treated separately in the design and modeling stage, any system configuration that uses the available components can be handled by the method. The contribution of the thesis can be summarized as follows:Multidisciplinary design method and investigation of couplings and correlations between engineering domainsModels and co-design methods to include nonlinear multi-degree of freedom mechatronic systemsExtended method to cover key aspects in discrete time systems, and key factors in embedded control implementationThe goal of this thesis is to improve system development efficiency by integrating engineering domains in an early design phase. Accordingly, the method in this thesis is a fundamental move in evaluation of mechatronic systems design which assists in better system development and analysis. However, there is no single `best' approach for the design of mechatronic systems; the presented method in this thesis facilitates an efficient simultaneous integrated design optimization and has a broader coverage of engineering domains. The results achieved by the method ensure an optimum system solution in regards to the different involved engineering domains.
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| 7. |
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| 8. |
- Rahimi, Fariba
(författare)
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Towards a formal framework for integrated design-optimization and control of mechatronicsystems
- 2021
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Ingår i: Science Progress. - : SAGE Publications. - 0036-8504 .- 2047-7163. ; 104:4
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Forskningsöversikt (refereegranskat)abstract
- This paper presents work towards a formal framework to support model-based integrated design and optimization of mechatronic products for early-phase conceptual design. This paper describes an integrated design framework through the introduction of its software implementation and a specific use case. The contribution is to introduce mathematical formalism to define the concepts, semantics, computation rules and system architectures of the formal framework. The advantage of the formal definitions is to clearly expose functionality and the limitations of the design framework and facilitate the software implementation. The modelling capability of the framework is enhanced to include non-linear mechatronic components, such as a two degrees-of-freedom arm. Further, an optimal proportional-integral-derivative control component is added to the software library supporting the framework.
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| 9. |
- Rahimi, Shadi, 1982, et al.
(författare)
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Co-culturing Bacillus subtilis and wastewater microbial community in a bio-electrochemical system enhances denitrification and butyrate formation
- 2020
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 397
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Tidskriftsartikel (refereegranskat)abstract
- Bio-augmentation could be a promising strategy to improve processes for treatment and resource recovery from wastewater. In this study, the Gram-positive bacterium Bacillus subtilis was co-cultured with the microbial communities present in wastewater samples with high concentrations of nitrate or ammonium. Glucose supplementation (1%) was used to boost biomass growth in all wastewater samples. In anaerobic conditions, the indigenous microbial community bio-augmented with B. subtilis was able to rapidly remove nitrate from wastewater. In these conditions, B. subtilis overexpressed nitrogen assimilatory and respiratory genes including nasD, nasE, narG, narH, and narI, which arguably accounted for the observed boost in denitrification. Next, we attempted to use the ammonium- and nitrate-enriched wastewater samples bio-augmented with B. subtilis in the cathodic compartment of bioelectrochemical systems (BES) operated in anaerobic condition. B. subtilis only had low relative abundance in the microbial community, but bio-augmentation promoted the growth of Clostridium butyricum and C. beijerinckii, which became the dominant species. Both bio-augmentation with B. subtilis and electrical current from the cathode in the BES promoted butyrate production during fermentation of glucose. A concentration of 3.4 g/L butyrate was reached with a combination of cathodic current and bio-augmentation in ammonium-enriched wastewater. With nitrate-enriched wastewater, the BES effectively removed nitrate reaching 3.2 mg/L after 48 h. In addition, 3.9 g/L butyrate was produced. We propose that bio-augmentation of wastewater with B. subtilis in combination with bioelectrochemical processes could both boost denitrification in nitrate-containing wastewater and enable commercial production of butyrate from carbohydrate- containing wastewater, e.g. dairy industry discharges. These results suggest that B. subtilis bio-augmentation in our BES promotes simultaneous wastewater treatment and butyrate production. © 2020 The Authors
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| 10. |
- Rahimi, Shadi, 1982, et al.
(författare)
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Ginsenoside Rg3 Reduces the Toxicity of Graphene Oxide Used for pH-Responsive Delivery of Doxorubicin to Liver and Breast Cancer Cells
- 2023
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Ingår i: Pharmaceutics. - : MDPI AG. - 1999-4923. ; 15:2
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Tidskriftsartikel (refereegranskat)abstract
- Doxorubicin (DOX) is extensively used in chemotherapy, but it has serious side effects and is inefficient against some cancers, e.g., hepatocarcinoma. To ameliorate the delivery of DOX and reduce its side effects, we designed a pH-responsive delivery system based on graphene oxide (GO) that is capable of a targeted drug release in the acidic tumor microenvironment. GO itself disrupted glutathione biosynthesis and induced reactive oxygen species (ROS) accumulation in human cells. It induced IL17-directed JAK-STAT signaling and VEGF gene expression, leading to increased cell proliferation as an unwanted effect. To counter this, GO was conjugated with the antioxidant, ginsenoside Rg3, prior to loading with DOX. The conjugation of Rg3 to GO significantly reduced the toxicity of the GO carrier by abolishing ROS production. Furthermore, treatment of cells with GO–Rg3 did not induce IL17-directed JAK-STAT signaling and VEGF gene expression—nor cell proliferation—suggesting GO–Rg3 as a promising drug carrier. The anticancer activity of GO–Rg3–DOX conjugates was investigated against Huh7 hepatocarcinoma and MDA-MB-231 breast cancer cells. GO–Rg3–DOX conjugates significantly reduced cancer cell viability, primarily via downregulation of transcription regulatory genes and upregulation of apoptosis genes. GO–Rg3 is an effective, biocompatible, and pH responsive DOX carrier with potential to improve chemotherapy—at least against liver and breast cancers.
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